•EPA
United States
Environmental Protection
Agency
Officaof
PvctictdM and
WMhington DC 20460
July 1984
Wood Preservative Pesticides:
Creosote
Pentachlorophenoi
Inorganic Arsenicals
Position Document 4
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WOOD PRESERVATIVE PESTICIDES
CREOSOTE, PENTACHLOROPHENOL, AMD THE INORGANIC ARSENICALS
POSITION DOCUMENT 4
REGISTRATION DIVISION
OFFICE OF PESTICIDE PROGRAMS
OFFICE OF PESTICIDES AND TOXIC SUBSTANCES
U.S. ENVIRONMENTAL PROTECTION AGENCY
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Executive Summary
The three wood preservatives considered in this Position Document 4
are creosote, which includes creosote, coal tar and coal tar neutral oil;
the inorganic arsenical compounds, which include chromated copper arsenate
(CCA), ammoniacal copper arsenate, (ACA), and fluor chrome arsenic phenol
(FCAP); and pentachlorophenol, including its sodium salt. These pesticides
preserve wood against attack by fungi, insects, bacteria, and marine borers.
Treated wood generally has a useful life at least five times longer than
untreated wood.
The wood preservatives may be applied by pressure-treatment or non-pressure
treatment methods. Pressure-treated wood is used for railroad ties, lumber,
timber and plywood, pilings, posts, crossarms, and poles. Non-pressure
uses are for poles at groundline, home and farm, and brush-on treatments of the
inorganic arsenicals for cut-ends of treated wood at construction sites,
sapstain control, millwork and plywood, and particleboard. For many uses,
creosote, the inorganic arsenicals, and pentachlorophenol are alternatives
for each other. There are several other wood preservatives as well, but
these three wood preservatives are by far the most commonly used.
On October 18, 1978, the Agency published a Notice in the Federal
Register initiating the Rebuttable Presumption Against Registration
(RPAR) for the three major wood preservatives under the authority of the
Federal Insecticide Fungicide, and Rodenticide Act (FIFRA). For creosote,
the risk criteria presented in the Position Document I {PD 1)were oncogenicity
and mutagenicity; for pentachlorophencol and its sodium salt they were
teratogenicity and fetotoxicity; and for the inorganic arsenicals they
were, onocogenicity, mutagenicity, and reproductive or fetotoxic effects.
Comments on this Notice were received and addressed in the Position
Document (PD) 2/3 which was made available to the public on February 19,
1981. The Agency indicated in the PD 2/3 that pentachlorophenol also
posed the additional potential risk of oncogenicity because of its hexa-
chlorodibenzo-p-dioxin (HxCDD) and hexachlorobenzene (HCB) contaminants.
Because each of the three wood preservatives are potential alternatives to
each other, they were addressed together in the PD 2/3. The PD 2/3 presented
the risks and benefits of use of the wood preservatives and proposed regulatory
measures to reduce these risks so that benefits would exceed risks. The
regulatory measures proposed in the PD 2/3 included canceling and denying
registrations of spray formulations of pentachlorophenol containing less
than 5% pentachlorophenol, prohibiting indoor applications of the wood
preservatives, prohibiting most indoor uses of treated wood and prohibiting
uses of wood preservatives likely to contaminate food, feed or drinking
water. Other proposed measures were requiring use of protective clothing
and equipment, such as gloves, coveralls, and respirators, requiring improved
industrial hygiene practices, and classifying most formulations of the
wood preservatives for use only by certified applicators. Other proposed
measures included requiring closed mixing systems for powder and granular
wood preservative formulations, and requiring improved treatment technologies
to reduce surface residues of the wood preservatives. Finally, the Agency
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also recommended that under the authority of the Toxic Substances Control
Act (TSCA) labeling measures be proposed for treated wood to instruct
users of treated wood in proper handling and safe use procedures.
The FIFRA Scientific Advisory Panel (SAP), U.S. Department of Agriculture
(USDA), industry, and other interested parties submitted written comments to
the Agency on the PD 2/3. As a result of these comments, the Agency modified
its PD 2/3 proposals and held a public meeting on April 14, 1983, to give
interested persons an opportunity to comment on the proposed changes. All
comments submitted in response to the PD 2/3 and the public meeting have
been evaluated and are addressed in the final Position Document 4 (PD 4).
This PD 4 presents regulatory measures to be enforced under FIFRA to
reduce potential risks to man and the environment. Most of these regulatory
measures are similar to those proposed in the PD 2/3. The most significant
new requirement would immediately limit the HxCDD contamination in technical
pentachlorophenol and sodium pentachlorophenate to 15 ppm and would require
industry to reduce this contaminant to 1 ppm or lower within 18 months.
A comparison of the PD 2/3 proposals and the PD 4 final positions is summarized
in the Executive Summary Table.
This PD 4 also describes a measure to require commercial wood treaters to
participate in a "Consumer Awareness Program" (CAP) whereby a Consumer Infor-
mation Sheet (CIS) would be distributed throughout the chain of commerce to
end-users. The CIS would inform end-users of treated wood about safe use and
proper handling precautions of the pesticide treated wood. If the Consumer
Awareness Program is ineffective in educating the public, the Agency will
initiate rulemaking under TSCA to propose that labeling material accompany
the treated wood, so that end-users of the treated wood will be adequately
informed about appropriate precautions to take when handling treated wood.
The final regulatory position is summarized in the Executive Summary Table
and in more detail in the paragraphs which follow.
For both pressure and non-pressure treatments, the Agency will:
Classify all three chemicals for Restricted Use only by Certified
Applicators (except for brush-on treatments of the inorganic
arsenicals).
- Require commercial wood treaters to participate in a Consumer
Awareness Program which would require a Consumer Information
Sheet (CIS) to be distributed with each shipment of pressure-
treated wood throughout the chain of commerce. The CIS will
instruct end-users about handling and disposal of treated
wood or treated wood products. The CIS will also contain
statements to reduce potential contamination of the environment
by recommending against the use of treated wood in contact
with food, feed, public drinking water (all 3 wood preservatives)
and with drinking water for animals (pentachlorophenol and
creosote). The CIS will also require that purchasers not use
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the wood treated with pentachlorophenol or creosote for interior
use with certain exceptions and that pentachlorophenol or
creosote treated wood should not be used in barns where domestic
animals might lick the wood.
- Require impermeable gloves for all three chemicals in all use
situations, and additional clothing and respirators in certain
situations.
- Prohibit eating, drinking, smoking during application of all
three chemicals.
For all products containing technical pentachlorophenol or its
salts, the Agency will require registrants to:
- Pile an application to amend the confidential statements of
formula (CSF) for products containing technical pentachloro-
phenol or its salts to indicate that the HxCDD contamination
does not exceed 15 ppm and that 2,3,7,8-tetrachlorodibenzo-
p-dioxin is below limits of detection using a gas chromatography-
mass spectrophototnetry method.
- File an application tc amend the CSFs for products containing
technical pentachlorophenol or its salts to indicate that,
effective 18 months after publication of the Notice or receipt
by the registrant (whichever occurs later), the HxCDD contamination
does not exceed 1.0 ppm. (The method used to lower the HxCDD
to 15.0 ppm or 1.0 ppm or lower must not increase the hexachloro-
benzene or chlorinated dibenzofurans above the levels in products
marketed at the time of publication of the FR Notice.)
- Finally, the Agency will require a teratogenicity/fetotoxicity
warning on the labels for all uses of pentachlorophenol and
salts of pentachlorophenol.
For Pressure Treatment Dses only, in addition to the actions listed above
the Agency will require applicators to:
- Wear a respirator when opening cylinder doors or entering
cylinders in pentachlorophenol and creosote treatment plants.
- Wear a respirator if arsenic air levels are unknown or exceed
10 ug/m3 over an 8 hour period as shown by monitoring. This
is consistent with the OSHA threshold Limit Value (TtV) of
10 ug/m3.
- Adhere to industry standards to reduce surface residues of
arsenic on treated wood.
- Wear protective clothing (i.e., overalls, jackets, gloves, and
boots) when entering cylinders for any wood preservative.
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- Use closed systems for mixing and emptying powdered formulations
of the inorganic arsenicals,
- Ose protective clothing and a respirator when mixing and emptying
prilled or flaked formulations of pentachlorophenol; closed
systems must be used after a 3 year "phase-in" period.
In addition to the requirements listed above for Non-Pressure Treatment
Uses, the Agency has determined that registrants must meet further
requirements as listed below for specific non-pressure use situations:
- Groundline treatment of poles - protective clothing.
- Home and farm uses of pentachlorophenol and creosote - restrict
use to certified applicators, protective clothing;
- Brush-on {arsenicals) - commercial construction use only;
protective clothing.
Sapstain Control (i.e., pentachlorophenol salts applied to
prevent staining of wood by black mold) - protective clothing
when entering vats; respirator and protective clothing for
spray applications if there is a visible mist; protective
clothing and a respirator when emptying and mixing powdered
formulations of sodium pentachlorophenate, but closed systems
must be used after a 3- year "phase-in" period.
- Millwork, Plywood, Particleboard - protective clothing for
entering vats; respirator and protective clothing for spray
applications if there is a mist; protective clothing and a
respirator when emptying and mixing prilled or flaked formula-
tions of pentachlorophenol, but closed systems must be used
after a 3 year "phase-in" period.
In an action separate from this PD 4, the registrants of technical
pentachlorophenol and salts of pentachlorophenol products of will be required
to submit the following to maintain existing registrations pursuant to
FIFRA Section 3(c)(2)(B):
- A description of the starting materials, manufacturing process
and reaction conditions including any steps to reduce HxCDD.
- Information on product identity relative to identification of
ingredients, statement of composition and a discussion of the
formation of impurities.
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- Data on the analysis and certification of product ingredients
relative to preliminary analysis, certification of limits, and
analytical methods for the enforcement of limits. An analytical
method employing combined gas chromatography and mass spectro-
photometry is acceptable (e.g., Buser and Eosshardt, 1976).
- HxCDD analyses every three months, the first analysis to be
submitted within 90 days.
- A description of any changes in the manufacturing process used
to lower HxCDD to 15 ppm and/or to 1 ppm. The methods used to
lower HxCDD must not increase the dibenzofurans or hexachloro-
benzene (HCB) contaminants.
- Information on the technical feasibility and costs of reducting
the HxCDD even further than the 1.0 ppm upper limit.
In addition the Agency will require registrants to submit the following
data via Section 3{c)(2)(B) of FIFRA:
- COM? (Chronic feeding, Oncogenicity, Reproductive effects, and
Teratogenicity) data for chemical alternatives to the three
wood preservatives.
- Data on the effectiveness of protection afforded by specific
protective clothing materials for creosote and the inorganic
arsenicals.
- An epidemiology study and air monitoring and dermal exposure
data for creosote workers at creosote wood treatment plants.
- Teratogenicity/fetotoxicity studies on inorganic arsenic to
enable the Agency to calculate a NOEL (No Observable Effect Level)
- Exposure data on spray applications of pentachlorophenol for
home and farm use.
The Agency has determined that there will be no unreasonable adverse
effects posed to man or the environment if registrants amend their
applications for registration of the three wood preservatives to include
these requirements.
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EXECUTIVE SUMMARY TABLE
Comparison of PD 2/3 Proposals with Agency's Final Position (PD 4)
for the Wood Preservatives
Use
PD 2/3 Proposal
PD 4 Final Position
1 . All Uses of
a. Penta* and
Penta salts
Not proposed
Immediate upper limit of 15
ppm HxCDD; TCDD below limits of
detection
In 18 months, Ippm HxCDD upper
limit
b. All Chemicals
2. Pressure-Treatment
a. All three chemicals
- Not Proposed
- Disposal of protective clothing
Statements regarding personal
hygiene during and after appli-
cation
- Recommended TSCA labeling of
wood to educate purchasers of
treated wood about proper use
and handling procedures.***
Restrict Use
Gloves and protective clothing
Teratogenicity/fetotoxicity label
warning.
Disposal of protective clothing
and unused formulations
Statements regarding personal
hygiene during and after
application
- FIFRA Mandatory Consumer Awareness
Program - distribution of CIS** to
educate purchasers of treated wood
about proper use and handling pro-
cedures.
- Restrict Use
- Gloves and protective clothing
* Penta = pentachlorophenol.
** CIS = Consumer Information Sheet, which will accompanying each shipment of pressure-treated wood.
*** Also recommended for non-pressure treated wood. The PD 4 requires the mandatory consumer Awareness Program
only for pressure-treated wood; exposure and risk are estimated to be minimal for non-pressure treated wood,
such that a Consumer Awareness Program is nt required for non-pressure wood treaters.
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Use
PD 2/3 Proposal
PD 4 Final Position
- Respirators when entering
cylinders
- Respirators when opening
cylinder doors (penta and
creosote
- Dust masks (Inorganic
arsenicals)
Closed mixing and emptying
system (powder inorganic
arsenicals; dry formulations
of penta and Na penta)
"clean wood" standards (in-
organic arsenicals)
Prohibitions on applying
formulations to wood
intended for use in interiors
(with certain exceptions) or
for use in contact with
food, feed, or drinking water
Respirators when entering
cylinders (penta and creosote)
Respirators when opening
cylinder doors (penta and
creosote)
Respirators if inorganic arsenic
in air is unknown or exceeds
10 ug/m^ averaged over 8 hours
Closed mixing and emptying
system immediately for arsenic
and within 3 years for dry penta
and Na penta formulations
"Clean wood" standards (in-
organic arsenicals)
- Prohibitions on applying for-
mulations to wood intended for
use in interiors (with certain
exceptions) or for use in
contact with food, feed, or
drinking water
vii
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Use
PD 2/3 Proposal
PD 4 Final Position
3. Groundline treatment
of poles (penta and
creosote)
4. Home and Farm
(including repair of
railroad ties) (penta
and creosote)
- Restrict Use
- Protective clothing
- Restrict use of all
creosote products
- Restrict use of penta-
chlorophenol products
containing more•than 5%
pentachlorophenol;
Cancel spray penta-
chlorophenol products
of less than 5% penta-
chlorophenol
- Prohibit application indoors
- Prohibit application to wood
intended for use in interiors
(with certain exceptions) or
for use in contact with food,
feed, or drinking water
- Restrict Use
- Protective Clothing
- Restrict use of all creosote
products
Restrict use of all pentachloro-
phenol products
- Prohibit application indoors
- Prohibit application to wood
intended for use in interiors
(with certain exceptions) or for
use in contact with food, feed,
or drinking water
- Additional precautionary
statements regarding
handling and disposal of
treated wood
viii
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Use
PD 2/3 Proposal
PD 4 Final Position
5.
Brush-on treatments of
the inorganic arsenicals
6.
Sapstain control
(salts of
pentachlorophenol)
- Restricted Use
- Protective clothing
- Prohibit application to
wood intended for use
in interiors (with
certain exceptions)
or in contact with food,
feed, or drinking water
- Restricted Use
Protective clothing;
respirator when entering
vats and during spray
operations
Closed mixing and emptying
systems for powdered Na penta
Prohibit application to wood
intended for use in contact
with food, feed or water
- Unclassified Use
- Protective clothing
- For commercial construction
use only; for application
to the cut ends of wood
pressure-treated with inorganic
arsenicals; not for household
use.
- Restricted Use
Protective clothing; respir-
ator when entering vats and
during spray operations only
if there is a visible mist and
the applicator is near the
automated spray apparatus.
Closed mixing and emptying
systems for powdered Na penta
within 3 years
No regulation (exposure not
expected)
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Use
PD 2/3 Proposal
PD 4 Final Position
7. Mi 1Iwork, plywood,
particle board (penta)
- Restrict use
- Protective clothing;
respirator when entering
vats and during spray
operations
Closed mixing and empyting
systems for dry penta
formulations
Prohibit the application to
wood intended for use in
interiors (with certain
exceptions) or for use
in contact with food, feed,
or water
- Restrict use
Protective clothing; respirator
when entering vats and during
spray operations only if there
is a visible mist and the appli-
cator is near the automated
spray apparatus.
Closed mixing and emptying
systems for dry penta formu-
lations within 3 years
No regulation for mi 11work, ply-
wood, particleboard (minimal
exposure)
Prohibit application to logs
intended for log homes
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Acknowledgements
I. Registration Division Team
Carol Langley - Project Manager
A. Wood Preservative Team
Katherine Devine - Review Manager
Betty Shackleford - Review Manager
Joan Warshawsky - Staff, Special Review Branch
B. Support Team
William Audia - Review Manager
David Brooks - Technical Manager
Henry Jacoby - Product Manager
Barbara Moore - Typist
Deborah Otehere - Review Manager
Paul Parsons - Review Manager
Lyn Smollar - Review Manager
II. Technical Support Team
A. Benefits and Field Studies Division
Willard Cummings - Pathologist
Don Eckerman - Economist
Robert Esworthy - Economist
George Ludvik - Entomologist
George Keitt - Physiologist
Bernard Smale - Pathologist
B. Hazard Evaluation Division
Harry Day - Chemist
Nancy Dodd - Chemist
Bertram Litt - Statistician
Amy Rispin - Chief, Science Integration Staff
Minnie Sochard - Microbiologist
Esther Saito - Chemist
Anne Stavola - Pish and Wildlife Biologist
John Tice - Science Advisor
David Van Ormer - Toxicologist
C. Office of General Counsel
Richard Bozof - Attorney Advisor
Cara Jablon - Attorney Advisor
Robert McLaughlin - Attorney Advisor
Alice Wegman - Attorney Advisor
xi
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D. Carcinogen Assessment Group
Steven Bayard - Statistician
Bernard Haberman - Pathologist
Robert McGaughy - Acting Technical Director/Toxicologist
Dharm Singh - Toxicologist
Todd Thorslund - Statistician
E. Reproductive Effects Assessment Group
Vicki Vaughn-Dellarco - Geneticist
Herman Gibb - Epidemiologist
Donna Kuroda - Senior Scientific Liaison Officer
III. Intra-Agency Advisors
Judith Bellin - Biochemist, Office of Solid Waste
Richard Homer - Staff, Office of Solid Waste and Emergency Response
Gate Jenkins - Environmental Scientist, Office of Solid Waste
Jack Neyland - Section Head, Compliance Monitoring Staff
John Mason - Compliance Monitoring Staff, Policy and Strategy Unit
Jitendra Saxena - Chemist, Office of Drinking Water
Richard Williams - Project Officer, Office of Water Enforcement
IV. Advisors from Other Federal Agencies
Joseph Collier - Director, Office of Consultation Programs, O.S.
Occupational Safety and Health Administration
MaryIn Cordle - Deputy Director, Residue Evaluation & Planning
Division, O.S. Department of Agriculture.
Joseph Hile - Associate Commissioner for Regulatory Affairs, U.S.
Pood and Drug Administration
William Menza - Project Manager, U.S. Consumer Product Safety
Commission
George Pauli, Ph.D. - Supervisor Consumer Safety Officer, U.S.
Food & Drug Administration
Dr. Peter Preuss - Associate Executive Director for Health Sciences
U.S. Consumer Product Safety Commission
Ed'-'ard Stein - Health Scientist, U.S. Occupational Safety and
Health Administration
xii
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Table of Contents
Page
Executive Summary
Acknowledgements
I. Introduction 1
A. Historical Background 1
B. Legal Background 3
II. Updated Risk and Benefit Information 5
A. Risk Information 5
1 . Inorganic Axsenicals 5
a. Inhalation Risk Model 5
b. Dermal/Oral Risk Model 8
2. Pentachlorophenol 10
a. Multi-stage Model for Estimating Oncogenic Risks lo
b. Reevaluation of the HxCDD Bioassay 10
3. Creosote 16
B. Exposure Information 18
1. Inorganic Arsenicals 18
2. Pentachlorophenol 24
3. Creosote 27
Ce Benefit Information 27
1. Uses of Pressure-Treated Wood 27
a. Railroad Ties 27
b. Lumber, Timber and Plywood 28
c. Pilings 32
d. Posts 33
e. Crossarms 34
xiii
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Page
f. Poles 34
2. Oses of Non-Pressure Treated Wood
a. Poles - Groundline 35
b. Home and Farm
36
c. Sapstain Control 36
d. Millwork and Plywood 37
e. Particleboard 37
III. Scientific Advisory Panel (SAP) Comments and Agency (EPA) Response 39
A. Pentachlorophenol 39
B. Inorganic Arsenicals 45
C. Creosote 50
IV. United States Department of Agriculture (DSDA) Comments and Agency 53
(EPA) Response
V. Analysis of PD 2/3 Rebuttals and Agency Responses 50
A. Comments on Risk g^
1 . Creosote ,n
ou
2. Pentachloropheno1
77
3. Inorganic Arsenicals
88
B. Comments on Benefits
108
C. Comments on Regulatory Options
108
VI. Final Agency Position and Risk/Benefit Determinations
131
A. Upper Limits for Hexachlorodibenzo-p-dioxin (HxCDD) Contamina-
tion in Technical Pentachlorophenol and Pentachlorophenol
Salts. 131
B. Teratogenicity/Fetotoxicity Warning on All Labels for Products
Containing Pentachlorophenol or Pentachlorophenol Salts
C. Pressure Treatment Uses: All three wood preservatives
1. Permissible Exposure Limit (PEL)/Respirators for Inorganic
Arsenical Treatment Plant Workers 141
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Page
2. Protective Clothing and Respirators/Entering Cylinders 143
3. Closed Mixing Systems for Prilled or Flaked Pentachloro- 145
phenol
4. No Visible Surface Deposits for Arsenicals 3.49
5. Use of Protective Gloves 150
6. Disposal of Protective Clothing and Pesticide Formulation 152
7. warnings Regarding Eating, etc. During Application 154
8. Risk Reduction Measures Regarding Opening Treatment 155
Cylinder Doors
9. Restricted Use 156
10. Closed System/Arsenical Powders 157
D. Poles-Groundline Uses: Pentachlorophenol and Creosote 159
1. Use of Protective Gloves 159
2. Use of Coveralls 160
3. Disposal of Protective Clothing and Pesticide Formulations 151
4. Warnings about Eating, etc., During Application 152
5. Restricted Use
E. Home and Farm Dses (Including Railroad Tie Repair) Penta-
chlorophenol and Creosote
1. Creosote: Restricted Use 163
2. Pentachlorophenol: Restricted Use 164
3. Interior Application Prohibited 166
4. Use of Protective Gloves 168
5. Protective Clothing 170
6. Disposal of Clothing and Pesticide Formulation 172
7. Warnings about Eating, etc., during Application 173
8. Contamination of Food, Feed, and Water 173
9. Other Restrictions on Application and Intended Use 174
of Treated Wood
xv
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Page
F. Brush-on Treatments of Inorganic Arsenicals
1. Unclassified Use 177
2. Materials for Protective Gloves . 178
3. Materials for Coveralls 179
4. Warnings about Eating, etc,, during Application 130
5. Disposal of Clothing and Pesticide Formulation ^gl
6. Intended Interior Use and Food/Feed/Water Issue 182
G. Use of Salts of Pentachlorophenol for Sapstain Control 133
1 . Use Directions for Spray Applications of Sodium 183
Pentachlorophe na te
2. Use Directions for Emptying and Mixing 185
3. Food/Feed/Water Issue 186
4. Materials for Protective Gloves 187
5. Use of Protective Clothing 138
6. Disposal of Clothing.and Pesticide Formulation 139
7. Warnings about Eating, etc., during Application igg
8. Restricted Use ,„,,
H. Non-Pressure Treatment Plant Dip/Flow and Spray igi
Uses of Pentachlorophenol
1. Use Directions for Millwork and Plywood Spray Operations 191
2. Use Directions for Mixing and Emptying lg,
3. Indoor Use of Pentachlorophenol-treated Millwork and 195
Plywood, Particleboard, and Logs for Log Homes
4. Food/Feed/Water Issue
5. Use of Gloves
198
6. Protective Clothing
200
7. Disposal of Protective Clothing and Pesticide Formulation 2Q1
8. Warnings about Eating, etc., during Application 202
xvi
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Page
9. Restricted Use
202
VII. Measures to Reduce End-User's Risk from Exposure to
Treated Wood 204
A. Elements of an Adequate Consumer Awareness Program 207
1. Use of Gloves 207
2. Use of Coveralls, Gloves, and Dust Mask 209
3. Disposal of Treated Wood 210
4. Indoor Use of Treated Wood 212
5. Animals/Food/Feed/Water Issue 217
6. Outdoor Uses of Pressure-Treated Wood 221
7. Use of Treated Wood for Beehives and Hive Platforms 222
B. Model Consumer Awareness Program 223
C. Consumer Information Sheets 224
1. Creosote 224
2. Pentachlorophenol 227
3. Inorganic Arsenicals 229
VIII. Modifications to the Terms and Conditions of Registration of Wood 231
Preservative Products.
A. Upper Limits for Hexachlorodibenzo-p-dioxin (HxCDD) 231
Contamination
B. Label Modifications 231
1. All Uses of Pentachlorophenol or Pentachlorophenol Salts 232
2. All Uses of Pentachlorophenol, Creosote and Inorganic Arsenicals
Which are Used for the Commercial Pressure-Treatment of
Wood
3. Pressure Treatment Uses for Inorganic Arsenicals 232
4. Pressure Treatment Uses for Creosote 237
5. Pressure Treatment Uses for Pentachlorophenol 240
XVll
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Page
6. Groundline Treatment Uses of Poles with Creosote and 243
Pentachlorophenol
7. Home and Farm Uses (Including Railroad Tie Repair) 244
of Creosote - Restricted Use
8. Home and Farm Uses (Including Railroad Tie Repair) 246
of Pentachlorophenol - Restricted Use
9. Brush-on Treatments of Inorganic Arsenicals-Unclassified 249
Use
10. Sapstain Use of Pentachlorophenol Salts 250
11. Non-Pressure Treatment Plant Dip/Flow and Spray Uses of 251
Pentachlorophenol
C. Data Requirements 252
Comments on the PD 2/3 and April 14, 1983, Public Meeting 254
References
259
Appendix A: Comparison of PD 2/3 Proposals with Final Regulatory Measures
283
Appendix B: Comparison of Risks for Pentachlorophenol and Inorganic Arsenic
Calculated in the PD 2/3, with and without Proposed Protective
Measures, with Recalculated Risks with and without Protective
Measures (Final Regulatory Measures)
Appendix C: Comparison of the Recalculated Exposures for Pentachlorophenol 320
and Inorganic Arsenic With and Without Protective Measures
(Final Regulatory Measures)
Appendix D: Scientific Advisory Panel (SAP) Comments 329
Appendix E: United States Department of Agriculture (USDA) Comments 340
xviii
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List of Tables
Page
1 . Summary of Incidences of Neoplastic
Nodules and Carcinomas in Livers of Female Rats ^2
2. HxCDD (gavage) Bioassay (NCI, 1980): Osborne-Mendel Rats 14
(2 years) - Incidences of Neoplastic Nodules and Hepatocellular
Carcinomas.
3. HxCDD (gavage) Biosasay (NCI, 1980): 15
B6C3P1 Mice (2 years) - Incidences of Hepatocellular Carcinomas
and Hepatocellular Adenomas
4. Summary of Exposure Assumptions for the Inorganic Arsenicals for ]_g
the PD 2/3 and PD 4.
5. Dermal Exposure during Pesticide Formulation 23
6. Summary of Exposure Assumptions for Pentachlorophenol, Sodium 26
Pentachlorophenate and HxCDD for the PD 2/3 and PD 4
7. Summary of Economic Impacts of Cancelling Creosote 29
8. Summary of Economic Impacts of Cancelling Pentachlorophenol (Penta) 30
9. Summary of Economic Impacts of Cancelling the Inorganic Arsenicals 31
10. Summary of Comments Submitted to the Wood Preservatives File 6^
t30000/28C
xix
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I. INTRODUCTION
A. Historical Background
On October 18, 1978, the U.S. Environmental Protection Agency published in
the FEDERAL REGISTER notices of rebuttable presumption against registration
(RPAR) for pesticide products containing coal tar, creosote and coal tar
neutral oil (these three products will be referred to as "creosote"),
inorganic arsenicals, and pentachlorophenol, including its sodium salts
(43 FR 48154, 48267, and 48443, respectively). For creosote, the rebuttable
presumption was based on oncogenicity and mutagenicity. For the inorganic
arsenical pesticides, the rebuttable presumption was based on oncogenicity,
mutagenicity and reproductive or fetotoxic effects. For pentachlorophenol,
the rebuttable presumption was based on teratogenicity and fetotoxicity.
On February 19, 1981 (46 FR 13020), the Agency published a preliminary
notice of determination concluding the RPAR for the wood preservative
uses of creosote, the inorganic arsenicals and pentachlorophenol (which
will be referred to as the wood preservative chemicals). In that preliminary
notice and the supporting position Document (PD) 2/3, the Agency determined
that the wood preservative chemicals continued to exceed the risk criteria
which were the bases for the RPARs. The Agency also determined that the use
of pentachlorophenol and its sodium salt pose the risk of oncogenicity
because of the presence of the contaminants hexachlorodibenzo—p-dioxin
(HxCDD) and hexachlorobenzene (HCB), which also have the potential to
produce teratogenic/fetotoxic effects. To reduce the risks from the use
of the wood preservative chemicals, the Agency proposed to modify the
terms and conditions of registration as follows:
o Cancel spray pentachlorophenol products available for
retail sale in concentrations of 5% or less.
o Classify some products for restricted use.
o Require protective clothing and equipment (e.g., respirators).
o prohibit eating, drinking and smoking while applying wood
preservatives.
o Require proper care and disposal of work clothing and equipment
o Require a closed mixing and a closed emptying system for all prilled
(granular) formulations of pentachlorophenol, powder and prilled
(granular) formulations of sodium pentachlorophenate and the powder
formulations of the inorganic arsenicals.
o Prohibit indoor application of the wood preservatives.
o prohibit the use of pesticide-treated wood indoors, except for a
few low exposure uses;
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o Prohibit application of the wood preservative pesticides in a
manner which may result in direct exposure to domestic animals or
livestock, or in the contamination of food, feed or drinking and
irrigation water.
o Require control technologies to reduce arsenic surface residues on
the treated wood.
In light of the high economic benefits resulting from the use of the
wood preservative chemicals, the Agency determined in the PD 2/3 that the
use of the wood preservative chemicals in accordance with these modifications
would satisfy the statutory standard for continued registration.
In addition, the Agency recommended that regulatory measures be proposed
under the Toxic Substances Control Act (TSCA) for the use of treated wood.
The proposed TSCA rule would have included a requirement that labeling to
explain use, handling, and disposal precautions to users accompany the
treated wood products. Among the recommended labeling measures were:
o The use of gloves when handling treated wood.
o The use of a dust mask and coveralls when sawing treated wood.
o The prohibition of interior uses of treated wood (with certain
exceptions).
o The prohibition of uses which may result in direct exposure to
livestock or the contamination of food, feed, or water.
o The prohibition of the burning of treated wood.
The Agency submitted its preliminary determinations to the PIFRA
Scientific Advisory Panel (SAP) and the tJ.S. Department of Agriculture
(USDA) for review pursuant to sections 6(b) and 25(d) of the Federal
Insecticide, Fungicide, and Rodenticide Act (FIFRA) . The Agency
also solicited comments from the registrants and any other interested
parties. After reviewing the comments from the SAP, the U.S. Department
of Agriculture, the registrants and other interested parties, the Agency
modified the proposed decision announced in the Preliminary Notice of
Determination. The Agency held a public meeting on April 14, 1983, to
give interested persons the opportunity to comment on changes to the
decision proposed in the Preliminary Notice. The Agency carefully con-
sidered the comments submitted in response to this meeting in the development
of the final decision; the comments are discussed in detail in this docment.
This position docvment discusses new information received since the
publication of the PD 2/3 and comments on the PD 2/3 from the SAP, USDA
and other interested parties; it describes the changes in exposure and risk
resulting from the new information; and it provides the Agency's final
regulatory position and the rationale and bases for that position.
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Section z is this introduction. Section II discusses new risk,
exposure and benefit information received by the Agency since the publi-
cation of the PD 2/3. Sections III, IV, and V summarize the SAP, USDA and
other public comments, and the Agency's responses to those comments. Each
of the Sections VI.A through VI.H describes a specific exposure situation
of concern, the PD 2/3 proposal to reduce the exposure and risk, comments
and/or new information, and the Agency's final regulatory position and the
rationale and bases for that position.
Section VII discusses the Consuner Awareness Program in which commer-
cial wood treaters must participate to inform end-users of treated wood
about safe handling practices and uses of the pesticide treated wood.
Section VII.C contains a sample Consumer Information Sheet (CIS) which
would be distributed with each shipment of pressure-treated wood through-
out the chain of commerce and which would be available to the end-user or
purchaser of the treated wood. Section VIII summarizes the Agency's
final regulatory position listing the required modifications to the terms
and conditions of registration for the three wood preservatives. Section
VIII also summarizes additional data requirements which will be imposed
on the registrants by the Agency to continue in effect existing registrations
of the wood preservatives. The registrants will be notified of the additional
data to be submitted by them in an action separate from this PD 4 pursuant
to Section 3(c)(2)(B) of FIFRA.
The worker protection requirements specified in this document are
established pursuant to FIFRA which provides no means of regulating
occupational safety and health hazards except insofar as they are directly
associated with use of a registered pesticide* EPA has made no attempt to
regulate any workplace hazard except those associated with the use of
pesticide products containing creosote, pentachlorophenol (and its salts)
and the inorganic arsenicals as wood preservatives. EPA in developing
these worker protection requirements has only considered the hazards directly
attributed to the use of these pesticides.
Appendix A presents a comparison of the PD 2/3 proposals with the Agency's
final regulatory position. Appendix B is a table comparing the risks with
and without protective measures as calculated in the PB 2/3 with the risks
with and without protective measures recalculated based on new data and
other information received since publication of the PD 2/3. Appendix C is
a table comparing the recalculated exposures used in this position document
to calculate new risks for the three wood preservatives in various use
situations, with and without protective measures. Appendices D and E contain
the SAP and USDA comments in their entirety.
B. Legal Background
To obtain a registration for a pesticide under the Federal Insecticide,
Fungicide, and Rodenticide Act ("FIFRA"), as amended, an applicant for
registration must show that the pesticide satisfies the statutory standard
for registration. That standard requires, among other things, that the
pesticide perform its intended function without causing "unreasonable
adverse effects on the environment." FIFRA § 3(c)(5).
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The term "unreasonable adverse effects on the environment" is defined
as "any unreasonable risk to man or the environment, taking into account
the economic, social and environmental costs and benefits of the use of
any pesticide" FIFRA § 2(bb). To register a pesticide, the Administrator
must find that the benefits of each use of the pesticide exceed the risks
of use, when the pesticide is used in accordance with commonly recognized
practice and in compliance with the terms and conditions of registration.
The burden of proving that a pesticide satisfies the registration
standard is on the proponents of registration and continues as long as
the registration remains in effect. Under section 6 of FIFRA, the
Administrator may cancel the registration of a pesticide or modify the
terms and conditions of registration whenever it is determined that the
pesticide causes unreasonable adverse effects on the environment. The
Agency created the RPAR process to facilitate the identification of pesticide
uses which may not satisfy the statutory standard for registration and to
provide an informal procedure to gather and evaluate information about the
risks and benefits of these uses.
The regulations governing the RPAR process are set forth in 40 CFR
162.11. Among other things, this section provides that a rebuttable
presumption against registration shall arise if a pesticide meets or exceeds
any of the risk criteria set out in the regulations. The Agency announces
the commencement of the RPAR process by publishing a notice in the Federal
Register. After an RPAR is issued, registrants and other interested persons
are invited to review the data upon which the presumption is based and to
submit data and information to rebut the presumption by showing that the
Agency's initial determination of risk was in error, or by showing that
use of the pesticide is not likely to result in any significant exposure
to hunians or the environment with regard to the adverse effects in question.
In addition to submitting evidence to rebut the risk presumption, respondents
may submit evidence as to whether the economic, social and environmental
benefits of the use of the pesticide outweigh the risks of use.
in determining whether the use of a pesticide poses risks which are
greater than the benefits, the Agency considers possible changes to the
terms and conditions of registration which can reduce risks, and the impacts
of such modifications on the benefits of use. If the Agency determines
that such changes sufficiently reduce risks to the level where the benefits
outweigh the risks, it may conclude the RPAR process. The Agency announces
this type of conclusion to an RPAR review by publication of a Notice of
Determination in the Federal Register. That Notice states and explains the
rationale for the Agency's regulatory position, provides that the registrant
may avoid cancellation by implementing the modifications to the terms and
conditions of registration set forth in the Notice, and sets forth the
hearing rights of the affected parties.
4
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II. UPDATED RISK AND BENEFIT INFORMATION
Since the publication of the PD 2/3, the Agency has received additional
information from the United States Department of Agriculture (USDA), the
wood preserving industry, and published articles on risk and exposure to
the wood preservatives.
As a result of the new information received and evaluated by the Agency,
the exposure and risk estimates for certain uses of the wood preservative
chemicals were recalculated. In some instances the change in risk estimates
caused the Agency to modify the regulatory proposals set forth in the PD
2/3. The changes in regulatory position and the reasons for these changes
are discussed in this document in Sections VI through VII.
This section of the document describes the new information and presents
the Agency's rationale for modifying or not modifying the exposure and
risk assumptions as stated in the PD 2/3.
A. Risk Information
1. Inorganic Arsenicals
a. Inhalation Risk Model
PD 2/3 Risk Model; The risk model (GAG, 1978) used in PD 2/3 (p. 215) for
inhalation exposure to inorganic arsenicals was based on three epidemiological
studies, namely, two of copper smelter workers in Anaconda, Montana (Lee
and Fraumeni, 1969), and Tacoma, Washington (Pinto et a.l, 1977), and one
of a pesticide manufacturing plant (Ott, et al., 1974). These studies
analyzed the relationship between mortality and exposure to arsenic. The
risk equation used in the PD 2/3 to estimate potential risks from inhalation
exposure was
p = 1-e-2.95x10-3x
where X is the arsenic exposure expressed in ug/m3 (PD 2/3, p. 215). The
airborne arsenic in the smelters was in the trivalent form while the
airborne arsenic in the pesticide manufacturing plant was in the
pentavalent form (PD 2/3, p. 108).
PD 4 Risk Model; New information received since the PD 2/3 was published
was evaluated by the Agency and used to reestimate the potential inhalation
risk due to arsenic exposure. A summary of the data and the development of
the risk equation used to estimate the risks presented in this document are
contained in the paragraphs which follow- The Agency's Carcinogen Assessment
Group (CAG) evaluated, the new data in preparing a document for the Office
of Health and Environmental Assessment (OHEA) on arsenic risk assessment
(U.S. EPA, June 1983).
Several studies (Higgins, et al., 1982; Enterline and March, 1983; and
Lee-Feldstein, 1982) were used by the CAG in revising its 1980 (PD 2/3)
risk assessment for inhalation exposure (U.S. EPA, June 1983). In addition,
new analyses by Brown and Chu from the National Cancer Institute (NCI) were
also used in the risk revisions (Brown and Chu, 1983a and 1983b) . A detailed
discussion of the inhalation risk analysis for arsenic is presented in
Chapter 5 of the OHEA (U.S. EPA, June 1983) document on arsenic.
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The Enterline and Marsh (1982) study included 2802 men working at a Tacoma,
Washington, smelter for a year or more between 1940 and 1964. Individual expo-
sures to arsenic were estimated using work histories and measurements of
arsenic in urine. The study cites 104 deaths due to respiratory cancer.
This study is summarized on pp. 5-120 to 5-123 of the OHEA document (U.S.
EPA, June 1983).
The Lee-Feldstein (1982) study surveyed 8047 smelter workers in Anaconda,
Montana. This large study followed mortality for 39 years and included observa-
tions of a considerable number of respiratory cancer deaths. Enough detail of
exposure levels and work histories was available for estimations of individual
exposures and dose-response. This study is summarized in the OHEA document
(U.S. EPA, June 1983, pp. 5-94 to 5-99)
The Higgins et al. (1982) study contains additional data on 1800 men from
the Anaconda smelter. Cumulative exposures were estimated and information on
smoking habits was obtained for most of the cohorts. This study is summarized
in the OHEA document (U.S. EPA June 1983, pp. 5-105 to 5-107).
Brown and Chu {1983a, b, and c) applied the multi-stage theory of carcino-
genesis to the Anaconda smelter studies, taking into account exposure rate, dura-
tions of exposure, age at initial exposure and time since cessation of exposure.
Their analysis is described in the OHEA document (U.S. EPA, June 1983, pp.
5-110 to 5-119).
The inhalation oncogenic risk of arsenic is based soley on the epidemio-
logical studies by Higgins et al., Lee-Feldstein, and Enterline and Marsh,
and the series of analysis for NCI by Brown and Chu. The Agency (U.S. EPA,
1983) esimated unit risk per ug/m3 ranging from 1.25 x 10"-* (ug/m3)""1
to 7.60 x 10~3 (ug/m3)""1 using linear models. Taking a geometric
mean, the CAG's usual statistical procedure, the final unit risk was estimated
to be 4.209 x 10~3 (ug/m3)"1.
To estimate inhalation risk, the equation
-3
p = -|_e-4.29x10 X
was derived (McGaughy, April 14, 1984) where p is the lifetime cancer risk
based on a lifetime continous exposure and where X is the continous expo-
sure in ug/m3. The equation is based on a linear non-threshold risk model
which assumes that the age-specific rate increases proportionally to the
cumulative exposure experienced up to that point in time. As a result
partial lifetime exposures of equal level and duration would have a differ-
ent effect depending upon when they occurred during a lifespan (McGaughy,
April 14, 1984). For an individual exposed from age 30 to age 60, the
risk equation is approximately
(1) P » 2.73W
where W is the exposure in mg/kg working day (McGaughy, April 14, 1934).
The assumptions made are that the median lifespan is 76.2 years, a 60 ka
applicator while working breathes 10m3 of air per day for 240 days per
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year for 30 years, and the applicator was exposed to arsenic from age 30
to ag« 60. Exposure from age 18 to 48 or 40 to 70 would result in potential
risk estimates that are 38% higher or 32% lower, respectively (McGaughy,
April 14, 1984). The potential risk estimates presented throughout this
document for inhalation exposure to the inorganic arsenicals in arsenic
treatment plants were calculated using equation (1) above.
However, for estimating risks to residents (with everyday exposure at
10m~3 per day) in homes constructed with All-Weather-Wood-Foundations
(AWWF) made from arsenic pressure-treated wood, the risk equation becomes
P « 2.73(70 x 365)W „ 9 7W
(3TTX"2W) **7W
where W is expressed in mg/kg/day assuming a daily exposure over an average
lifetime of 70 years (McGaughy, April 14, 1984). (One home out of 50 is
constructed with AWWF's.)
For estimating risk from inhalation absorption for those who saw or
fabricate structures made out of arsenic-treated wood, the "unit risk" is
adjusted by a factor of 1 in order to reflect "absorbed dose" (McGaughy,
THT
April 14, 1984). The OHEA document (p. 2-22) states that 30% of the arsenic
would be absorbed when inhaled as arsenic trioxide in the air in copper smelters.
Thus, the inhalation risk equation for sawing (handling/fabricating) arsenic
treated wood is
a 9.1W
where W is exposure to arsenic-laden sawdust expressed as mg/kg/working day
reflecting absorbed dose (McGaughy, April 14, 1984). The inhalation risk
estimates for arsenic presented throughout this position document (PD 4)
were calculated using the above equations appropriate for the various use
situations.
OHEA (O.S. EPA, 1983) states that the linear non-threshold model used to
estimate arsenic inhalation risk was adopted as the primary basis for risk
extrapolation at low levels of exposure because, although the scientific basis
is limited, it is the best of any of the current mathematical extrapolation
models. However, OHEA (O.S. EPA, 1983, p. 5-88) also states that the impre-
cision of presently available technology for estimating cancer risks to humans
at low levels of arsenic exposure should be recognized. The linear extrapola-
tion model used here provides a rough but plausible estimate of the upper limit
of risk: that is, with this model it is not likely that the true risk would.be
much more than the estimated risk, but it could be considerably lower (U.S.
EPA, 1983).
7
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Therefore, the potential inhalation risk estimates presented throughout
this PD 4 should be viewed as upper-limit estimates and not as accurate
representations of true cancer risks.
The exposures to inorganic arsenic for various use situations are
contained in Appendix C of this position document. The estimated risks to
inorganic arsenic are summarized in Appendix B and are compared to those
calculated for the PD 2/3.
b. Dermal/Oral Risk Model
In the PD 2/3, the Agency used a risk model for dermal and oral exposure
to arsenic based on an epidemiologic study of skin cancer in more than 40,000
people in a section of Taiwan with high arsenic concentrations in the well
water (PD 2/3, p. 216). The Taiwan well water was predominantly pentavalent
arsenic (80% pentavalent and 20% trivalent) (Irgolic, 1982).
The risk equation used in the PD 2/3 (p. 216) to estimate potential oncogenic
risks from dermal and oral exposure (gastro-intestinal absorption) was
Risk = 2.41423 x C
2.41423 X C + 6.02793
where C is the concentration of arsenic (mg/liter) in drinking water. Since
the PD 2/3 was published, the Agency received new information on exposure
to arsenic in drinking water including submissions from Koppers (#72:30000/28C)
These studies are summarized in Chapter 5 of the OHEA document (U.S.
EPA, 1983) on arsenic. The Agency has concluded (U.S. EPA, 1983) that the
best data available for the risk assessment for oral ingestion of arsenic
remains the study of skin cancer from exposure to arsenic in the Taiwan
well water (PD 2/3, p. 104) as reported by Tseng et al. (1968).
Using a Weibull dose-response model, incorporating both dose and time
where dose is linear and where time is raised to the power of 3.853, the
CAG derived a risk equation based on the data from Tseng et al. (1968) to
estimate the potential risks of skin cancer from oral (gastro-intestinal)
or dermal exposure to arsenic. The development of this model is presented
in the OHEA (U.S. SPA, 1983) document in Chapter 5 (pp. 5-136 to 5-143).
This method of risk estimation provides an excellent fit to the data, as
evidenced by the dose-response curves (U.S. EPA, 1983, p. 5-142). It was
assumed that the probability of contracting skin cancer was related to age
and concentration of arsenic in ppm. The incidence rates are age-specific
and are linearly related to dose. The prevalence rates were lower for
younger ages and lower arsenic concentrations than for older ages and
higher arsenic concentrations (U.S. EPA, 1983, p. 5-138). To obtain a
unit risk estimate, lifetime risk was assumed to be approximately equal to
8
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the risk calculated for the median lifespan (76.2 years) in the absence of
competing risk (U.S. EPA, 1983, p. 5-140). The risk equation for skin
cancer derived for low oral exposure to arsenic is
P = 0.430 X
where X is the exposure in mg/liter or ppm in the water (U.S. EPA, 1983,
p. 5-141).
For a "working lifetime" of 30 years, it is desirable to express exposure
in mg/kg/working day. For this purpose, the risk equation for skin cancer
due to ingestion becomes
P = 3.64 W
where W is the arsenic exposure from ingestion expressed in mg/kg/working
day, assuming a 60 kg person drinks 2 liters of water a day and works 240
days per year for 30 years over an average lifetime of 70 years (McGaughy,
April 14, 1984). In calculating the slope in units of mg/kg/day absorbed
dose, it is also assumed that 100% of the arsenic in the water is absorbed
through the gut (U.S. EPA, 1983, p. 5-141). The above equation (P =3.64 W)
was also used to estimate the skin cancer risk from dermal exposure to
arsenic for the activities of bag emptying, mixing solutions, handling
freshly treated wood, "brushing-on" arsenic to the cut ends of treated
wood and gastrointestinal exposure while sawing or fabricating with arsenic
treated wood (McGaughy, April 14, 1984).
For exposure in flooded basements in homes with All-Weather-Wood-Foundations
made from arsenic pressure treated wood, the unit risk factor is decreased
by a factor of
1
240 x 30
because it is assumed that there is a once in a lifetime exposure. Thus,
for risk from dermal exposure to flooded basements, the risk equation is
P = 3.64 ( 1 )W
( 240 x 30 )
where W is the exposure in mg/kg/day (McGaughy, April 14, 1984).
For similar exposure estimates, the new model results in risk estimates
which are slightly higher (by less than a factor of 2) than the risk estimates
calculated using the model described in the PD 2/3.
The estimated dermal and oral risks estimated by the Agency for inorganic
arsenic were calculated using the above equations. The estimated cancer
risks for inhalation, dermal, and gastrointestinal exposure to arsenic are
summarized in Appendix B in this position document and are compared to
those calculated for the PD 2/3.
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The PD 2/3 in some instances added the estimated risks for skin cancer
and the estimated risks for respiratory cancer to present a "total" risk
for arsenic. However, the Agency has determined that adding these two
risks together is improper (Bayard, June 11, 1984). Exposure to arsenic
taken orally has been shown to cause skin cancer in humans. Exposure to
arsenic by inhalation has been shown to cause respiratory cancer in humans.
The potential risk of skin cancer is separate and distinct from the potential
risk of respiratory cancer. Therefore, where the risks have been recalculated
for this P.D 4, the potential dermal risk will not be added to the potential
respiratory risk.
2. Pentachlorophenol
a. Multi-stage Model for Estimating Oncogenic Risks
The pentachlorophenol risk estimates for oncogenicity presented in this
document vary slightly from the estimates derived in the PD 2/3, partly
because the Agency has refined its oncogenic risk assessment method to use
the "multi-stage model" rather than the "one-hit" model. For similar
exposure estimates, the estimated oncogenic risks for pentachlorophenol
derived by this revised methodology fall essentially in the same range as
the PD 2/3 estimates. A comparison of the PD 2/3 risk estimates with the
recalculated risk estimates is presented in Appendix B of this document.
The Agency described the rationale for using the multi-stage model
instead of the one-hit model in the "Water Quality Criteria Document"
published in the Federal Register, November 28, 1980 [45 FR 79318]. The
multi-stage model is more appropriate based on mathematical, theoretical,
and biological grounds, as summarized in the Appendix of that document.
The "one-hit" model can be considered the first stage of the multi-stage
model. The multi-stage model reduces to the one-hit model when there is
only a control group and one active dose level. Most oncogenic studies
include two or three active doses and thus the dose-response relationship
is frequently more complex than suggested by the "one-hit" model (Litt,
Feb. 22, 1984).
b. Reevaluation of the HxCDD Bioassay
In the PD 2/3, the Agency based its oncogenic risk analysis for the HxCDD
contamination in pentachlorophenol on a chronic feeding study performed by
the National Cancer Institute (NCI, 1980) using 1,2,3,6,7,8- and 1,2,3,7,8,
9-HxCDD. The study showed an increased incidence in combined benign and
malignant liver tumors in male and female rats and mice. The "one-hit"
model was used to estimate carcinogenic potency^ The slope derived from
the female rat data was used to estimate risk to humans, as the female rat
appeared to be more sensitive than the male rat or male and female mouse
(PD 2/3, p. 303).
10
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AWPI (78:30000/28c) commented that "...EPA has improperly relied on the
NCI gavage bioassay..." and submitted a report by Robert A. Squire Associates,
Inc. (1983) in support of this statement. Squire Associates (1983) reviewed
the NCI (1980) study and, based on Dr. Squire's histopathological evaluations,
reported lower incidences of neoplastic nodules and carcinomas in high dose
female rats than the incidences reported by NCI (1980).
At the request of EPA, the National Toxicology Program (NTP) recently
reviewed the histopathology slides to reexamine the lesions in the liver
tissues of the female rats. NTP (Hildebrandt, 1983) concluded that HxCDD
administered to female rats causes a toxic hepatitis and an increase in
the incidence of neoplastic nodules. The toxicity effects were characterized
by cytomegalia, karyoraegaly, bile duct proliferation, and varying degrees
of cytoplasmic vacuolization (fatty change). In determining the incidence
of neoplastic nodules, Dr. Hildebrandt found that although the cells in
neoplastic nodules were often vary similar to foci of cellular alteration,
two differentiating features could be used; a) the degree of compressing
adjacent tissue (sometimes bulging from the surface), and b) perhaps more
importantly the degree of bile duct proliferation within the focus of
proliferating cells. A nodule (focus) of proliferating cells compressing
adjacent tissue and not containing bile ducts was diagnosed as a neoplastic
nodule. A similar focus of cells that contained small bile ducts and/or
small proliferating bile ducts was diagnosed as a focus of cellular alteration.
The nodules, or foci which Dr. Hildebrandt called neoplastic nodules,
were either devoid of bile ducts, contained a bile duct at the periphery
which was interpreted as entrapment, or had only a hint of bile duct proli-
feration in one small region of the nodule. Dr. Hildebrandt stated that
there is some subjectivity in the criteria he used to determine the number
of neoplastic nodules in the liver tissues. For example, a few neoplastic
nodules would have been diagnosed as foci of cellular alterations if a
reviewer was of the opinion that neoplastic nodules have no bile ducts
whatsoever.
Dr. Hildebrandt found that two livers had a lesion that was compatible
with hepatocellular carcinoma.
The incidences of neoplastic nodules and carcinomas reported by Dr.
Hildebrandt may be compared with the findings by NCI (1980) and Squire
Associates (1983) as summarized in Table 1.
1 1
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Table 1
Summary of Incidences of Neoplastic Nodules
and Carcinomas in Livers of Female Rats
Neoplastic Nodules Carcinomas
Dose (ug/kg/wk) Low Mid High Low Mid High
1.25 2.5 5.0 1.25 2.5 5.0
NCI, 1980 10/50 12/50 30/50 0/50 0/50 4/50
Squire Associates, 1983 4/50 7/50 7/50 0/50 0/50 0/50
The NTP reevaluation {Hildebrandt, 1983) shows incidences of liver
tumors in the range of 50% less than that of the original 1980 analysis (30
vs. 16 neoplastic nodules and 2 vs. 4 hepatocellular carcinomas at the
highest dose).
The Agency's Carcinogen Assessment Group (CAG) evaluated and accepted
the findings of NTP (Hildebrandt, 1983) and used those data of incidences of
neoplastic nodules and carcinomas in female rats as part of the assessment
of the carcinogenic potency of HxCDD.
Other data which were used were contained in the orginal report of the NCI
(1980) bioassay and include incidences of tumors for male rats, male mice, and
female mice. These data and the data from the NTP reevaluation (Hildebrandt,
1983) are presented in Tables 2 and 3.
Dr. McGaughy of CAG (April 24, 1984) summarized and evaluated the
results of the bioassay. He stated that the bioassay showed positive
results for male and female rats (combined liver neoplastic nodules or
hepatocellular carcinomas) with the greater response in the females. In
the females, carcinomas appeared only in the high-dose group, with a
significant dose-response trend for both neoplastic nodules and nodules
and carcinomas combined. In the male rats, there was also a trend for
neoplastic nodules and carcinomas combined, but this was only marginally
significant. These results are presented in Table 2, which includes the
recent NTP reevaluation of the female rat liver slides. The review shows
responses in the range of 50% less than that of the original analysis.
The responses for neoplastic nodules and combined nodules and carcinomas
are statistically significant.
In female mice, there was a dose-related trend in hepatocellular carcinomas,
but only the combined adenomas and carcinomas were significant. In male mice
there was a minor trend in hepatocellular adenomas, but no increase, statistical
or otherwise, in hepatocellular carcinomas (Table 3).
Although no statistically significant increase in carcinomas occurred in
mice or rats of either sex, when neoplastic nodules in the rats and hepatocellular
adenomas in the mice were included in the data, the results became significant
12
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for all groups. The neoplastic nodules in the rats are viewed as evidence
of a progression response for cancer development; hepatocellular adenomas
in mice are interpreted as indications of potential cancer, though the
adenomas may be reversible.
In order to estimate the carcinogenic potency of HxCDD, these combined
results were then fitted to the multistage model for all four groups. As
shown in Tables 2 and 3, the 95% upper-limit unit risk estimates are:
Rat - male q.j* = 0.59 ( ug/kg/day)~1
female q1* - 3.5 (ug/kg/day)~1
Mouse - male q^* » 11.0 (ug/kg/day)~1
female q.j* = 2.9 (ug/kg/day)'1
The Agency's usual procedure is to use the most sensitive sex-species for
unit risk (McGaughy, April 24, 1984). Under that procedure, which for esti-
mating the upper limit is based on the linearized multistage model with sur-
The Agency's usual procedure is to use the most sensitive sex-species for
unit risk (McGaughy, April 24, 1984). Under that procedure, which for esti-
mating the upper limit is based on the linearized multistage model with sur-
face area correction for animal-to-man extrapolation, the male mouse data
yielding a
q.j* = 11.0 (ug/kg/day)-1
would be selected to provide the upper-limit estimate of potency. However, as
examination of Tables 2 and 3 ahows, there are several reasons to give weight
to the female rat data base also. These are:
a. Low spontaneous (control) rates in the rat versus the male mouse liver.
b. Statistically significant increases in both the mid and high level
dose groups versus control for the female rat; the male mouse
response was significant only at the high dose.
c. A more distinct dose response trend in the female rat versus the
male mouse.
d. The only hepatocellular carcinomas in the female rat were in the
high dose group. There were none in 148 control animals. By com-
parison, the male mouse showed no clear trend in carcinomas.
Finally, for TCDD the female rat (different strain) has been shown to
be more sensitive than the mouse. Based on the above qualifications, the
Agency has decided to modify its procedure slightly and to take the geometric
mean of the 95% upper-limit estimates from the male mouse and the female
rat. The final estimate (McGaughy, April 24, 1984) is
q,* = (3.5 x 11.0)1/2 = 6.2 (ug/kg/day)"1
13
-------
Table 2. HxCDD (Gavage) BIOASSAY (NCI, 1980):
OSBOHNE-MENDEL RATS (2 years)-INCIDENCES OF NEOPLASTIC NODULES
AND HEPATOCELLULAR CARCINOMAS
Tumor
Vehicle
Control
Untreated
Control
Low-Dose
1.25
Mid-Dose
2.5
High-Dose
5
Estimates of q..*
(ug/kg/day)'1
MALE (700g)b
Number of animals examined 74 75
Hepatocellular carcinoma (HC) 0 0
Neoplastic nodule (NN) 0 2(3%)
HC + NN combined 0 2(3%)
Human equivalent dose 0 0
ug/kg/day
FEMALE (450g)d
Number of animals examined 75 73
Hepatocellular carcinoma (HC) 0 0
Neoplastic nodule (NN) 2(3%) 1(1%)
HC + NN combined 2(3%) 1(1%)
Human equivalent dose 0 0
ug/kg/day
49
0
0
0
0.04
50
0
5(10%)
5(10%)
0.03
50 48
0 1(2%)
1(2%) 3(6%) 5.6 x 10~1
1(2%) 4(8%)° 5.9 x 10~1
0.08 0.15
50 50
0 2(4%) 3.2 x 10~1
7(14%)° 16(32%)e 3.3
7(14%)° 18(36%)e 3.5
0.06 0.12 —
a. 95% upper-limit estimate of linear term in the multistage model based on human equivalent dosages using
surface area correction.
b. Analysis by NCI (1980)
c. p < 0.05 versus vehicle-control
d. Reevaluation by Hildebrandt (1983)
e. P < 0.001
14
-------
Table 3. HxCDD (Gavage) BIOASSAY (NCI, 1980):
B6C3F1 MICE (2 years)-INCIDENCES OF HEPATOCELLULAR CARCINOMAS AND HEPATOCELLULAR ADENOMAS
Tumor
(MALES)
Number of animals examined
Hepatocellular carcinoma (HC)
Hepatocellular adenoma (HA)
Combined HA and HC
Human equivalent daily
dose (ug/kg/day)
(FEMALE)
Animal dose (ug/kg/wk)
Number of animals examined
Hepatocellular carcinoma (HC)
Hepatocellular adenoma (HA)
Combined HA and HC
Human equivalent daily dose
ug/kg/day
Vehicle Untreated
Control Control
73
8(11%)
7(10%)
15(21%)
0
0
73
1(1%)
2(3%)
3(4%)
0
75
12(16%)
15(20%)
27(36%)
0
0
74
0
2(3%)
2(3%)
0
Low -Dose
1.25
50
9(18%)
5(10%)
14(29%)
O.O14
2.5
48
0
4(8%)
4(8%)
0.027
Mid-Dose
2.5
49
5(10%)
9(18%)
14(29%)
0.027
5.0
47
2(4%)
4(9%)
6(13%)
0.054
High-Dose Estimates3 of q.j*
5.0 (ug/kg/day)-1
Aft «._-—,-_-. — —.—*-—
9(19%) 3.71
I5(31%)b 6.99
24(50%)° 11.00
m ___ — _______
47
2(4%) 9.15 x 10-1
9(19%)b 2.61
10(23%)b 2.94
01 n-j _______ __ _
a. 95% upper-limit estimate of linear term in the multistage model based on human equivalent dosages using
surface area correction.
b. p < 0.01 versus vehicle-control
c. P < 0.001
15
-------
Although the q.,* for HxCDD could be as high as 11.0 (ug/kg/day) "*1, the Agency
prefers to use the q.,* of 6.2(ug/kg/day)~^ for risk estimation for the reasons
discussed above.
To estimate the potential risk(R)to humans from exposure to the HxCDD
contaminant in pentachlorophenol and sodium pentachlorophenate, the Agency
used the following equation:
R = 6.2 x exposure
where the exposure is expressed in ug/kg/day averaged over a lifetime.
The Agency assumes that the average worklife is 30 years.
The hunan exposure estimates for the various use situations for penta-
chlorophenol with its HxCDD contaminant are summarized in Appendix C of
this document; the human risk estimates are suamarized in Appendix B.
For similar exposure estimates, the potential estimates for HxCDD
would be of the same order of magnitude as those presented in the PD 2/3.
Although the tumor incidences for female rats are lower than originally
reported, it only takes a very small amount of HxCDD (5 ug/kg/week or
less) to produce a positive tumorigenic effect, and thus the slope or Q-)*,
as an indicator of potency would not be expected to decrease appreciably.
When comparing the risk estimates calculated in the PD 2/3 with those
calculated for this PD 4, it can be seen that for some uses the risk has
increased by an order of magnitude or more. This is due mainly to the
changes made in the exposure assumptions discussed in section II B of
this document.
3. Creosote
No new information was received by the Agency which changed the Agency1s
position regarding the rebuttable presumptions for creosote. As summarized
in the PD 2/3 (pp. 36-46 and p. 85), creosote and many of its component
chemicals have been shown to cause cancer in laboratory animals; there have
also been many case reports linking human cancer to exposure to creosote.
These findings have been updated and supported by a recent review of polynuclear
aromatic hydrocarbons (IARC, 1983). However, as stated in the PD 2/3 (p. 85),
the Agency still has no definitive data on the identity of the airborne
component chemicals of creosote to which workers are exposed in wood treatment
plants where creosote is used. Moreover, there are no quantitative data on
dermal exposure to these workers. This lack of information precludes a
quantitative assessment of risk of carcinogenicity in humans.
The Agency is aware that some researchers are studying the feasibility
of interpolating results from skin painting studies which are validated
against human carcinogens. However, creosote has not been tested or
validated through this system.
16
-------
Because the Agency continues to be concerned about the potential for high
cancer risk from exposure to creosote, the Agency will, in a separate action
apart from the requirements described in this PD 4, request registrants to
submit a cross-sectional retrospective epidemiology study of creosote treat-
ment plant workers to provide data with which to quantitatively estimate
the oncogenic risk to humans. Study parameters such as sample size,
identification of appropriate treatment plants, identification of comparison
or control populations and other study parameters must be reviewed and
accepted by the Agency prior to actual conduct of the study. Industrial
hygiene air monitoring for exposure in creosote treatment plants will
also be necessary and must include area and breathing zone data. Survey
techniques should currently conform to standard methodologies approved by
the Agency for regulatory purposes. The request will be made under the
authority of F3FRA Section 3(c)(2){B) to maintain in effect the existing
registration of creosote products used as wood preservatives. The Agency
believes the retrospective epidemiology study and creosote treatment plant
monitoring survey will enable the Agency to quantitatively assess the
potential human oncogenic risk from creosote exposure.
17
-------
B. Exposure Information
The Agency received new information on exposure to the three wood
preservatives which convinced the Agency to alter the assumptions made in
the PD 2/3. The bases for the changes in exposure assumptions are presented
in detail below. The changes are summarized in Tables 4 & 5 (Inorganic
Arsenica^s) and in Tabj.e 6 (Pentachxorophenoj. and its sodium sa^t) . There
is no table for creosote, as there was oniy one change.
1. INORGANIC ARSENICALS
a. AWPI (|36:30000/28C) stated that the air i.evej. of arsenic ^evel
to which workers may be exposed over an 8 hour period in wood treatment
plants would not be as high the 0.07 mg/ra3 level estimated by the Agency
in the PD 2/3. The 0.07 mg/m3 estimate represented a time weighed average
(TWA) found by the California Health Department (1979) in a survey of an
arsenical treatment plant. The AWPI comment demonstrated that 0.07 mg/m3
was based on the air level near a mixing area therefore overestimated
the worker exposure. The Agency agrees and, in addition, the Agency has
concluded that this plant was atypical because (1) its operations involved
the mixing of powder formulations which are not widely used today/ and (2)
the formulations were mixed in an open area, not a closed system. AWPI
stated that the ^eve^. of 0.01 mg/m3, would be more appropriate to use for
purposes of estimating exposure. AWPI ao.so submitted data (f36C:300QO/28C)
on urine level/airborne arsenic correlations which have convinced the Agency
that 0.01 mg/m3 is a more reasonable estimate (Day, Feb. 28, 1984).
Because of the above considerations the Agency has adopted the estimate
of 10 ug/m3 of arsenic in the ambient air for calculating exposure to appli-
cators at arsenic treatment plants. The exposure estimates in Appendix B
reflect this decision.
b. In the PD 2/3, the Agency assumed that respirators would provide 90%
protection against inhalation exposure to the inorganic arsenica^s. OSEA has
found that "high efficiency filter" respirators provide 99% protection (29
CPR 1910.1018, Table 1). Because the Agency wixl require this type respirator
if arsenic j.evels are either unknown or exceed 10 ug/m3 in inorganic arsenical
pressure treatment plants (see Section VI.C.l.), it will be assumed, as OSHA
states, that the inhalation exposure is reduced by 99% instead of 90%. The
inhalation exposure and exposure estimates with applicators using respirators,
as presented throughout this PD 4, reflect the 99% reduction.
c. In the PD 2/3, the Agency assumed 100% inhalation absorption of arsenic
from arsenic-laden sawdust, because no data were available to indicate other-
wise. The Agency has revised the estimated inhalation absorption rates for
sawdust containing inorganic arsenicals from 100% (PD 2/3) to 27% for chromated
copper arsenate (CCA) and from 100% (PD 2/3) to 65% for ammoniacal copper
arsenate (ACA) (Zendzian, Rebuttaj. Analysis, 1982; Zendzian, January 25, 1984;
and Rispin, April 18, 1984). The revisions are based on an unpublished study
by Peoples (1979) (AWPI Rebuttaj. |36:30000/28C) in which two beagle dogs were
fed 2.0 grams of CCA-treated wood or 2.0 grams of ACA-treated sawdust for eight
days. Neither dog showed signs of arsenic toxicity.
18
-------
Table 4
Summary of Exposure Assumptions for the Inorganic Arsenicais
for the PP 2/3 and PD 4*
Exposure
Situations
PD 2/3 Assumption
PD 4 Assumption
a. Ambient arsenic
air levels at
treatment plants
b. Percent protection
by high efficiency
filter respirators
c. Inhalation
absorption rates
for CCA-and for
ACA-laden sawdust;
arsenic-laden dust
d. Dermaj. absorption
rate for arsenic
from arsenic-
laden sawdust
(CCA or ACA)
e. Dermal absorption
rate for inorganic
arsenic for:
-liquid formulation
-dry arsenic-
laden dust
f. Dermal, exposure
to FCAP when
emptying bags
of FCAP powder
g. Inhalation absorb-
tion for sawing
arsenic treated
wood
h. Arsenic air levels
in homes construct-
ed with arsenic
treated wood
0.07 mg/m3
90%
100%
100%
100%
0.01%
0.1%
0.01%
up to 10 grams
0.36 mg/m3
0.031 ug/m3
0.01 mg/m3
99%
27%
65%
100%
Negligible
0.1%
0.1%
0.0038 to 0.142 mg/hr.
0.024 mg/m3
0.004 ug/m3
*See text for the bases of the exposure assumptions
19
-------
The percentage of arsenic excreted in the urine and feces was measured.
This study indicated that in the CCA-treated dog, 97.6 percent of the dose
was excreted, with 27% of that amount excreted in the urine. The gastroin-
testinal absorption was thus calculated to be approximately 27% (i.e., 27%
of 97.6%). In the ACA-treated dog, 80.7% of the dose was. excreted, with
82% of that excreted in the urine. The gastrointestinal absorption was
calculated to be approximately 65% (82.% of 80.7%).
Lacking other data, the Agency assumes that absorption of arsenic from
arsenic-laden sawdust from inhalation exposure is the equivalent to absorption
by the oral route (Rispin, April 18, 1984). The Agency assumes that 10% of the
arsenic-laden sawdust wixx be respirabxe and that the remaining non-respirabie
dust will enter the gastrointestinal tract (PD 2/3, p. 213). The material would
be deposited in the bronchia^, passageways, brought up by ciliary action and
swallowed; absorption would then follow from the digestive tract (Zendzian,
Rebutta^ Analysis, 1982). Based upon the results of the study, the Agency has
lowered the estimate of inhalation absorption rates for arsenic from sawdust
containing arsenic, accordingly. Even though only two dogs were studied,
the Agency determined that these data would be used to calculate an estimate
for inhalation absorption rates for arsenic-laden sawdust in the absence of
other existing data.
The Agency continues to assume, as in the PD 2/3 (pp. 203 and 210) ,
that the inhalation and gastrointestinal absorption rate of arsenic-laden
dust found in the ambient air at arsenic treatment plants or in homes con-
structed with Aij.-Weather-Wood-Foundations is 100%, since the Agency xacks
data that indicate otherwise (Rispin, April 18, 1984).
d. The Agency assumed in the PD 2/3 that the dermal absorption of arsenic
from arsenic-laden sawdust was 0.01% (PD 2/3, pp. 199 and 209). A dermal
absorption study by Peoples (unpublished, July 1979) submitted by AWPI
(#36:30000/280) has convinced the Agency that the dermai absorption of arsenic
from arsenic-.Laden sawdust or dry arsenic-treated wood is negligible (Zendzian,
Rebuttal Analysis, 1982? and Zendzian, April 16, 1982).
An area of skin on the back of each of two dogs was closely clipped. Urine
from each dog was collected daii.y during the control (2 days) and treatment
periods and was analyzed for arsenate (As V), arsenite (As III) , methyl arsenate
(MA) and dimethyl arsenate (DMA).
After the two-day controi period, one dog had 1.5 gm fine southern pine
sawdust from wood treated with CCA-C spread on a pad which was applied for
two days in intimate contact to the skin with a plastic bandage. The sawdust
contained 3.0% pentavaj.ent arsenic.
After the-two day controt period the second dog had 1.5 gm of ACA treated
Douglas fir sawdust containing 6.7% arsenate applied in the same manner for
three days.
20
-------
No evidence of arsenic absorption was seen with either dog. Therefore, the
Agency assumes there is negligible dermal absorption of arsenic from arsenic-
laden sawdust or dry treated wood. The exposure estimates presented in this
PD 4 reflect this change.
e. The Agency assumed (PD 2/3, p. 195) that the dermal absorption of
inorganic arsenic in aqueous solution was 0.1% and that the dermal absorption
from skin contact with dry arsenic-laden dust was 0.01%.
The Agency has revised the assumption for dermal absorption of inorganic
arsenic from arsenic-laden dust from 0.01% to 0.1% based on a study by
Datkizwicz (1977) which showed the upper limit for dermal absorption of
arsenic from aqueous solutions of sodium arsenate was 0.1% (Zendzian, 1980).
The dry arsenic-laden dust could become wet with perspiration and thus have
a dermal absorption equivalent to that of arsenic in an aqueous solution.
The exposure estimates summarized in Appendix C of this document reflect the
assumption that dry arsenic-laden dust found in such settings as treatment
plants or homes has a dermal absorption rate of 0.1% (Zendzian, April 14, 1982) .
The dermal absorption for inorganic arsenic in aqueous solution remains 0.1%
(Rispin, April 18, 1984) , as assumed in the PD 2/3 and is aiso based on studies
by Datkizwicz (1970) .
f . Regarding the emptying of bags of powder Fluor Chrome Arsenic Phenol
(FCAP) , the Agency estimated in the PD 1 and PD 2/3 that applicators would be
dermaa.j.y exposed to up to 10.0 grams of the dust concentrate. This estimate
was not based on any actual exposure data. There are, however, exposure
studies in which dermal exposure was measured during formulation and bagging
operations with pesticide powders and dusts. (Comer et al. , 1975; Jegier,
1964; and Wolfe et a,*.. , 1978) . In the absence of data on FCAP, the Agency
beiieves that the data from the cited studies can be used to estimate potential
dermal exposure (Tabj.e 5). Assuming a maximum dermal absorption of 0.1% and
9.59% arsenic in FCAP, the Agency estimates the dermal exposure for FCAP
during bag emptying to range from 0.0038 to 0.142 mg/hr. The Agency assumes
bag emptying occurs one hour per day during an 8-hour work shift (Rispin,
Apr la. 18, 1984). The Agency continues to assume, as in the PD 2/3, that the
inhalation and gastrointestinal rate of absorption for water soluble salts of
inorganic arsenic is 100%; the Agency has no data to indicate otherwise
(Rispin, April 18, 1984).
g. The Agency had estimated the air concentration of arsenic
sawing, nailing or fabricating with arsenic treated wood to be 0.36 mg/m^,
(PD 2/3, p. 199). Data from a study at the University of Minnesota submitted
by AWPI (f 36C:30000/28C) convinced the Agency that a more reasonable estimate
is 0.024 mg/m-*, the highest value in a Time-Weighted -Average (TWA). The
exposure and risk estimates for sawing arsenic-treated wood in this PD 4
reflect this modification. However, the Agency continues to assume as in the
PD 2/3 (p. 208) that 10% of the arsenic-laden sawdust particides will be
respirab^e and that 90% is non-respirable but is deposited in the gastro-
intestinai tract (Rispin, Aprij. 18, 1984). As discussed above, 27% CCA-
^aden sawdust and 65% ACA-laden sawdust inhaled or swallowed will be absorbed
by the body (Zendzian, Rebuttabj.e Analysis, 1982) .
h. The Agency had estimated (PD 2/3, p. 186) the air concentration of
arsenic at 0.031 ug/m^ in homes with Alx-Weather. Wood Foundations. Data
2!
-------
submitted by Koppers (Nov. 15, 1983} has convinced the Agency that a more
realistic estimate for homes constructed with arsenic pressure-treated wood
is an upper .Limit of 0.004 ug/m3. The highest net increase over "bxank"
controls was 0.002 ug/m3. The oncogenic risk estimation for people living in
such homes reflects this change in exposure estimation, i.e. 0.004 ug/in3
instead of 0.031 ug/m3.
22
-------
TABLE 5
Dermal Exposure (rag/hr)a During Pesticide Formulation
Mean
Range
Dermax
Estimate
for Arsenic in FCAP
Mixing and bagging of
4-5% carbaryl dustc: 73.9
Formulating 25% Gathion
wettabxe powder^: 10.1
Formulating disuifoton
as 0.5% dry mix
fertilizer®: 2.0
0.8-1209
4.9-20.9
0.1-10.5
142
3.8
38
a. Assumes workers were wearing short-sleeved shirts, no gloves or hats,
and that covered areas of the body were protected from exposure.
b. Assumes worker is handling bags of (FCAP) containing 9.59% arsenic as
c. From Comer et al. (1975) *
d. From Jegier (1964) .
e. From Wolfe et al., (1978).
-------
2. PENTACHLOROPHENOL
a. AWPI (Rebutta^. |36:30000/28C) took issue with the Agency's
estimate of the maximum amount of time workers spend opening and emptying
bags of priced or flaked pentactuorophenol and mixing pentachlorophenol
solutions. AWPI stated that, with the Agency's PD 2/3 estimate, more penta-
chlorophenoi. would be mixed than is used annually. Based on the informa-
tion provided in the rebuttal and evaluated by the Agency, the Agency has
determined that a more accurate exposure estimate for workers who open and
empty bags of prilled pentachlorophenol and mix prilxed or flaked formulations
of pentachiorophenol is 2 hours a day for two days a week instead of the PD
2/3 estimate of 4 hours a day for 5 days a week. The Agency has made the same
assumption for mixing and emptying bags of powdered sodium pentachlorophenate.
b. Inhalation exposure data submitted by the USDA in response to the PD
2/3 confirmed that volatilization of pentachlorophenoj. from treated wood in an
enclosed area is expected. The Agency had assumed (PD 2/3, p. 330) that for
brush-on home and farm use the concentration of pentachiorophenoi in the air
in interior settings was 40 ug/m3. However, the USDA (1981) supplied data which
indicate that vaporization of pentachlorophenol from non-pressure treated wood
should be revised to 34-140 ug/m3 for vaporization in interiors for industrially
dipped treated wood. Data aiso indicate that for o^der structures containing
pentachlorophenol pressure-treated wood the pentachiorophenoi concentrations in
the air range from 0.5 to 10 ug/m3 (Day, 1982). In addition, USDA (1981) pro-
vided the Agency with data which demonstrate that sealers can decrease by 85%
the volatilization of vapors from pentachiorophenol-treated wood. The Agency
has used the above measured levels to calculate risk from exposure to treated
wood in interiors. Since available data do not suggest a significant differ-
ence between air ^eveis from pressure-treated wood and those produced from brush-
on applications of over-the-counter formulations (PD 2/3, p. 335) , these estimates
also wil* apply to potential exposure estimates in this document resulting from
the use of pressure-treated lumber indoors.
c. Based on acute animax studies (Gaines, 1969), the Agency reassessed
the dermal absorption rate for pentachlorophenol in organic solvents and has
revised the assumption of 10% absorption (PD 2/3) to 50% absorption (Zendzian,
1981). The Agency has utilized the acute toxicity data of Gaines to determine
an "apparent" dermal absorption rate. Gaines reported that in rats the oral
LDjQ of pentachlorophenol dissolved in peanut oil is 146 mg/kg in males and
175 mg/kg in females whi^e the dermal LDgQ of pentachlorophenol dissolved
in xy^ene is 320 mg/kg in males and 330 mg/kg in females. Prom these data,
the Agency calculated an "apparent" dermal absorption rate of 50%, because
the dermal LD50 is approximately twice that of the oral LD5Q. Exposure by
the dermal route has been recalculated accordingly, using 50% instead of
10%, in this document for pentachlorophenol.
d. For sodium pentachlorophenate, in the PD 2/3 the Agency had assumed
that the dermal absorption was the same as for pentachlorophenol, i.e.,
10%. After reconsidering this estimate, the Agency has concluded that the
dermal absorption of sodium pentachlorophenate would be no more than 1.0%
24
-------
because it is in an aqueous solution, not an organic solvent as is penta-
chlocophenoi (Day, Dec. 9, 1983). A sodium salt of pentachlorophenol in an
aqueous solution is expected to have ^ess dermax absorption than pentachio-
rophenoi in an organic solvent. The risk estimates for uses of sodium pen-
tachlorophenate in this document reflect this revised exposure (1.0% instead
of 10%).
e. For HxCDD, the Agency assumed in the PD 2/3 that the dermal absorption
rate was same as for pentachlorophenol, i.e., 10%. New data (Poiger and
Schlatter, 1980) on another dioxin, tetrachiorodibenzo-p-dioxin (TCDD),
indicate that the dermal absorption rate in rats for TCDD is approximately
50%. Because the cnemicai structure of HxCDD is more similar to that of TCDD
than to pentachlorophenol, the Agency assumes the dermal absorption rates for
HxCDD and TCDD are more nkely to be similar. Therefore, the Agency assumes
the estimated rate of dermaj. absorption for HxCDD is 50% instead of 10%
(Rispin, Aprix 24, 1984).
f. In the PD 2/3, the Agency assumed that gloves afforded 99% protection
from dermal exposure to the hands when applying pentachiorophenoi formulations.
New data by Siikowski (1982) on penetration of pentachiorophenoi through
various materials [rubber, poiyvinyl chloride (PVC), neoprene, and nitride
rubber] has convinced the Agency that PVC, neoprene, and nitriie rubber wij.1
provide the best protection for the applicator of pentachxorophenoj. products.
Based on these data and normal use patterns for workers wearing gloves, the
Agency estimates that gloves made from PVC, neoprene, or nitrile rubber can
be relied upon to provide 90% protection to the applicator (Rispin, April 24,
1984). This estimate takes into account the possibility of some of the pesti-
cide formulation seeping around the cuff of the glove or contacting the
treatment solutions on the gloves themselves when the gloves are taken off.
g. A study presented at the International Symposium on Indoor Air PoiiU-
tion, Heaxth and Energy Conservation (1981) and a rebuttal submitted by AWPI
(|36:30000/28C) provided intormation on the time a resident would spend in a
home. Instead of using the PD 2/3 estimate of 24 hours as the time spent at
home, tne Agency has evaluated the additional information and has revised
this to the more representative estimate of 15 hours (8 hours resting, 1 hour
heavy work, and 6 hours light work) (Day, Exposure Analysis, 1982). This
exposure estimate was used in the determinations of risk in this document
from inhalation exposure to treated wood in interiors. The Agency is aware
that various sub-groups of the population of the United States may spend as ,
much as 24 hours 'in the home, such as some housewives and young children in
the winter, the elderly at home, and people in nursing homes, hospitals,
nurseries. Section VIII of this document outlines the Agency's regulatory
measures which will reduce exposures form pentachiorophenoi vaporization
from treated wood in interior settings.
The risk estimates which result from the changes in exposure assumptions
for pentachiorophenoi and the inorganic arsenicais are presented in this docu-
ment in the sections discussing the specific uses of these wood preservatives.
The risks from exposure to pentachlorophenol and the inorganic arsenicaxs
are summarized in Appendix B.
25
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Table 6
Summary of Exposure Assumptions for Pentachlorophenol, Sodium
Pentachlorophenate and HxCDD for the PD 2/3 and PD 4*
Exposure
Situation
PD 2/3 Assumption
PO 4 Assumption
a. Emptying bags of
priced or fxaked
pentachiorophenoj.,
or powdered sodium
pentachiorophenate
b. Inhalation expo-
sure for penta-
chlorophenoo. in
interiors from
pentachiorophenoj.
treated wood:
non-pressure
pressure
c. Dermal absorption
rate for penta-
cluorophenol
formulations
d. Dermal absorption
for sodium penta-
chlorphenate
formulations
e. Dermal absorption
rate for HxGDD
f. Protection from
pentachlorophenoi
afforded by gloves
g. Hours spent at
home
4 hrs/day
5 days/week
40 ug/m3
40 ug/m3
40 ug/m3
10%
10%
10%
99%
24 hours
2 hrs/day
2 days/week
34-140 ug/m3
34-140 ug/m3
0.5-10
50%
1.0%
50%
90%
15 hours
(8 hours rest, 1
hour heavy work, 6
hours light work).
*See text for the bases of the exposure assumptions.
26
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3. CREOSOTE
The Agency has assumed (PD 2/3) that the concentration of creosote
particles in the plant environment ranged from 45 to 95 ug/m3. AWPI
(#36A:30000/28C) submitted data which showed the concentration ranged from
20 to 9,000 ug/m3. The Agency has reviewed these data and accepts the higher
estimate for creosote particulates in the air in the plant environment (Day,
December 9, 1983). However, as explained previously in Section II.A.3, no
risk estimates have been calculated for creosote exposure due to a j.ack of
data on (1) the identity of the airborne chemicals and (2) dermai exposure
for workers using creosote. Because the Agency is concerned about the risk
of cancer in applicators and the lack of data for quantification of risk,
the Agency will require registrants to perform an epidemiology study including
adequate air monitoring and dermai exposure data for risk estimation as de-
scribed previously in Section II.A.3.
C. Benefit Information
The application of wood preservative chemicals protects wood from attack
by fungi, insects, bacteria, or marine borers. In most situations, treating
wood increases its life expectancy to five or more times that of untreated wood.
Pressure-treated wood is primarily used for: railroad ties; lumber, timber
and plywood; pipings; posts; crossarms; and poles. Non-pressure treatment
methods are used for poles groundline; home and farm; sapstain control; mill-
work and plywood; and particieboard.
For many uses, creosote, pentachiorophenol, and the inorganic arsenicais
are potential substitutes for each other. Other alternative chemicals vary
in cost and efficacy. Alternative materials such as steej., concrete, or
untreated wood also vary in cost and practicality.
The Agency has estimated the economic impact of cancelling each use by
calculating the cost of substituting other registered wood preservatives
or alternative materials. The PD 2/3 contains a complete discussion of the
impact estimation methodology. No new information has been received since
the PD 2/3 which significantly changes the estimates made at that time. A
brief summary of the projected economic impact for each use pattern is provided
below.
Tabies 7 to 9 briefly summarize and characterize the extent of the economic
impacts of various cancellation scenarios.
1. Uses of pressure-Treated Wood
a) Railroad ties.
Raiiroad cross and switch ties used in the United States are treated
with wood preservatives. Approximately 99.6% of these ties were treated
with creosote and the remaining 0.4% with pentachiorophenol. The predomi-
nant use of creosote-treated ties reflects their greater suitability in
27
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terms of performance and cost. Inorganic arsenica^ treatment is considered
unacceptable for railroad tie use because inorganic arsenic-treated ties are
brittle and do not hoxd fasteners weo.i,
Concrete ties are technically feasible substitutes for treated wood ties;
however, treated wood ties and concrete ties cannot be used in the same sec-
tion of a railway tie system. Thus, replacing wood ties with concrete neces-
sitates the replacement of ail the ties in a given section of track.
The impact of canceling creosote products registered for this use was
analyzed in terms of the "annualized" or average annual cost, which represents
the average yearly investment which is required to maintain the railroad
system for a finite time period (the time period selected for this analysis
was 100 years). The Agency considered three regulatory alternatives: (1)
cancellation of creosote only; (2) cancellation of pentachlorophenoi only; and
(3) cancellation of both creosote and pentachlorophenoi.
The Agency has determined that there would be an annuaiized long term cost
increase of $40.5 million if creosote were cancelled and pentachlorophenoi were
still available for railroad tie use. During the first year, there would be a
decline in cost of $18.2 million, due to the lower installation costs for penta-
chiorophenol-treated ties compared to creosote-treated ties.
Since less than 1% of railroad ties in the United States are treated with
pentachlorophenoi, there would be little or no adverse economic impact if
pentachlorophenoi were cancelled and creosote were still available to the
railroad industry.
If both creosote and pentachlorophenoi were cancelled, the most nkeiy
substitutes would be copper naphthenate-treated ties and concrete railroad
ties. Either of these alternatives would substantially increase the cost of
the nation's railroad tie system. The annualized cost of the system would
increase by $0.58 billion during the first year and $0.74 billion thereafter
if copper naphthenate-treated ties were used. It would increase by $3.7
billion during the first year and by $2.4 billion annually thereafter if
concrete ties were used.
b. Lumber, timber and plywood. Declining supplies and higher prices for
naturally resistant woods such as cedar and redwood have resulted in an
increased demand for treated wood. Based on efficacy and other performance
characteristics, wood treated with the inorganic arsenicals is suitable for
most end-uses of lumber, timber and plywood. Inorganic arsenical-treated
wood is clean, odorless, paintabie, easy to handle, harmless to plants and
more durable than other treated wood. Its uses include patios, decks, play-
ground equipment, cooling towers, greenhouses, horticultural nurseries and
ali-weather wood foundations. In contrast, pentachlorophenoi and creosote
treated lumber, timber and plywood have limited uses due to odor, objection-
able vapors, and oily, unpaintabie surfaces. Despite its disadvantages,
creosote is the only wood preservative which is satisfactory for use in
interior industriaj. block flooring to protect the wood from mechanical wear.
28
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Tatue 7
Summary of Economic Impacts of Cancelling Creosote*
Use
Creosote Cancex Creosote Cancel Creosote Cance^ all
only & Pentachlorophenol & Arsenicais Three
Pressure:
Railroad Ties
Lumber, Timber
Minor
Major
Minor
Major
and Plywood
Pixing
Posts
Crossarms
Poles
Non Pressure:
Poles-g round * me
Home and Farm
Minor
Major
Moderate
Minor
Major
Minor
Minor
Moderate
Major
Minor
Minor
Major
Major
Minor
Major
Major
Major
Minor
Major
Minor
Minor
Major
Major
Major
Major
Major
Major
Minor
* Impact descriptors were determined taking into account the following factors:
1) do^iar impact and 2)total market, 3) disruption due to change to alternatives
(e.g. capital investment), 4) aesthetic considerations, 5) cost and availability
of alternatives and, 6) other use specific factors. For a more complete discussion
of the economic impacts, see the PC 2/3 and material referenced there.
29
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Tatue 8
Summary of Economic Impacts of Cancelling Pentachiorophenol (Penta)*
Use
Cancel Penta
onxy
Cancel Penta
and Creosote
Cancel Penta
and Arsenicals
Cancel all
Three
Pressure:
Railroad Ties
Lumber, Timber
Minor
Major
Major
Major
and Plywood
Piling
Posts
Crossarms
Poles
Non Pressure:
Poles-groundline
Home and Farm
Saps tain**
Miiiwork and***
Plywood
Particieboard
Major
Major
Moderate
Minor
Major
Minor
Minor
Moderate
Minor
Minor
Moderate
Major
Minor
Minor
Major
Major
Minor
Moderate
Minor
Minor
Major
Major
Moderate
Moderate
Major
Minor
Minor
Moderate
Minor
Minor
Major
Major
Major
Major
Major
Major
Minor
Moderate
Minor
Minor
* Impact descriptors were determined taking into account the following factors:
1) dollar impact and 2)total market, 3} disruption due to change to alternatives
(e.g. capita^, investment), 4) aesthetic considerations, 5) cost and availability
of alternatives and, 6) other use specific factors. For a more complete discussion
of the economic impacts, see the PD 2/3 and material referenced there.
** Sodium pentachlorophenate
*** While the economic impacts of a cancellation are considered to be minor in terms
of absolute dollars, the impact would be significant for users who would not have
any equally efficacious alternative chemical to apply.
30
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Table 9
Summary of Economic Impacts of Cancelling the Inorganic Arsenicals*
Use
Cancel Arsenicals Cancel Penta** Cancel Arsenicals** Cancel all
only and Arsenicals and Creosote Three
Pressure:
Lumber, Timber
and Plywood
Piling
Posts
Crossarms
Poles
Major
Minor
Moderate
Minor
Major
Major
Major
Moderate
Moderate
Major
Major
Major
Major
Minor
Major
Major
Major
Major
Major
Major
* Impact descriptors were determined taking into account the following factors:
1) dollar impact, 2)total market, 3) disruption due to change to alternatives
(e.g. capital investment), 4) aesthetic considerations, 5) cost and availability
of alternatives and, 6) other use specific factors. For a more complete discussion
of the economic impacts, see the PD 2/3 and material referenced there.
** Pentachlorophenol.
31
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In 1978, more than 70% of the total treated lumber and timber, about
73.32 million cubic feet, was treated with inorganic arsenicals and about
20%, or about 21.21 million cubic feet of lumber and timber, was treated with
pentachlorophenol.
Because of the wide variety of uses for treated lumber, timber and plywood,
the Agency has not been able to quantify the anticipated economic impact if
ail three wood preservatives were cancelled for these uses. The Agency
expects that non-wood materials such as piastic, steel or concrete would be
substituted for the treated wood, and that these materials would have a higher
cost than the wood.
The Agency believes that there would also be a major adverse economic
impact if the inorganic arsenicals were cancelled, because pentachlorophenol
and creosote-treated lumber, timber and plywood are not generally acceptable
alternatives to the inorganic arsenical-treated lumber, timber and plywood.
If creosote were cancelled but the other two preservatives remained
available, the Agency anticipates a first year cost increase in chemical
costs and additiona^. capital investiment of $39 million. The Agency anti-
cipates an increase in cost of $18 million if only pentachiorophenol were
cancelled. If both were cancelled, the estimated initial economic impact
would be an increased cost of $5.2 million (a decrease in chemical cost
coupled with increased capita^, costs) . The costs of disruption in a major
treated wood market would not be easily quantified.
c. Pilings. All three wood preservatives are currently being used to
treat pilings. In 1978, creosote was used to treat 82.7% of pilings,
pentachj.oropheno.1. for 9.5% and inorganic arsenicals for 7.8%.
Creosote is the preservative commonly used for building foundations and
marine uses. Arsenic may be an acceptable substitute for creosote for both
uses. However, treatment of wood with inorganic arsenicals makes it more
brittle, increasing the likelihood of breakage of pipings both during mechan-
ical driving and shipping. Pentachlorophenoi may be used as an alternative
to creosote for treating pilings for foundations but is not recommended or
used for marine pipings. Both concrete and steel provide technically accept-
able alternative materials for pilings in foundation uses. However, steel
would be subject to corrosion in highly acidic soils or in marine environments.
The Agency believes that there would be an adverse economic impact if
pentachlorophenoi or creosote were cancelled for use on pilings. It antici-
pates a $9-10 million first year increase if creosote were cancelled and a
$8.3-9 million first year increase if pentachlorophenol were cancelled.
Since creosote would be an acceptable substitute for the inorganic arsenicals,
the anticipated economic impact of cancelling the inorganic arsenicals would
be minor.
If aj.1 three wood preservatives were cancelled, the most likely substitutes
would be concrete for marine uses and steel for foundation uses. The costs
for steel and concrete pilings (including installation costs) are higher than
32
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for treated wood pipings. Assuming a one to one replacement for the wood
pipings, the total average annuaiized installed cost of pilings would increase
33.3% ($64.5 million) for concrete and 67% ($129.1 million) for steel compared
to the 1978 cost of treated wood pipings.
However, if concrete and steel pij.es are assigned heavier loads than
previously assigned to the treated wood piles, the total installed cost of
pilings could decrease by as much as 11% for concrete and increase by as much
as 11% for steel, compared to the 1978 annuaiized cost of treated wood pilings.
The xikexihood of assigning higher levels to concrete and steel pilings is
entirely dependent upon the specific characteristics of the site and the
building under construction.
d. Posts. Creosote, pentachiorophenoi and the inorganic arsenicals are
ail used to treat fence posts. In 1978, 22.9% of the posts were treated with
creosote, 54.8% with pentachloropheno.1. and 22.3% with the inorganic arsenicals.
The estimated plant value of treated wood posts in 1978 was $66.1 million
(USDA, |1980, p. 321).
If pentachiorophenoi were canceled, there would be an annual increase
of $0.75 million to $5.1 million in the cost of treated wood posts, depending
on whether creosote or inorganic arsenicais are used as an alternative. If
creosote were cancelled, there would be a $3.3 million annual cost increase
for the first and subsequent years. If the inorganic arsenicais were canceled,
the first year and annual long-term impacts would be a cost increase of $4.0
million to 4.5 million in treated wood posts depending on which alternative
.(e.g., creosote or pentachiorophenoi) is chosen.
If both creosote and the inorganic arsenicals were cancelled, the annual
cost increase is estimated to be greater than $7 million for treated wood
fence posts. If both the inorganic arsenicals and pentachiorophenoi were
cancelled, there would be an annual increase in post cost of greater than
$5.1 million. Under this cancellation scenario, steel posts would probably
replace treated wood posts for suburban uses since creosote-treated posts
are unacceptable replacements. If both creosote and pentachiorophenoi were
cancelled, this impact is estimated, based on current levels of usage, to be
an annual cost increase of $383,000.
If aii three wood preservatives were Canceled, steel or concrete posts
would be the most likely alternative materials that could be used for fence
posts. T-type steel posts, which serve as substitutes for treated wood posts
in farm uses, are priced competitively with treated wood posts. Thus,
substitution of stee^. posts in many farm uses would not necessarily lead to
much higher fencing cost. An increase in demand, however, could lead to
increased costs of steei posts. Farmers' preference for treated wood posts
would indicate that treated wood posts are superior to the metal posts from
the standpoint of cost or performance (USDA, 1980, p. 325). Concrete posts
would be more expensive than steel and would not be substituted in most farm
situations.
33
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e. Crossarms. Crossarms are the cross members of assembled utility
poles. The distribution of crossarms by preservative treatments was 2.5% for
creosote, 95.8% for pentachlorophenol and 1.7% for the inorganic arsenicals.
The 1978 cost of treated crossarms was estimated as $14.86 million. Steel
crossarms are used as alternatives for treated wood crossarms by some utility
companies (USDA, 1980, p. 313).
If pentachlorophenoi were cancelled for the crossarm use, there would
be economic impacts for both the first and subsequent years ranging from a
decline in annua^ cost of $0.23 million to an additional annual cost of $1.2
million, depending upon which alternative (creosote or inorganic arsenicals}
is chosen. If creosote were canceled, there would be first year and annual
long-term impacts, ranging from a decline in cost of $15,000 to $30,000, also
depending on which alternative (e.g., inorganic arsenicals or pentachlorophenol)
is chosen. These economic impacts are based on current preservative prices
and do not include any additional investment costs for conversion from one
treatment process to another. If the inorganic arsenicals were cancelled,
there would be a slight increase in treated crossarm cost.
If both the inorganic arsenicals and pentachlorophenol were cancelled,
there would be an additiona* annua^. cost of $1.2 million for treated cross-
arms. If both the inorganic arsenicals and creosote were cancelled for the
crossarm use, there would be an annual decline in costs of $0.2 million. If
pentachlorophenol and creosote were cancelled, there would be a small decline
in the annua^ cost of treated crossarms.
If ail three wood preservatives were cancelled, the most likely substitute
would be steel crossarms. Steel crossarms would perform competitively with
treated crossarms (USDA, 1980). This cancellation scenario would, however,
most likely result in higher crossarm costs.
f. Poles. The distribution of the three preservatives for pole treatment
by volume in 1978 was 65.3% for pentachlorophenol, 38.4% for creosote and
6.3% for the inorganic arsenica^s. There are no viable chemical alternatives
for the three major wood preservative agents for pole treatment with the
possible exception of copper naphthenate for certain limited uses. Non-wood
alternatives for treated poles include the use of concrete and steel as pole
construction materials and the installation of underground distribution and
transmission lines in urban areas or in new subdivisions.
If pentachi.orophenol were cancelled for poles, there would be a first
year cost increase, ranging from $19.9 million to $24.2 million depending
upon which alternative is chosen (e.g., creosote or the inorganic arsenicals).
The long-term economic impact for the cancellation of pentachlorophenol would
range from a total annuaiized cost decrease of $43.6 million to an annualized
increase of $32.8 million. If creosote were cancelled, there would be a first
year additional cost of $9.4 million to $20.7 million. The additional costs
include the impact of a preservative price increase and the capital expenditures
required for plant modifications (USDA, 1980, p. 306). The long-term impact
34
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would range from an average annual decline in cost of $43.6 million to an addi-
tional cost of $17.8 million depending on the alternative chosen. If the inor-
ganic arsenicals were cancelled, there would be an additional cost of $1.9
million for the first year and an additional cost of $17.8 million to $32.8
million for each subsequent year.
If pentachlorophenol and creosote were cancelled, there would be an addi-
tional first year cost of $28 million and an annual decline in cost of $43.6
million in subsequent years. This is due to the estimated service life of
arsenic-treated poles being much longer than creosote or penta chlorophenol
treated poles, thus reducing the average annual cost. If pentachlorophenol
and the inorganic arsenicals were cancelled, there would be a cost increase
of $34.5 million in the first year and an average annual cost increase of
$32.5 million in the subsequent years. The cancellation of creosote and the
inorganic arsenicals would result in an additional first year cost of $24.3
million and an average annual cost increase of $18 million in subsequent
years. If all three major wood preservatives were cancelled for poles, the
most likely substitutes would be concrete and steel. Under this cancellation
scenario, there would be large cost increases ranging from $1.3 billion to
$2.1 billion annually depending upon the alternative chosen.
2. Non*pressure uses of treated-wood
a. Poles-groundline. Although the treatment of inplace utility poles
at groundline (poles-groundline) represents a small segment of the wood
treatment industry, it is an important wood preservative use. Wood preservatives
are applied to a previously installed pressure-treated pole over a section
covering the six inches above and sixteen inches below the ground level of
the pole. This treatment can delay decay and subsequent pole failure for 20
years or more. Approximately 1 million poles received groundline treatment
in 1978.
The two major formulations of commercial poles-groundline treatments
marketed in the United States contain both creosote and pentachlorophenol.
One of these formulations has a high creosote content and the other a high
pentachlorophenol content (the latter product also contains sodium fluoride).
Currently, the high creosote formulation is used for about two-thirds of all
poles-groundline treatments and high pentachlorophenol content product is
used for about one-third.
If either pentachlorophenol or creosote were cancelled, the economic
impact would be minor, because the remaining registered wood preservative
would be substituted for the cancelled one. However, if both pentachlorophenol
and creosote were both cancelled for the poles-groundline use, the anticipated
longterm economic impact would be major. There would be an average annual
cost ("annualized") increase of about $36.8 million. Moreover, if the current
level of groundline treatment doubles in the next five years (USDA, 1980, p.
378) , the increase in annualized pole replacement costs would exceed $70 million.
There would be an initial savings of $10.2 million per year (the estimated
cost for the treatment of 1 million poles) if the poles were not being treated
with either pentachlorophenol or creosote (USDA, 1980 p. 378).
35
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b. Home and farm. Homeowners, fanners, and on-the-job carpenters apply
pentachlorophenol and creosote for home and farm uses, by a variety of techni-
ques, including brushing, rolling, dipping, soaking and spraying. The inorganic
arsenical preservatives are not generally available to home and farm applicators
because of current marketing practices.
About 1.6 million pounds of pentachlorophenol and 2.0 million pounds of
creosote are used around homes and farms to protect various wood structures
and products exposed to natural elements. They extend the useful service
life of wood in above-ground applications and provide limited protection for
wood in contact with the ground. Typical treated wood items include decks,
siding, millwork, lumber, fences, shingles and outdoor furniture.
Homeowners and farmers would have alternative means of protecting struc-
tures and products exposed to the elements if pentachlorophenol or creosote
were cancelled.
Copper naphthenate, copper-8-quinolinolate, zinc naphthenate and tributyltin
oxide (TBTO) are currently available to homeowners and farmers, but cost some-
what more than either pentachloropheol or creosote. Moreover, these chemicals
do not have the wide range of control characterisitics of the latter.
Pressure treated lumber may be purchased at a cost somewhat higher
than lumber treated by brush or dip application. However, it is not a suitable
alternative for all non-pressure home and farm uses. (Where it can be
appropriately used, pressure-treatment provides better protection to wood
than non-pressure applications.)
Non-wood materials such as aluminum and concrete can replace treated wood
in some circumstances at comparable prices. However, the comparability of
cost does not take into account the aesthetic value of wood.
c. Sapstain control. Although the most serious structural damage to
wood is caused by insects and decay, infestation with sapstain fungi increases
the capacity of the wood to absorb moisture, thus making the wood more
vulnerable to decay. Sapstain fungi infestation also causes discoloration which
reduces the market value of the wood. Currently, sodium pentachlorophenate
(sodium penta) is the primary antimicrobial used to control sapstaining and
surface staining fungi in the United States. About 1.15 million pounds of
sodium penta are used annually for this purpose. These sodium penta solutions
often include the salts of other chlorinated phenols.
The alkali salts of tetrachlorophenol (tetra) have been used effectively
for sapstain control for over 40 years; in recent years, however, sodium
penta has replaced sodium tetra as the primary antimicrobial for sapstain
control. Copper-8-quinolinolate (Cu-8) is also currently registered for
sapstain control; however, information is unavailable on the volume of Cu-8
used for sapstain control and the effectiveness of this chemical for this
use. Kiln drying can be used to prevent sapstain for most softwoods; however
kiln drying cannot be utilized in those situations where freshly-cut lumber
cannot be placed in the kiln within 48 hours. Kiln drying is also not appro-
priate for a number of hardwood species which are subject to warping and
honeycombing during kiln drying.
36
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The Agency has determined that there would be a minor adverse economic
impact if. sodium penta were cancelled. The most likely substitutes for
controlling sapstain would be the alkali salts of tetrachlorophenol (e.g.,
sodium tetra or potassium tetra), which are equal in cost and efficacy to
sodium penta. Other alternatives (e.g., Cu-8) are available at a slightly
increased cost; these alternatives, however, may not provide adequate protec-
tion for sapstain control.
d. Millwork and plywood. Millwork and plywood are usually treated
with a 5% pentachiorophenol solution in mineral spirits (containing water
repellants) which is applied by spraying, brushing, dipping or by the vacuum
process. Available chemical alternatives for millwork include TBTO and copper-
8-quinolinolate (Cu-8) but some formulations may not be as efficacious as
pentachlaorophenol (PD 2/3, p. 526). A water-based Cu-8 formulation has not
yet been shown to be effective. A 0.75% TBTO has shown effectiveness for
above ground exposure when the millwork is painted (PD 2/3, p. 527). The
available chemical alternative for plywood is TBTO for those uses where the
treated plywood could be painted. The effectiveness of Cu-8 for plywood has
not been proven by actual field use experience (PD 2/3, p. 528).
The Agency has determined that there would be a minor adverse economic
impact to the millwork and plywood industry if pentachiorophenol were cancelled.
Millwork and plywood manufacturers could choose to use 0.75% TBTO, which
costs about the same as pentachiorophenol, and is effective for above ground
exposure if the TBTO treated wood is painted.
The water-based Cu-8 solution., may prove to be efficacious. If so,
many pentachiorophenol users could use this formulation. Other alternative
materials that could be substituted for pentachiorophenol are untreated
wood, which would require frequent replacements and increase the demand for
wood products, naturally resistant wood, and non-wood materials (e.g., aluminum).
Due to the short supply of naturally resistant wood and the frequent replacements
required for untreated wood, the most likely non-chemical alternative would
be the use of non-wood materials. Naturally resistant wood (e.g., red cedar
and redwood) can cost 2 to 3 times as much as treated southern pine (USDA,
1980, p. 340-345). Non-wood materials (e.g., concrete, metal, aluminum,
plastic, etc.) can cost more than or less than treated wood depending on the
material and the end use. Aesthetics and the purpose or function of a structure
are important determinants in selection of materials. It is difficult to
estimate the value associated with these determinants.
e. Particleboard. In some areas of the United States, it may be necessary
to use treated particleboard to prevent attack by dry-wood termites and other
wood destroying insects. Pentachiorophenol is presently the only preservative
used for this specific purpose. There is currently only one known plant
producing pentachlorophenol-treated particleboard. The treated particleboard
constitutes less than 1% of the average annual particleboard production at
the plant and represented a very small part (about 0.005%) of the 3.9 billion
square feet of particleboard produced in the United States in 1978 (USDA, 1980
p. 385) .
37
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The production of treated particleboard generates an annual revenue of about
$35,000. Thus, even though there are no registered alternatives for the particle-
board use, the economic impacts to the user would be minor if pentachlorophenoi
were cancelled for this use. Untreated particleboard would be used in place of
treated board. Although less expensive, the untreated particleboard would be
more susceptible to potential infestation of termites and other wood-destroying
insects.
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III. SCIENTIFIC ADVISORY PANEL (SAP) COMMENTS AND AGENCY RESPONSE
The Scientific Advisory Panel (SAP) held an open meeting on June 17-19/
1981, in Arlington, Virginia, to review the Preliminary Notice of Deter-
mination concluding the RPAR for the wood preservative chemicals. At
this meeting, the SAP heard presentations by the Agency, the registrants,
and other interested members of the public. The Agency requested the
SAP to review several issues relating to the wood preservatives. The
SAP submitted its comments on the Preliminary Notice of Determination and
its recommendations on July 15, 1981. This submission is included in its
entirety in this document as Appendix D. A summary of the SAP comments and
the Agency's response to those comments is as follows:
A* Pentachlorophenol
Issue fl
The Agency stated in the PD 2/3 that a no-observed-effect level (NOEL)
for teratology could not be accurately determined and asked the SAP if the
occurrence of delayed skull ossification at 5.0 mg/kg/day would preclude the
establishment of a NOEL at that level. The SAP commented that the establish-
ment of a NOEL is precluded both by the litter loss phenomenon and by the
delayed skull ossification at 5.0 mg/kg/day.
Agency Response
Although the Agency agrees with the SAP that an accurate teratogenicity/
fetotoxicity NOEL for pentachlorophenol cannot be determined, in order to
estimate the margins of safety for teratogenic/fetotoxic effects, the Agency
has chosen a provisional NOEL of 3 mg/kg/day based on a one-generation
reproduction study by Schwetz et al. (1978)« SChwetz reported a trend toward
decreased neonatal weight at a dose of 3 mg/kg/day (Van Ormer, May 21, 1982).
The margins of safety (MOS) for pentachlorophenol, cited throughout this
Position Document and summarized in Appendix B, were calculated on the basis
of the provisional NOEL of 3 mg/kg/day.
Issue 12
The Agency asked the SAP for their opinion whether human health would
be adequately protected if over-the-counter sales of 5% or less pentachloro-
phenol were allowed to continue. The SAP stated that human health would be
adequately protected if the label required that protective clothing, including
rubberized gauntlets, goggles, and coveralls be worn, and that all applications
take place in a well-ventilated area.
Agency Response
Because of the changes in risk and exposure estimates discussed in Section
II of this document, the risks to homeowners and farmers applying pentachloro-
phenol formulations containing less than 5% pentachlorophenol have increased.
The potential oncogenic risks for applicators using gloves have increased by
a factor of approximately 5 from 1.3 x 10~6 (PD 2/3, p. 656) to 6.2 x 10~6.
39
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However, the margin of safety for fetotoxic effects has decreased from
560 (PD 2/3, p. 660) to 12. Thus, women who are pregnant and who use a 5%
pentachlorophenol wood preservative product have a potential margin of safety
(MOS) of 12 for giving birth to a child with evidence of some degree of
fetotoxicity. The assumptions made for risk estimation were that a woman
wearing gloves with 90% protection accidentally spills 6.0 mis to cover both
hands during one application of a 5% pentachlorophenol solution.
The Agency has concluded that for this use situation, the benefits of use
of "over-the-counter" pentachlorophenol products by home and farm applicators
do not outweigh the risks. Therefore, the Agency requires that use of these
products will be for certified applicators only, that there be a warning on
the labels concerning potential hazard for fetotoxic effects as discussed in
Section II of this document, and that impermeable gloves and protective
clothing be worn by the certified applicators as discussed in Section VI.E
of this document.
Regarding the SAP recommendation for wearing gauntlets, the Agency has
learned from field observations by Agency personnel that workers found
gauntlets cumbersome and too hot to wear, and often cut them to "glove"
length. The Agency has concluded that gloves impermeable to the pesticide
will adequately protect the worker from hand dermal exposure and that coveralls
will adequately protect the applicator from dermal exposure to parts of the
body other than the hands.
Regarding the SAP recommendation that applicators wear goggles, the
Agency agrees that goggles are necessary for certified applicators, to prevent
the pentachlorophenol formulations from getting into their eyes during appli-
cation.
Application of pentachlorophenol in residential interiors, will be
prohibited, but outdoor application will be allowed. This satisfies the
SAP recommendation that application of pentachlorophenol take place in a
well-ventilated area.
Issue »3
The PD 2/3 proposed prohibiting the use of pentachlorophenol on the
interior surfaces of living quarters. At the meeting with the SAP, the
Agency asked the Panel for opinions regarding the need for further exposure
studies of log homes constructed with pentachlorophenol-treated wood. The
SAP recommended a more critical review of the fate of pentachlorophenol in
the environment, an assessment of human urinary excretion of pentachlorophenol,
and the development of additional exposure and epidemiological studies.
Agency Response
The Agency has determined, as discussed in Section VI.H.3., that application
of pentachlorophenol to logs which are intended for use in the construction of
log homes must be prohibited.
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The Agency has further determined, based on information discussed in
Section VII.A.4 of this PD 4, that pentachlorophenol pressure-treated wood
should not be used in residential interiors, except for laminated beams and
building components which are in ground contact and are subject to decay or
insect infestation, and then only if two coats of an appropriate sealer are
applied.
The rationale for this decision is based in part on information on effects
'in people exposed to pentachlorophenol in interiors provided in response to
the PD 2/3 and the public meeting held April 14, 1983, by Levin (#60:30000/280,
Friends of the Earth (#70:30000/280), and the Center for Disease Control
(#71:30000/28C) as well as reports entered into the U.S. EPA Pesticide Inci-
dent Monitoring System (PIMS, 1981).
As discussed in Section II of this PD 4, USDA (1981) submitted exposure
data on the vaporization of pentachiorophenol from non-pressure dip-treated
wood with and without sealers. The data showed that sealers reduce
pentachiorophenol vaporization by approximately 85%, but there were no data
to indicate the length of time of effectiveness of the sealers. A reapplica-
tion of sealer may be necessary at a latter date for continued vapor reduction.
Information was also submitted to the Agency on pentachlorophenol levels
in the urine of occupants of a new state office building constructed with
pentachlorophenol pressure-treated beams in Long Beach, California (#86:30000/
28C, Jackson and Stratton, Oct. 19, 1983). None of 37 volunteers had a
detectable level of free pentachlorophenoi in their urine prior to occupancy,
but more than half did after the first two weeks of occupancy. After the
pentachlorophenoi was sealed, there were measurable levels averaging 5 ug/m3
pentachlorophenol in the air inside the building. Prior to sealing the wood,
air levels were 50 ug/m^, a level previously shown to be associated with acute
toxic effects (#86:30000/280.
AWPI (#36B:30000/28C, p. 44) commented that in highly enclosed spaces,
pentachlorophenol should not be used to preserve a large portion of interior
wall space.
Regarding log homes, Amburgey and Williams of Mississippi State University
(Dec. 1982} stated that chemical alternatives are available as wood treatments.
Based on the above information, applying pentachlorophenol (non-pressure
treatment) to logs to be used in the construction of log homes will be prohi-
bited and the Consumer Information Sheet (Section VII. C) will state that
pentachlorophenol-treated wood (pressure-treated) should not be used in
interiors except for limited uses and then only if properly sealed.
As discussed in Section V of this document, epidemiological studies of
workers exposed to pentachlorophenol (AWPI#81:30000/280 were submitted and
evaluated by the Agency, but the results were inconclusive. The Agency is
satisfied that the changes to the terms and conditions of registration out-
lined in Section VI of this document will assure adequate protection to man
and the environment from exposure to pentachlorophenol when taking the benefits
of use into account, and that further studies on pentachlorophenol are not
necessary for regulatory decision-making.
41
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Regarding the fate of pentachlorophenol in the environment, see Issue #5
and the Agency Response below.
Issue 14
The Agency asked if EPA should investigate the subject of the photolytic
conversion of pentachlorophenol to hexachlorodibenzo-p-dioxin {HxCDD) and
hexachlorobenzene. The Panel recommended that this area be investigated.
Agency Response
The Agency has concluded that the required regulatory measures will
provide adequate protection to the environment such that, taking into account
risks and benefits, there will be no unreasonable adverse effects from the use
of pentachlorophenol contaminated with HxCDD and HCB if registrants lower
the HxCDD contamination to 1.0 ppm or lower. The process used to reduce
HxCDD must not increase HCB or chlorinated dibenzofurans. The rationale and
bases for this requirement is discussed in Section VI.A of this PD 4.
The Agency is not stating that a level of 1 ppm HxCDD is not of regulatory
concern. This level has been based in part on the availablity and
ecomomic feasibility of existing technologies. The Agency is requiring
additional data to determine the feasibility of reducing this upper limit
further.
Regarding photolytic conversion, Dr. A.J. Dobbs (personal communication,
March 12, 1984) has conducted a study which shows that sunlight does not
significantly increase the HxCDD content of pentachlorophenol-treated wood.
The Agency will review any additional pertinent data on the subject that come
to its attention, but sees no need to seek such data at the present time. The
Agency believes that the existing data on pentachlorophenol, HxCDD, HCB and
chlorinated dibenzofurans are sufficient to provide for regulatory decision-making.
Issue #5
In the PD 2/3 (pp. 273-274) the Agency addressed the role of the wood pre-
serving industry as a source of ambient background levels of pentachlorophenol
in the environment. The Agency assumed that the amount of ambient pentachloro-
phenol levels contributed by an industry is related to the amount of the
chemical used by that industry. The wood preserving industry uses about 80%
of the pentachlorophenol in the United States. The Agency asked the SAP if
they agreed with this approach to determine the source of pentachlorophenol
in the environment and, if not, could the Panel suggest a feasible/appropriate
method of more accurately addressing the question.
The SAP stated that the Agency's reasoning appeared to be sound, but
stressed the need for determining the use(s) of the remaining 20% of the
pentachlorophenol in the U.S.
Agency Response
In addition to the wood preservative uses of pentachlorophenol, there are
also "non-wood" uses, including use as a herbicide, defoliant, mossicide, and
biocide. Therefore, the Agency assumes that these uses also contribute to
the ambient levels of pentachlorophenol in the environment. The Agency is
addressing "non-wood" uses in a separate position document detailing the
42
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risks and benefits and presenting proposed regulatory actions to reduce
potential adverse effects on the environment, including man, from these
uses.
OSDA (1981, pp. 9099) summarized the fate of pentachlorophenol in the
environment stating that the chemical has been found in air, water, and soil
to varying degrees. Its presence may be from direct contamination, degrada-
tion of other organic compounds, chlorination (in water), or volatilization
into the atmosphere.
Several offices within the Agency are coordinating to keep current with
data on the subject. The Agency proposed [48 PR 14514] listing as acutely
hazardous the waste from the production and manufacture of pentachlorophenol
as well as unused formulations and their derivatives.
The Agency's Office of Solid Waste is collecting and evaluating information
on this subject to reduce pentachlorophenol and HxCDD contamination in the
environment (air, water, soil). The waste from wood treatment plants using
pentachlorophenol will also be addressed in the future.
In this Position Document, the Agency is attempting to reduce environmental
contamination of pentachlorophenol by several regulatory measures. Regarding
contamination in the air, the Agency is requiring that the consumer Information
Sheet (CIS), which will accompany the shipments of pressure-treated wood and
will be distributed to purchasers of pressure-treated wood, contain statements
advising against interior use of treated wood except for limited uses and
then only if a sealer is used. The Agency also is prohibiting application
of pentachlorophenol in interiors and is prohibiting the application of
pentachlorophenol on logs which are intended for use in the construction of
log homes.
With regard to contamination in water, the Agency is requiring in this
Position Document that the CIS contain statements advising against the use
of pentachlorophenol-treated wood where it may come into direct or indirect
contact with public drinking water or drinking water for animals, except for
incidental contact such as docks or bridges. The Agency's Office of Pesticide
Programs and Office of Drinking Water, and PDA coordinated on this particular
issue.
Pentachlorophenol residues have also been found in food and animal feed
(USDA, 1981). The CIS advises consumers against use of pentachlorophenol-
treated wood in barns where domestic animals may contact food or animal
feed. The Pood and Drug Administration (FDA) sets tolerances for indirect
food additives; therefore, registrants may file a petition with PDA to set
tolerances to provide for the safe use of treated wood which may contact
food and feed (e.g, silos, food troughs, feed bins). Since the FDA has not
set tolerances for this use, the Agency has included in the CIS a statement
that pentachlorophenol-treated wood should not be used where the pesticide
may become a component of food and feed. The FDA has stated that pentachloro-
phenol-treated wood with surface residues not exceeding 50 ppm may come into
contact with raw agricultural products (e.g., apples and bananas with skins
intact) [21 CFR 178.3800].
Any further information that becomes available will be distributed to all
Offices within EPA (Office of Pesticide Programs, Office of Toxic Substances,
43
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Office of Solid Waste, Office of Drinking Water) and will be submitted to
other Federal agencies such as FDA and OSDA. Regarding the wood preserving
uses of pentachlorophenol, the Agency has determined that the modifications
to the terms and conditions of registration as outlined in Section VIII of
this document will serve to significantly decrease environmental contamination
by pentachlorophenol.
Issue f6
The Agency presented to the SAP the proposed regulatory actions and
modifications listed in the PD 2/3 relating to pentachlorophenol. The SAP
concurred with the Agency's proposals, but made the following additional
recommendations:
- elbow length rubberized gauntlets, not merely gloves, be required for
protective clothing.
- closed systems during emptying and mixing operations be recommended
rather than required: otherwise, the Agency would be placing an unfair
burden on small operators in terms of additional capital investment.
The SAP also concurred on the Agency's proposal to limit application of
the pesticides or use of treated wood to outdoors. The SAP did not disagree
with the several exceptions for use of treated wood indoors as listed in the
PD 2/3, such as all-weather wood foundations, support structures, certain
uses of millwork, and wood treated for sapstain control with 0.5% sodium
pentachlorophenate.
Agency Response
Regarding use of gauntlets, the Agency has determined, as discussed in
the Agency's response to Issue #2 above, that gloves impermeable (90% pro-
tection) to the pesticide will offer the applicator protection from hand
dermal exposure and that long-sleeved coveralls will offer further protection
from dermal exposure in certain use situations.
As discussed in Section VI.C.3 of this PD4, the Agency reevaluated the
PD 2/3 proposal that closed systems be required for emptying and mixing
prilled or flaked formulations of pentachlorophenol and powder formulations
of sodium pentachlorophenate. The Agency has concluded that, in order for the
benefits of use to outweigh the risks, closed systems must be used. Protective
clothing and respirators reduce exposure, but not to as low a level as the
Agency expects if closed systems are used. However, in order for the small
treatment plant operator to plan for the financial investment in closed systems,
the Agency will provide a 3-year "phase-in" period for treatment plants to
install closed systems. In the meantime, protective clothing and a respirator
must be worn by applicators.
Regarding the use of treated wood indoors, the Agency requires that
pentachlorophenol pressure-treated wood may be used only for laminated beams
and building components in contact with the ground and only if properly
sealed, as described in the Consumer Information Sheet in Section VII.C of
this document. If the Consumer Information Sheet is not adequately distributed
by industry such that the public is not sufficiently informed of this require-
44
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ment regarding use of pressure-treated wood in interiors, then the Agency
will promulgate a rule under TSCA to require that this information accompany
treated wood.
The Agency is also requiring that labels for home and farm pentachloro-
phenol and creosote products state "Do not apply in residential interiors."
Application of pentachlorophenol outdoors will be allowed. The Agency is
prohibiting home and farm application to wood intended for use in residential
interiors, except for millwork which has outdoor surfaces and then only if
it is sealed. As discussed in Section II.B. of this document, new data
submitted by Koppers (Nov. 15, 1983) has indicated than arsenic air levels in
homes constructed with arsenic treated wood were measured at 0,004 ug/m3, a
level lower than background air levels in some cities (USDA, 1980). Therefore,
the Agency will not restrict the use of arsenic treated wood in interiors, as
long as th« surfaces are cleaned thoroughly and all dust is removed from the
wood.
Issuet7
The SAP stated that EPA should require industry to reduce the dioxin {HxCDD)
content of pentachlorophenol to as low a level as is technologically and
economically feasible.
Agency Response
The Agency considered (PD 2/3, p. 642) requiring the registrants to
reduce the HxCDD contamination in pentachlorophenol and sodium pentachloro-
phenate from a representative upper limit of 15 ppm HxCDD to 1.0 ppm, but
concluded that (1) the benefits of use would outweigh the risks if certain
proposed regulatory measures (e.g., protective clothing and equipment,
restricted use requirements, prohibition against interior use) were adopted
and (2) some companies might cease manufacturing these products due to the
costs involved in the production conversion to the purer form.
As fully discussed in Section VI.A. of this document, the Agency has
reevaluated its position regarding HxCDD. In light of the SAP recommendation
and increased estimated risks since publication of the PD 2/3, the Agency has
concluded that it is necessary to set a current upper limit of 15 ppm HxCDD
contamination for all technical pentachlorophenol and sodium pentachiorophenate
products and to require that registrants reduce this contamination to 1.0 ppm
or below within 18 months. The process used to reduce the HxCDD must not
increase the chlorinated dibenzofuran and hexachlorobenzene contaminants.
The Agency has concluded that industry must decrease HxCDD contamination
in pentachlorophenol and sodium pentachiorophenate to protect the public from
unnecessary exposure to this oncogen, that it is economically and technologi-
cally feasible, and that this is necessary for the benefits of use to outweigh
the risks. Section VIII of this document summarizes the modifications to
the terms and conditions of registration which registrants must make and the
time frames required for these modifications.
B. Inorganic Arsenicals
Issue #1
The Agency asked the SAP how to determine the species of arsenic in the
Taiwanese well-water study (PD 2/3, p. 104) and further asked if pentavalent
45
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arsenic will convert in the body to trivalent arsenic if it is absorbed. The
SAP stated that there was not sufficient evidence to resolve these questions.
Agency Response
The Agency has received additional information since the time of the SAP's
response to indicate that (1) the arsenic in the Taiwanese well-water was 80%
pentavalent (As V) (Irgolic, 1982) and (2) if pentavalent arsenic is absorbed,
most of it will convert to the trivalent (As III) form (Rispin, 1983) , as
shown in both _in vivo and j.n vitro studies.
A study performed in 1979 by Yamauchi and Yamamura provides suggestive
evidence that in vivo reduction takes place in the human body. In this study/
a human subject ingested extract of seaweed containing 86% of the arsenic as
arsenate. More arsenite than arsenate was excreted in the urine. In vitro
studies also support the hypothesis that pentavalent arsenic may be reduced by
tissues. Incubations of arsenate with human erythrocytes (Ataullakhanov et
al., 1978) and tissue homogenates {Uthe and Reinke, 1975) led to formation of
trivalent arsenic.
In a series of experiments, in mice and rabbits, Marie Vahter and colleagues
(1983) have proved definitively that arsenate is reduced to arsenite in vivo.
Not only has arsenite been found in the urine and plasma of mice one hour after
dosing with arsenate, but rabbits dosed at very low levels of arsenate excreted
10% of the total administered dose as arsenite in 4 hours.
This new information does not necessitate any change in the Agency1s
regulatory position on inorganic arsenic because the Agency based its
evaluation of the mutagenic and teratogenic potential of inorganic arsenic
on studies involving both valence states of the chemical. The two states
of arsenic have somewhat similar effects. Similarly, the Agency's Carcinogen
Assessment Group based its determination of oncogenicity on epidemiology
studies involving populations exposed to both forms of arsenic.
Issue #2
The Agency asked if the SAP agreed with the proposed regulatory actions
to reduce risk due to arsenic exposure. The SAP stated that with the addi-
tional recommendations it was making in connection with the Agency's proposed
regulatory action in the PD 2/3 (see Issue |5 below), the risk from arsenic
exposure will be reduced to a satisfactory level.
Agency Response
Though the Agency has modified somewhat the regulatory actions proposed in
the PD 2/3 to arrive at the final regulatory position described in this
Position Document, the Agency has determined that the risks of use as
calculated for this position document will be outweighed by the benefits
of use if certain protective measures are required as outlined in Section
VIII of this position document. The Agency's response regarding the addi-
tional recommendations made by the SAP is discussed in Issue 15 below.
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Issue 13
The Agency asked the SAP if additional sampling was needed to determine
exposure to arsenic in all-weather-wood-foundations. The SAP stated that
additional measurements were not necessary.
Agency Response
As stated above in SAP Issue 16, upon receipt of new data by Koppers
(Nov. 15, 1983) which caused the Agency to change the exposure estimate from
Ot03 ug/m^ to 0.004 ug/m^ arsenic in the air of homes with arsenic-treated
wood, the Agency will not restrict the use of arsenic in interiors, as long
as surfaces are cleaned and free of dust. The exposure is not significantly
different from background (controls).
Issue 14
The Agency asked the SAP if the present teratology and fetotoxicity RPAR
"triggers" for the inorganic arsenicals needed to be reconsidered; i.e., did
the SAP agree that th« inorganic arsenicals meet or exceed the RPAR criteria
for teratology and fetotoxicity? The SAP stated though they believed the
RPAR criteria did not need to be reconsidered, additional exposure data on
the arsenicals are needed.
Agency Response
The Agency has reevaluated the studies on teratogenicity/fetotoxicity
and has concluded that although none have been performed according to com-
monly recognized and currently acceptable methodologies, the teratology and
fetotoxicity "triggers" have not been rebutted for the inorganic arsenicals
(Sochard, Oct. 24, 1983).
The studies all contain one or more of the following deficiencies:
1. Gavage not continued daily throughout organogenesis.
2. Maternal toxicity not reported.
3. Administration of only one or two dose levels.
4. Absence in any study of one or more of the following: no observed
effect levels (NOEL) and lowest effect levels (LEL) for fetotoxicity and
maternal toxicity, ar.d for teratogenicity (if the latter is observed).
The Agency has concluded that the protective measures required in this
PD 4 will reduce the teratogenic/fetotoxic potential risk from exposure to
inorganic arsenicaisj there will be an increase in the margin of safety for
these effects, (Sochard; Oct. 24, 1983). However, in an action separate
from this PD 4, pursuant to FIFRA Section 3(c)(2)(B), the registrants will be
required to submit appropriate teratogenicity/fetotoxicity studies in order for
the Agency to determine a NOEL for the inorganic arsenicals. After receipt
and evaluation of that data, the Agency will take further regulatory action
if necessary.
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Regarding the SAP's statement foe the need for more exposure data on the
arsenicals, the Agency reviewed a study by NIOSH (1983) which demonstrated
that the level of arsenic to which workers in arsenical treatment plants are
exposed was lower than that estimated in the PD 2/3. Also, as discussed in
Section II of this document, the Agency assumed that 10 ug/m3 is the upper
limit of arsenic to which workers are exposed over an 8-hour workday and
incorporated this in the calculations for risk estimation. The Agency has
concluded that workers must wear respirators if the air level of arsenic is
unknown or if worker exposure exceeds 10 ug/m3 averaged over an 8-hour work-
day.
Issue 15
The Agency asked the SAP to review and comment on the regulatory actions
proposed in the PD 2/3 to reduce exposure to the inorganic arsenicals. The
SAP concurred with all the proposed actions, but recommended the following
concerning arsenic:
- elbow length rubberized gauntlets, not merely gloves, be required,
closed systems during emptying and mixing operations be recommended,
rather than required, for powder formulations of the inorganic
arsenicals,
- limiting use of treated wood to outdoors (except for all-weather
wood foundations),
reduction of arsenical residues on treated wood,
- development of a good sealant for outdoor wood treated with arsenic.
Also, the SAP deferred to the Agency's judgment the decision regarding
prohibiting use of arsenic-treated wood which is likely to come into contact
with food, feed, or potable water.
Agency Response
As discussed in Issue #2 for pentachlorophenol, the Agency has deter-
mined that gloves impermeable to the pesticide will offer the applicator
adequate protection from hand dermal exposure and that, for pressure-treatment
uses, overalls, jackets, and boots will offer adequate protection from dermal
exposure other than through the hands. For the brush-on treatments of inor-
ganic arsenicals, gloves and disposable coveralls or other suitable protective
clothing must be worn by applicators.
For mixing and emptying operations using powder formulations of the
inorganic arsenicals, the Agency has determined that closed systems are
required. Without closed systems for mixing/emptying such formulations, the
dermal risk is 7.3 x 10~3, and the inhalation is 4.1 x 10~3, assuming
10 ug/m3 arsenic. These risks are considered by the Agency as too high to
be offset by the benefits.
Regarding the SAP's recommendation to limit the use of treated wood to
outdoors, the Agency has determined that arsenic pressure-treated wood does
not pose undue risk when used for All-Weather-Wood-Foundations and other
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limited uses. This issue is addressed in the model Consumer Information
Sheet which is required to be distributed by industry. The model CIS is
contained in Section VII.C of this document.
The SAP also recommended that arsenical residues on treated wood be
reduced by using clean wood for treatment. The Agency has concluded that
arsenical residues will be adequately reduced if applicators are required
to adhere to industry standards as defined by AWPA Standard C-l and AWPB
Standards LP 2 and LP 22, discussed in Section VI.C.4 of this document.
These standards require that the processes used to apply inorganic arsenical
formulations shall leave no visible surface deposits on the wood, i.e.,
that the treated wood shall not have a surface residue or crystallization.
Reducing the surface residues on treated wood will reduce the inhalation
and dermal exposure to treatment plant applicators as well as end-users of
the arsenical treated wood.
The Agency has no data at the present time on sealants for arsenic
treated wood to be used outdoors. As discussed in Section II.B of this PD 4,
dermal absorption of arsenic from arsenic-treated wood is expected to be
negligible; therefore, the Agency has concluded that sealants are not necessary
for treated wood to be used outdoors for picnic tables, playground equipment,
and similar items.
The Panel deferred to the Agency on the issue of using treated wood
which may come in contact with food, feed, or potable water. The
United States Food and Drug Administration (FDA) has advised the Agency
that FDA has the authority to issue food additive regulations for residues
of the wood preservatives that may -become a component of food or feed
through contact with treated wood (Heil, 1383). Section VII.A.5.of this
document contains a more detailed discussion of this issue. In summary,
FDA has issued a regulation setting a safe level of pentachlorophenol
and sodium pentachlorophenate in wood which may contact raw agricultural
products, but has not issued regulations setting safe levels of the three
wood preservatives (including arsenic) which may become a component of food
or animal feed (Heil, 1383), Therefore, EPA is requiring that the CIS, which
will accompany each shipment of pressure-treated wood, contain the following
statement:
Do not use treated wood under circumstances where the
preservative may become & component of food or animal feed.
FDA has indicated they concurred with this statement (FDA, February 2, 1984)
Regarding treated wood which may come into contact with potable water,
EPA recommends that a statement be included in the Consumer Information Sheet
which would advise against the use of treated wood where the preservatives
might come into direct or indirect contact with public drinking water and
would advise against the use of pentachlorophenol and creosote treated wood
where there may be contact with animal drinking water, except for incidental
contact such as docks and bridges, section VIII.E of this document also
contains a more detailed discussion of this issue.
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C. Creosote
Issue #1
The Agency asked the SAP if they agreed with the Agency's conclusion
that creosote is a mutagen. The SAP stated that they did agree with the
Agency's reasoning; i.e., (a) Creosote is a complex mixture exhibiting toxi-
city as well as mutagenicity: Creosote P 1 and P 2 are demonstrably toxic
in microbial and mammalian test systems; and (b) the Ames Test is positive
for the mutagenicity of creosote as well as other complex creosote mixtures.
[A typical blend of the various creosote distillates for P1 would be solvent
naphtha, naphthalene still residue, and uncorrected creosote; for P2, coal
tar and uncorrected creosote (USOA, p. 22, 1980).]
Agency Response
The Agency agrees with the SAP's statements confirming that creosote
is a mutagen (Anderson, 1983). The Agency has received no data since the
publication of the PD 2/3 which would indicate otherwise.
Issue #2
The Agency asked the SAP if the Tabershaw (1980) and Association of
American Railroads (AARH1979) surveys could be used to substantiate the
need for well-conducted epidemiology studies to estimate the oncogenic risk
to humans from exposure to creosote and if the information from the surveys
could be used in the design of improved studies. The SAP recommended that,
in light of the inadequacies of the surveys, EPA conduct additional epidemio-
logical studies to obtain the necessary data. The SAP stated that EPA could
use the data in the Tabershaw and AAR studies in the design of improved
studies.
Agency Response
The Agency determined, as set forth in the PO 2/3, that creosote is an
oncogen. The Agency will follow the SAP's recommendation to take the two
surveys into account in the design of further epidemiological studies to
estimate oncogenic risk. As summarized in Section VIII of this PD 4, the
Agency will require that registrants conduct a retrospective epidemiology
study on wood treatment applicators exposed to creosote and submit air moni-
toring and dermal exposure data on creosote in order to provide a quantita-
tive basis for estimating potential risk to applicators exposed to creosote.
For the present, the Agency will allow current registrations of creosote
products to continue, with certain modifications as summarized in Section
VIII of this document, but will, in an action separate from this PD 4 require
registrants to conduct the studies to maintain in effect existing registra-
tions pursuant to FIPRA Section 3(c)(2)(B).
Issue 13
The Agency performed a qualitative evaluation, rather than a quantitative
risk assessment for the oncogenicity of creosote. Therefore the Agency asked
the SAP if the Agency should ask for rodent inhalation studies using creosote
aerosols, epidemiology studies of wood preservative treatment plant workers,
and more extensive exposure studies in wood preservative pressure treatment
plants where creosote vapor and polycyclic particulate organic matter would
50
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be sampled.
The SAP stated that though there are enough rodent data available on
creosote, they would recommend additional epidemiological studies of wood-
preservative treatment-plant workers and more extensive exposure studies in
such plants.
Agency Response
As stated above in the "Agency Response" to Issue |2, the Agency will
require registrants to conduct an epidemiology study of creosote treatment
plant workers; the study will include air monitoring and dermal exposure
data on creosote.
Issue |4
The Agency asked the SAP if they would advise the Agency to seek expo-
sure data to estimate the hazard to workers from exposure to creosote in
non-pressure treatment plants. The SAP stated that EPA should seek such
information.
Agency Response
As stated in the Agency's response to Issue #2, the Agency will require
the registrants to conduct a retrospective epidemiology study in workers
exposed to creosote in treatment plants and to provide air monitoring data
and creosote dermal exposure data. These data will enable the Agency to
perform a quantitative risk assessment for creosote.
If the risks are unacceptably high even after considering the risk reduc-
tion afforded by the protective measures outlined in this document (Section
VIII) , then the Agency will take further regulatory action as appropriate to
insure that the benefits of use of creosote outweigh the risks.
Issue 15
In the PD 2/3, the Agency proposed restricting the use of creosote
for home and farm use, railroad tie repair, and groundline treatment of
poles to certified applicators. The Agency asked the SAP if this proposed
restriction was justified in light of the lack of exposure data. The SAP
stated that the certified applicator requirement was justified except in the
case of farm use where it appeared to be too restrictive and suggested the
Agency examine ways to enable farmers with small farming operations to use
creosote without becoming certified.
Agency Response
The Agency has determined that the potential risks of oncogenicity and
mutagenicity from exposure to creosote are not outweighed by the benefits of
use unless registrants modify the creosote labels for home and farm use, rail-
road tie repair, and groundline treatment of poles to include the requirements
for certain protective clothing and to specify use precautions, as outlined
in Section VIII of this document. Because of the Agency's continued concern,
all formulations of creosote must be classified for Restricted Use.
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Issue |6
The Agency recommended promulgating a rule under TSCA which would prohibit
interior use of creosote-treated wood. The SAP recommended that EPA examine
the possible use of sealants in connection with indoor uses of creosote because
industry claims some of the indoor uses are essential in industrial settings.
Agency Response
The Agency followed the SAP's recommendation and has determined that wood
pressure-treated with creosote does not pose undue risk when used in interiors
of industrial buildings for wood-block flooring and industrial building compon-
ents which are in ground contact and are subject to decay or insect infestation,
but only if two coats of an effective sealer are applied. A statement to this
effect is currently contained in the model Consumer Information Sheet, which
must be distributed by industry as described in detail in Section VII of this
document. The Consumer Information Sheet gives examples of specific sealers
which would be appropriate for use in interior settings. The information must
be distributed to consumers at the time of purchase of pressure-treated wood.
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IV. UNITED STATES DEPARTMENT OF AGRICULTURE (USDA) COMMENTS AND
AGENCY RESPONSE
The United States Department of Agriculture (USDA) also responded to the
PD 2/3 on the wood preservatives. Their comments are contained in their
entirety in Appendix E of this position document. The Agency carefully con-
sidered the USDA comments in the development of the final regulatory position.
USDA concurred generally with the Agency's proposal to continue the
registration of the wood preservative uses of pentachlorophenol, creosote
and the inorganic arsenicals, with modifications to the terms and conditions
of the registrations. A summary of USDA comments and the Agency responses
to these comments follows.
Issue 11
USDA concurred with the Agency's proposal in the Preliminary Notice of
Determination to cancel registrations for pentachlorophenol available for
retail sale in concentrations of 5% or less intended for application by a
spray method.
Agency Response
In the PD 2/3, the Agency proposed cancelling registrations for penta-
chlorophenol spray products available for retail sale in concentrations of
less than 5% pentachlorophenol. The Agency's goal was to eliminate these
products for use by home and farm applicators, but retain pentachlorophenol
spray products containing greater than 5% pentachlorophenol for use by Certified
Applicators only. The Certified Applicators would, if they so wished, be
able to buy pentachlorophenol products which were more concentrated than 5%,
mix and dilute them to any concentration they deemed appropriate and then
spray these products onto wood. Therefore, the Agency reasoned that the
"Ready-to-Use" spray pentachlorophenol products with less than 5% penta-
chlorophenol were unnecessary. However, the Agency has reevaluated this
issue and has concluded that if Certified Applicators wished to spray a
pentachlorophenol concentration of less than 5% onto wood, it would be more
convenient and safer if they could buy a product already diluted to that
concentration. This would eliminate the extra step of mixing and diluting
and would thus eliminate the exposure due to possible splashing. Therefore,
the Agency has concluded that registrations for pentachlorophenol spray
products containing less than 5% pentachlorophenol will be retained, but will
be for use by certified applicators only. Protective clothing and respirators
will be required to be worn as described in Section VI.E (Home and Farm
Uses).
Issue |2
USDA stated its concern that EPA had underestimated the economic impacts
that could result if specific uses of the wood preservatives were cancelled
or restricted.
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Agency Response
The Agency believes that it has taken the considerations of economic
impacts into account in reaching its conclusions about continued use of the
wood preserving chemicals (Eckerman, 1982). However, the Agency believes
that restricted use classification is necessary for all uses of the wood
preservatives, except for brush-on treatments of the inorganic arsenicals,
in order to assure that they are used by applicators with the requisite
training to handle these products properly. Section VIII of this document
summarizes the uses of the wood preservatives which will be classified as
Restricted Use pesticides.
Issue 13
USDA has suggested that more data are needed on applicator exposure,
disposal of treated wood, and residue levels of wood preservatives in water,
air, food, and feed.
Agency Response
The Agency is always receptive to additional data pertinent to its
regulatory positions, and will consider any data that are submitted bearing
on any of the positions taken in this document.
Regarding applicator exposure and disposal of treated wood, the Agency
has adequate data (PD 2/3, pp. 263-344, and p. 701, and Section VII.A.3
of this PD 4) to require that certain precautionary measures be taken. -
There are also adequate data on residues of wood preservatives in water to
allow the Agency to prohibit certain uses of treated wood which may come
into contact with potable water (Section VII.A.5 of this PD 4) .
As previously discussed (Arsenic, Issue 15), FDA issues food additive
regulations addressing treated wood which may come into contact with food
and feed.
The Agency's recommendations regarding statements which should be included
in the Consumer Information sheet regarding disposal of treated wood and pos-
sible contact of treated wood with food, feed, and water are summarized in
Section VII.C of this position document. The bases for these recommendations
are discussed in Sections VII.A.3 (Disposal of Treated Wood) and VILA.5
(Food/Feed/Water Issue).
Issue |4
USDA commented that respirators are not necessary for applicators who enter
arsenical pressure treatment cylinders because the inorganic arsenicals are
inorganic salts which have no measureable vapor pressure and do not release
arsenic fumes. USDA stated that a dust mask which would prevent inhalation of
arsenate particles or mist would be sufficient.
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Agency Response
The Agency agrees with USDA that, because there are no arsenic vapors,
respirators are not necessary to reduce the inhalation risk for applicators
exposed to arsenic "vapors" who enter inorganic arsenical pressure treatment
cylinders. However, the Agency has concluded that respirators are necessary
to reduce inhalation of arsenic-laden dust particles if the air concentration
exceeds a certain level. The Agency assumes that the inorganic arsenic-laden
dust level will be no greater inside the cylinder than the level throughout
the rest of the treatment plant.
The Agency has adopted a Permissible Exposure Level standard whereby res-
pirators will be required for workers in arsenical plants if the air level of
arsenic is unknown or exceeds 10 ug/n»3 averaged over an 8-hour period. The
Agency believes that this requirement will be effective in minimizing inhala-
tion exposure of all employees, including applicators who enter cylinders at
arsenical plants. The rationale for this determination is described in
Section VI.C.I of this document.
Issue |5
USDA stated that for home and farm applications of creosote or
pentachlorophenol which contain concentrations of pentachlorophenol greater
than 5%, both certified and noncertified applicators who may be applying the
chemical under the supervision of a certified applicator should wear the same
protective clothing. USDA further stated that for pentachlorophenol solutions
of 5% or less, long-sleeved shirts and trousers offer adequate protection.
Agency Response
The Agency has determined that, in order for the benefits to exceed the
risks, home and farm use of all pentachlorophenol and creosote products must
be restricted for use by certified applicators only. Section VI.E. of this
document discusses the rationale and bases for this determination. Those
creosote and pentachlorophenol products classified for Restricted Use must
contain label instructions specifying the type of protective clothing (e.g.,
gloves, disposable coveralls) to be worn by certified applicators and
applicators under their direct supervision. Section VIII of this document
describes in more detail the protective clothing requirements.
Issue 16
USDA commented that wood preservatives which are used by homeowners
and by contractors performing construction for homeowners should not be
classified for restricted use because these persons will have relatively
limited exposure to the pesticides. USDA questioned whether current certi-
fication programs apply to new groups of workers who do not fit into the
classification of commercial forestry or farm-oriented certified applicators.
Agency Response
The Agency continues to be concerned about the potential oncogenic and
55
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mutagenic effects from exposure to creosote and about the potential oncogenic,
teratogenic and fetotoxic risks from exposure to pentachlorophenol. Because
the Agency now estimates the dermal absorption rate of pentachlorophenol to
be 50% rather than 10% (Section II) and the protection afforded by gloves to
be 90% rather than 99% (Section II), the margins of safety for potential tera-
togenic/fetotoxic effects from exposure to pentachlorophenol have decreased
from 560 (PD 2/3) to 12.
The Agency considers a margin of Safety of 12 to be a significant potential
fetotoxic risk to pregnant women. Therefore, as described more fully in Section
IV.E, all home and farm pentachlorophenol and creosote products will be for
Restricted Use only in order for benefits of use to outweigh the risks. The
Agency will contact the states regarding this requirement so that they may
provide for training home and farm applicators and others in their State
Certification programs.
The Agency has concluded, however, that it is not necessary to classify
the brush-on arsenicals as a restricted use pesticide. The label will indicate
that brush-on treatments with arsenicals are for commercial construction
use only. It is only used by carpenters at construction sites to apply
to the cut ends of arsenic treated wood and must not be used for household
puposes. Section VIII of this document summarizes which wood preservative
products will be classified for restricted use. Several sections of this
document present the rationale for restricting the use of the various wood
preservative formulations.
Issue |7
USDA expressed concern that the Agency's proposed limitations on interior
uses of treated wood were too stringent, and would result in the unavailabi-
lity of treated wood for some uses for which there are no substitutes. USDA
commented that exposures can be reduced by effective sealers to a level where
the pesticides can be used safely. USDA (1981) submitted data to support that
position.
Agency Response
After evaluating the data submitted by USDA on sealers, the Agency recom-
mends that interior use of pressure-treated wood be permitted where exposures
to pentachlorophenol or creosote vapors can be reduced to a level such that
this use will not pose undue risk. Section VII.A.4 of this position document
presents the bases for this recommendation. Appendix B presents the oncogenic
risk estimates for pentachlorophenol and arsenic as well as teratogenic/fetotoxic
margins of safety for pentachlorophenol. In addition, however, there are
also acute toxic effects from exposure in interiors to treated wood. The
model Consumer Information Sheet which must be distributed by industry to
purchasers of pesticide pressure-treated wood addresses interior use and
states that pentachlorophenol-treated wood should not be used in residential,
industrial, or commercial interiors with certain exceptions, namely laminated
beams and building components which are in contact with the soil and which
are subject to decay or insect infestation. However, an appropriate sealer
should be applied. The CIS states that creosote-treated wood should not be
56
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used in residential interiors, and should only be used in industrial interiors
for wood-block flooring and building components in soil contact where they
may be subject to decay or insect infestation. However, an appropriate
sealer should be applied.
As described above in SAP Issue #3 (Arsenic), the Agency will include
statements in the CIS allowing the use of arsenic-treated wood in interiors,
as long as the surface is clean and free of dust.
The model Consumer Information Sheet (Section VII.C.) gives examples of
the appropriate sealers to be applied for pentachlorophenol and creosote-
treated wood.
Issue |8
The Agency's Preliminary Notice of Determination recommended promulgating
a rule pursuant to TSCA which would require wood to be labeled with precau-
tionary information. Statements in the labeling information would prohibit
application of wood preservatives to wood that will be used in a manner which
may result in direct exposure of animals or contamination of food, feed, drink-
ing or irrigation water. USDA has commented that such prohibitions are unneces-
sarily broad and "could prohibit virtually all agricultural uses of treated
wood" and could prohibit the use of treated wood on docks and bridges. USDA
commented that available data do not support the contention that these uses
will result in significant exposure to the public.
USDA further commented that the restrictions proposed for arsenical
treated wood for agricultural uses are inappropriate.
Agency Response
Food/Feed; As previously stated in this section (Arsenic, Issue f5), FDA
issues food additive regulations for residues of wood preservatives that may
become a component of food or feed through contact with treated wood. Uses
of treated wood which contact food and feed could include such items as
vegetable stakes, food crates, feedlot bins, or other similar food/feed
agricultural uses. FDA has issued a regulation providing that pentachloro-
phenol and sodium pentachlorophenate may be safely used on wooden articles
that are used or intended for use in holding raw agricultural products if
the levels do not exceed 50 ppm in the treated wood [21 CFR 178.3600]. FDA
has not issued food additive regulations for residues of creosote and arsenic
which may become components of food or feed, nor for pentachlorophenol which
may become a component of food or feed items (other than raw agricultural
products). Therefore, the Agency has included a statement in the Consumer
Information Sheet (Section VII.C. of this PD 4) which prohibits the use of
treated wood where the pesticide may become a component of food arid animal
feed. For a more detailed discussion of this issue, see Section VII.A.5 of
this document.
Drinking Water; Based on data discussed in Section VII.A.5 of this document,
the Agency is requiring that pressure-treated wood (all three wood preserva-
tives) not be used where it may come into contact with human drinking water,
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and that neither creosote nor pentachlorophenol-treated wood should come into
contact with domestic animal drinking water (e.g., water troughs). Use of
treated wood, such as for docks and bridges, in incidental contact with human
or animal drinking water be allowed. The rationale for these requirements is
also discussed in Section VII.A.5. The statements regarding these prohibi-
tions are contained in the sample Consumer Information Sheet (Section VII.C).
The issue of possible contact of non-pressure treated wood with human or
domestic animals' drinking water is discussed in Section VII.A.5 of this
document.
Issue 19
USDA objected to a proposed labeling requirement in the Preliminary Notice
of Determination dictating the method to be used to reduce surface deposits on
wood treated with arsenical compounds, and favored a labeling requirement that
"arsenical treated wood must be visibly clean."
Agency Response
The Agency has evaluated certain industry standards for obtaining clean
wood and has determined that surface residues of arsenic will be effectively
reduced if the product labels are modified as discussed in Section VLB.4
of this document. This requirement will ensure that the arsenical-treated
wood will be visibly clean.
Issue |10
USDA objected to the requirement proposed in the Preliminary Notice that
treated wood be disposed of by on-site burial, and that wood wastes in excess
of 1,000 kilograms per site be disposed of in accordance with the provisions
of the Resource Conservation Recovery Act (RCRA).
USDA stated that there are over 4,000 bridges on National Forest System
lands which utilize treated wood as bridge components, that the total weight
of each bridge would exceed 1,000 kg in almost every case, that unusable
materials from these bridges are often burned when the bridges are replaced,
and that the costs of disposing of this material in approved disposal sites
would be significant. USDA further states that the hazards of current
disposal methods have not been quantified.
Agency Response
The PD 2/3 (p. 701) stated that if creosote-treated wood is burned,
various oncogenic or mutagenic compounds may be formed; if arsenic-treated
wood is burned, one of the combustion products is arsenic trioxide ash
(a teratogen, mutagen, and oncogen). New information indicates that if
pentachlorophenol-treated wood is burned, dioxins (including HxCDD) are
produced (Rappe and Markland, 1978; and Jansson and Sundstrom, 1978).
Therefore, the Agency has concluded that treated wood should not be burned,
unless certain precautions are taken.
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The Agency does not currently list treated wood as a "hazardous waste," so
its disposal is not regulated under the Resource Conservation and Recovery Act
(RCRA). Currently, there is no regulation which addresses disposal of treated-
wood in excess of 1,000 kg per month per site. However, the Agency has con-
cluded that, for the reasons listed above, treated wood should not be burned
in open fires or in stoves or fireplaces, but should be disposed of "by ordinary
trash collection or burial." Burial could be either at the site or in a land-
fill approved by state or federal regulations. The Agency believes that the
disposal of treated wood in this way will not pose unreasonable risk to human
health and the environment, because the toxicants of concern are not likely
to leach into the environment to any significant degree. See Section VII.A.3
of this PD 4 for a more detailed discussion regarding potential leaching.
The Agency has also concluded that burning large quantities of treated
wood from commercial or industrial use (for example, from construction
sites) would not pose an undue hazard if the treated wood is burned in
commercial or industrial incinerators in accordance with state and Federal
regulations. The heat of the fire is expected to be higher than in an open
fire or fireplace, resulting in combustion of the toxic chemicals.
Therefore, the Agency requires that statements be included in the CIS
which would prohibit burning unless the treated wood was incinerated at
commercial or industrial installations in accordance with existing state and
Federal regulations. Section VII.C contains a summary of the statements in
the model CIS.
Issue ft11
USDA expressed concern about the Agency's recommendation to promulgate a
rule under TSCA requiring end-use labeling which would advise all persons
handling treated wood to wear impervious gloves, and requiring individuals who
saw treated wood to wear protective clothing and a dust mask. It characterized
such regulations as unrealistic and unenforceable.
Agency Response
The Agency believes that such precautions are desirable to minimize inhala-
tion and dermal exposure to the wood preservatives. Section VII of this docu-
ment discusses the qualitative and quantitative risks of sawing treated wood.
The Agency has concluded that, in order for the benefits of use of treated wood.
to outweigh the risks, commercial producers of wood or wood products which
have been treated with the wood preservatives will be required to participate
in a Consumer Awareness Program (CAP) to alert users of wood preservatives
to these and other precautions to be taken in the use of pressure-treated
wood through dissemination of the Consumer Information Sheet (CIS) which
will accompany each shipment of pressure-treated wood. The model CIS contains,
among others, the following statements: "When handling the treated wood,
wear tightly woven coveralls and use gloves imperious to the chemicals (for
example, gloves that ate vinyl-coated). When sawing and machining treated
wood, wear a dust mask." The Agency will assess the effectiveness of the
CAP after it has been operative for a period of one year. If the CAP is
successful, as the Agency expects, in informing end-users of treated wood
about handling precautions, a TSCA rule may not be necessary.
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V. ANALYSIS OF PD 2/3 AND REVISED PROPOSAL^/ COMMENTS
Fifty-nine respondents commented on the wood preservatives PD 2/3, with a
total of 67 separate submissions to the public comment file (30000/28C).
Twenty-two respondents commented on the Agency's wood preservative proposal
presented at the April 14, 1983, public meetingV, with a total of 29 separate
submissions to the comment file (30000/28C). In total, 88 submissions
were received from 81 different commenters. Refer to Table 10 for a list of
the issues discussed and commenters.
A. Comments on Risk
1. Creosote
Comment Issue #1: Microbiological assays as evidence of creosote mutagenicity
The American Wood Preservers Institute (AWPI) (36A) judges the Salmonella
experiments of Simmon and Poole (1978) as unreliable evidence of the mutagenicity
of creosote/coal tar because of the contradictory results found by Litton
Bionetics, Inc. (1978a, 1978b, 1978c) in the Salmonella microsome assay
for this complex mixture. The AWPI states that these contradictory results
indicate the "inherent weakness" of the Salmonella (Ames) assay in predicting
creosote/coal tar mutagenicity.
Agency Response:
Simmon and Poole (1978) as well as Simmon and Shepherd (1978) were able
to demonstrate in three independent experiments using Salmonella with
exogenous metabolic activation that creosote/coal tar caused a dose-related
increase in frameshift mutations. Recent studies by Bos et al. (1983)
confirm these positive findings (Vaughn-Dellarco, 1983). Therefore, the
Agency concludes that the results of Simmon and Poole (1978) as well as
Simmon and Shepherd (1978) provide acceptable evidence for the mutagenicity
of creosote/coal tar in Salmonella.
In general, the Salmonella test has been effective in the evaluation
of many different environmental complex mixtures, such as tobacco smoke
condensates, drinking water, soot from city air, fly ash, and other combustion
products. One major problem in evaluating the potential mutagenicity of
\J The Agency held a public meeting on April 14, 1983 (See PR 13257, March
30, 1983, for announcement of meeting) to give interested persons the
opportunity to comment on certain changes to the decision proposed in the
Preliminary Notice of Determination (46 FR 13024-13029, February 19, 1981)
as set forth in the Position Document 2/3. The comments received have
been considered in the development of this final decision and are discussed
in detail in this Position Document (PD 4). The final position reflects
changes made in response to such comments and further evaluation by the
Agency since receipt of the comments.
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Table 10. Summary of Comments Submitted to the
Wood Preservatives Pile #30000/280
Subject
Commenter (Number)
Mutagenie potential of creosote
Oncogenic potential of creosote
Creosote respiratory and dermal exposure
Pentachlorophenol teratogenicity and
fetotoxicity
Pentachlorophenol bioaccumulation
Dioxin contamination and related oncogenic
risk of pentachlorophenol
Pentachlorophenol respiratory and dermal
exposure
Interconversion of arsenate to arsenite
Mutagenic potential of inorganic arsenicals
Inorganic arsenicals teratogenicity
Sensitivity of animals and humans
to arsenic toxicity
Oncogenic potential of inorganic arsenicals
Inorganic arsenicals PD 1 testimonials
as supporting evidence
Inorganic arsenicals respiratory
and dermal exposure
Benefits of wood preservatives usage
American Wood Preservers Institute (36A)
American Wood Preservers Institute (36A)
American Wood Preservers Institute (36A)
The Dow Chemical Company (32); American
Wood Preservers Institute (36B); National
Forest Products Association (36B)
Friends of the Earth (55, 64 and 70)
American Wood Preservers Institute (36B,
and 78); National Forest Products
Association (36B)
American Wood Preservers Institute (36B);
National Forest Products Association (36B)
American Wood Preservers Institute (36C);
Society of American Wood Preservers (53)
American Wood Preservers Institute (36C)
American Wood Preservers Institute (36C)
Society of American Wood Preservers (53)
American Wood Preservers Institute (36C);
Society of American Wood Preservers (53)
American Wood Preservers Institute (36C)
American Wood Preservers Institute (36C)
Sentinel Wood Treating, Inc. (2);
Gibson-Homans Company (3); Coopers
Creek Chemical Corporation (4); Illinois
Power Company (5); National Solvent
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Table 10. (cont'd) Summary of Comments Submitted to the
Wood Preservatives File #30000/28C
Subject
Commenter (Number)
Treated wood disposal
Protective gloves
Corporation (6); Soult Wholesale Company
(8); Cedar Fence Distributors Company,
Inc. (9); Dries Building Supply
Company (11); Sampson Paint Manufacturing
Company, Inc. (12); Standard Concrete
Products Company (13); Lloyd H. Daub,
Inc. (15); Harboro Lumber Fuel Co. (16);
Philadelphia Reserve Supply Company (17);
C.A. Niece Company (19); GAF Supply
Center (21); RABCO Products (22);
National Woodworks, Inc. (24); Michlin
Chemical Corporation (25A); Missouri
Department of Agriculture (28); Carson's
Hardware (29); N.Y. Power Pool (30);
Consumers Power Company (31); Association
of American Railroads (34); Edison
Electric Institute (35); Missouri
Forest Products Association (39);
Detroit Edison (40); Osmose (41);
Niagara Mohawk Power Corporation
(42); Nebraska Cooperative Extension
Service (51); Good-Life, Inc. (58)
Department of the Army (1); Illinois
Power Company (5); Association of American
Railroads (34 and 71); Edison Electric
Institute (35); American Wood Preservers
Institute (36F); National Forest Products
Association (36F); Iowa-Illinois Gas and
Electric Company (50); Portland Cement
Association (66)
Sentinel Wood Treating, Inc. (2); Illinois
Power Company (5); National Woodworks,
Inc. (24); Association of American
Railroads (34); Edison Electric
Institute (35); American Wood Preservers
Institute (36C, 36F and 78); National
Forest Products Association (36F);
Detroit Edison (40); Osmose (41); U.S.
Department of Energy (44); Iowa-Illinois
Gas and Electric Company (50); Nebraska
Cooperative Extension Service (51);
International Woodworkers of America (68)
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Table 10. (cont'd) Summary of Comments Submitted to the
Wood Preservatives File #30000/280
Subject
Commenter (Number)
Protective overalls
Protective clothing disposal
Leaving protective clothing at
treatment plant and cleaning of
protective clothing
Respiratory protective equipment
Animal, food, feed and water contami-
nation due to treated wood exposure
Sentinel Wood Treating, Inc. (2); National
Woodworks, Inc. (24); Association of
American Railroads (34); Edison Electric
Institute (35); American Wood Preservers
Institute (36B and 36C); National Forest
Products Association (36B and 73);
Detroit Edison (40); Osmose (41); Iowa-
Illinois Gas and Electric Company (50);
Nebraska Cooperative Extension
Service (51)? International Woodworkers of
America (68)? Association of American
Railroads (71)
Association of American Railroads (34);
American Wood Preservers Institute (36B
and 36C); National Forest Products
Association (36B); Osmose (41)
American Wood Preservers Institute (36C);
International Woodworkers of America (68)
Sentinel Wood Treating Company (2);
Illinois Power Company (5)f Kerr-McGee
Corporation (33); Association of
American Railroads (34); Edison Electric
Institute (35); American Wood Preservers
Institute (36B, 36C and 78); National
Forest Products Association (36C); U.S.
Department of Energy (44); Friends of
the Earth (64); International Woodworks
of America (68); Koppers Company (72)
Illionis Power Company (5); Missouri
Department of Agriculture (28); Consumers
Power Company (31); Association of
American Railroads (34); Edison Electric
Institute (35); American Wood Preservers
Institute (36B and 36C); National Forest
Products Association (36B); Missouri
Forest Products Association (39); Iowa-
Illinois Gas and Electric Company (50)
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Table 10. (cont'd) Summary of Comments Submitted to the
Wood Preservatives File #30QOO/28C
Subject
Commanter (Number)
Interior uses of treated wood
Restricted use classification:
Home and farm use of creosote
Creosote - other
Pentachlorophenol
American Institute of Timber Construction
(10); Structural Wood Systems (14);
Roberts Consolidated Industries (20);
Missouri Department of Agriculture (28);
American Wood Preservers Institute (36B,
36C and 78); National Forest Products
Association (36B); Jenson-Wright
Corporation (37); Forest Products
Association of Missouri (39); Nebraska
Cooperative Extension Service (51);
Levin (60); Friends of Earth (64 and 70);
Portland Cement Association (66); Center
for Disease Control (69); Koppers
Company, Inc. (89)
Gibson - Romans Company (3); Coopers
Creek Chemical Corporation (4); National
Solvent Corporation (6); National Paint
Center (7); Soult Wholesale Company (8);
Dries Building Company (11); Sampson
Paint Manufacturing Compay, Inc. (12);
Standard Concrete Products Comapany (13);
Lloyd H. Daub, Inc. (15); Hatboro Lumber
and Fue1 Company (16); Doylestown Lumber
and Millwork Company (18); C.A. Niece
Company (19); GAF Supply Center (21);
RAECO Products (22); Monsey Products (23);
Michlin Chemical Corporation (25A);
Carson's Hardware (29); G.M. Deck &
Sons (45); Ecological and Specialty
Products, Inc. (47); Walpole Wood
workers (56); and The Reliance
Company (59)
Association of American Railroads (34);
Osmose (41); Iowa - Illinois Gas and
Electric Company (50)
Michlin Chemical Corporation (25);
Missouri Department of Agriculture (28);
Association of American Railroads (34);
Osmose (41); Arneson Timber Company (46);
McPhillips Manufacturing Company (49);
Iowa - Illinois Gas and Electric
Company (50); Nebraska Cooperative
Extension Service (51)
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Table 10 (cont'd) Summary of Comments Submitted to the
Wood Preservatives Pile #30000/28C
Subject
Commenter (Number)
Inorganic arsenicals
Pentachlorophenol restriction based
on active ingredient
Labeling
Closed environment for pentachlorophenol
and sodium pentachlorophenate treat-
ment plant usage
Regulation of applicator vs.
handler and end-user
Eating and smoking area
Classification of selected non-pressure
treatment uses
Regulation of pentachlorophenol on
millwork
Regulation of pentachlorophenol and
soduim pentachlorophenate spray
treatment
Agency regulation of selected wood
preservatives together
American Wood Preservers Institute (36C)
American Wood Preservers Institute (36B);
National Forest Products Association (36B)
Osmose (41)
National Woodworks, Inc. (24); Missouri
Department of Agriculture (28);
Association of American Railroads (34);
Edison Electric Institute (35); American
Wood Preservers Institute (36A, 36B, 36C
36H, 361, 36J, and 78); Forest
Products Association of Missouri
(39); Friends of the Earth (64)
Michlin Chemical Corporation (25);
American Wood Preservers Institute (36B
and 78); National Forest Products
Association (36B); International Wood-
workers of America of Oregon (63) and
Washington (68)
Consumers Power Company (31); Osmose (41)
Association of American Railroads (34);
American Wood Preservers Institute (36B
and 36C); National Forest Products
Association (36B)
Edison Electric Institute (35); U.S.
Department of Energy (44); Association
of American Railroads (71)
McPhillips Manufacturing Company (49);
McPhillips Manufacturing Company (49);
Publishers Paper (54); International
Woodworkers of America of Oregon (63)
and Washington (68)
McPhillips Manufacturing Company (49)
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preservatives together
Table 10. (cont'd) Summary of Comments Submitted to the
Wood Preservatives File #30000/280
Subject
Commenter (Number)
Alternative wood preservatives
Exterior use of treated wood
EPA jurisdiction
Poles - groundline treatment
Support of EPA action
Pentachlorophenol risk estimates and
recommended use modifications
Environmental fate of pentachlorphenol
Standards for clean, arsenic-treated
wood
Michlin Chemical Corporation (25 and
25A); Osmose (41); Louisiana-Pacific
Corporation (43); Nebraska Coopera-
tive Extension Service (51); Seymour
Chemicals, Inc. (52)
Portland Cement Association (26); American
Wood Preservers Institute (36B); National
Forest Products Association (36B)
Kerr-McGee Corporation (33); American
Wood Preservers Institute (36B, 36C
36E, and 36H); National Forest Products
Association (36B); U.S. Department
of Energy (44)
Edison Electric Institute (35)
Coopers Creek Chemical Corporation (4);
Illionis Power Company (5); National
Solvent Corporation (6); Monsey Products
(23); Consumers Power Company (31); Walpole
Woodworkers (56); Osmose (61); Georgia
Department of Agriculture (62); Louisiana -
Pacific Corporation (73); McFarland Cascade
(74); National Forest Products Association
(75); J.G. Baxter Company (76); Koppers
Company, Inc. (77); Allied Chemical (79)
The Dow Chemical Company (32)
Friends of the Earth (64); American
Wood Preservers Institute (78)
American Wood Preservers Institute (36C)
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complex mixtures, however, is their toxicity to the test organism. Creosote/
coal tar is no exception in that toxicity to Salmonella presents a testing
problem. Because of the toxicity of creosote/coal tar, the mutagenic
activity was only demonstrable within a narrow concentration range. Responses
in the Simmon and Pooie (1978) and Simmon and shephard (1978) studies were
roughly linear from approximately 5 to 100 ug/plate. Nesnow (EPA, 1979)
also indicated that this heterogeneous mixture is toxic to Salmonella and
is technically difficult to study (Vaughn-Dellarco, 1983).
Thus, the contradictory (negative) results reported by Litton Bionetics,
Inc. (1978a, 1978b, 1978c) may reflect the difficulties in testing creosote/
coal tar. Litton Bionetics, Inc. only evaluated log intervals that covered
a large concentration range, and thus could have missed a positive response
in their initial 1978 experiments because of toxicity. Also, after a
Salmonella retest of the material, Brusick (1978) concluded that creosote/
coal tar is mutagenic and that attempts to repeat the negative results
originally reported by Litton Bionetics, Inc., were unsuccessful. Brusick
(1978, 1981) attributed the negative results in the earlier experiments
to the quality of the S9 preparations used (Vaughn-Dellarco, 1983).
Comment Issue #2: Mouse lymphoma studies as evidence of creosote mutagenicity
The AWPI (36A) argued that the experiments of Mitchell and Tajiri
(1978) do not demonstrate the mutagenicity of creosote/coal tar in mouse
lymphoma cells in vitro because mutagenic activity was found only at
concentrations that were toxic.
Agency Response:
The Agency acknowledges that there is debate among investigators who
use the mouse lymphoma TK +/- assay as to whether data collected at 10%
survival are acceptable for evaluating the mutagenicity of a chemical
substance. However, Mitchell and Tajiri (1978) demonstrated a significant
(P < 0.001) dose related increase in mutagenic response in a study using
eight dose points. At concentrations that resulted in approximately 11% -
15% total relative growth, weak mutagenic responses were detected (i.e.,
approximately a twofold increase in the spontaneous mutuation frequency)
(Vaughn-Dsllarco, 1983). Consequently, the Agency considers the results
of Mitchell and Tajiri as evidence that creosote/coal tar is mutagenic in
mouse lymphoma cells when an exogenous source of hepatic metabolic activation
was added.
The results in the mouse lymphoma TK +/- assay strongly suggest that
creosote/coal tar is mutagenic in mammalian cells in culture. The toxicity
of the complex mixture to the cells may mask the mutagenicity of components
present at low concentrations, thus the results may underestimate the
mutagenic potential of this material. Therefore, the results in the mouse
lymphoma TK+/- assay strongly suggest that creosote/coal tar is mutagenic
in mammalian cells in culture (Vaughn-Dellarco, 1983).
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Comment Issue #3: Extrapolation of creosote mutagenicity bacterial test
results to humans
The AWPI (36A) states that it is inaccurate to extrapolate the results
from bacterial test systems to conclude that creosote/coal tar is a human
mutagen.
Agency Response:
The Agency agrees that it is not accurate to extrapolate directly
from bacteria to the likely human response and classify any chemical sub-
stance as a "hunan mutagen." The purpose of jji vitro tests, such as the
Salmonella assay, is to screen chemicals for their potential mutagenicity
and/or carcinogenic!ty- The Agency's conclusion is that the weight-of-
evidence (i.e., positive data derived from in vitro tests in bacteria and
mammalian cells as well as data regarding the mutagenic and/or carcinogenic
activity of the individual components of creosote/coal tar) suggest that
creosote/coal tar have the potential to cause mutations in humans and not
that creosote/coal tar is a human rautagen {Vaughn-Dellarco, 1983).
It is recognized that creosote/coal tar was evaluated in in vitro tests
only, when evaluating the risk posed by exposure to a mutagenic agent,
several factors, including absorption and metabolism, may alter the muta-
genic response in a mammal compared to that in in vitro tests. Although
in vivo studies in mammals are necessary to better characterize the risk of
creosote/coal tar, this does not negate the results from the in vitro
studies which do indicate the intrinsic mutagenicity of creosote/coal tar
(Vaughn-Dellarco, 1983).
Comment Issue #4: Mutagenic components of creosote do not render the mixture
mutagenic
The AWPI (36A) points out that while flaked coal tar pitch and components
of coal tar epoxy were shown to be mutagenic in the Escherichia coli WP2
reverse mutation assay, creosote/coal tar was not (Mortelmans and Ricco, 1980)
In their view, to assume that the mutagenic components of a complex mixture
necessarily render the mixture itself mutagenic is an invalid conclusion.
Agency Response:
The Agency agrees that the mutagenicity of the individual chemical
components of a complex mixture do not necessarily reflect the mutagenicity
of the mixture as a whole. There may be interactions (e.g., synergisms
and antagonisms) among the chemicals in the complex mixture that alter
their mutagenic potential. However, this does not negate the concern with
effects of the compounds individually because differential absorption of
the constituents of complex mixtures may also occur. It should be emphasized
that interactions between the compounds in creosote/coal tar have not been
characterized in the study by Mortelmans and Ricco (1980). In addition,
flaked coal tar pitch and coal tar epoxy are different complex materials
and are not representative of the spectrum of chemicals and the amount of
the individual chemicals present in creosote/coal tar (Vaughn-Dellarco, 1983)-
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Comment Issue #5: Nonspecific toxicity as the cause of unscheduled
DNA synthesis
The AWPI (36A) pointed out that nonspecific toxicity may have caused
the unscheduled DNA synthesis in the human fibroblast diploid cell line
WI-38 (Litton Bionetics, Inc., 1978d).
Agency Response:
Toxicity should not cause an increase in unscheduled DNA synthesis.
In this WI-38 cell assay, toxicity would be indicated by a depression or
lack of 3u-TdR incorporation. Unscheduled DNA synthesis is indicative of
damage to DNA, and therefore indicative of potential mutagenicity (Vaughn-
Dellarco, 1983).
Comment Issue #6: Lip cancer in fishermen
The AWPI (36A) questions Shambaugh (1935), which reports on fishermen who
held tar-soaked needles in their mouths and developed lip cancer, as evidence
of the carcinogenicity of creosote/coal tar. The AWPI (36A) cites Spitzer et
al. (1975) as evidence that holding a tar-soaked needle in one's mouth
does not increase the risk of lip cancer.
Agency Response:
The Agency has reviewed the Spitzer et al. study (1975), and concludes
that the absence of definitive exposure data precludes the use of Spitzer
et al. (1975) to refute the Shambaugh (1935) study. For example, it is
unclear as to whether the Spitzer et al. (1975) fishermen placed needles
moist with coal tar and/or coal tar-soaked nets in their mouths. Also,
the type of "tar" used in Spitzer et al.'s study is not defined. It seems
likely that pine tar or some less toxic tar would have replaced coal tar
used as a preservative in Shambaugh1s (1935) study by the time of Spitzer
et al.'s (1975) study (CAG, 1982).
Comment Issue #7: Coal tar distillates and cancer
The AWPI (36A) cites "Of Mice and Men and Coal-Tar Distillates: A
Rebuttal of Popular presumptions and Dogmas on Cancer Causation" (Poel,
1980) as evidence that there is no increased incidence of skin or respiratory
cancer associated with occupational exposure to coal tar distillates.
Agency Response:
Poel (1980) cited mortality studies by Lloyd (1971), Redmond (1976) and
Redmond et al. (1979) as epidemiological evidence that worker exposure to
coal tar or coal tar distillates was not associated with cancer of the
scrotum, skin, or lung; studies by Reid and Back (1956) as evidence that
there was no increased mortality to coking plant employees from lung cancer;
and studies by Doll et al. (1965, 1972) which concluded that men exposed
to coal carbonization by-products did not experience excess mortality risk
from cancer of the lung, bladder, skin, scrotum or other sites.
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The Agency has carefully reviewed the studies cited above and and does
not concur with the authors' conclusions. The mortality studies conducted
by Lloyd (1971), Redmond (1976), and Redmond et al. (1979) may not demonstrate
excess risk of skin cancer from coal tar distillates because of the low
case-fatality rate of skin cancer. With regard to lung cancer mortality,
the Lloyd (1971) and Redmond (1976) studies found no increased lung cancer
mortality for the non-oven areas of the coke plant. However, for coke ovens,
where exposure to polycyclic aromatic hydrocarbons was believed to be the
highest, particularly the top side of coke ovens, there was a significantly
increased lung cancer risk. The non-oven areas consisted of the coal
handling area and the by-products area. There is little evidence that coal
handling produces a lung cancer risk. The decreased risk of lung cancer
that was found in the by-products area is unexplained (Rispin, June 14, 1984).
Reid and Buck (1956) failed to adequately define the basic study population.
In studying the causes of death during 1949-1954, it is unclear if the
study population includes all dying men who were "on the books" in a coke
plant during 1949-1954, or only those found through a special 1952 census.
If the cohort consisted of workers employed in 1952, and because there was
little or no follow up of any of these members, it appears that this study
is basically a cross-sectional study of mortality in a conglomerate of
several different coke plants. The observed deaths appear to have occurred
to members of the study group employed during 1949-1954. Therefore, the
number of cancer deaths observed may have been deficient since it was
reported by Lloyd (1971) that men were removed from the books after prolonged
absence from work. Because there were no follow-ups after 1954, latent
effects were not adequately considered. It is not known how the death
rates were derived or defined; therefore, it is not clear if they are
compatible with the definition the authors used to derive the study popula-
tion (GAG, 1982).
With regard to the Doll et al. study, the likelihood of detecting a
statistically significant elevation in lung cancer deaths given the number
of expected lung cancer deaths (number = 2.14) in the study population of
by-product workers is less than 0.8 even if the number of lung cancer cases
had been elevated 3.5 fold (assuming a Poisson distribution). The likelihood
of detecting a statistically significant excess of mortality from bladder,
skin, scrotum, and other sites is even less. Skin cancer mortality is a
poor indicator of the skin cancer risk from exposure to coal tar distillate
products because the case-fatality rate is so low. Finally, there was no
control for smoking (CAG, 1982).
Comment Issue |8: Dermal oncogenic potential of creosote and coal tar
The AWPI (36A) claims that the Agency relied primarily on animal studies
to evaluate the dermal oncogenic potential of creosote and coal tar because of
the unavailability of adequate epidemiological studies. They pointed out
that Maugham et al. (1980) completed a long-term follow-up study of persons
treated with coal tar medicinals for psoriasis (the Goekerman Treatment)
which demonstrates no increased incidence of non-melanoma skin cancer in
these patients.
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Agency Response:
The Agency has based its qualitative conclusion that creosote is an
oncogen on both animal studies and human case studies. The EPA rejects
AWPl's position that creosote is not an oncogen based on the Maugham et al.
(1980) study to evaluate the dermal oncogenic potential of creosote and coal
tar because of methodological deficiencies and because the short duration of
the Goekerman treatment (2-4 weeks) is not comparable to an occupational
exposure to creosote/coal tar, (e.g., wood treaters).
The Maugham et al. (1980) study population consisted of persons who had
undergone the Goekerman treatment for psoriasis, in which 2% - 5% crude
coal tar ointment was applied to body areas generally below the head,
approximately 2-3 times a day, for 2-4 weeks. In 1979, the authors contacted
305 of the 426 persons (72%) identified as receiving the treatment during
the years 1950-1954. The loss of 28% of the study population could have skewed
the study results. The Goekerman treatment patients ranged in age from one
year to late adulthood, therefore the recall of information by members of
the study population who were very young at the time of the study would not
be expected to produce reliable data (CAG, 1982).
The incidence rates used to calculate the expected number of skin cancer
cases were derived from medical record abstractions and from 1970 census
data for four geographic areas of the United States. Comparing incidence
rates derived by abstracting medical records to rates derived by survey
people surveyed for disease incidence may not report that they ever had
skin cancer. In analyzing the data, Maugham et al. (1980) compared the
number of nonmelanoma skin cancers among persons who had undergone the
Goekerman treatment with the number that would have been expected had the
patients lived in four different geographic areas of the United States.
This resulted in an incidence of cancer among the study group which was
higher than expected for three of the four comparison areas. The authors
concluded, however, "that because the study group was a varied group geo-
graphically, there would seem to be no significant increase from the reported
incidence figures." The Agency does not concur because of the potential
biases indicated above and because there was no adjustment by geographic
areas of the incidence rate (CAG, 1982, and Rispin, June 14, 1984).
Comment Issue #9: Skin carcinoma due to creosote/coal tar exposure
The AWPI (36A) cites a study dealing with industrial disease benefits
(Lederer and Phillips, unpublished) as evidence that creosote/coal tar
exposure does not lead to an excess incidence of skin carcinoma among
workers exposed to coal tar and coal tar products.
Agency Response:
The Agency has reviewed the Lederer and Phillips (unpublished) report
which is a comparison of the incidence of squamous cell carcinoma among
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United Kingdom workers in "coal tar-related industries" to the incidence of
squamous cell carcinoma in England and Wales. The Agency finds that it
cannot agree with the report's analysis because of invalid statistical
methodology concerning incidence rates. By definition, for a disease
incidence rate, those people qualifying as the population must also qualify
as potentials for the actual cases. However, in this study, the squamous
cell carcinoma cases were identified for the year 1973, the worker population
represented the year 1977, and the incidence rate included industrial
classifications which apparently differed with the employment categories
used to derive the prescribed disease data.
A comparison of incidence rates for United Kingdom (Ireland, Scotland,
Wales and England) workers in coal tar-related industries to population
incidence rates for England and Wales may be biased if the incidence
of skin cancer in England and Wales is substantially different from that
of the United Kingdom. Comparison of incidence rates among any working
population with population rates may also be a biased comparison because
of the "healthy worker effect." For example, persons who develop skin
cancer or precancerous lesions from working with coal tar materials may
change occupations or drop out of the working population altogether.
Also, the comparison of a squamous cell carcinoma crude incidence rate for
the coal tar-related industrial workers and for the general population is
biased because the age distribution of a working population is considerably
different from that of the general population (CAG, 1982).
Finally, the comparison of incidence data derived from disease benefit
awards with incidence data for the population is also a biased comparison
because the disease benefit award is a selective process and population
incidence data are not selective (CAG, 1982). Therefore, no conclusions
can be drawn from the Lederer and Phillips (unpublished) study about the
incidences of skin carcinoma among workers exposed to coal/coal tar products.
Comment Issue #10: Increased risk of skin, bladder or lung cancer due to
creosote exposure at wood treatment plants
The AWPI (36A) cites Flickinger's (1980) conclusion that creosote
exposure at wood treatment plants did not increase the risk of skin, bladder,
or lung cancer. Flickinger based his conclusion on the Tabershaw Occupational
Medicine Associates' (1980) health study of wood treatment plant workers.
Agency Response:
This industrial hygiene report (Flickinger, 1980) provides some
indication as to the amount of benzene-soluble material and different
polycylic constituents of creosote and coal tar to which wood treaters are
exposed. However, the report provides no indication of the carcinogenic
risk that such exposure may present (CAG, 1982).
The Agency carefully reviewed the Tabershaw Occupational Medicine
Associates (1980) cross-sectional health examination survey of workers at
five work treatment plants and cannot agree with the conclusion because of
several analytical problems.
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The population examined (329) is not large enough to assess the effect
of creosote exposure on cancer prevalence. If the U.S. prevalence rates
for skin cancer (National Center for Health Statistics or NCHS} used by
the authors for comparison were used to calculate the expected number of
cases, it would have required as much as a 2.9-fold increase over the
expected in order to detect a P < 0.05 difference (statistical power =
80% probability) (GAG, 1982).
Blacks experience very little skin cancer, and blacks comprised 46.5%
of the total plant population. Therefore, the comparison of a skin cancer
rate from the NCHS prevalence statistics to the observed skin cancer rate
in the study population would be a biased comparison that would underesti-
mate a skin cancer risk if it was present (CAG, 1982) ..
Although a cross-sectionally-designed study will assess current pro-
blems at the treatment plants, workers who have skin cancer may have left
the plants. The study population did indicate significant (P < 0.05)
increases in benign growths, a condition which sometimes is a precancerous
lesion. There was also a significant elevation of pseudofolliculitis in
the study population. These eruptions were located in areas where clothing
rubbed against the skin rather than in sun-exposed areas, which suggests
that this effect is a result of the preservative and that workers are
being exposed to creosote through their clothing (CAG, 1982).
Cancer latency, or the time from carcinogen exposure to cancer development,
may be as long as 25 years. Seventy percent of those examined in the
Tabershaw Study had worked 10 years or less in the treatment plants. Only
13% of the study population had between 10 and 15 years of exposure, while
6% of those in the study group .had worked between 15 and 20 years in the
plants. The majority of workers that were exaxmined by Tabershaw Occupational
Medicine Associates had probably not been at the treatment plants long enough
to develop cancer, if exposure to creosote is, in fact, a risk factor for
skin or other types of cancer (CAG, 1982 and Rispin, June 14, 1984).
There is no indication in this study whether those that were examined
were actually exposed to creosote and coal tar. It is expected that some
of those examined were office workers and would have had little contact
with the preservative. The inclusion of such persons in the study popula-
tion would have reduced the prevalence rates of skin cancer or precancerous
lesions if creosote and coal tar were increasing the risk of skin cancer
among treatment workers (CAG, 1982).
Comment Issue #11: Creosote and lung cancer among roofers
The AWPI (36A) states that the excess lung cancer mortality among
roofers in the Hammond et al. (1976) study is probably attributable
to smoking rather than to exposure to coal tar and asphalt. The AWPI
(36A) also suggests that because only five skin cancer deaths were recorded
among the 5,939 roofing workers, the incidence rates of skin cancer among
the roofers and the general population are not significantly diferent.
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Agency Response:
Sterling and Weinham (1976) noted that, based on the National Center for
Health Statistics Health Interview Survey (HIS) of 1970, 72% of roofers
and slaters are reported to smoke while only 45% of males aged 45 to 61 are
reported to smoke. The number of roofers and slaters surveyed was only 36.
While smoking may be more common among roofers and slaters than in the general
population, the results from such a small sample size would not necessarily
invalidate the conclusion of Hammond et al. (Rispin, June 14, 1984).
Also, the number of skin cancer deaths among the roofers was more than
expected, which is contrary to what the AWPI (36A) has implied. Among roofers
who belonged to the union for 9-19 and 20 or more years the mortality ratios
for skin cancer were 4.65 and 4.00, respectively. These ratios are based on
small numbers, however, and are not statistically significant (GAG, 1982).
Comment Issue #12: Creosote animal oncogen studies
The AWPI (36A) states that EPA persists in maintaining in the PD 2/3
that creosote and many component chemicals have been well characterized
as carcinogens in laboratory animal studies (PD 2/3, p. 85). The AWPI
(36A) reiterates its PD 1 rebuttal criticism of EPA's animal oncogen
studies and maintains that these studies are indeterminate, inapplicable
to humans and irrelevant in light of overwhelming modern epidemiological
evidence.
Agency Response:
As stated in the PD 1, the animal studies presented show tumor production
following dermal and inhalation exposure to coal tar (Fed. Register, 43 FR
48154, Oct. 1978) . The Agency has also presented in the PD 2/3 numerous
laboratory animal studies which demonstrate an unequivocal correlation between
creosote exposure and animal carcinogenesis. The Agency has cited various
human case reports implicating creosote as a human carcinogen. Moreover,
various chemical components of creosote such as benzo(a)pyrene, benzo(a)-
anthrancene, quinoline, and many others are known carcinogens (PD 2/3).
These data provide an overwhelming qualitative assessment of the inherent
hazard associated with creosote exposures (CAG, 1982).
For an analysis of the creosote epidemiological studies see Comment Issues
#6 through #11.
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Comment Issue #13: Treatment plant creosote/coal tar inhalation exposure and
risk
The AWPI (36A) claims that there are certain inaccuracies regarding
the Agency's determination of potential inhalation exposure for creosote/coal
tar pressure treatment workers (PD 2/3, p. 68-74). The AWPI (36A) reiterates
the EPA's statements in the PD 2/3 that insufficient data exist to accurately
evaluate creosote inhalation exposure. AWPI (36A) states the probable range
of ambient air concentration of creosote particulates is estimated by the
EPA as 45-95 ug/m3.
The AWPI (36A) states that the inhalation monitoring studies, cited in
Volume III of AWPI's rebuttal to PD 1, establish anticipated levels of specific
constituents in the treatment plant workers* breathing zone. Based on data
AWPI USA) resubmitted (AWPI PD 1 Rebuttal; Volume III, Section 2) and additional
data (AWPI, 1981 (36A), Table II), the concentration of total particles in
the breathing zone range from 20-9,000 ug/ra3.
In response to the Agency's PD 2/3 contention that sufficient data are
unavailable to identify specific constituents in airborne particulates in
treatment plant workers' breathing zone, the AWPI (36A) states that only
benzo(a)pyrene is generally recognized as carcinogenic, and, if fluorene,
whose vapor pressure is higher than benzo(a)pyrene_V, is difficult to detect
in wood treatment atmospheres, benzo(a)pyrene would be undetectable with
available air monitoring techniques-
Agency Response:
The Agency agrees that the submitted data (36A) indicate a higher range
of variability and accepts the higher estimate of 20-9,000 ug/m3 (Day,
March, 1982; Day, December, 1983).
Although the benzene-soluble components of creosote contain many different
compounds of variable concentrations which preclude an accurate risk estima-
tion, the positive results of the animal oncogenicity studies, listed in
the PD 2/3, (page 40, table II, B-1) cannot be disregarded and provide
an adequate basis for a regulatory decision (CAG, 1982).
_1/ Estimated vapor pressure of benzo(a)pyrene and fluorene at ambient
temperature equal .3 x 10~6 mm and 1 x 10~2 nun, respectively (AWPI, 1981)
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Comment Issue #14: Creosote dermal exposure
The AWPI (36A) contends that the NIOSH study of roofers (NIOSH, 1977)
(cited in the PD 2/3), which mentions skin sensitization, burns, conjunctivitis
and eye irritation as evidence of occupational dermal exposure to creosote/
coal tar, has no relation to exposure of creosote/coal tar wood treating
plant workers because the materials to which they are exposed are different.
Roofers are exposed to pitch and asphalt while wood treatment plant workers
are exposed to creosote/coal tar.
Agency Response:
Creosote, pitch and asphalt are a mixture of various hydrocarbons.
Creosote is the distillation product of coal tar {NIOSH, 1983); pitch a
distillation residue of organic materials, especially tars; and asphalt,
a residue in petroleum or coal tar refining. While the similarity of the
derivation of these three substances suggests that roofer exposure to
pitch and asphalt is similar to treatment plant worker exposure, the
Agency is not using this study as support for its regulatory decisions.
Comment Issue #15: Creosote exposure due to railroad crosstie and
poles groundline application
The Association of American Railroads (34) contends that no long-term
carcinogenic effects from creosote usage have been recorded in the railroad
industry; the machinery employed reduces exposure to a minimum.
Osmose (41) expects that exposure due to poles-groundline treatment is
minimal since the actual application process is a small percentage of total
inspection and treatment time.
Agency Response:
The Agency agrees that because railroad crosstie wood treatment is by
remote control, such equipment would reduce exposure, when compared
to applying creosote by other methods such as spray or brush-on. However,
the applicator may also be involved in loading, maintenance and cleaning,
and mixing and/or diluting, which provides an opportunity for exposure.
The Agency has concluded, therefore, that railroad crosstie applicators
must be certified or work under the direct supervision of a certified
applicator. Protective clothing will also be required for applicators,
as described in Section VI.E of this document.
Once dermal contamination occurs during wood treatment processes such
as poles-groundline application, the exposure persists until the contaminated
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skin surfaces have either absorbed the chemical or been washed free of
the chemical. Therefore, the Agency is concerned about the actual exposure
which could occur during poles-groundline application and not the length
of treatment time.
2* Pentachlorophenol
Comment Issue t1: Pentachlorophenol teratogenicity - evidence of reproductive
effects
•Hie Dow Chemical Company (32) questions the Agency's use of data
concerning "decreased litter size" (Pahrig et al., 1978) to provide
supporting information on pentachlorophenol reproductive effects when
the Agency has also concluded this observation (on litter size) should only
be considered as an ancillary comment.
The Dow Chemical Company (32) also states that the degree of dilation
of renal pelvis observed in fetuses treated with HxCDD (Schwetz et al., 1973)
was consistent with retardation of kidney development (a reversible effect).
Thus, HxCDD should not be considered teratogenic on the basis of its effect
on the developing kidney (The Dow Chemical Company, 32).
Agency Response:
The Agency maintains that taking the Schwetz et al. (1973) study into
account, regardless of Fahrig et al. (1978), establishes the terato-
genicity of HxCDD. That is, the reversibility of dilated renal pelvis
can be properly ascertained only upon postnatal examination, particularly
for hydronephrosis, an irreversible-effect with which dilated renal pelvis
may be associated. Postnatal data were not included in the Schwetz et al.
(1973) study. However, production of cleft palate (47% at 100 ug/kg/day)
is evidence of HxCDD teratogenicity (Van Ormer, 1982a).
The Agency reiterates the comment that "decreased litter size" is an
ancillary issue and has not used this data in developing the current
regulatory position.
Comment Issue #2: Pentachlorophenol teratogenicity/fetoxicity - choice
of proper NOEL
The Dow Chemical Company (32), the American Wood Preservers Institute
(AWPI) (36B) and The National Forest Products Association (NPFA) (36B) contend
that EPA1s reduction of the pentachlorophenol NOEL from 5.8 rag/kg/day (Schwetz
et al., 1974) to 3.0 mg/kg/day (Schwetz et al., 1978} is unjustified. These
commenters state that the data used to establish this fetotoxicity/teratogenicity
NOEL utilized pentachlorophenol which varied in purity from one set of animal
data to the other; they argued that data based on "purified" pentachlorophenol
are not relevant to regulation of commercial pentachlorophenol. Although
Schwetz et al. (1978) indicate a NOEL between the two doses of 3.0 and
30.0 which were tested, the Agency has identified 3.0 as the proper NOEL.
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Agency Response:
The Agency considers all relevant available data. Purified pentachloro-
phenol data are not irrelevant to the regulation of commercial pentachlorophenol.
Because the Agency is not aware of any teratogenicity study conducted according
to Agency guidelines on any current commercial pentachlorophenol, such data
provide the only basis for regulation.
The provisional NOEL value of 3.0 mg/lzq/day was chosen from a one-
generation reproduction study (Schwetz et al., 1978), which reports a trend
toward decreased neonatal weight at 3.0 mg/kg/day of purified pentachlorophenol,
which is consistent with the effects produced by the 30.0 mg/kg/day dosage,
but is not statistically significant at 3.0 mg/kg/day (Van Ormer, 1982b). A
thorough discussion of the Agency's rationale for the selection of a NOEL
value of 3.0 mg/kg/day is presented in the PD 2/3 (pages 347-353).
The teratogenicity study of Schwetz et al. (1974) is inadequate to
establish a fetotoxicity NOEL for either the commercial or purified penta-
chlorophenol. There was a statistically significant increase in skull bone
delayed ossification at the lowest tested dose of purified pentachlorophenol
(5 mg/kg/day). The study also lists increased incidence of delayed skull
ossification at the low dose (commercial grade pentachlorophenol, 5.8 mg/kg/
day); lumbar spurs (commercial and purified pentachlorophenol at 5.8 and 5.0
mg/kg/day, respectively); and anomalous sternebrae (purified pentachloro-
phenol, 5.0 mg/kg/dayJ. Also, the commercial grade pentachlorophenol pro-
duced some exencephaly (dose and incidence not listed) which was reported in
a public meeting as not significant (Van Ormer, 1982a).
Comment Issue #3: Pentachlorophenol - concern for the fetus in uterp
The Dow Chemical Company (32) disagrees with the Agency's PD 2/3 p. 257
contention that, from a regulatory standpoint, a fetotoxic effect may repre-
sent as unacceptable a risk to the human fetus as would a teratogenic effect.
Agency Response:
The Dow Chemical Company's (32) claim concerning the difference
between reversible (fetotoxic) and irreversible (teratogenic) effects
would mandate a difference in the required margin of safety for the two
effects, and implies that fetotoxic effects have been shown to be reversible
based on adequate postnatal observation. The claim also implies that data
exist on the relative variability of the thresholds for these two types of
effects. The Agency is not aware of data on pentachlorophenol which show
either the reversibility c.c the variability of the measured fetotoxic effects,
which (in any case) could appear in another species as a different type of
functional or behavioral deficit, e.g., retardation. Above all, the Agency
has concern for health of the embryo and fetus in utero, as well as concern
that no reversible or irreversible effects manifest after birth (Van Ormer,
1982a). Therefore, a fetotoxic effect may represent as unacceptable a risk
to the human fetus as would a teratogenic effect.
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Comment Issue #4: Pentachlorophenol fetotoxicity/teratogenicity margin
of safety
The AWPI (36B and 36P), the NFPA (36B and 36F) and the Dow Chemical
Company (32) state that the EPA's requirement for a fetotoxic margin of
safety (MOS) of 400 is unsupported and excessive. They argue that there
are data available on the reversible nature of the fetotoxic effects of
pentachlorophenol; they claim that it is highly unlikely that any fetotoxic
effects would be evidenced if permissible exposures were limited to one-tenth
of the NOEL. Without submitting pentachlorophenol postnatal data, the commentors
reiterate the claim that fetotoxic effects such as delayed ossification
found in Schewtz et al. (1974) can be reversible. An MOS as low as 100 is
suggested as appropriate.
Agency Response:
The assignment of an acceptable MOS is largely a risk/benefit, question.
A fetotoxic effect such as delayed skull ossification (reversible or
irreversible) is merely the indication of an effect in one species (A) which
may extrapolate in another species (B) into another type of effect, such as
retardation. In the field of teratogenicity, there is a relative lack of
ability to make qualitative extrapolations. Since the type of response in
species (B) cannot easily be predicted, regulation must be based upon the
absence of fetotoxic effects in the species in question (A) by applying an
MOS which reflects this lack of qualitative correspondence between species,
(i.e., by applying a margin of safety which includes components for both
qualitative and quantitative uncertainty.) The Agency is unaware of any
pentachlorophenol data bearing on the reversibility of effects such as
delayed ossification or dilated renal pelvis (Van Ormer, 1982a).
The Agency did not require an MOS of 400 for fetotoxic effects
in the PD 2/3 for pentachlorophenol. The measures proposed in the PD 2/3 to
reduce the oncogenic risk from pentachlorophenol to an Agency-acceptable
level would provide "margins of safety greater than 400 for fetotoxicity."
The assignment of an acceptable MOS must be determined on a case by case,
use by use basis by weighing risks and benefits.
Comment Issue #5s Pentachlorophenol bi©accumulation
Friends of the Earth (FOE) (55, 64, 70) contends that there is widespread
pentachlorophenol exposure and subsequent blood, urine, semen and sperm
cell contamination of pentachlorophenol in humans. FOE states that eighty-six
percent of Americans have pentachlorophenol contaminated urine and that
pentachlorophenol has been found in the semen and sperm cell of the average
male and bioaccumulates in the sperm cell at a level 20-40 times higher
than semen. Based on Dougherty et al. (1980), FOE contends "there appeared
to be good reason [from the data] to believe that penta causes a reduction
in sperm counts." Moreover, FOE further contends that there has been a
trend showing decreased sperm counts in American males over the years.
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Agency Response:
The Agency has carefully reviewed the study by Dougherty et al. (1980)
and finds that it cannot concur with the report's analysis due to uncertain-
ties in interpretation. Dougherty et al. (1980) compares the sperm densities
to toxicant residues (in the participants' semen and sperm cells) obtained
in a negative chemical ionization screening procedure, for a group of 132
college-aged males. Residues were obtained for a number of unknown polychlor-
inated substances, as well as polychlorophenols, polychlorobiphenyls, hexa-
chlorobenzene, DDT metabolites, and polychloronaphthalenes. Multiple linear
regression^/ was used in an attempt to correlate toxicants uncovered in the
negative chemical ionization screening to sperm density. Among the nine
tabulated toxicants, the polychlorobiphenyls uniformly gave negative correla-
tions with sperm densities. The overall resultant correlation coefficient
for all toxicants was reported as 0.52, which would indicate, according to
the report, that the toxicants account for roughly 27 percent of the variance
in sperm density distribution. Therefore, there does appear to be an associ-
ation between sperm density and some of the polychlorinated toxicant residues
(Heath, March 16, 1982).
However, the analysis presents uncertainties in interpretation: 1)
concentrations of toxicants were not reported, 2) original, individual data
were not presented, so that the nature of the distribution and the possibility
of extreme values can not be determined, 3) tabulated statistics are not
adequately specified as referring to individual or collective toxicants,
4) several statistical assumptions are made (e.g., that no association exists
among any of the variables being used in the analysis to explain variation
in sperm density) and 5) the contribution of each toxicant to sperm density
variation can depend upon the ordering of these variables in the regression
equation (Heath, March 16, 1982).
From the format of data presentation and description of data in
the study, there is no apparent association (within reasonable significance,
stated in the study as 0.01) between the sperm density and the occurrence of
pentachlorophenol in study subjects' seminal fluid (Dougherty et al.,
1979; Table 2) (Van Ormer, Sept. 22, 1983).
The Agency disagrees with FOE's contention that sperm density data
demonstrate a density decrease in the general population during the past 30
years. There are no data on sperm densities in a random sample of the general
population. Knowledge of sperm densities is based almost entirely on clinical
data for males from infertile marriages and fertile males prior to vasectomy.
There are limited data for volunteer groups as in Dougherty et al. (1980),
but such groups are not random samples from the general population (Heath,
1983).
Comparisons of the arithmetic means of sperm density distributions can
\J Regression analysis is a statistical procedure for expressing in equation
form, (Y = a + b X, + bX2«..bX) the relationship between a dependent variable
(Y or sperm density) and independent variables (X-j X2....Xn or (the toxicant
concentrations) associated with the dependent variable (Heath, March 16, 1984),
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be misleading, as pointed out by MacLeod and Wang (1979). Because such
distributions are typically skewed to the right, occasional especially high
densities can increase the mean considerably, whereas the median is not
affected by such values and should be included in such comparisons. A more
meaningful approach compares the frequencies (percentages) of counts by sperm
density categories, usually in increments of 20 million per ml (MacLeod and
Wang, 1979). Densities below 20 million per ml are considered to constitute
oligosperinia and are of particular importance (Heath, 1983).
Review of the first two sperm density references used by Dougherty et al.
(1980) (Macombre et al., 1929 and Hotchkiss et al., 1983) revealed conditions
that properly negate the use of either reference to demonstrate a secular
decrease in density, the Macrombre mean density and graphic presentations
are reportedly based on 271 donors? however, the graphic presentation, intended
to portray a frequency distribution of sperm densities, is based on only 223
donors. There is no explanation for this discrepancy, and there are no
tabular data to determine the 48 excluded values. The data of Hotchkiss et
al. are for 200 fertile males comprising two sets of 100 each. Data for one
set (Group 1) were provided by the New York University College of Medicine,
Department of Obstetrics and Gynecology; data for the other set (Group 2)
were from the New York Hospital, Cornell University Medical College. Compari-
son of the frequency distributions for the two groups, and of the medians
calculated from these distributions, indicates that the two sets of data are
statistically different (P<0.05). The estimated median density for Group I
is 69 million per ml and that for Group II is 106 million per ml. The Group
I median is well within the range of medians of various post-1950 data sets
(Heath, 1983).
Probably the most comprehensive data for examining the hypothesis of a
general decrease in sperm density during the past 30 years are provided by
MacLeod in his data on 10,000 males from infertile marriages. His median
value for 1,000 such males, published in 1951 (MacLeod and Gold), was 74
million/ml, representing specimens collected during a 1-year period in the
late 1940's. Macleod's median values for nine sets of 1,000 specimens each,
collected sequentially from 1966 to 1977, are 77, 74, 74, 74, 72, 74, 85, 88
and 71 million per ml (Macleod, 1979). Indeed, there is no suggestion of a
secular trend during the past 30 years in the total MacLeod data (Heath,
1983).
James (1980) evaluated sperm density data from 17 papers published from
1934 to 1979 to demonstrate a secular reduction in reported counts of fertile
men. He fails to consider, however, that MacLeod's counts from 1969-1977 of
7,000 males from infertile marriages are significantly higher (P<0.05) than
counts of fertile men, by five authors, used in the James analysis (Heath,
1983).
Review of more than 20 sets of data from the literature spanning the
past 40 years demonstrates no clear substantiation of an overall decrease in
sperm density. MacLeod and Wang (1979) also contend that such a reduction
has not been demonstrated (Heath, 1983).
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Comment Issue #6: Pentachlorophenol oncogenicity and dioxin contamination
. The AWPI (36B) and title NFPA (36B) claim the EPA's contention that
technical pentachlorophenol presents an oncogenic risk due to hexachlorodi-
benzo-p-dioxin (HxCDD) and hexachlorobenzene (HCB) is incorrect, the AWPI
(36B, 78) and the NFPA (36B) remark that pentachlorophenol does not contain
the 2,3,7,8-TCDD dioxin, most frequently associated with adverse human
health effects; and pentachlorophenol's toxic effects are manifested before
any such evidence from HxCDD's presence, so that regulatory measures for
pentachlorophenol will prevent HxCDD exposure.
AWPI (36B) further contends that the oncogenic risk analysis should
be adjusted for the Science Advisory Board's (SAB)(1978) report that 25%
of total HxCDD is comprised of isomers most likely to promote tumors.
AWPI (36B) and NFPA (36B) comment that typically the HxCDD content in technical
pentachlorophenol is well below the 15 ppm listed in the PD 2/3.
The AWPI (36B) and the NFPA (36B) also contend that the EPA's
use of the one-hit model to determine the carcinogenicity of HxCDD based
on the National Cancer Institute (NCI) gavage assay (1980) is inappropriate
because HxCDD is a "promoter" rather than an "initiator" of cancer. They
further comment that Schwetz et al. (1978) and other investigators, including
Kimbrough and Linder (1978), indicate pentachlorophenol is not an oncogen;
any oncogenic potential of HxCDD is through tumor promotion, not initiation.
Thus, any HxCDD-related carcinogenic activity would operate through a dose-
response mechanism, i.e., the greater the toxic dose above the no-effect
level, the greater the promotion response. In addition, they claim the
absence of positive epidemiological data, together with negative animal
test results, support the "promoter" conclusion (AWPI, 36B and NFPA, 36B).
Agency Response:
The regulation of both pentachlorophenol and HxCDD is necessary because
both pentachlorophenol and HxCDD exposure can cause acute and chronic toxic
effects (PD2/3, pp. 247-367). The oncogenic risks associated with HxCDD
exposure have been estimated in this PD 4 (Appendix B) to be of the order
of magnitude of 10~3 based on 15 ppm HxCDD in technical pentachlorophenol
even with the protective measures required. Because the required protective
measures (e.g., gloves, protective clothing, respirators, etc.) which reduce
the acute toxicity and potential teratogenic/fetotoxic risks from pentachloro-
phenol exposure do not reduce the potential oncogenic risk from long-term
exposure to HxCDD to levels where benefits of use outweigh risks, this
contaminant must be regulated concurrently and independently. The Agency is
requiring an immediate upper limit of 15 ppm HxCDD, a level cited by Rakshpal
(1980), SAB (1978), and AWPI (1979) as representative in technical pentachloro-
phenol, and requiring that this contaminant be further reduced to an upper
limit of 1 ppm. The potential oncogenic risk associated with pentachlorophenol
results from exposure to the contaminant HxCDD and was discussed in the PD
2/3 (pp. 347-363).
Although HCB has also be shown to be an oncogen in laboratory animals
82
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(PD 2/3, p. 345) the potential risks from the HCB contaminant in technical
pentachlorophenol are negligible compared to those of HxCDD. The quantitative
oncogenic risk (PD 4) from pentachlorohenol is based on the HxCDD contaminant
alone, because the HCB slope (potency) is significantly lower than the HxCDD
slope, such that including the HCB-related risk estimate would have only a
negligible effect on the total risk. This was also true for the risk estimates
calculated in the PD 2/3 (p. 363).
Buser and Bosshardt (1976) report that the forms of dioxins most prevalent
in commercial pentachlorophenol are hexa-, hepta-, and octachlorodibenzo-p-
dioxins (HxCDD, HpCDD and OCDD, respectively). A small amount of tetra-
chlorodibenzo-p-dioxin (TCDD) has also been found in pentachlorophenol
(Buser and Bosshardt, 1976) but proved not to be the extremely toxic
2,3,7,8-isomer. Because the principle contaminants of pentachlorophenol are
the higher order dioxins, the oncogenic potential of pentachlorophenol has
been estimated using information which includes the NCI bioassay of 1,2,3,6,7,8-
and 1,2,3, 7,8,9-hexachlorodibenzo-p-dioxins (Litt, May 24, 1982)*
Although it may be that only 25% of the isomers of HxCDD have been
shown to cause tumors in laboratory animals, the Agency assumes, for the
purpose of developing regulations, that there may be a structure-function
relationship for isomers of the same chemicals and takes a conservative
regulatory position in the absence of data to the contrary. The HxCDD oncogenic
risk estimate therefore reflects this position; i.e., that 100% of the isomers
of HxCDD which are contaminants of pentachlorophenol and sodium pentachloro-
phenate are potential human carcinogens.
Regarding AWPI's (36B) comment that the HxCDD content is typically
below 15 ppm, the Agency received data from several manufactures which
indicated that the HxCDD concentration in technical pentachlorphenol could
be as high as 23 ppm but was usually approximately 15 ppm. The Agency
chose 15 ppm as representative level for purposes of risk estimation in the
PD2/3 as well as this position document (PD4). The Agency has received no
data on HxCDD to the contrary.
The issue of whether the isomers of HxCDD are promoters rather than
initiators is not germane to model fitting. Seven low-dose extrapolation
models were used and the one with the best data fit is the multistage model
(Litt, May 24, 1982). The multi-stage model has proven to be a more appropriate
choice based on mathematical, theoretical and biological grounds (Appendix
to Water Quality Criteria Document; November 28, 1980 [45 FR 79318]). Further
discussion of the multi-stage model is provided in Section II.A.2 of this
document.
The Agency agrees that pentachlorophenol itself has not been shown to be
oncogenic in laboratory animals (PD2/3 p. 344), but this does not negate
the findings by NCI (1980) that HxCDD, a contaminant in pentachlorophenol,
has been shown to cause tumors in laboratory animals. It is the Agency's
position that exposure to pentachlorophenol containing HxCDD presents a
potential oncogenic risk to humans.
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Epidemiological data submitted by AWPI (#81:30000/280 indicated no
increased deaths or cases of cancer occurred from exposure to pentachlorophenol
(or inorganic arsenic) in workers at a wood-treating plant in Hawaii. The
Agency reviewed these data and concluded the study was inadequate to assess
whether a cancer risk existed among the wood treaters (Gibb, 1983). Section
V.A.2 (Comment #10) of this PD4 discusses this evaluation more fully.
In the absence of adequate epidemiological data, the Agency continues to
assume that pentachlorophenol containing HxCDD poses a potential unreasonable
adverse effect. Animal data exist which allow the quantitation of risks and
provide an adequate basis for regulation.
A recent reevaluation of the NCI (1980) study showed liver lesions from
HxCDD dosed rats confirms that HxCDD is oncogenic in laboratory animals.
When compared to historical controls, neoplasia incidence is increased among
female rats exposed to the highest dose [NTP (Hildebrant), 1983]. There is
a clear indication that liver neoplasia in the female rats was associated
with HxCDD exposure (Moore, Nov. 4, 1983). Therefore, based on these
findings, the Agency has concluded that technical pentachlorophenol presents
a potential oncogenic risk to humans due to the HxCDD that is present.
See Section II.A of this FD 4 for a more detailed discussion.
Comment Issue #7: Pentachlorophenol inhalation exposure due to interior
use of treated wood
Several aspects of the EPA's exposure analysis for interior use of
treated wood are of concern to the AWPI (36B) and the NFPA (36B). These
commenters reiterate from the PD 1, that the Agency's assumption of 100%
absorption of pentachlorophenol through the lungs is unsubstantiated and
based on Thomson and Pavia (1974) and Patty (1978), only 70% of inhaled
particles of a 5 micron diameter are retained in the human lung six hours
after a single exposure.
The AWPI (36B) and the NFPA (36B) also contend that the Agency's estimated
30 ug/m^ pentachlorophenol airborne concentration due to interior use of
treated wood is an extreme worst case situation. Whitney and Gearhart (1979)
and Krause and Englert (1980) have observed concentrations that are one to
two orders of magnitude less.
The AWPI (36B) and the NFPA (36B) state that the EPA overlooked the
effectiveness of sealants to reduce pentachlorophenol volatilization,
including studies (e.g., Thompson, et al., 1979; Ingram, McGinnis and
Ferst, 1980), which investigated volatilization reduction for hand-dipped
and commercially-treated wood.
The AWPI (36B) and the NFPA (36B) comment that if the Agency were to use
70% absorption and maintain the worst case air concentration estimate of 30
ug/m3, the MOS for pentachlorophenol would be over 400, an Agency-acceptable
level for toxic effects. Based on these statistics, in conjunction with
residence-use being less prevalent than storage and farm buildings use, of
84
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pentachlorophenol, the proposed severe restrictions are unjustified (AWPI,
36B and NFPA, 36B).
Agency Response:
One hundred percent absorption by the inhalation route does not mean
that 100 percent of inhaled material is actually absorbed by the body*
Biologically, this is rarely true. The Agency assumed that 100% of inhaled
airborne pentachlorophenol was absorbed in determining the pentachlorophenol
exposure analysis. This practice is consistent with the Agency's policy
of using worst case situations for risk assessments. Toxicologically, an
oral dose and an inhalation dose are considered to be equal or totally
absorbed by the body for regulatory risk estimations. Determination of the
actual absorption of materials by the body can only be assessed experimentally
for each specific exposure situation {Zendzian, 1982).
Thomson and Pavia (1974) present results of an experiment in which
individuals inhaled "several" 750 milliliter breaths of an aerosol of 5 micron
diameter polystyrene particles. It is unclear as to how these experimental
conditions relate to pentachlorophenol inhalation exposure. Pentachlorophenol
may be in the air as a spray, an aerosol, a vapor, or any combination,
which may be inhaled in a single breath, several breaths or continuously.
Unlike the solid polystyrene particle, pentachlorophenol is a liquid which
can dissolve in the tissue lining the airways and be directly absorbed
(Zendzian, 1982).
Data submitted by the AWPI (36B) and the NFPA (36B) (Ingrim and McGinnis,
1980) show that volatilization of pentachlorophenol from treated wood in
an enclosed area produces concentrations which vary from the Agency's
original estimate. The Agency accepts the AWPI (36B) and the NFPA (36B)
comments concerning the effectiveness of sealers in reducing the indoor air
concentration of pentachlorophenol from commercially dipped or pressure-
treated wood and aged pressure-treated wood (see Section VII.A.4). Freshly
treated home application of pentachlorophenol produces concentrations of
34.0-140.0 ug/m3, industrially dipped pentachlorophenol-treated wood
produces concentrations of 4.8-20.4 ug/m3 while older structures containing
pentachlorophenol-treated wood produces concentrations of 0.5-10.0 ug/m3
(Day, May 19, 1983). The Agency has evaluated these data and has used these
levels in the Agency's pentachlorophenol exposure assessment. Refer to
Appendix C for the revised pentachlorophenol exposure analysis.
The assignment of an acceptable MOS is largely a risk benefit question
and must be determined for each exposure situation. See Comment Issue #4
for further discussion.
Comment Issue #8: Pentachlorophenol inhalation and dermal exposure
due to bag emptying and mixing
The AWPI (36b) and the NFPA (36B) state that the Agency's exposure
analysis for manual mixing of pentachlorophenol does not support the
proposed closed mixing system requirement. The EPA has assumed four hours
daily exposure for opening and emptying prilled and flaked pentachlorophenol
85
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while, in most cases, a person would not spend more than two hours a day,
twice a week at this operation (AWPI, 36B and NFPA, 36B).
The AWPI (36B) further comments that the Agency has used a theoretical
maximum exposure projection from powdered pentachlorophenol to calculate
inhalation and dermal exposures for mixing while prilled, flaked and granular
formulations are used. Using an AWPI/NFPA proposed eight-hour threshold
limit value (TLV) of 0.5 mg/m3 for pentachlorophenol airborne exposure
[based on OSHA's established permissible exposure limit (PEL) for occupational
exposure to pentachlorophenol of 0.5 mg/m3], a 70% inhalation absorption
(based on Thompson and Pavia, 1974; Patty, 1978), and a two-hour mixing
time (see paragraph above), inhalation exposure equals 48.59 ug/kg/day.
Dermal exposure calculated with protective clothing equals 6.75 ug/kg/day;
the MQS for total exposure (based on a total of 55.34 ug/kg/day) is 105.
The AWPI (36B) and NFPA (36B) also contend that the Agency has failed
to take protective gear into account when calculating the risks associated
with bag emptying and mixing.
Agency Response:
The Agency agrees that four hours per day for 5 days a week is
excessive bag opening/emptying and mixing time. The commenters' values
(2 hrs/day for 2 days/wk) were used in revising the inhalation and dermal
exposure estimates for bag emptying and mixing of pentachlorophenol in
treatment plants (Day, March 26, 1982).
The Agency used the maximum inhalation and dermal exposure projection
for pentachlorophenol for mixing powdered, prilled, and flaked formulations,
because there are no other data available. The Agency is continuing to
rely on these data to estimate upper limit exposure for mixing and empting
dry formulations of pentachlorophenol (Day, May 19, 1982). Using the 40 to
400 mg/hr assumption to estimate dermal exposure (PD 2/3, p. 319) for
sodium pentachlorophenate should be a more accurate reflection since this
chemical is formulated as a powder. The 40 to 400 mg/hr exposure was based
on powdered Guthion and powdered fertilizer, respectively.
Inhalation absorption will also remain at 100% (see Comment Issue #7 for
explanation). The Agency does not believe that the TLV concept is adequate
for pentachlorophenol exposure estimation and will require a "phase in" of
closed systems over the next three years for these mixing operations.
For a more detailed discussion of this issue, see Section VI.C.3 of this
document.
Comment Issue #9: Pentachlorophenol dermal exposure v
The AWPI (36B) and the NFPA (36B) contead that because the PD 2/3
states that NCI's dermal bioassay (NCI, 1980) was negative, the Agency
should discount all dermal exposure for all use situations (e.g., handling
treated wood as well as applying pentachlorophenol) when calculating potential
pentachlorophenol carcinogenic risk. The AWPI (36B) and the NFPA (36B)
further contend that the Agency recognizes that HxCDD volatilization is
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unlikely (PD 2/3, p. 338, Table II.D.14) and coupled with the lack of
dermal exposure, pentachlorophenol risk would be zero from treated wood
end-uses.
The Association of American Railroads (34) claims application equipment
for crosstie treatment reduces occupational exposure to a minimum; hence,
regulation is unnecessary.
Agency Response:
The Agency has concluded that protective clothing is necessary for those
applying pentachlorophenol or handling pentachlorophenol-treated wood. That
is, although the NCI dermal bioassay (NCI, 1980) is negative, the dermal
absorptions of pentachlorophenol including HxCDD in solvent and sodium
pentachlorophenate during the treatment process are estimated by the Agency
to be 50% and 1%, respectively (Section II.B). After wood is treated and
shipped for use, the solvent is assumed to have volatilized and dermal
absorption is reduced to 1%. Likewise, if pentachlorophenol-treated
wood becomes wet from rainwater, perspiration or the like, dermal absorption
is estimated as 1% (Day, Oct. 27, 1983).
The Agency agrees that an applicator using the automated railroad
crosstie equipment would have a decreased opportunity for exposure since
the pentachlorophenol applied is by remote control. However, the applicator
may also be involved with mixing, diluting and/or loading the wood preservatives
into the equipment as well as cleaning and maintaining the machinery.
Also, the wind may carry aerosolized or windborne droplets resulting in
applicator exposure. The Agency has concluded, therefore, that applicators
must be certified or work under the direct supervision of a certified
applicator so that through proper training and education the potential for
exposure would be reduced. Protective clothing will also be required
during application as outlined in Section VI.E.5 (Home and Farm Use/Protective
Clothing).
Comment Issue f10: Pentachlorophenol epidemiology study
AWPI (#81) submitted a study by Gilbert et al. (1981) on the effects of
chemical preservatives on the health of wood-treating workers in Hawaii
exposed to pentachlorophenol and arsenic. AWPI (81) commented that the
study concluded that no excess morbidity or mortality that can be attributed
to exposure to wood preservative chemicals.
Agency Response:
The study consisted of two parts: a cohort-comparison study and a
historical perspective study. The Agency has concluded that the cohort-
comparison study which consisted primarily of current workers, was an
inappropriate approach to assessing whether a cancer risk existed among
wood treaters. There is a good likelihood that persons who develop cancer
while working have either died or left employment. In the historical
perspective part of the study, the sample size was too small and the follow-
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up was probably not long enough to have detected an excess risk of cancer.
Therefore, because of these limitations, no conclusion can be drawn from
this study regarding the potential cancer risks for wood treaters (Gibb,
1983).
3. Inorganic Arsenicals
Comment Issue #1s Interconversion of arsenate to arsenite
The American Wood Preservers Institute (AWPI) (36C) state that the
Agency's PD 1 used studies on arsenite (trivalent inorganic arsenic) to
reach conclusions on oncogenic, mutagenic and teratogenic effects of arsenate
(pentavalent inorganic arsenic) present in wood preservatives, although the
PD 2/3 (p. 102) states that reduction of arsenate to arsenite in vivo has not
been demonstrated with sufficient experimental evidence. Koppers Company,
Inc. (72 & 85) also states that a recent review (Woolson, 1983) of studies
on arsenic interconversion, including Vahter (undated) and Yamauchi and
Yamamura (1979) indicates that arsenate has not been shown to be reduced
to arsenite in vivo in man or animal. Arsenite is neither a metabolite of
arsenate as defined by 40 C.F.R, 162.3(2) nor is it a "degradation product"
as defined by 40 C.F.R. 162.3(1) {AWPI, 36C). AWPI (36C) states that
arsenite is oxidized to arsenate in the environment.
The SAW? (53) states that arsenate is reduced to arsenite only under
certain conditions. Humans do not reduce arsenate to arsenite; arsenite is
found in urine only after an overload, which is not the usual exposure
situation. The SAWP (53) further comments that if one acknowledges the EPA
contention that arsenite and arsenate are present in biological systems in
equilibrium at any given time, then the risk factor should be adjusted to
take into account the small amount of arsenite present.
According to the AWPI (36C), the EPA has found no convincing evidence
in support of in vivo interconversion of arsenate to arsenite and, therefore,
the Agency should acknowledge that arsenate and arsenite should be treated
as separate chemicals and cease regulating on an unfounded association.
Agency response:
The scientific literature contains many studies showing that man and
other mammals oxidize trivalent arsenic (arsenite) to pentavalent arsenic
(arsenate) (PD 2/3). However, until recently, there was no firm evidence
demonstrating the in vivo reduction of pentavalent arsenic to trivalent
arsenic. Because of analytical difficulties in speciating inorganic
arsenic and separating it from its methylated metabolites, the older
metabolism studies of arsenic did not provide clear information about in
vivo conversion of arsenic valence states (Rispin, 1983).
However, Yamauchi and Yamamura (1979) provide suggestive evidence that
in vivo reduction of arsenate takes place in the human body. In this
study, a human subject ingested extract of seaweed containing 86% of the
arsenic as arsenate. More arsenite than arsenate was excreted in the
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urine. Ibis would suggest that in vivo reduction took place in the human
bo^y* In vitro studies also support the hypothesis that pentavalent arsenic
may be reduced by tissues. Incubations of arsenate with human erythrocytes
(Ataullakhanov et al., 1978) and tissue homogenates (Uthe and Reinke,
1975) led to formation of trivalent arsenic (Rispin, 1983).
In a series of experiments, in mice and rabbits, Marie Vahter and Col-
leagues (1983) have proven definitely that arsenate is reduced to arsenite
iii vivo. Not only has arsenite been found in the urine and plasma of mice
one hour after dosing with arsenate, but rabbits dosed at very low levels of
arsenate excreted 10% of the total administered dose as arsenite in 4 hours
(Rispin, June 27, 1984).
The results of these studies demonstrate the in vivo reduction of arsenate
to arsenite. Accordingly, the interconversion of arsenate and arsenite is
firmly established, justifying regulation of the two chemicals together (Rispin,
June 27, 1984).
Comment Issue #2: The analyses of Jung, Petres and co-authors cannot be
used as evidence that pentavalent arsenic is mutagenic
The AWPI (36C) states that there are no reliable data pertaining to
the mutagenic potential of arsenate using mammalian systems for the following
reasons: The analyses of Jung, Petres and co-authors (Jung et al., 1969;
Jung and Trachsel, 1970; Petres et al., 1970; Petres and Berger, 1972;
Petres et al., 1974; Petres et al., 1975) pertaining to arsenate muta-
genicity and cited by the Agency in the PD 2/3 (Table II.C.1, 112-116),
contain errors in methodology and conclusion (AWPI, 36C), Any in
vitro mammalian assay system must have fortification with mammalian
serum and the serum will reduce pentavalent arsenic to trivalent
arsenic early in the test. Serum contains free cysteine; cysteine
may also be added to the culture medium (AWPI, 36C). Cysteine and
serum will then quickly chemically reduce the arsenic as demonstrated
byOtheetal. (1975) (AWPI, 36C).
Agency Response:
The issue of mammalian interconversion of pentavalent and trivalent
arsenic has been extremely important to the development of the Agency's
regulatory position on the inorganic arsenical wood preservatives. Recent
studies indicate that arsenical interconversion occurs jji vivo (Yamauchi
and Yamamura, 1979; Vahter, 1983). Because of this metabolic intercon-
version of pentavalent and trivalent arsenic in mammals, the Agency
believes that exposure to the two forms cannot be dealt with separately
for the purpose of assessment of health effects. Arsenic in treated
wood occurs primarily in the pentavalent state. The Agency has
based its evaluation of the mutagenic (and teratogenic) potential
of inorganic arsenic on studies involving both valence states of the
chemical. Not only do the two states of arsenic have somewhat similar
effects and possibly similar mechanisms, but the potential for inter-
conversion of the two forms in vivo (see Agency Response to Comment
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Issue, tl) lends credence to this position (Sochard, 1982 and 1984a).
Until new studies are presented to the Agency refuting the work of
Jung et al. and others as cited by AWPI (36C) the policy of employing a
worst case risk estimate compels the EPA to accept that work as providing
positive evidence of pentavalent arsenical mutagenicity.
The Agency is aware that serum fortification is necessary for mammal-
ian cell cultures, and that serum may contain free cysteine which
can act as claimed by AWPI. However, since all mammalian systems
contain serum in the in_ vivo situation, and living systems are of
concern, there is little reason to object to the use of serum fortifi-
cation of in vivo mammalian cell systems (Sochard, 1982).
Comment Issue #3: B. Subtilis assay of pentavalent arsenic mutagenicity
The AWPI (36C) states that Nishioka's (1979) B. subtilis mutageni-
city is unacceptable because meat extract was used in the test,
which would cause reduction of arsenate to arsenite. This methodology
could lead to an erroneous conclusion concerning interconversion of
arsenate to arsenite*
Agency Response:
The nutrient medium used by Nishioka (1975) was Difco Nutrient Broth
which probably contained meat extract. If the medium is heated to temper-
atures above that necessary to achieve sterilization, certain pyrolysis
products may be formed which are mutagenic. Indeed this medium may produce
false positives; likewise, false positives would also be apparent in the
experimental control. No evidence of false positives was shown by Nishioka
(1975) (Sochard, 1984a).
The _B, subtilis assay is a standard method, and the Agency has no reason
to reject the data provided until new studies are published in the literature
or presented to the Agency for evaluation (Sochard, 1982 and 1984a).
Comment Issue #4: The mutagenicity of inorganic arsenic due to genotoxic
(DNA alteration) effects
The AWPI (36C) states that neither valence state of arsenic (i.e.,
trivalent or pentavalent) is capable of causing genotoxic results and,
therefore, is not mutagenic. Koppers Company, Inc. (85) also submitted
a review of published literature and laboratory experiments (Simmon, 1983)
which concludes that arsenical compounds may be clastogenic (cause chromosomal
breakage) but that the evidence does not support the EPA's contention that
arsenic is mutagenic.
Agency Response:
In its review and reevaluation of available mutagenicity studies
involving both trivalent and pentavalent arsenicals, the Agency has found
that available data support the position that arsenic is mutagenic.
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Results of a dominant-lethal assay (University of California, 1977)
submitted by the AWPI indicated a significant increase in implantation
deaths of fetuses due to arsenite exposure. This increase was noted at
three weeks post-treatment at which time the mating of the animals represents
meiotic division. In support of these observations, the study by Benko et
al. (1968) shows direct histological evidence that mouse gonadal tissue
deteriorates following forced feeding (gavage) of arsenite (Sochard, 1984a).
Koppers Company (85) presented as supportive evidence for the nonmuta-
genicity of trivalent and pentavalent arsenic a "Review of Evidence for
Hutagenicity of Inorganic Arsenical Compounds" compiled by Clement Associates,
Inc., dated December 20, 1978. On page 6 of that document is the following
statement: "Weighing all this (mutagenicity) evidence, we believe the most
balanced interpretation to be that there is a substantial amount of indirect
evidence suggesting that certain arsenic compounds, primarily trivalent
arsenic, may be mutagenic; only sketchy direct evidence for mutagenicity
and limited data against the hypothesis." The following is stated on page
7: "Given the evidence reviewed herein, we believe that it is fairly
likely that trivalent arsenic compounds would prove to be mutagenic in E.
coli and mammalian systems when properly tested. The evidence for the
mutagenicity of pentavalent arsenic compounds is much more sketchy, however."
The Agency agrees with the views cited above by Clement Associates. In
the Agency's view, employing the "worst case risk estimate" compels acceptance
of the evidence for mutagenicity of both trivalent and pentavalent arsenicals
(because they interconvert in_ vivo) until appropriate test evidence is
provided refuting this interpretation (Sochard, 1984a).
Comment Issue §5: Inorganic arsenic mutagenic assay measurement of the zone
of inhibition
The AWPI (36C) contends that the Nishioka (1975) study does not demon-
strate a mutagenic effect for arsenate because it is virtually impossible
to accurately quantitate a 1 mm difference in the assay system used. Because
of the lack of sensitivity in the assay system used, it can not be concluded
that pentavalent arsenic was mutagenic< Conversely, the zone of inhibition
with trivalent arsenic was an order of magnitude greater.
Koppers Company, Inc. (85) also states that Simmon (1983) concluded that
arsenic cannot be considered a mutagen based on microbial assays and experiments
with human lymphocytes because the studies cannot be reproduced.
Agency Response:
Although it may be better to utilize a more sensitive bacterial strain
which would provide a larger inhibitory zone, if an experimental result is
reproducable by another laboratory, it has been validated.
Studies by Kada et al. (1980) have shown using a similar test system
(B. subtilis rec. assay with strains H 17 and M 45) that 45 different
inorganic arsenicals, including As (4-3) and As (+5) species, produced
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positive results for mutagenicity. Until new studies are presented to EPA
refuting these data, the Agency will continue to assume that both arsenate and
arsenite are potential mutagens (Sochard, 1984a, and Griffin, 1983).
Comment Issue #6: jn situ test for arsenic mutagenicity
The AWPI (36G) contends that Casto (1977) used an in situ technique
that is obsolete and. considered of limited value by today's standards.
Agency Response:
The Agency agrees with the AWPI's contention in that studies such as
Casto's, which provided positive results concerning arsenite and point
mutations, may have limited value. However, obsolescent test methodology
does not necessarily invalidate the results of any such studies (Sochard,
1982).
Comment Issue t7: PD 2/3 references and arsenic mutagenicity
Koppers Company, Inc. (85) submitted an analysis of all PD 1 arsenic
mutagenicity studies (reviewed in the PD 2/3) (Clement Associates, 1978)
which concludes that none of the studies provide direct evidence of pentavalent
arsenic mutagenicity. The AWPI (36C) also states that none of the references
reviewed in the PD 2/3 should be used to indict arsenic as mutagenie.
Moreover, Koppers (85) states that Simmon concluded in post-hearing
comments to the July 1982 OSHA Hearings on the inorganic arsenicals
that arsenic cannot be considered a mutagen based on microbial assays and
experiments with human lymphocytes because the studies can not be reproduced.
Agency Response:
A reevaluation of these PD 2/3 studies (Tables I-III, Sochard, 1982)
indicates that there is multi-test evidence that both arsenate and arsenite
interact with DNA to produce chromosomal aberrations, somatic cell OKA
damage and gonadal damage, all with potential ensuing heritable effects
(Sochard, 1982, and Sochard, I984a).
In addition, the Environmental Health Committee of the Science Advisory
Board of EPA has reviewed the "Health Assessment Document for Inorganic
Arsenic" (U.S. EPA, June 1983) and has concurred with the Agency's statement
that arsenic is to be judged as an environmental mutagen (Griffin, 1983).
The Agency is aware that metals other than arsenicals are frequently
negative in microbial assays. These compounds actively produce cytogenic
effects, various kinds of tumors, and other effects reflecting mutagenicity
and/or genotoxicity in a spectrum of mammalian test systems.
Inorganic arsenicals have been shown to depress humoral immunity.
Current evidence indicates the expression of this immune response involves
activation of a gene. The demonstration of immunodepression by inorganic
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arsenicals plus their activity as clastogens in human lymphocytes suggests
a cause and effect relationship. The immunosuppressive effect could be due
to the clastogenic effect of inorganic arsenicals on the immune genes
(Sochard, 1984b).
A number of positive mutagenic or otherwise genotoxic effects remain as
evidence for inorganic arsenicals. These include: clastogenic effects,
interference with DNA repair mechanisms, direct toxicity to mammalian
gonads, depression of the humoral immune response, and positive effects in
selected microbial test systems for mutagenicity (Sochard, 1984b). The
Agency reiteriates its position that inorganic arsenicals are mutagenic.
Comment issue #8: Inorganic arsenic teratogenicity/fetotoxicity
Friends of the Earth (FOE) (64) state that inorganic arsenic causes
birth defects. The AWPI (78) states that the Agency has failed to distinguish
between the fetotoxic effects of pentavalent and trivalent inorganic arsenic.
The AWPI (36C) also contends that the Agency has relied upon studies which
use inappropriate routes of exposure to demonstrate teratogenic and fetotoxic
effects, which may vary qualitatively or quantitatively, depending upon changes
in metabolism (detoxification, elimination) associated with the different
routes of administration. In addition, the AWPI (36C) presents discussions
of animal fetotoxicty studies (Hood et al., 1978; Baxley et al., 1981; Hood,
1978; Hood, 1979; Hood et al., 1977), some of which indicate that maternal
toxicity occurs in the same narrow dosage range as fetotoxicity, thus implying
that adequate protection of the parent provides adequate protection of the fetus.
Agency Response:
The Agency has reevaluated the studies cited in the PD 2/3 (pages 130-
138, Table II.C-2) and has determined that they should not be used to develop
a human teratogenic/fetotoxic risk assessment because the arsenic was
administered by injection, an inappropriate route of administration for
humans (PD 2/3 p. 128). However, these studies are still considered to be
supportive of the teratology and fetotoxic presumption.
The Agency also recognizes several deficiences in studies cited in the
PD 2/3 [Hood et al. (1977), Matsumoto et al. (1974), Kimmel and Fowler (1977)
and Baxley et al. (1977)] to support a provisional teratogenicity no-observed-
effect level (NOEL) at 5.0 mg/kg/day for inorganic arsenite or arsenate which
used oral administration, a more appropriate route of exposure for occupational
risk analysis of teratogenic/fetotoxic effects. In one or more of these studies:
1) Gavage was not continued daily throughout organogenesis. Human
occupational teratogenic/fetotoxic risk assessments require an animal
model in which dosing is conducted at least daily throughout
organogenesis, rather than for just a few days (Van Ormer, 1982c,
and Sochard, 1983).
2) Maternal toxicity was not reported so that the excess risk to the
fetus could be determined. It is necessary to compare the dosage
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producing significant maternal toxicity to the dosage causing
significant terato-fetotoxicity (Van Ormer, 1982c, and Sochard, 1983).
3) The effect level or the no-observed-effect level (NOEL) are unclear,
suggesting that any observed effect is in a range which extends
beyond the one or two dose levels used in the study. Generally,
teratology studies using less than three dosage groups do not provide
sufficient data to develop adequate dose-response curves for feto-
toxicity, teratogenicity and maternal toxicity (Van Ormer, 1982c, and
Sochard, 1983).
4) A NOEL was not reported for fetotoxicity in the same study with an
effect level for either teratogencity or fetotoxicity (Van Ormer,
1982c, and Sochard, 1983).
Consequently, the Agency has determined that the provisional teratogeniciti
NOEL of 5.0 mg/kg/day for inorganic arsenite or arsenate, cited in the PD 2/3,
cannot be supported with the studies currently available (Van Ormer, 1982).
Deficiencies in the studies cited above cause the Agency concern
that teratogenic/fetotoxic effects may be produced by oral administration
of an inorganic arsenic species. Therefore, the Agency will require
teratogenicity/fetotoxicity studies using Agency approved protocols to
fill all data gaps pursuant to Section 3(c)(2)(B) of FIFRA.
Comment Issue #9: Sensitivity of animals and humans to arsenic toxicity
The Society of American Wood Preservers, Inc. (53), referring to the
PO 2/3 (pgs. 233-240), states that "Comparisons between man and animal are
for LD-jo and LDso levels, respectively. Acute toxicity comparisons of
the same lethality indicate that man and animals are affected by about the
same dose."
Agency Response:
The Agency agrees that the referenced data do not show a difference in
sensitivity to arsenic between man and animals. However, the data presented
are Lethal Dose Lowest Observed (LDLO) for man (not LD-IQ) and Lethal Dose
Fifty (LD5Q) for animals. The LDLO is an uncommon notation and is used in
an attempt to indicate how small a dose can kill a person. An LDLO in man
should not be compared directly with an LDso in animals since the human
data can represent a range of values from a true ID. through an LD10Q.
A human LDLO is comparable to an animal LD-) or LD10. If the human value
is higher than either of these values, chere is no difference between man
and the test animal (Zendzian, 1982).
In the referenced PD 2/3, LD-j or LD-JQ data are not available. In
general, if the human LDLO is no lower than approximately one tenth of
the animal LD5Q, man is no more sensitive than the laboratory animal.
On the basis of the data presented, there is no indication that man is
more sensitive to the lethal effects of arsenic than other animals
(Zendzian, 1982).
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Comment Issue #10: Inorganic arsenic oncogenicity: genotoxic carcinogens
(alters the DMA structure) vs. epigenetic carcinogens
(prevents DNA repair once a break has occurred).
The AWPI (36C), Osmose (41) and the SAWP (53), state that while the
Agency's Carcinogen Assessment Group's (CAG) risk model may accurately
apply to direct (genotoxic) carcinogens, a threshold exists for indirect
(epigenetic) carcinogens; that is, arsenic may be acting as a co-carcinogen,
or in conjunction with other causative agents. The commenters state that
the CAG's risk model does not accurately describe risks associated with
indirect carcinogens and would indicate risk exists in low dosages even
though none exists.
Agency Response:
The CAG has used the linear model to estimate an upper bound for
risk from inhalation exposure to inorganic arsenic. The data are consistent
with this model. While the "threshold" hypothesis, mentioned by the AWPI
(36C) is also consistent with the data, one cannot conclude that there is no
risk. There is no indication as to what is actually occurring at low doses.
Therefore, the Agency has concluded that it would be prudent to adopt a
conservative approach and use the linear model to estimate carcinogenic
risk to humans (U.S. EPA, June, 1983, and SAB Transcript, 1983). See Section
II.A for a detailed analysis of the risk model.
Comment Issue #11: Higher skin cancer rates should be found in U.S. cities
with high levels of arsenic in drinking water
The AWPI (36C) contends that if the CAG dose response model (a predictor
equation) (Albert, 1978) is correct, U.S. populations should have the skin
cancer rates predicted through use of Taiwan drinking water data (Tseng,
1968). Morton et al., (1976), Southwich et al. (1980), Vig (to be published)
and Harrington et al. (1978) found that, since selected counties or cities
in Oregon, Utah, Nevada and Alaska had high arsenic levels in their drinking
water and no increase in skin cancer, there must be another factor causing
skin cancer in Taiwan (AWPI, 36C).
Koppers (72) submitted a study by Southwick et al. (1981) which
presented epidemiological data concluding there was no significant increase
in mortality associated with exposure to arsenic in drinking water in
Mi Hard, Utah.
Agency Response:
The Taiwan study (Tseng, 1968) surveyed the prevalence of skin cancer
among 40,421 lifetime Taiwanese residents. The sample sizes, water concent-
rations and duration of exposure for the studies in each of the selected
U.S. populations, cited in the above comment, are not large enough to
detect the increases in skin cancer above the base level which is estimated
by the CAG dose-response model (Albert, 1978). A feasibility study at the
University of Pittsburgh's Center for Environmental Epidemiology (Andelman,
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1983) on finding increased evidence of U.S. skin cancer by arsenic oral
ingestion concluded: "From this review, it can be seen that the available
information regarding the relationships between arsenic in drinking water
and non-melanoma skin cancer in exposed populations in the United States
is inadequate for determining whether the Taiwan experience is generalizable
to this country."
The available data are not inconsistent with the Taiwan studies.
The arsenic levels present in the communities studied in the United States
were lower, and the duration of exposure shorter than for the Taiwan
population. It is evident that if a suitable study population could be
found, further study of the problem would be warranted. Such a population,
besides having been exposed to high drinking water arsenic levels for a
sufficiently long time, would need to be large enough for a statistically
significant increase in non-melanoma skin cancer to be seen, over and
above the background levels predicted from solar U.V. radiation" (Kuroda,
1983).
With regard to the GAG dose-response model, estimated increases in
cancer rates are too small to be observed in epidemiology studies involving
populations much smaller than that studied in the Taiwan analysis. Therefore,
the observed negative results of epidemiology studies on skin cancer in
individuals drinking water with moderately increased arsenic levels do not
contradict the positive findings in the Taiwan studies (Kuroda, 1983).
The Southwick study was taken into account by CAG in the review of risk
from oral exposure to arsenic. However, because of limitations in the protocol
of the Southwick study {small cohort and low levels of arsenic contamination in
the water), CAG did not use these results to change the risk estimates for
oral exposure. The study was conducted on citizens of West Millard County,
Utah, in which arsenic is a naturally occurring contaminant in the public
drinking water supply. The concentration of arsenic was considerably smaller
than that in the drinking water in Taiwan. A total of 250 people (145 exposed,
105 controls) participated in the Southwick study. Although no significant
increase in mortality was associated with exposure to arsenic, the study was
comprised of a cohort which was too small for meaningful statistical analysis.
This study is summarized on pp. 5-69 to 5-72 in the OHEA document (U.S. EPA,
1983); however, the data were not incorporated into the development of risk.
Comment Issue f12: Absence of clinical effects expected after drinking
water that contained arsenic
The AWPI (36C) states that certain clinical effects associated with
arsenic exposure were not found in residents of Ester Dome, Alaska, who
drank well water with a high arsenic content. Harrington et al. (1978)
studied the dermatological and neurological effects of high arsenic levels
in the well water upon Ester Dome residents. No evidence was found for
increased prevalance of leukopenia, relative lymphocytosis or eosinophilia
in any exposure group. For the high exposure group, the authors state
"specifically, there was no increased prevalence of abnormalities in the
skin or in the peripheral nervous system."
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Agency Response:
Harrington et al. (1978) attempted to do a thorough study on the Ester
Dome residents. However, the study has some significant deficiencies and
there are important factors, presented by the investigators, which may be
responsible for the absence of clinical findings (Kuroda, 1983).
The size of the study population (232 observations) is too small to
detect increases in skin cancer or dermatological changes associated with
arsenic ingestion.
The authors state: "The mean well-water arsenic concentration in
Ester Dome (244 ug/liter) was less than half that seen in Chile (Irgolic,
1981, Tseshelashvili et al., 1980) or in Taiwan (Tseng, 1968), and 85
percent of Ester Dome residents had lived in the area for less than 10
years." The well-water arsenic levels appear to vary as a function
of drawdown rate or seasonal water changes.
The authors noted that there was a poor correlation among biologic
arsenic estimates, (hair, urine and nails) which may be a reflection of
differences in the mode of arsenic excretion _V.
The blood parameters selected for measurement (leukopenia, relative
lymphocytosis or eosinophilia) are not specifically related to arsenic and
are of limited value for demonstrating clinical arsenic effects (Kuroda,
1983).
The authors further speculate that the lack of positive clinical findings
in the Ester Dome, Alaska, study, when compared to Taiwan and Chile, may be
due to good nutrition of the Ester Dome residents, lack, of additional
environmental contaminants, and/or differences in exposure to sunlight
(Kuroda, 1983).
Comment Issue #13: NO health problems in populations with high arseriate levels
in drinking water
The AWPI (36C) states that a new epidemiology study (Vig, unpublished)
shows no health or skin problems in populations drinking water with high
arsenate levels. The study compared the rate of chromosome aberrations,
birth defects and incidence of cancer for people living in Fallen, Nevada,
a city with drinking water containing 0.1 ppm to 0.5 ppm, with people
living in Reno, Nevada, where the drinking water arsenic level is less than
.005 ppm. The Reno control group had a slightly higher frequency of chromo-
some aberrations than the Fallen group. The Fallen group had no increase
in sister chromatid exchange, no malformations or birth defects, and no
increase in cancer (Vig, to be published).
_V Urine arsenic levels correlate well with calculated daily doses, while
arsenic concentrations in hair and nails represent a mean value over several
months and may provide a better integrated measure of past exposure to
arsenic (Kuroda, 1983).
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Agency Response:
The study "Chromosome Studies on Human Subjects Exposed to Arsenic in
Drinking Water," (Vig, unpublished) has several critical limitations which do
not permit the Agency's agreement with the conclusions concerning the effects
from arsenic in drinking water: (1) The sample size was too small to result
in statistically valid conclusions (there were only 201 individuals in the
study, 96 control and 105 exposed); (2) the exposure period to higher arsenic
levels was only 5 years; and (3) the cohorts were not matched.
This study, with a small population and short arsenic exposure time,
could not be expected to detect the increases in oncogenicity or birth
defects. Although no increases in chromosome aberrations or sister chromatid
exchanges were found, this does not negate the positive findings of skin
cancer in the Taiwan study by Tseng (1968) (Kuroda, 1983).
Comment Issue #14: Taiwan drinking water contains alkaloids which cause
Blackfoot disease and cancer.
The AWPI (36C) states that the drinking water from the endemic area of
Taiwan is known to contain other chemical substances that may be the cause
of the cancer and other diseases. The AWPI (36C) and the SAWP <53) contend that
the water contains alkaloids which were tentatively identified as derivations
of ergotamine tartrate, one of the alkaloids that can cause gangrene-like
Blackfoot disease, that was associated with skin cancer in endemic areas.
The AWPI (36C) suggests that the EPA review Kraybill and Shimkin (1964) and
Fishbein (1972), which describe the carcinogenic properties of alkaloids.
Agency Response:
Although the alkaloid compounds may account for the finding of Blackfoot,
a vaso-constrictive disease, there is no evidence that the alkaloids are
related to carcinogenesis. A review of Kraybill and Shimkin (1964),
"CarcinQgenesis Related to Poods Contaminated by Processing and Fungal
Metabolites" reveals nothing relevant to the types of alkaloids identified
in the Taiwan drinking water. Fishbein (1972) mentioned that "Indole
alkaloids such as vinblastine and vincristine from Vinca rosea and from
ergot, the lysergic acid derivations, lyseric acid diethylamide (LSD) and
bromolysergic acid diethylamide have been shown to induce foetal malforma-
tions in hamsters." Neither one of these references, which are only secondary
sources, support the contention that the alkaloids found in the Taiwan
drinking water are carcinogenic (Kuroda, 1983).
Comment Issue #15: Beryllium caused the cancer found Antofagasta, Chile, which
had high levels of arsenic in drinking water
The AWPK36C) claims that the Antofagasta, Chile, water supply is reported
to have a mean arsenic concentration of 0.58 ppm and to have caused peripheral
vascular diseases and skin cancer. However, as the AWPI (36C) states, it is
now known that the untreated water supply had 7.4 ppm of beryllium (Irgolic,
1981). The discovery of beryllium, a metal with salts that are known to
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cause cancer in laboratory animals and primary DMA damage, should be sufficient
evidence to indicate that arsenic is not responsible for the increased cancer
in the people drinking the water (AWPI, 36C).
Agency Response:
Beryllium has been shown to cause lung and bone cancer in test animals.
The Agency is unaware of any evidence, however, of beryllium causing skin
cancer in either man or animals. Although it is possible beryllium salts
may have caused the skin cancer observed in Antofagasta, the presence of
beryllium does not rule out arsenic as a causative factor (Kuroda, 1983).
Comment Issue 116: Due to exposure to many known or suspected carcinogens,
arsenic cannot be indicted as the cause of lung cancer
in smelter workers
The AWPI (36C) states that in the epidemiological studies listed in the
PD 2/3, especially those involving smelters, indicate workers were exposed
to many known or suspected lung carcinogens, including compounds of sulfur,
antimony (antimony trioxide) and lead (lead acetate). It is illogical to
indict arsenic as a cause of lung cancer (AWPI, 36C). Osmose (41) states
that epidemiology studies cited by the Agency in the PD 2/3 indicate a
statistical association but not cause-and-effect proof between arsenite
exposure and cancer. If arsenite is an indirect carcinogen then the irritating
effect of arsenite at high exposure is an indirect mechanism (Osmose, 41).
Osmose (41) further comments that reviewers of metal carcinogenesis (Furst,
1978; Furst and Bars, 1969; Sunderman, 1978; 1979) conclude that certain
metals, alone or in combination with other metals and sulfur, are potential
indirect carcinogens but are not carcinogenic themselves. The SAWP (53)
also comments that the arsenate in smelters, acting as a co-carcinogen,
prevents repair of DNA breaks caused by SO2, 803 and K2&®4 i-n the lung.
Agency Response:
The Agency believes there are numerous epidemiology studies which
demonstrate that arsenic is a cause of cancer found in smelter workers.
(PD 1, pp. 152-153 and PD 2/3, pp. 104, 107-109) . Although the workers
have been exposed to other known or suspected carcinogens, this does not
exclude arsenic as the cause of cancer. Brown and Chu (to be published)
evaluated smelter worker data and, by adjusting for the confounding effect
of sulfur dioxide, determined that arsenic rather than S02 was the more
probable carcinogenic contaminant (Kuroda, 1983).
Welch et al. (1982) studied the effects of exposure to arsenic, sulfur
dioxide, asbestos, and smoking habits on copper smelter workers and determined
that (1) a clear dose-response relationship between arsenic and respiratory
cancer was demonstrated and (2) sulfur dioxide and asbestos did not appear to
be as important as arsenic exposure (Kuroda, 1983).
The Agency is unaware of any studies demonstrating the carcinogenic
ability of antimony trioxide but would welcome the opportunity to review them.
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Comment Issue |17: Inorganic arsenic and excess respiratory cancer
Koppers Company, Inc. (72) and the AWPI (81) contend, based on numerous
submissions made to the Agency, that inorganic arsenic poses no risk of
excess respiratory cancer at exposures below 500 ug/m3 (Schlesselman,
1983; Chemical Manufacturers Association Arsenic Panel, September 3, 1982;
Consultants in Epidemiology and occupational Health, September 2, 1982;
Broraberg, September 1, 1982; Chemical Manufacturers Association Arsenic
Panel, August 13, 1982; Consultants in Epidemiology and Occupational Health,
August 13, 1982; Lamm, July 15, 1982; Consultants in Epidimiology and
Occupational Health, July 30, 1982; Furst, no date; Woolson, August 13,
1982; University of California, February 18, 1978; Lederer, July 15, 1982,
Marsh, July 18, 1982; Chemical Manufacturers Association Arsenic Panel,
June 18, 1982; Consultants in Epidemiology and Occupational Health, June 2,
1982; Harding Barlow, May, 1982; McGraw, June 11, 1982; Koppers Co., Inc.,
June 17, 1982; AWPI, 1979; Gilbert et al., 1981; Higgins et al., 1983
Lederer and Fensterheim, eds., 1983).
Agency Response:
The Agency does not believe the cited studies support the commenters'
contention that inorganic arsenic exposure levels below 500 ug/m^ will not
lead to excess respiratory cancer.
The Agency responded to comments on arsenic and cancer by AWPL, 1979
("AWPI Response to EPA Position Document (PD 1) Volume 1: Discussion and
Analysis of Risks and Benefits Associated with Inorganic Arsenic Used as a
Wood Preservative") in the PD 2/3 (pp. 95-193). The submissions listed
above, except for Gilbert et al. (1981), Higgins et al. (1982), and Lederer
and Fensterheim (eds., 1983) were discussed at a series of hearings held
by the Occupational Safety and Health Administration (OSHA) on July 13-16,
1982. OSHA published a thorough analysis of the information presented
during and after the hearings. This analysis appeared in the Federal
Register, Volume 48, pp. 1864-1903, on January 14, 1983. The Agency's
Carcinogen Assessment Group (CAG) used this information, with other sources,
to prepare the risk estimate section of the "Health Assessment Document
for Inorganic Arsenic" U.S. EPA, June 1983 - External Review Draft (McGaughy,
1983) .
Studies available after PD 2/3 publication include Gilbert et al. (1981),
Higgins, et al. (1982), Entertine and Marsh (1983); Lederer and Fenitercheim,
eds.); Lee-Feldstein (1983 Lederer and Fensterheim, eds.), Southwick, et al.
(1983, Lederer and Fensterheim, eds.) The Agency's review of Gilbert et al.
(1981) will be incorporated into the Agency's final OHEA "Health Assessment
Document for Inorganic Arsenic." The protocol of this study had many
limitations and will not lead to any revisions in the risk calculations.
Higgins et al. (1982), Enterline and Marsh (1983) and Lee-Feldstein (1983)
are studies of Anaconda and Tacoma smelter workers. These new studies and
a series of new analyses from the National Cancer Institute by Brown and
Chu (1983 a, b, and c) were used by CAG to revise its 1980 risk estimates
for inhalation exposure (Rispin, 1984) (see Section II.A.I).
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Comment Issue 118: Lung tumors in vineyard workers are caused by copper not
arsenic
The AWPI (36C) and the SAWP (53) report that Villar (1974) found tumors in
vineyard workers lungs ("vineyard sprayer's lung") in Portugal, where arsenic
had never been used on the vineyards. Bordeaux mixture (copper sulfate and
lime) was used and Villar ascribed the "vineyard sprayer's lung" to copper.
Agency Response:
Villar"s (1974) study/ which analyzed 15 cases, concerned pathological
changes involving granulomas that were not necessarily cancerous. There
is, at best, a tenuous connection between lung cancer and inflammatory
reactions in the lungs not specifically diagnosed as cancer. This study
does not provide sound data to attribute vineyard sprayer's lung cancer to
inhaled copper sulfate (Kuroda 1983).
Comment Issue #19: EPA did not adequately consider the AWPI's comments on
the NIOSH orchard worker study
The AWPI (36C) states that there is no reasonable basis for the NIOSH and
Milham (1974, 1975) conclusion that lead arsenate was the probable cause of
increased lung cancer among the orchard workers. The AWPI (36C) contends that
during the 20-30 years prior to the observation of increased lung cancer, at
least 10 compounds were used in addition to lead arsenate and it seems likely
that the combination of oils and sulfur, or DDT in combination with other
pesticides, was the real cause.
The AWPI (36C) also contends that even though the workers in the Milham
study (1975) were exposed to many pesticides prior to their deaths, a
comparison of the predicted mortality rate (PMR) for respiratory system
cancer reveals that the younger workers, least exposed to lead arsenate
(usage discontinued in approximately 1948), had the excess cancer.
Agency Response:
A more recent study by Milham (1983) found an increasing trend over time
of lung cancer among orchard workers. Milham reported that "The lung cancer
excess seems to be increasing in that the PMR for deaths during 1950-1959
was 102; 1960-1969, PMR=121; and 1970-1979, PMR=143." Milham (1983) suggests
that "The orchard workers excess is probably related to the use of arsenical-
based pesticides before 1945." However, since the only agriculture-related
populations, i.e., orchardists and nurserymen, exposed to arsenic developed
respiratory cancer, this provides evidence that arsenic, and not combinations
of oils and sulfur, or DDT and other pesticides, is the cause of cancer
(Milham, 1975). Also, male workers who were occupationally exposed to arsenic
pesticides during the manufacturing process had increased mortality
from lung cancer (Mabuchi et al., 1980) (Kuroda, 1983).
The basis for the statement concerning younger workers developing the
excess cancer is not clear (Kuroda, 1983).
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Comment Issue 120: Arsenic in drinking water of animals has a strong cancer
inhibiting effect
The AWPI (36C) contends that the Kerkvliet and Steppan study (1974)
demonstrated that levels of arsenate in drinking water as high as 100 ppm
increased the latent period and decreased the incidence of viral-induced
tumors in mice caused by injection of MSB sarcoma cells.
Agency Response:
The Agency is not persuaded by the Kerkvliet and Steppan (1974) study
which relates only to transplanted cancer cells and not to cancer induction;
therefore, it is not relevant to the mechanism by which arsenic causes
cancer. Also, the relationship of the immunotoxicologic effect of sodium
arsenate in mice inoculated for 12 weeks to the carcinogenic potential of
arsenic toward the induction of primary tumors in animals and humans with
chronic exposure is not clear. Although decreased tumor incidence and
increased latency of tumor formation occurred with arsenic treatment,
tumor formation (with decreased survival afterwards) still was evident in
treated animals. The authors did not report survival rates for animals
which did not have tumors. A serious consideration is whether the arsenate
levels which affect tumor growth (25 ppm and 100 ppm) are toxic over lifetime
exposure (Kuroda, 1983).
Arsenic was effective as a tumor inhibitor with inoculation of 10^ MSB
cells but not with 10& MSB cells which suggests the effect is dependent
on experimental conditions. Dose-related cytotoxicity was found in spleen
and lymph node cells with inoculation of MSV tumor cells but not MSB cells;
however, arsenic had no effect on regression of MSV tumor cells. The fact
that arsenic inhibits tumor growth is not inconsistent with the fact that it
induces skin and lung cancers. Many clinically used antineoplastic agents
are known to be carcinogens. Moreover, conclusions from this study to life-
time exposure are extremely limited because 12 to 16 weeks is a very short
time for animal arsenic exposure. Therefore, if arsenic had any inhibiting
effect on cancer cells, it is of very limited scope and not found over the
lifetime of the test animal (Kuroda, 1983) .
Comment Issue 121: Sodium arsenite inhalation oncogenicity experiment
The AWPI (36C) cites a new arsenite inhalation oncogenicity study by
Berteau et al. (1980) to support its position that "inhaled sodium arsenite
is probably not a carcinogen to mice." An Ames test on mouse urine gave
negative results.
Agency Response:
The Agency is not persuaded by the Berteau et al. (1980) study cited by
AWPI which contends inhaled sodium arsenite is probably not carcinogenic
to mice. Following daily inhalation of various doses of sodium meta arsenite,
female test mice and controls were sacrificed at varying times during and
after exposure. Berteau et al. examined and weighed select organs; the
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lung was reviewed histopathologically. The authors found no significant
increases in lung tumors and concluded that inhaled sodium arsenite is
probably not a mouse carcinogen. However, this study has several flaws,
so that the results cannot be considered to demonstrate a noncarcinogenic
response: (1) only female mice were used; (2) exposure time was too
short, i.e., 46 weeks with an additional 120 days for observation, instead
of 102 weeks (exposure for lifetime); (3) histopathological examination of
only lung tissue; and (4) high incidence of background neoplasia in both
cage mates and controls (Kuroda, 1983).
The Ames test performed is of 1 united value since only one tester strain,
TA 1538, was used. TA 1538 is not one of the more sensitive strains and is
not sensitive to base-pair substitution (Kuroda, 1983).
The absence of an animal model to demonstrate arsenic oncogenicity does
not refute the positive epidemiology evidence that arsenic is a carcinogen
(Kuroda, 1983).
Comment Issue 122: EPA has failed to demonstrate with reliable animal studies
that arsenic is an oncogen
Osmose (41) contends that the EPA relied on inadequately controlled and
documented epidemiology data, instead of confirmatory animal studies, as a
basis for arsenic cancer theory. "Drinking Water and Health" (NAS, 1977)
indicates that animal studies have not shown arsenic to be carcinogenic,
even when administered as a maximally tolerated dose for a long period of
time (Osmose, 41). The AWPI (36C) states that animal studies, used by the
Agency to support the contention that arsenic is an oncogen, are invalid.
The AWPI (36C) further comments that the Ivankovic et al. (1979) study
concerns test animals exposed to a mixture of chemicals, one of which was
calcium arsenate; and the oncogenicity study of Oswald and Goertler (1971) ,
cited by the Agency as evidence that arsenic exposure resulted in positive
tumor responses, consists of inadequate data.
Agency Response:
The Agency agrees that there are no good animal tests demonstrating that
arsenic causes cancer and, consequently, the mechanism of arsenic oncogenicity
is not fully understood. However, the human evidence (e.g., Brown and Chu,
1983; Tseng, 1968; Welch et al. 1982) is convincing that arsenic induces
cancer (Kuroda, 1983}.
The Ivankovic et al. study (1979) found lung carcinomas after intra-
trachial installation of a mixture of calcium arsenate, calcium oxide, and
copper sulfate in rats. The EPA (FD 2/3, pp 106-107) has stated "This
experiment strongly indicates that pentavalent arsenic can induce lung
carcinomas, although the contribution of sulfate, copper, and calcium
oxide cannot be ruled out until further experiments are carried out."
That is, arsenate is the probable cause of the lung carcinomas but since
other chemicals may have been responsible for or contributed to the lung
tumors, this experiment does not show unequivocally that inorganic arsenic
is a carcinogen in test animals (Kuroda, 1983) .
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Oswald and Goerthler (1971) do not provide convincing evidence that
arsenic is an oncogen, however, the Agency has never claimed this study
demonstrates arsenic oncogenicity (Kuroda, 1983).
Comment Issue #23: inorganic arsenicals PD 1 testimonials
The AWPI (36C) comments that the Agency must use as supporting evidence
the 216 testimonials submitted in response to the PD 1 that claimed, through
firsthand knowledge, that no adverse effects were associated with exposure
to arsenically treated wood.
Agency Response:
Reports based on first-hand experience involve limited numbers of people
and can involve many uncontrolled variables which only standardized testing
can control or monitor. Therefore, the Agency cannot use these submissions
as evidence due to the nontechnical nature of such claims.
Comment Issue #24: Dermal absorption of inorganic arsenicals
The AWPI (36C) states that the Agency has not distinguished between
insoluble arsenic per s>e and fixated arsenic on treated wood. The AWPI (36C)
states that the Agency has not properly interpreted the reason the Occupational
Safety and Health Administration (OSHA) decided not to regulate arsenical-
treated wood under the OSHA workplace standard (1978); and further cites
OSHA as stating that the Budy-Rashad study of Haiwaiian carpenter exposure
to pentavalent arsenic wood complex cannot be considered equivalent to
unbound pentavalent arsenic (43 FR 19599; May 5, 1978) .
The AWPI (36C) contends that the studies of Hood (unpublished, 1979) ,
supported by Dutkiewicz (1977), Peoples (unpublished, 1979) and Osmose (unpub-
lished, 1980) show that dermal absorption from handling arsenical treated
wood is negligible because of the highly insoluble characteristics of the
surface residue. Also, the soluble arsenic content of CCA-treated wood
residues is consistently low. AWPI (36C) further comments that in 1979
the ACA mixing technology was improved and resulted in increased surface
cleanliness of treated wood. The AWPI submits that dermal absorption from
exposure to ACA- or CCA- (oxide) treated wood should be .0000045 mg/ft2
(.0001% total residue absorption x 4.5 mg/ft2 Agency established surface
residue level for CCA-treated wood).
The AWPI (36C) also comments that although the Agency has revised the
short duration liquid dermal exposure estimate to 6 ml, it has overlooked
human exposure data (Fahlstrom, 1979; University of Hawaii at Monoa, 1977;
Tabershaw, 1978a, 1978b) which reduce the dermal absorption rate to 0.05%
in short-term duration, an insignificant dermal exposure in actual plant
operations.
Agency Response:
Inorganic salts of arsenic, no matter what their physical
properties, cannot be expected to penetrate the skin. These compounds
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vary considerably in water solubility but lack the solubility in organic
solvents that is associated with the ability to penetrate the skin
(Zendzian, 1982).
Although the Peoples (1979) arsenic dermal absorption study used
only two test animals (dogs), no evidence of arsenic absorption was seen
in either animal. Daily excretion of arsenic was on the order of 25
micrograms, all as dimethylarsenate (DMA). These negative results are
expected. Based on the properties of arsenic in the preservative form,
one would not expect dermal absorption from arsenic treated wood to occur
(Zendzian, 1982).
The Agency agrees that dermal absorption of arsenic from dry arsenic
treated wood or from arsenic-laden sawdust is estimated to be "negligible"
(Day, 1983). The exposure estimates presented in this document reflect the
aforementioned revised exposure assumption for CCA and ACA treated wood and
are detailed in Section II.B.1 of this PD 4.
The dermal absorbtion of inorganic arsenicals from liquid formulations
was discussed in Section II.B.1 of this PD 4 and was assumed to be 0*1%
(Rispin, April 18, 1984).
Comment Issue #25: Industrial plant workers background exposure to inorganic
arsenicals
The AWPI (35C) states that the Agency's estimated background exposure
level for inorganic arsenicals in industrial plants (.07 mg/m3) was assessed
using an outdated ACA mixing method. They point out that the EPA based
estimates of CCA oxides, CCA salts and ACA on a study by the California
Department of Health Services (1979), which apply only to ACA (AWPI, 36C),
and that they submitted data (Employees Insurance of Wausau, 1978; Hewitt,
Coleman and Associates, Inc., 1980; Koppers Co., Inc., 1978 and no date;
Osmose Co., 1978; Stewart Todd Associates, 1979; Stewart Todd Associates,
1980) indicating that the treating plants utilizing liquid or paste CCA
concentrates are within the OSHA airborne iorganic arsenic standards. Based
on these data, the AWPI claims that the CCA background level should be revised
to less than 0.005 mg/m3 (AWPI, 36C). Moreover, they believe the monitoring
data presented by Stewart-Todd Associates (1980a; 1980b) supports revision of
the ACA background level to less than 0.006 mg/m3.
The AWPI (36C) also comments that more recent data (NIOSH, 1981) indicate
0.001 mg/m3 represents background inorganic arsenic exposure levels in industrial
treatment plants.
Agency Response:
The EPA's estimate of 0.07 mg/m3 represents the upper limit of a time
weighted average (TWA) found by the California Department of Health Services
(1979) in an ACA plant. However, this plant may have been atypical in
that the mixing systems were open and involved the mixing of dry ingredients.
As discussed in Section II.B.1 of this document, the Agency has reevaluated
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data summarized in the PD 1 on arsenic air levels and has also reevaluated
data submitted by AWPI in response to the PD 2/3 (36C,, Exhibit 1 Vol. 1,
pp. 244-246) showing a correlation between urine levels in humans exposed to
airborne arsenic, which indicates that the level of 10 ug/m3 is a reasonable
estimate for airborne arsenic in a wood treatment plant. Therefore, the
exposure estimates in this document were based on 10 ug/m3 arsenic averaged
over an 8-hour workday. This is consistent with the OSHA TLV.
Comment Issue #26: Wood foundations
The AWPI (36C) contends that, based on recently-developed data on
CCA-treated wood leaching (Osmose, 1981), the Agency's revised exposure
estimate for a person cleaning a flooded all-weather wood fundation (AWWF)
basement (Osmose, 1981) is still too high (43.2 mg/ft2). In addition to
these leach test results, consideration of the ratio of edge grain to end
grain wood (i.e., most leaching should occur at edge grain), increase in
osmostic pressure in a flooded basement, as well as the fact that homeowners
usually pump contaminated water out of a basement (AWPI, 1981), would yield
an estimated leaching rate of 6.5 mg/ft2.
The AWPI (36C) suggests that the Agency lower its exposure estimates for
sweeping basement floors from 1,267 ppra to 354 ppm, because there are two
types of dust which would collect in a basement: (1) that already on the
surface of treated wood and (2) dust which accumulates over time. Also, a
study used by the Agency to establish dust exposure levels in wood foundation
homes (Sleater and Berger, 1977) states that "The samples taken from wood
surfaces were likely to contain wood particles." Therefore, the AWPI (36C)
contends that EPA's model based on sweeping basement floors, does not apply
to the high value of 1,267 ppm and that the Agency must use the next lowest
exposure level, 354 ppm, listed by Sleater and Berger (1977).
Agency Response:
The Agency will accept the commenter's recommendation of a leaching rate
of 6.5 mg/ft2 for flooded basements, based on the experimental evidence
presented (Day, 1982). This rate was used in developing the arsenic risk
(Rispin, April, 1984).
Secondly, the Agency reiterates the PD2/3 (p. 188) position that the
Sleater and Berger (1977) study reported levels of 2-1267 ppm of arsenic in
house dust. The higher levels were in homes where the treated wood was
exposed. These data were based on analytical reports for eleven dust
samples. Therefore, the Agency has determined that the highest value
reported is an accurate measure of arsenic in household dust.
Comment Issue #27: Inorganic arsenicals inhalation exposure from handling
and sawing wood
The AWPI (36C) states that in revising the PD 2/3 inhalation exposure
estimate for handling and sawing wood, the EPA ignored monitoring data of
workers handling and sawing treated wood in occupational settings. Based on
data (Minnesota State OSHA, 1974 and Wisconsin Department of Human and Social
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Services, 1977) submitted, the AWPI (36C) contends that 0.024 mg/m3 rather
than 0.36 mg/m3 is a more accurate reflection of workplace airborne arsenic
exposure during sawing and handling treated wood.
The AWPI (36C) also contends that for a handling and sawing wood
risk assessment the Agency must also take into account that: 1) 70% of
respirable dusts are retained in the lung (Thomson and Pavia, 1974), 2) an
estimated less than 20% of non-respirable sawdust particles reach the bronchi,
and 3) arsenic in treated wood is not the same as arsenic per se.
Agency Response:
Based on the data provided by the AWPI (36C) (Minnesota State OSHA,
1974 and Wisconsin Department of Human and Social Services, 1977), the
Agency will assume that persons working with arsenic treated wood (sawing,
nailing, fabricating) are exposed to an arsenic air concentration of
0.024 mg/m3 (Day, 1982).
The Agency assumes there is little or no arsenic absorption in the
lungs per se from dust or sawdust from arsenic treated wood. Most material
would be deposited in the bronchial passageways, brought up by ciliary action
and swallowed. Absorption would then follow from the digestive tract
(Zendzian, 1982).
Conversely, Peoples and Parker (1S79) have shown that significant
quantities of arsenic can be absorbed from ingested sawdust. The actual
portion of ingested arsenic absorbed is affected by the solubility of the
arsenic compounds and the size of the particles. It is estimated that 27%
and 65% of the arsenic form CCA-treated and ACA-treated wood particles
that are inhaled from handling and sawing such wood are absorbed
(Zendzian, 1982).
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B. Comments on Benefits
The Agency received several comments on the financial impact on the home
and farm market of restricted use pesticide classification from the Gibson-
Homans Company (3), Coopers Creek Chemical Corporation (4), National Solvent
Corporation (6), Soult Wholesale Company (8), Cedar Pence Distributors
Company Inc. (9), Dries Building Supply Company (11), Sampson Paint Manufac-
turing Co., Inc. (12) Standard Concrete Products Company (13), Lloyd H.
Daub, Inc. (15), Harboro Lumber Fuel Company (16), C. A. Niece Company
(19), GAP Supply Center (21), RAECO Products (22), Michlin Chemical Corporation
(25A), Missouri Department of Agriculture (28) and Carson's Hardware (29).
(39) Seven comments addressed additional costs to the consumer due to
wood preservative unavailability. Sentinel Wood Treating, Inc. (2); Illinois
Power Company (5) and Consumers Power Company (31) submitted comments pertain-
ing to renewable resource waste. Cedar Fence Distributors (9), Philadephia
Reserve Supply Company (17), Missouri Department of Agriculture (28), N.Y.
Power Pool (30), Niagara Mohawk Power Corporation (42), Missouri Forest
Products Association.
Five commenters (41) made statements concerning utility and railroad
company hardship which would occur if the wood preservatives were^unavailable.
Illinois Power Company (5), the Association of American Railroads (34), *
Edison Electric Institute (35), Detroit Edison (40) and Osmose (41).
Sentinel Wood Treating, Inc. (2), National Woodworks, Inc. (24), Missouri
Department of Agriculture (28), the Association of American Railroads (34),
Missouri Forest Products Association (39) and the Nebraska Cooperative Extension
Service (51) submitted comments concerning the effects of wood preservative
cancellation on the wood industry. Good-Life, Inc. (58) commented on penta-
chlorophenol soil treatment.
Agency Response:
The Agency acknowledges the numerous benefits associated with wood
preservatives. The comments provided no additional information which sub-
stantially changed the Agency's assessment of benefits. See Section II.C
for a summary of benefits associated with wood preservative usage. Although
select market segments will incur additional costs due to regulatory decisions,
the Agency's risk/benefit assessment indicates that the health hazards
associated with some aspects of usage are considered sufficient to warrant
the required protection outlined in this document. The three wood preservatives
will continue to be available for both commercial and home farm use by certified
applicators.
C. Comments on Regulatory Options
Comment Issue #1: Disposal of treated wood
Illinois Power Company (5), Association of American Railroads (34), Edison
Electric Institute (35) and Iowa-Illinois Gas and Electric Company (50) consider
the regulation of treated wood disposal a waste of recyclable resources.
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Portland Cement Association (66) reported a poisoning incident which occurred
from burning treated wood. The American Wood Preservers Institute (AWPI)
(36P), the National Forest Products Association (NPPA) (36P) and the Association
of American Railroads (71) contend that there is no evidence burning creosote-
treated ties creates a health risk or pollution problem. The Department of
the Army (1) states that a nonhazardous landfill should be an acceptable
disposal site for treated wood.
The AWPI (36P) and the NPPA (36P) contend that the issue of treated
wood disposal is related to the Toxic Substances Control Act (TSCA) and
recommend burial as the most appropriate disposal measure although the EPA
has no evidence that arsine gas is generated from burning arsenic-treated
wood.
Agency Response:
The Agency is concerned that people will burn treated wood in fireplaces,
wood-burning stoves, and the like, and be subject to adverse health effects.
Jansson and Sundstrom (1978) and Rappe and Markland (1978) show polychlorinated
dibenzo-p-dioxins (including HxCDD) are formed from burning or heating
chlorophenates and from burning pentachlorophenol treated wood. When creosote-
treated wood is burned, various oncogenic or mutagenic compounds may be
formed. Wood treated with the inorganic arsenical compounds can produce
toxic, arsenic containing combustion products such as arsenic trioxide ash,
which is a teratogen, mutagen and oncogen, (PD 2/3, page 701). Therefore,
treated wood should not be burned in open fires or fireplaces, thereby
eliminating the potential for exposure to the toxic combustion products that
results from burning treated wood. Treated wood may be disposed of in the
ordinary trash or in accordance with the Consumer Information Sheet (CIS)
guidelines detailed in Section VII.A.3 of this document. Large quantities
of treated wood may be burned in commercial or industrial incinerators in
accordance with state and Federal regulations.
Industry will be required to provide disposal guidelines to users of
treated wood through a mandatory Consumer Awareness Program. If this program
is ineffective, the Agency will promulgate a rule under TSCA to provide
labeling instructing users of treated wood in proper handling and disposal
precautions. Por a detailed explanation of this issue see Section VII.C.
Comment Issue #2s Applicators must wear impervious gloves in all situations
where dermal contact with wood preservatives is possible.
The Nebraska Cooperative Extension Service (51) and the International
Woodworkers of America (IWA) (68) agree that protective clothing is necessary
although the IWA offers rewording suggestions concerning potential exposure.
The Illinois Power Company (5), the Association of American Railroads (34),
Edison Electric Institute (35), Detroit Edison (40), Iowa-Illinois Gas and
Electric Company (50), the U.S. Department of Energy (44) and Sentinel Wood
Treating, Inc. (2) express concern that the recommended materials confine a
lineman's movements with and on poles (35f 40, 50), are too hot (2), can
crack in cold weather (35), are of questionable efficacy (44, 68) and can
lead to serious electrical injury if breakthrough occurs (5).
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Osmose (41) states that the applicators already wear rubber gloves. The
AWPI (36F) and the NFPA (36F)recommend gloves where significant dermal contact
is expected for selected usesj/. Osmose further comments that spray applicators
of cresote and pentachlorophenol for industrial and home/farm use should
also wear head covering and eye protection, if required to wear a respirator
and protective clothing.
The AWPI (36C) suggests a clarified option for inorganic arsenicals which
would apply to liquid as well as freshly-treated wood. For brush-on application
of inorganic arsenicals, the AWPI suggests revising the PD 2/3 proposal to
read "impervious gloves which will reduce exposure."
The National Woodworks, Inc. (24) questions the glove requirement for
handling dried pentachlorophenol-treated wood. The AWPI (36C) states that
the glove requirement should not pertain to handling arsenic-treated wood
because Peoples (1979) and Hood (1979) have demonstrated that there is no skin
absorption of arsenic from dried CCA-treated wood because the arsenicals are
fixed in the wood and surface deposits are insoluble. (See Section V. A.3.;
Comment Issue #24).
Agency Response:
The Agency has not estimated a creosote dermal exposure/risk due to the
variation in chemical composition of creosote. However, the oncogenic and
mutagenic potential of creosote (see Section V.A.1, Comment Issues 1-12) is
a sufficient basis for requiring protective clothing.
For pentachlorophenol, the revised exposure/risk estimates (see Section
VI and Appendix B) justify the requirement for protective gloves and clothing.
Based on the Peoples (1979) data submitted by the AWPI (36C), the Agency has
determined that end-users need not wear gloves to handle dry, inorganic
arsenic-treated wood since dermal absorption is neligible (Zendzian, 1982).
However, the Agency has considered the comments received pertaining to
the proposed glove requirement language and has revised the proposed label
language on gloves presented in the PD 2/3. The PD 2/3 proposed labeling
required gloves "where dermal contact with creosote, pentachlorophenol and
inorganic arsenicals is possible." The proposal has been modified to require
gloves "where dermal contact is expected." For exact wording for the various
use situations, see Sections VI.C (pressure treatment uses), VI.D (poles-
groundline), VI.E (home and farm), VI.F (brush-on treatments for inorganic
arsenicals), VI.G (sodium pentachlorophenate), VI.H (millwork and plywood
and particleboard), and VILA (end-use). The Agency has concluded
that in order for the benefits of use to outweigh the risks, protective
gloves impervious to the preservative being used must be worn in the specified
_1/ Pentachlorophenol pressure treatment; pentachlorophenol/creosote poles-
groundline; industrial, home and farm use of creosote/pentachlorophenolfuse
of sodium pentachlorophenate; millwork, plywood and particleboard spray.
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use situations. This label modification should eliminate any requirement to
wear such protective clothing where it is not necessary.
Examples of glove materials required by the Agency for each chemical
will be identified on the pesticide label (see Section VI.C.2). However, it
should be noted that the use of rubber gloves (listed in the comment) is not
considered acceptable except for waterborne pentachlorophenol, based on data
received since the PD 2/3 was published (AWPI, June 7, 1983 and Silkowski,
1982). The Agency's recommendation of protective materials for pentachloro-
phenol is based on Silkowski (1982) who studied "breakthrough" times (the
time it takes a chemical to go through a barrier of protective material such
as polyvinylchloride) for various glove materials. Because the Agency has
no data on the degree of protection afforded by certain materials for creosote
or arsenic formulations, the Agency will request such data in a Notice to the
Registrants pursuant to FIFRA Section 3(c)(2)(B), in the meantime the Agency
will require applicators to use gloves made from materials recommended by
AWPI (June 7, 1983).
Comment Issue #3: Comments on Protective Clothing.
The Nebraska Cooperative Extension Service (51) agreed with the Agency's
protective clothing recommendations for the three wood preservatives. The
International Woodworkers of America (68) also agreed with the Agency's
protective clothing proposals for creosote and pentachlorophenol usage. The
AWPI (36B) and the NFPA (36B) recommended protective clothing for applicators
entering pressure-treatment cylinders, those applying pentachlorophenol as a
groundline treatment for poles, applying pentachlorophenol to millwork,
plywood and particleboard, applying sodium pentachlorophenate when "hazard
exists" and when applying 1% or greater sodium pentachlorophenate.
The Association of American Railroads (71) contends that adequate pro-
tection against creosote and pentachlorophenol applicator exposure is already
provided for railroad workers due to railmounted spray rigs. The AWPI (36C)
contends that protective clothing, such as disposable coveralls, is not
necessary for brush-on application of inorganic arsenicals.
Sentinel Wood Treating, Inc. (2) expressed concern that the recommended
protective clothing will lead to heat prostration. Monona Glove Clinic
(27), the Association of American Railroads (34), Edison Electric Institute
(35), Detroit Edison (40) and Osmose (41) also express this concern regarding
protective clothing for pentachlorcphenol and creosote usage. Edison Electric
Institute (35) and Iowa-Illinois Gas (50) suggest cotton clothing for protection
against exposure to creosote and pentachlorophenol during groundline treatment
of poles.
National Woodworks, Inc. (24) questions the need for protective coveralls
when handling dry, pentachlorophenol-treated wood. The AWPI (36C) contends that
the Agency has provided no evidence that this requirement is necessary for
dry, arsenic-treated wood.
Osmose (41) and Edison Electric Institute (35) also contend that the
11 1
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recommended protective clothing is not quantitatively justified for protection
against creosote and pentachlorophenol during groundline treatment of poles
and for sawing wood. Detroit Edison (40) and Osmose (41) state that regulation
will increase creosote and pentachlorophenol poles groundline treatment cost;
Detroit Edison (40) estimates that changing clothes will consume 25% of each
workday, or amount to $25 million (1982 dollars assumed).
Agency Response:
Most of the comments are in agreement with the Agency's proposed protective
clothing requirements. Those which did not agree on specific points are
discussed below.
As stated previously, in the Agency response to Comment Issue #16 on
creosote (Section V.A.1) and Comment Issue #9 on pentachlorophenol (Section
V. A. 2) the Agency agrees that, with remote control application equipment
for non-pressure treatment of railroad ties, exposure would be lower than
with other application methods, such as spray or brush-on. However, the
applicator may also be involved in loading, maintaining and cleaning the
equipment as well as mixing and/or diluting the preservatives, which provides
an opportunity for exposure. Therefore, protective clothing will be required
for workers applying wood preservatives to railroad ties.
Due to exposure which could result from brush-on treatment with
inorganic arsenicals (Section VI.F), the Agency has concluded that impermeable
coveralls are necessary for this use.
Because the specified protective clothing must be worn only at certain
times (i.e., relatively short periods of time, such as entering pressure
treatment cylinders, during actual non-pressure treatment application or
handling freshly-treated wood), heat stress should not be a major problem.
Cotton coveralls, however, do not provide adequate protection against exposure
to creosote and pentachlorophenol. See Section VI.C.2 for further discussion
of the types of materials which minimize dermal exposure to wood preservatives.
The Agency has reconsidered its proposal concerning the use of protective
coveralls while handling dry, arsenical treated wood and concluded, based on
review of potential dermal exposure data that protective overalls are not
needed. Gloves will be required for handling creosote and pentachloropenol-
treated wood. (See Section VII.A.1.)
Creosote for poies-groundline treatment poses potential oncogenic and
mutagenic risks to humans, and pentachlorophenol poses potential oncogenic
and teratogenic/fetotoxic risks, though these risks have not been quantified.
Dermal exposure to poles-groundline applicators occurs during handling and
applying the wet wood preservative paste. Potential splattering of solutions
onto exposed skin surfaces warrants protective coveralls when using creosote
and pentachlorophenol formulations.
Any increase in industrial treatment costs due to clothing modifications
would be relatively minor. That is, neoprene-coated cotton overalls cost an
estimated $10.50 - $18.50 per pair; a jacket costs $10.50 - $20.35. It is
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estimated that if this protective clothing were replaced annually, total cost
to industry would equal an estimated $28,055 (Esworthy, 1980). Because
wearing protective clothing in the area of the cylinder is already required
by many plant safety rules (AWPI, 1980), the Agency believes that implementa-
tion costs should have little economic impact on the wood preservative in-
dustry.
Although dermal and inhalation exposures for sawing creosote or penta-
chlorophenol-treated wood have not been quantified, the Agency maintains that
there is a potential risk associated with such activity. The oncogenic risk
of sawing arsenic-treated wood has been quantified (see Section VII.A.2).
The potential risks involved with sawing creosote and pentachlorophenol
treated wood warrants requiring coveralls for this activity. The requirement
of a dust mask when sawing treated wood is also necessary.
Comment Issue #4: Protective clothing disposal
In lieu of the Agency's PD 2/3 proposal to dispose of contaminated
protective clothing in accordance with the instructions for pesticide container
disposal, the Association of American Railroads (34) suggested general trash
disposal as an adequate method of discarding contaminated protective clothing.
Osmose (41), the AWPI (36B and 36C) and the NFPA (36B) contend that this
proposal is duplicative of existing regulations (e.g., RCRA).
Osmose (41) requested specification of disposable clothing.
Agency Response:
The intent of the Agency's position on disposal of contaminated protective
clothing is to prevent continued usage of obviously contaminated clothing,
and to provide for safe disposal of the materials. Disposable clothing
would include relatively inexpensive, lightweight materials which are impervious
to penetration by the pesticides.
The Agency has concluded that protective clothing should be changed when
it shows signs of contamination, that it should be left at the treatment plant
at the end of the workday, and that worn-out protective clothing or disposable
clothing should be disposed of in a general landfill, in the trash, or any
other manner approved for pesticide disposal* Protective clothing that has
been contaminated with inorganic arsenicals must be disposed of in a manner
approved for pesticide disposal and in accordance with State and Federal
regulations. See Section VI.C.6 of this document for additional details.
This is consistent with existing regulations for disposal of unused pesticide
formulations [subtitle C of RCRA (Resource Conservation and Recovery Act)].
Comment Issue #5: Leaving protective clothing at treatment plant and
cleaning of protective clothing
The AWPI (36C) agreed with the PD 2/3 recommendation that protective
clothing/equipment should be left at the plant. The International Woodworkers
of America (68) questioned whether wearing contaminated clothing on successive
days will be discouraged, whether cleaning of protective clothing will be
required, as well as specific details (replacement and frequency of cleaning)
of this requirement.
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Agency Response:
The Agency has concluded that, in industrial settings, protective clothing
should be left at the plant at the end of the day to avoid potential household
contamination and that protective clothing should be changed when it shows
obvious signs of contamination (Section VI). For home and farm uses, poles-
groundline, and brush-on treatments of the inorganic arsenicals, the Agency
has concluded that protective clothing should be changed when contaminated
with the pesticides, non-disposable protective clothing should be laundered
seperately from other household clothing, and disposable or worn-out protective
clothing should be disposed of in a general landfill, in the trash, or any
other manner approved for pesticide disposal. Inorganic arsenically con-
taminated protective clothing must be disposed of in a manner approved for
pesticide disposal and in accordance with State and Federal regulations.
The Agency will not address the specific details regarding replacement
or frequency of cleaning protective clothing; these are issues that should be
resolved by the industry/union negotation process.
Comment Issue #6: Respiratory protective equipment
Sentinel Wood Treating Company (2), Kerr-McGee Corporation (33), the
Association of American Railroads (34) and Edison Electric Institute (35)
commented on the PD 2/3 proposals for the use of a respirator for various
exposure scenarios for the three wood preservatives. Comments refer to
worker discomfort, lack of quantifiable pentachlorophenol and creosote air
concentrations as a basis for the requirement, unnecessary Agency exposure
limits due to existing OSHA standards, workers affected and reliance on
manager's discretion. The U.S. Department of Energy (44), also commenting
on PD 2/3 stipulations, states that a respirator should be NIOSH-approved.
The AWPI (36B) and the MFPA (36B) stated that either the concept of a
"threshold limit value" (TLV), which would trigger the respirator requirement,
or OSHA's Permissible Exposure Level (PEL), which sets the maximum air con-
centration over an 8-hour period at 0.5 mg/m^ should be adopted for
pentachlorophenol/sodiura pentachlorophenate for opening and/or entering
millwork/plywood pentachlorophenol vats, pressure treatment and spray cylinders,
and for cleaning sapstain control tanks.
The AWPI (36C) also stated, with regard to the PD 2/3 inorganic arenical
proposed regulatory options, that inhalation exposure in or around a cylinder
is no greater than background air arsenic dust levels in treatment plants,
which does not justify requiring use of a respirator, and therefore a respirator
should not be required in cylinders. AWPI (36) also state that if a respirator
is required, the Agency should specify the type.
The AWPI (78), commented that proper respirator use and fitting should
be covered by state training programs for restricted-use applicators. AWPI
(36C) contends the dust mask requirement for working outdoors in arsenic
wood-treating plants should be dropped since revised exposure data (see
Comment Issue #22) indicates background and most personal monitoring levels
are less than OSHA requirements (AWPI, 36C). However, the International
Wood Workers of America (IWA) (68) and Friends of the Earth (FOE) (64) are
concerned that a dust mask requirement for treatment plant applicators,
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proposed at the wood preservatives April 14, 1983, public meeting^/, would
not provide sufficient protection for arsenic pressure treatment plant applicators.
The IWA (68) also questions whether required air samplings refer to personal
or area samples.
The AWPI (78) comments that pentavalent arsenic is not associated with
excess respiratory cancer risk, at less than 500 ug/m3 (Higgins, 1983), and
therefore, the dust mask requirement proposed in the PD 2/3 and April 14,
1983, public meeting is not necessary.
Illinois Power Company (5), the Association of American Railroads (34) and
Edison Electric Institute (35) object to the dust mask restriction for sawing
and fabricating pesticide-treated wood and request clarification of "fabrication"
with wood. The AWPI (36C) agrees with the dust mask requirement for
sawing treated wood only because general sawdust exposure presents a
health hazard.
Agency Response:
Based on the PD 2/3 qualitative estimates of creosote risks, revised
pentachlorophenol and sodium pentachlorophenate air concentrations and dermal
absorptions (see Section II), the Agency has concluded that MSHA/NIOSH-
approved respirators are required for those pentachlorophenol and creosote
uses which include opening and entering pressure treatment cylinders. Based
on qualitative and quantitative data, respirators will also be required if a
visible mist (aerosolized solution) is present in the vicinity of an enclosed
spray booth during non-pressure uses of pentachlorophenol and sodium
pentachlorophenate. The requirement of a respirator is necessary for the
benefits of use to outweigh the risks in these exposure situations.
The Agency has reevaluated the regulation proposed in the PD 2/3 which
would require that all arsenic treatment plant workers wear dust masks. In
view of new data and a revised risk assessment (see Section II of this PD-4)
the Agency has chosen a permissible exposure limit (PEL) of 10 ug/m3 averaged
over eight hours for airborne arsenic. Employees in the work area of an
arsenical-wood treatment plant must wear properly fitting, well maintained,
high efficiency MSHA/NlOSH-approved filter respirators if the level of
inorganic arsenic in the plant is unknown or exceeds the 10 ug/m3 PEL.
For a more detailed discussion of this issue see Section VI.C.1.
_V The Agency held a public meeting on April 14, 1983 (See 48 PR 13257,
March 30, 1983 for announcement of meeting) to give interested persons the
opportunity to comment on certain changes to the decision proposed in the
Preliminary Notice of Determination (46 PR 13024-13029, February 19, 1981)
as set forth in the Position Document 2/3. The comments received have been
considered in the development of this final decision and are discussed in
detail in this Position Document (PD 4). The' final position set forth herein
reflects changes made in response to such comments and further evaluation by
the Agency since receipt of the comments.
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Fabrication can be defined as construction or manufacture with treated
wood (e.g., machining or nailing), which would include activities which may
lead to user inhalation exposure to airborne treated wood particles and
which can be prevented by using a dust mask. The Agency is recommending
the use of dust masks for all treated wood end-users who will be exposed to
airborne treated-wood particles, regardless of the actual occupation (e.g.,
utility, railroad workers, home and farm) of such users. A more detailed
discussion of the basis for this requirement is contained in Section VII.A.2.
Comment Issue #7: Prohibition of treated wood use to prevent direct exposure
to domestic animals, livestock, as well as contamination
of food, feed, drinking and irrigation water
Illinois Power Company (5), the Missouri Department of Agriculture (28),
Consumers Power Company (31), the Association of American Railroads (34), Edison
Electric Institute (35), the Missouri Forest Products Association (39) and Iowa-
Illinois Gas and Electric Company (50) commented that the wording of this PD 2/3
proposed prohibition, if strictly interpreted, would eliminate all agricultural
uses of pentachlorophenol (28), utility poles support structures (31) and
treated wood bridges (34). Edison Electric Institute (35), stating that
exposure does not constitute contamination, suggested a prohibition against
continuous exposure. The Missouri Department of Agriculture (28) and the
Missouri Forest Products Association (39) cite a study (Van Gelder, 1977)
which concludes that inadvertent exposure of cattle to pentachlorophenol-treated
wood could not result in adverse health effects to humans. According to the
Illinois Power Company (5), the relatively short life span of an animal would
prohibit any measurable milk and meat preservative level increase, while the
Missouri Forest Products Association (39) contends that contamination of
animals would be controlled through threshold limit values (TLV's) for feed
and water.
The AWPI (368) and the NFPA (36B) cite several studies (Firestone et al.,
1979; McConnell et al., 1980? Forsell et al., 1980; Kinzhill et al., 1980;
Osweiler, 1980; (unpublished); Van Gelder and Greichers et al., 1979) which
indicate that, at the actual levels of exposure within a barn containing
pentachlorophenol, no adverse health effects are expected with the exception
of pig farrowing houses and poultry bedding, for which a voluntary information
program can warn users of the hazards. These commenters contend that wood
treaters cannot be required to know the end-use of their wood.
The AWPI (36B) states that the Agency should clarify whether concern with
domestic animals is due to food contamination or animals' health. The Missouri
Forest Products Association (39) and the AWPI (36C) state that use of treated
agricultural stakes show no additional dietary contamination (Levi et al.,
1974; Jelinek and Cornelinsen, 1977; and Yoder, 1981) and that prohibition of
use of stakes would also be very costly. The AWPI (36C) maintains that
brush-on inorganic arsenicals should be allowed on these stakes because the
Agency and the FDA have already determined that low level organic arsenical
food residues are acceptable.
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Agency Response:
The intent of the Agency's proposed restriction concerning treated wood
and domestic animals is to prohibit domestic animals from continued treated
wood exposure. The principal problem regarding animal contact with treated
wood is potential chemical residues in food products of animal origin rather
than toxicity in animals. For example, the relatively short life span of a
food animal does not preclude measurable amounts of pentachlorophenol in
milk and meat (Firestone et al., 1979).
According to the 1971 Environmental Protection Agency/Food and Drug
Administration memorandum of understanding regarding matters of mutual
responsibility under the Federal Food, Drug, and Cosmetic Act (FFDCA) and
the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA), the EPA has
the responsibility for food additive regulations for pesticides that are
added to food contact materials to protect the food from pests. All other
petitions for the use of pesticides in food contact materials are assigned
to FDA. Wood preservatives) therefore,, are subject to regulation by FDA if
the wood is used as a food contact material. Specifically, preserved wood
cannot be used where the preservative may become a component of food or feed
unless such use has been shown to be safe and a food additive regulation
promulgated under section 409 of the FFDCA (Kile, 1983). However, registration
and labeling of the preservatives themselves which may be required by FIFRA
are under EPA's jurisdiction (Hile, 1983).
FDA has issued a regulation (21 CFR 178.3800) for the use of penta-
chlorophenol and sodium pentachlorophenate at levels up to 50 parts per
million in wood contacting raw agricultural products. Creosote and inorganic
arsenicals are not currently authorized for uses where they come in contact
with raw agricultural products (Hile, 1983). FDA has also not issued any
regulations for wood preservatives in treated wood which may come in contact
with food or feed. Therefore, the Agency is requiring that the consumer
information sheet (CIS) contain a statement prohibiting treated wood coming
in contact with food and feed. If registrants wish to provide for use of
treated wood in contact with food and feed, FDA must be petitioned to obtain
approval for that use.
EPA has established human drinking water restrictions and has recommended
discontinuation of use of coal tar-based and associated materials, which may
result in drinking water contact (Cotruvo, 1983). Accordingly, the Agency
will require either through the CIS or, if that proves to be ineffective,
under TSCA that creosote-treated wood should not be used where it will come
in contact with drinking water. Based on health-related criteria established
by the National Academy of Sciences (NAS) Committee on Waste Treatment
Chemicals (1983), the EPA will also require through the CIS or under TSCA
that neither pentachlorophenol-treated or arsenic-treated wood be used
where it may come into contact with public drinking water (Cotruvo, 1983).
Use of treated wood for docks and bridges where there may only be incidental
contact with drinking water will not be prohibited. Lastly, the EPA will
also require through the CIS that pentachlorophenol-treated and creosote-treated
wood not be used where it may come into contact with drinking water for
1 17
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domestic animals. Arsenic-treated wood will be allowed for such uses, however,
because the arsenic levels in water which is in contact with treated wood
are below 200 ppb, a level stated to be acceptable (U.S. EPA, March 1973).
Comment Issue #8s The prohibition of applying creosote, pentachlorophenol
and inorganic arsenicals to wood intended for indoor use
Several commenters contend that the benefits of indoor use of treated
wood justify continued use and proposed alternative means of reducing exposure.
The American Institute of Timber Construction (10) and Structural Wood Systems
(14) request that interior use of pentachlorophenol-treated and inorganic
arsenical-treated wood be permitted for glued laminated timber structural
members because current technology does not provide other preservatives that
are protective, gluable and accept finish. The AWPI (36B) and the NFPA (36B)
support interior use of wood preservatives by stating that pentachlorophenol
is essential for pre-treatment of wood in laminated beams because it is the
only pesticide for wood pressure treatment that allows proper glue bond strength.
Levin (60) commented that occupants of California State buildings with
pressure-treated glued laminated structural beams have been exposed to penta-
chlorophenol levels which may have caused physiological irritation. Levin
(60) stated that sealing this wood with two coats of polyurethane would
reduce exposure substantially. The AWPI (78) has recommended ventilation or
sealers as a solution to pentachlorophenol exposure due to interior use
of treated wood.
Roberts Consolidated Industries (20) also requests that interior use of
5% pentachlorophenol-based water repellent wood preservative, which binds
to wood cells and does not migrate, be allowed with subsequent sealer usage.
The Jenson-Wright Corporation (37), which manufactures and seals creosote-
treated and pentachlorophenol-treated wood block flooring with coal tar
pitch and urethane, states that the Agency has not presented data which make
this proposed regulation necessary.
The Missouri Department of Agriculture (28) and the Forest Products
Association of Missouri (39) contend that the proposed treatment of the
bottom six inches of stall skirtboards, which measure four to five feet high,
is unreasonable and impractical; this area would soon be covered with dirt.
The AWPI (36B) and the NFPA (36B) state that the prohibition of applying
pentachlorophenol to wood intended for indoor use would severely restrict
pentachlorophenol use in farm, storage and public buildings where the low
volume of pentachlorophenol-treated wood, sealant usage and lack of prolonged
occupancy of public buildings precludes health risks. These commenters
suggest that the Agency prohibit interior use over large surface areas, except
for cases in which sealants are used; support structures, subject to decay,
should also be excluded (AWPI, 36B and NFPA, 36B).
The AWPI (36C) believes that the prohibition of inorganic arsenic-
treated wood intended for indoor use should apply to brush-on inorganic
arsenicals, excluding this usage for machined, pressure treated wood.
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Koppers Company, Inc. (89) and AWPI (36C) commented that the Agency should
allow arsenic-treated wood for all interior uses where wood is subject to
decay or termites.
However, other commenters state that the risks of indoor use of treated
wood warrant the proposed restriction. Nebraska Cooperative Exterior Service
(51), Friends of the Earth (FOB) (64 and 70), Center for Disease Control (COC)
(69) and the NFPA (75) support the restricted interior use of treated wood.
The FOE (70), CDC (69), and California Department of Health Service (Jackson
and Stratton, 87) comment that breathing pentachlorophenol-treated wood
fumes, including log homes, can result in skin, respiratory and nervous
system disorders as well as relatively high blood and urine pentachloro-
phenol levels. Portland Cement Association (66) requests .that in order to
reduce health hazards, arsenic-treated all-weather wood foundations be
included in these restrictions.
Agency Response:
Although the benefits of preserved wood for glued laminated structural
members may be greater than the Agency originally thought, these commenters
did not provide, and (as at the time of the PD 2/3) the Agency is unaware of
data allowing quantitative benefits estimates (Eckerman, 1981).
The Agency has revised its risk estimates concerning indoor usage of
pentachlorophenol treated wood. Estimates for pentachlorophenol treated wood
are based on revised daily exposure [International Symposium on Indoor Air
Pollution Health and Energy Conservation, 1981 and the AWPI (36B), 1981]
and volatilization information provided by USDA (1981), the AWPI (36B) and
the NFPA (36B) (Day, March, 1982 5/82/May 1982, and Dec. 1983). Based on
these revised estimates, as well as sealer information (USDA, 1981) and
comments from the AWPI (36B) and the NFPA (36B), the Agency has concluded that
pentachlorophenol-treated wood should not be used in residential, industrial, or
commercial interiors except for lamintated beams or building components which are
in ground contact and are subject to decay or insect infestation and where two coats
of an appropriate sealer are applied. Creosote-treated wood should not
be used in residential interiors. Creosote-treated wood in interiors of industrial
buildings should only be used for wood-block flooring and industrial building
components which are in ground contact and are subject to decay or insect
infestation and where two coats of an appropriate sealer are applied. (See
Section VI.E.9 and VI.H., and A.4. for more detail.) For use of treated wood
in farm buildings, see Section VII.A.5 for restrictions dealing with the
potential for cribbing or licking treated wood. Pentachlorophenol or creosote
treated wood may be used where animals cannot crib (bite) or lick the wood,
only if a sealer is used.
The Agency will allow industrial use of creosote pressure-treated wood
block flooring if an appropriate sealer is used. The model CIS contained in
Section VII.C of this PD 4 summarizes the restrictions on interior use of
treated wood.
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For inorganic arsenical-treated wood, revised estimates were based on
exposure data submitted by Koppers (Nov. 15, 1983). Based on these
estimates, waterborne arsenic-treated wood may be used inside residences
as long as the wood surfaces are vacuumed, thus reducing exposure to
arsenic-laden dust. The Agency will also allow brush-on treatments of the
inorganic arsenicals for the cut-ends of arsenic pressure-treated wood. In
estimating risk to residents of homes containing arsenic-treated wood,
the Agency assumed an arsenic air concentration of 0.004 ug/m3 based on
Koppers (Nov. 15, 1983).
The estimated upper limit exposure and risk are summarized in "Appendix
B and Appendix C. USDA (1980) indicated that the maximum arsenic air level
in homes constructed with masonary basements was 0.019 ug/m3. This value
does not significantly differ from that found for homes with all-weather-
wood-foundations; it is lower by less than a factor of 2. The Agency has
concluded that the benefits of use of all-weather-wood-foundations outweigh
the estimated upper limit risk and that if surfaces are cleaned, arsenic
pressure-treated wood may be used in interiors of residences.
Comment Issue #9: Restricted use pesticide classification
Several commenters object to restricted use classification of creosote
for home and farm use: the Gibson-Homans Company (3), Coopers Creek Chemical
Corporation (4), National Solvent Corporation (6), National Paint Center
(7), Soult Wholesale Company (8), Dries Building Supply Company (11), Sampson
Paint Manufacturing Company Inc. (12), Standard Concrete Products Company
(13), Lloyd H. Daub, Inc. (15), Hatboro Lumber and Fuel Company (16), Doyles-
town Lumber and Millwork Company (19), C.A. Niece Company (21), GAF Supply
Center (22), RAECO Products (23), Monsey Products (25), Michlin Chemical
Corporation (29), Carson's Hardware (38), G.M. Deck & Sons (47), Ecological
and Speciality Products, Inc. (56), Walpole Woodworkers (57) and The Reliance
Company (59). Iowa-Illinois Gas and Electric Company (50) and Osmose (41)
disagreed with restricted use classification of all creosote products for
poles groundline while the Association of American Railroads (34) does not
agree with the Agency's restricted use classification for crossties treatment.
The Agency received comments concerning pentachlorophenol restricted
classification for home and farm use (Michlin Chemical Corporation, 25),
pressure treatment use (Missouri Department of Agriculture, 28), use on
adzed crossties (Association of American Railroads, 34), poles-groundline
use (Osmose, 41 and Iowa-Illinois Gas and Electric Company 50) as well as
non-site/use specific comments on pentachlorophenol'restricted classification
(Arneson Timber Company, 46 and McPhillips Manufacturing Company, 49).
Nebraska Cooperative Extension Service (51) approved of the restricted use
classification.
The AWPI (36C) agreed with the restricted use classification for brush-on
inorganic arsenicals, but commented that restricted use classification for
sodium pentachlorophenate is unnecessary since EPA-proposed work practices
would eliminate exposure.
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Agency Response:
The Agency is concerned that home and farm (creosote and pentachlorophenol),
poles groundline (creosote and pentachlorophenol) and brush-on (inorganic
arsenicals) application of wood preservatives by untrained applicators will
lead to potentially unacceptably high risk for such users. The Agency
continues to be concerned about the potential oncogenic and mutagenic risks
for creosote, the potential oncogenic and teratogenic/fetotoxic risks for
pentachlorophenol (MOS=12 for home and farm use even with protective gloves),
and the potential oncogenic and teratogenic risks for the inorganic arsenicals*
After review and analysis of all available data and information, the Agency
believes the potential risks associated with exposure to wood preservatives
mandate a restricted use classification with one exception. The Agency
has determined upon reevaluation of certain exposure situations, that the
restricted use classification is not necessary for inorganic arsenical brush-on
treatments to the cut-ends of arsenic treated wood during commercial con-
struction. Moreover, the Agency has determined that the restricted use
classification should also be required in light of the potential oncogenic
and teratogenic/fetotoxic risks from uses of sodium pentachlorophenate (see
Section VI and VIII for modifications to the terms of registration for the
wood preservatives). Appendix B presents a summary of the quantifiable
risks associated with pentachlorophenol and the inorganic arsenicals.
Comment Issue f10: Restriction of wood preservative products with greater
than 5% pentachlorophenol active ingredient
The AWPK36B) and the NFPA <36B) re'quest that the pentachlorophenol
restriction be modified to 6% technical pentachlorophenol products since over-
the-counter products contain 5.3%-5.5% technical pentachlorophenol. Osmose
(41) states that this restriction is unnecessary because products contain-
ing pentachlorophenol are sold "over-the-counter," therefore, classifying
these products as restricted use pesticides would do little in the way of
reducing exposure.
Agency Response:
The Agency has recalculated the pentachlorophenol risk using a multi-
stage oncogenic risk model and determined, based on these revised data,
that the potential oncogenic risks associated with pentachlorophenol are
higher than originally calculated. The potential teratogenic/fetotoxic
risks are also higher than those estimated in the PD 2/3 due to changes in
the exposure estimates as described in Section II.B.2 of this document.
Because of these high potential risks, the Agency has concluded that all
wood preservative products containing pentachlorophenol must be classified
for restricted use by certified applicators or must be applied under the
supervision of a certified applicator. For a detailed review of the risk
model see Section II.A.3. A comparision of the PD 2/3 potential risk
estimates with the current risks is provided in Appendix B.
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Comment Issue #11: Labeling of treated wood
Several commenters were opposed to the implementation of a labeling rule
under the Toxic Substance Control Act (TSCA). National Woodworks, Inc. (24)
does not understand the need to label their millwork products while the
Association of American Railroads (34) state that such an action would be
impractical. The Missouri State Department of Agriculture (28) and the
Forest Products Association of Missouri (39) comment that the Agency is
holding wood treaters responsible for end-use of these products. Edison
Electric institute (35) comments that as end users all utility companies
would be required to comply with labeling precautions.
^
The AWPI (36A, 36B, and 78) and the NFPA (36B) comment that labeling under
the Toxic Substances Control Act (TSCA) would be costly, inflexible, ineffective
and would invite product liability suits (e.g., allegations of negligence);
that disposal controls should be promulgated under the Resource Conservation
and Recovery Act (RCRA); and that a voluntary program would be faster and more
efficient.
Edison Electric Institute (35) comments that the end-use hazards are
not sufficient to warrant TSCA-action. The AWPI (36A, 36B and 78) and
the NFPA (36B) state that long-term risks associated with treated wood usage
are unknown. The AWPI (36C) also comments that the TSCA labeling recommenda-
tions concerning protective clothing and dust masks for handling and/or
sawing arsenic-treated wood, interior usage of arsenic-treated wood and the
use of arsenic-treated wood for vegetable stakes, mushroom trays, feedlots
and feed bins is unnecessary because there are no exposure problems associated
with these uses.
Friends of the Earth (FOE) (64) contends that any proposed warning that
is voluntary would be unsatisfactory. Also, FOE (64) suggests that any
consumer awareness information include the fact that pentachlorophenol contains
dioxin.
Agency Response:
The Agency agrees that it is unreasonable to expect the wood treaters
to know how their products will be used. However, the Agency believes
end-users of treated wood should be informed about the safe handling, use
and disposal of treated wood. The Agency recommended several labeling
regulations enforceable under Section 6 of the Toxic Substance Control Act
(TSCA) in the PD 2/3. Promulgating such regulations would take three to five
years. As an alternative, the wood preserving industry, representated by
AWPI and SAWP, developed a "Consumer Awareness Program" (CAP) to inform the
public about proper use and handling of treated wood. Because of this need
to inform end-users of the hazards associated with using treated wood, and
because the Agency views the "successful implementation" of the CAP as a
viable mechanism for achieving this objective, the CAP will be required as a
condition of registration. Wood treaters will be required to participate in
a Consumer Awareness Program including the distribution of a Consumer Informa-
tion Sheet (CIS) with each shipment of pressure-treated wood throughout the
chain of commerce. The program requirements are detailed elsewhere in the
document (see Section VII.C). Statements in the CAP regarding disposal of
treated wood are consistent with RCRA.
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Utility companies, as end-users of treated wood, are expected to acknowledge
and comply with the regulatory precautions described in the CAP to minimize
risks to utility workers.
The Agency believes that the risks associated with interior use, handling
and sawing arsenic-treated wood warrant the suggested protective requirement.
(See Sections VII.A.4 and VI.F for details.) Inorganic arsenicals are not
presently authorized for uses where they may become components of food and
feed. Registrants must petition the FDA for such a provision.
Comment Issue #12: Closed emptying and mixing system required for all
prilled (granular) or flaked formulations of
pentachlorophenol and for powdered sodium pentachloro-
phenate
Michlin Chemical Corporation (25) contends that there is no hazardous exposure
associated with their manufacturing process. In order to make pentachlorophenol
preservatives from prilled/granular raw material, Michlin Chemical (25)
calculates that the 1980 total exposure time equaled 50 minutes (10 batches
made at 5 minutes per batch to open and empty bags}, with applicators wearing
protective clothing and respirator.
The International Woodworkers of America (IWA) of Oregon (63) and
Washington (68) contend that the exposure and risk associated with mixing
warrants closed systems.
The AWPI (36B) and the NFPA (36B) suggest that persons engaged in mixing
pentachlorophenol or sodium pentachlorophenate wear protective clothing and
a respirator if the airborne level exceeds an 8-hour threshold limit value
(TLV) of .5 mg/m3. The AWPI (36B, 78) and the NFPA (36B) also suggest
that treaters be allowed the option of either protective clothing and respirator
or a closed system, in order to avoid imposing an adverse economic impact on
small treatment operations.
Michlin Chemical Corporation (25) states that a "closed system" is not
defined.
Agency Response:
The Agency has evaluated exposure time associated with opening and emptying
bags of powdered pentachlorophenol formulations and has revised its PD 2/3
exposure estimates from four hours/day for five days/week, to a maximum of
two hours/day for two days/week. With use of closed systems, exposure will
be comparable to ambient levels. If protective clothing and respirators are
used, the Agency's re-evaluation of risks indicates that the oncogenic risk
will be sufficiently reduced to a level where benefits exceed risks, taking
into account that the risk is based on a maximum exposure time (see Section
VI.C.3).
To minimize the economic impact of installing closed systems for mixing
prilled/flaked formulations of pentachlorophenol and for powdered sodium
pentachlorophenate formulations, the Agency is requiring that these systems be
"phased in" over a three-year period, with their use becoming mandatory after
September 1, 1987, for mixing and emptying prilled or flaked formulations of
pentachlorophenol and for powdered sodium pentachlorophenate.
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Closed systems are defined as any containment which prevents release
of subject chemicals into the surrounding external environment thereby
preventing human exposures above ambient air levels (PD2/3, p. 528).
Comment Issue #13: Regulation of applicator vs. handler and end-user
Consumers Power Company (31) contends that there should be logical,
practical rules for applicators who are exposed during a majority of the
workday. They further comment that handlers and end-users, whose exposure
is relatively much less than applicators, should adhere to less stringent
regulations minimizing inflationary and productivity impacts.
Osmose (41) requests clarification of the term "applicator" as a person
who is actually applying the wood preservative; since the exact terminology
used will affect the risk estimates.
Agency Response:
Protective measures are based on estimated exposure and risks for
the various uses of wood preservatives. That is, the wood preservative
applicator, whose inhalation and dermal exposure would be greater than an
individual handling dry treated wood, will be required to adhere to more
stringent protective regulatory measures. The Agency also concludes that
the requirements for the handler and end-user of treated wood minimally
affect worker productivity while providing necessary protection against
health hazards.
The Agency considers all workers associated with the treatment proces to
be "applicators" regardless of their individual activities during the work
day (PD 2/3 p. 577). Wood treatment plant workers perform varied activities
during the work day, and may be directly exposed to the wood preservatives
as a result of the treatment process.
Coment Issue #14: Prohibition of eating, drinking and smoking during appli-
cation of wood preservatives
The Association of American Railroads (34), the AWPI (36B, 36C) and the
NFPA (36B) and Osmose (41) request clarification of this prohibition concerning
the extent of area limitation and "clean" area.
Agency Response:
The Agency has clarified its label language in order to alleviate any
wood preservative misuse, and potential subsequent exposure, which could
occur due to any ambiguous label language. Section VIII summarizes all
mandatory label statements.
Comment Issue #15: Classification of selected non-pressure treatment uses
of wood preservatives
Edison Electric (35) is concerned that the Agency has not proposed
specific standards for the brush-on application of pentachlorophenol or
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creosote solutions other than for home and farm use. The Association of
American Railroads (71) contends that pentachlorophenol and creosote
brush-on/spray application, if considered a home and farm use, should not be
restricted by the Agency because of the low spray drift potential. The U.S.
Department of Energy (44) questions the Agency concerning the application
classification (e.g., poles-groundline, home and farm) of their programs,
which include powerline pole inspection and necessary subsequent treatment.
Agency Response:
Utility workers who treat wood will be subject to the same regulations
as other applicators and must be certified or under the direct supervision
of a certified applicator. The Agency is requiring that all railroad industry
applications of pentachlorophenol and creosote be made by workers who are
certified or who are under the direct supervision of certified applicators.
The U.S. Department of Energy workers will be subject to the same regulations
as other poles-groundline applicators.
Comment Issue #16: Restricted use of pentachlorophenol for millwork
McPhillips Manufacturing Company Inc. (49) challenges the need for re-
stricted use classification of pentachlorophenol for millwork. This commenter
states that the PD 2/3 fails to recognize differences in the hazards associated
with handling wet pentachlorophenol for millwork treatment vs. dry
pentachlorophenol-treated millwork products.
Agency Response: ^
\v-'
The Agency maintains, as in the PD 2/3, that applicators untrained in
the safe handling practices of pentachlorophenol for millwork could have
greater exposure than trained applicators. Therefore, pentachlorophenol
for application to millwork will remain a restricted use.
Upon reconsideration of information concerning use of pentachlorophenol
treated millwork, exposure, and sealers, the Agency has determined prohibition
of interior uses of millwork with outdoor surfaces is unnecessary. Use of
treated millwork is necessary to prevent mold or insect infestation. Because
millwork is usually painted or varnished, the Agency expects exposure from
this use of pentachlorophenol to be minimal. (See Section VII.A.4.)
Comment Issue #17: Regulation of pentachlorophenol and sodium pentachloro-
phenate spray treatment
McPhillips Manufacturing Company inc. (49) questions the need to regulate
pentachlorophenol in the millwork industry because there are no known employees
or end-users suffering physical harm from, such usage. Publishers Paper (54)
is concerned that pentachlorophenol spray booth operations will be cancelled.
However, Oregon and Washington International Wood Workers of America (63 and
68, respectively) recommend mandatory and explicit engineering controls,
e.g., spray booths and dip tanks for these uses, which they believe would be
more effective long-run measures than personal protective equipment.
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Agency Response:
Based on the exposure/risk assessment for sapstain control (sodium penta-
chlorophenate) and millwork and plywood (pentachlorophenol) the Agency is
requiring the spray apparatus be operated to minimize overspray (i.e., no
visible mist), be free of leaks, and that individuals in contact with appli-
cation equipment wear appropriate protective clothing. Based on the risk
analysis, respirators would only be required if there is a visible mist.
See Sections VI.G and VI.H for a more detailed discussion.
The Agency's regulatory options are designed to minimize risks by economical,
technologically feasible, practical mechanisms.
Rebuttal Issue #18: Agency regulation of selected wood preservatives
together
McPhillips Manufacturing Company Inc. (49) states that because of the
differences in creosote, pentachlorophenol and inorganic arsenicals, each
class of wood preservatives should be regulated differently, recognizing
different levels of toxicity, application, in-plant handling and end-uses.
Agency Response:
Creosote, pentachlorophenol and inorganic arsenicals comprise the most
widely used industrial pesticide wood treatments available (Federal Register
Notice, Oct. 18, 1978, Part II) and are often alternatives to one another.
The Agency has regulated these three preservatives together to minimize the
impact on each individual marketplace. However, the risks and benefits of
each wood preserving chemical have been evaluated separately and appropriate
regulatory measures determined accordingly.
Comment Issue #19: Alternative wood preservative
Michlin Chemical Corporation (25 and 25A) states that the alternative
wood preservatives considered in the Agency's risk/benefit analysis are not
adequate substitutes. Louisiana-Pacific Corporation (43) states that latex
paint is a suitable alternative for wood preservation without the harmful
side effects of the wood preservatives- The Nebraska Cooperative Extension
Service (51) claims that an AWPI test indicates that creosote is a superior
product for stake decay prevention.
Osmose (41) states that copper naphthenate and tributyl tin oxide (TBTO)
can only be considered "test" alternatives and cost much more than pentachlo-
rophenol. Seymour Chemicals, Inc. (52) objects that copper-8-quinolinolate
is not adequately addressed as a creosote and pentachlorophenol alternative.
Osmose (41) believes that the EPA has not made the necessary differentiation
between salt and oxide CCA formulations; ACA and CCA: and FCAP and CCA.
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Agency Response:
The Agency has received no new economic data on alternatives which would
alter the current regulatory decision. Based on the PD 2/3 benefits analysis,
the regulatory restrictions listed in this document will have a relatively
minor economic impact on the wood treatment industry.
Copper-8-quinolinolate, while it may be efficacious, does not appear to
be economically competitive with creosote and pentachlorophenol (Eckerman, 1982).
The Agency agrees with the comments that the alternatives to the three wood
preservatives used for risk/benefit analysis are not adequate substitutes in all
cases,- however, factors such as efficacy and cost of alternatives were considered
when evaluating the benefits of wood preservatives.
The comment concerning latex paint is very general. Paint would not be
considered suitable for wood preservation in situations involving ground
contact of treated wood. Also, paint allows moisture to penetrate the wood
but does not allow for water to escape.
With respect to creosote alternatives, pentachlorophenol brush-on treatment
does have the same efficacy as creosote brush-on treatment (USDA, 1980).
Also, all stake decay tests have been factored into the benefits estimate.
Comment Issue #20: Exterior use of treated wood
Portland Cement Association (26) recommends that the proposed prohibition
of interior use of inorganic arsenical-treated wood be extended to exterior
uses (e.g., patios, decks and chairs), and in lieu of this action, protective
materials should be required on these sites. The AWPI (36B) and the NFPA
(36B) contend that pentachlorophenol-treated millwork with outdoor exposure
should be excluded from regulation.
Agency Response:
Based on a negligible dermal absorption estimate for dry, inorganic
arsenic-treated wood and 0.1% dermal absorption estimate for arsenic-treated
wood which subsequently becomes wet (Day, 1983), sealers are considered
unnecessary where dermal contact is the exposure of concern. As explained
in Section VII.A.4, the Agency will not impose regulations on pentachloro-
phenol-treated millwork in interiors? the exposure is assumed to be minimal,
since millwork is normally painted or treated with a sealer, such as shellac.
Comment Issue #21: EPA jurisdiction
Kerr-McGee Corporation (33) contends that the EPA's proposed regulations
are within OSHA's jurisdiction, while the U.S. Department of Energy (44)
more specifically states that comprehensive OSHA groundline treatment standards
already exist. The AWPI (36E) contends that the Agency's labeling program is
an intrusion on other regulatory agencies' responsibilities and that the
proposed end-use restrictions are beyond the scope of FIFRA (36B and 36C).
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Agency Response:
FIFRA authorizes regulation of pesticidal uses, in order to prevent
unreasonable adverse effects to the environment including man. The Agency
is concerned about notifying consumers of certain potential risks associated
with exposure to the pesticides in treated wood, and will promulgate a rule
under TSCA if the mandatory Consumer Awareness Program is ineffective.
The EPA has coordinated with other Federal agencies of concern (e.g.,
Food and Drug Administration, Occupational Safety and Health Administration)
and has defined, by inter-agency agreement or by mutual jurisdictional
interpretation, EPA's regulatory responsibilities. In a memorandum to EPA
dated November 8, 1979, OSHA states "that it will defer to EPA on workplace
regulation of uses and impregnation/application so long as OSHA has full
assurance from EPA of an active program in that agency to investigate any
public or occupational health risks from these wood preservatives that are
brought to its attention, and full assurances that regulatory action to
eliminate any significant risks also will be forthcoming from EPA." Therefore,
the worker protection requirements specified in this document pursuant to
FIFRA provide no means of regulating occupational safety and health hazards
except insofar as they are directly associated with use of a registered
pesticide. The EPA has made no attempt to regulate any workplace hazard
except those associated with the use of pesticide products containing creosote,
pentachlorophenol (and its salts) and the inorganic arsenicals as wood
preservatives. EPA in developing these worker protection requirements has
only considered the hazards directly attributed to the use of these pesticides.
Comment Issue #22: Poles-groundline treatment
Edison Electric Institute (35) comments that poles-groundline treatment
extends 15-18 inches below and 3-6 inches above ground level, as opposed to
the Agency's inaccurate statistics of 6 inches above and below ground.
Agency Response:
The Agency accepts this comment; it is consistent with the USDA (1980)
estimate of 6 inches above and 16 inches below the ground level.
Comment Issue #23: Support of EPA action
Six commenters registered support of the EPA's acknowledgement of wood
preservatives benefits or the Agency's health concerns [Coopers Creek Chemical
Corporation (4), Illinois Power Company (5), National Solvent Corporation
(6), Monsey Products (23), Consumers Power Company (31)., and Walpole Wood-
workers (56)]. Six respondents registered approval of EPA's April 14, 1983,
proposal to conclude the RPAR [Osmose (61), Georgia Department of Agriculture
(62), Louisiana-Pacific Corporation (73), McFarland Cascade (74) the NFPA
(75), J. G. Baxter and Company (76), Koppers Company (77) and Allied Chemical
(79)].
Agency Response: The Agency acknowledges these comments and has considered
them in developing the final regulatory position.
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Comment Issue #24: The relationship between risk estimates and recommended
use modifications
The Dow Chemical Company (32) questions the relationship between calculated
pentachlorophenol risk estimates and the recommended handling procedures and
use modifications proposed in the PD 2/3.
Agency Response:
It is unclear from the statement whether the comraenter is referring
specifically to handling procedures and use modifications in the plant or
end-uses of treated wood or wood products. Based on the risk estimates
calculated by Agency scientists (see Section VI and Appendix B), the required
regulatory measures are considered necessary to adequately protect users
from health hazards associated with application of wood preservatives.
These risk estimates also warrant dissemination of treated wood handling,
use, and disposal precautions to consumers who may not be aware of the potential
risks involved with using such wood (Section VII.C).
Comment Issue #25: The environmental fate of pentachlorophenol
Friends of the Earth (64) contends that the Agency has not assessed
the environmental fate of pentachlorophenol and registers concern that the
dioxins from pentachlorophenol bioaccunulate in the environment. The AWPI
(78), however, contends that pentachlorophenol is not an environmental hazard;
that it biodegrades in water and soil, does not migrate in soil, -and that
light biodegrades pentachlorophenol and chlorodioxins to harmless constituents
{AWPI, 78). Also, according to the AWPI (78), the U.S. Department of the
Interior (Columbia National Fisheries Research) has shown (although no data
were submitted with comment) that pentachlorophenol accumulation by fathead
minnows is minimal and that plants in an open exposure are not adversely
affected by pentachlorophenol-treated wood (AWPI, 78).
Agency Response;
The PD 1 on wood preservatives contains readily available information
concerning evidence of pentachlorophenol in the air, water, soil, plants
and animals. Pentachlorophenol and its degradation products, including
dioxins, are known to persist in the environment. According to the comment
submitted by the AWPI (Crosby 1980), pentachorophenol and degradation products
have been shown to be persistent in bottom sediments after accidental spillage
(Pierce, 1978; Pierce, etal., 1977).
Comment Issue #26: Engineering controls and other requirements for the
arsenic pressure treatment process.
The AWPI (36C) comments that the wood industry has a clean wood standard.
The American Wood Preservers Association (AWPA) does not prescribe methods
which treaters must use to meet these standards because judgments concerning
cleaning methods should be left to individual applicators (AWPI, 36C). AWPI
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(36c) comments that a final vacuum step would adversely affect treatment of
some commodities. Osmose data (1980) shows clean wood can be produced without
these costly processes (AWPI, 36C). Post rinsing and sheds would be both
unnecessary and uneconomical requirements (AWPI, 36C).
Agency Response:
The Agency has reevaluated its PD 2/3 proposal and has determined that
the public will be protected if industry standards for clean wood are required.
The revised label will include a requirement that the pressure treatment
used to apply inorganic arsenical formulations that leave no visible surface
deposits on the wood, as defined by the AWPA standard C-1 and the American
Wood Preservers Bureau (AWPB) Standard, LP2 and LP22. Visible surface deposits
means that the treated wood shall not have surface residue or crystallization.
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VI. FINAL AGENCY POSITION AND RISK/BENEFIT DETERMINATIONS
This section presents the Agency's final regulatory position regarding
the pesticidal uses of the three wood preservatives. This section is
organized as follows:
A) upper limits for hexachlorodibenzo-p-dioxin (HxCDD) contamination
in technical pentachlorophenol and pentachlorophenol salts;
B) teratogenicity/fetotoxicity warning on all labels for products
containing pentachlorophenol or pentachlorophenol salts;
C) pressure-treatment uses of all three wood preservatives;
D) poles-groundline uses of pentachlorophenol and creosote;
E) home and farm (including railroad tie repair) uses of pentachlorophenol
and creosote;
F) brush-on treatments of the inorganic arsenicals;
G) use of pentachlorophenol salts for sapstain control; and
H) non-pressure treatment plant dip/flow and spray uses of pentachloro-
phenol .
Each of those sections (VI.A through VI.H) describes the exposure
situation of concern and the estimated potential oncogenic and teratogenic
risks, the PD 2/3 proposal to reduce the risk, comments and/or new informa-
tion received since the PD 2/3 was published, and the Agency's basis for
the final regulatory position.
A. Upper Limits for Hexachlorodibenzo-p-dioxin (HxCDD) Contamination in
Technical Pentachlorophenol and Pentachlorophenol Salts
Exposure/Risk; The estimated potential oncogenic risks for the various use
situations where applicators and end-users of treated wood are exposed are
summarized in Appendix B of this PD 4 and are discussed in detail below in
Sections VI and VII. The potential oncogenic risks from exposure to the
HxCDD contaminant in pentachlorophenol and sodium pentachlorophenate without
protective measures range from 1.5 X 10-2 for bag emptying activities to
1.0 X 10-4 for home and farm brush-on treatments. The potential oncogenic
risks with protective measures range from 2.4 X 10"^ for millwork and
plywood spray applications to no risk where interior use of pentachloro-
phenol is prohibited. Section II.A.2 describes the bases for the Agency's
estimation of potential human oncogenic risk.
The Agency assumed in the PD 2/3 that 15 ppm was a representative
upper limit for hexachlorodibenzo-p-dioxin (HxCDD) contamination in penta-
chlorophenol and sodium pentachlorophenate based on data submitted by
manufacturers (Rakshpal, 1980; SAB, 1978; and AWPI Rebuttal to the PD 1
#30000/30, 1979). This upper limit was used in the PD2/3 in calculating
the potential oncogenic risk from exposure to this contaminant in penta
chlorophenol and sodium pentachlorophenate products. Fifteen ppm was also
used in this position document (PD 4) for risk estimation in exposure
situations without taking into account the protective measures required.
The oncogenic risks for the various use situations are summarized in
Appendix B of this PD 4.
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PD 2/3 Proposal; Because Dow Chemical Company had shown (SAB, 1978) it
could manufacture a pentachlorophenol product (Dowicide-EC7) with less
than 1 ppm HxCDD, the Agency considered proposing that all registrants
lower the HxCDD, the contamination in pentachlorophenol and sodium
pentachlorophenate to a maximum concentration of 1.0 ppm (PD2/3, p. 566).
However, in the PD 2/3 the Agency decided not to propose that registrants
reduce the HxCDD in their products from 15.0 ppm to 1.0 ppm because: (1)
The Agency believed that at 15.0 ppm the benefits of use of these products
outweighed the risks if certain protective measures proposed in the PD 2/3
were adopted (protective clothing, protective equipment, restricted use)
and (2) though Dow had the technical capability to produce pentachlorophenol
with less than 1 ppm HxCDD, requiring production conversion by other companies
to the purer form might cause them to cease manufacturing this wood preser-
vative because of cost consideration.
Final Agency Position and Rationale; The Scientific Advisory Panel (SAP)
reviewed the proposals presented in the PD 2/3 and strongly recommended
that "EPA should require industry to reduce the dioxin content of penta to
as low a level as is technologically and economically feasible." In addition,
since the PD 2/3 was published the potenial estimate risk due to exposure to
the HxCDD contaminant in pentachlorophenol products has increased due to
modifications in exposure assumptions and risk estimation. These changes
were discussed in Section II of this document. Because in some cases,
depending on the use situation, the potential risks increased one or more
orders of magnitude, the benefits of use of the pentachlorophenol products
no longer outweighed the risks; continued use of pentachlorophenol products
containing 15 ppm HxCDD would pose unreasonable adverse effects to applicators.
In the light of the SAP recommendations and the increase in risk estimates
the Agency has reevaluated its position on regulating the levels of HxCDD
contamination.
The Agency has concluded, after evaluating the information available,
that the HxCDD contamination in pentachorophenol and sodium pentachlorophenate
products must be reduced within 18 months to a level which will not exceed
1.0 ppm. This will reduce potential risks by a factor of 15 (15 ppm reduced
to 1.0 ppm HxCDD). Until this limit of 1.0 ppm is achieved, the HxCDD
contamination must not exceed 15 ppm. The rationale and justification for
the Agency's decision is contained in the paragraphs which follow. This
requirement and others presented in this PD 4 are expected to reduce the
potential risks due to HxCDD exposure such that there will be no unreasonable
adverse effects to man or the environment.
Information reviewed by the Agency indicates that it is technologically
feasible to produce pentachlorophenol products which contain no greater
than 1.0 ppm HxCDD. A product manufactured by Dow Chemical Company, Dowicide
EC-7, has been shown by chemical analysis to contain less than 1.0 ppm HxCDD.
Data supporting this has been summarized by Rakshpal (1980) and the Science
Advisory Board (SAB, 1978). AWPI (Rebuttal to the PD1, #30000/30, pp. 52-
55, 1979) also summarized data which showed that purified (distilled)
pentachlorophenol contained less than 1.0 ppra HxCDD and in some instances
contained less than 0.03 ppm.
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More recently, Idacon, Inc., has developed a purification method to
remove chlorodibenzo-p-dioxin and chlorodibenzofuran contaminants from
pentachlorophenol (United States Patent No. 4,228,309, Oct 14, 1980). A
description of this method was submitted to the Agency for review by Pazianos
Associates (1984) . The Agency has evaluated this purification method and
has concluded that the process does reduce levels of chlorodibenzop-dioxins
and chlorodibenzofurans and theoretically should also reduce other chlorinated
impurities such as hexachlorobenzene, though no chemical analysis was
presented for the latter (Dodd, March 29, 1984). In its description of
the method, Idacon stated that "costs to purify the pentachlorophenol
would be in the range of 10 cents per pound of pentachlorophenol" and
that, "based on today's market prices for wood preservatives, the added
cost would not render pentachlorophenol non-economic as wood preservative."
The Agency has no data to substantiate or refute this economic assessment.
In addition, after reviewing published literature on possible manufac-
turing methods (Pesticides Process Encyclopedia, 1977), the composition of
technical pentachlorophenol (Journal of Dairy Science, 1981), and the
composition of commercial grade pentachlorophenol and production of impurities
(Firestone, 1972), the Agency believes, based on theoretical considerations,
that an extraction of an alkaline aqueous solution of pentachlorophenol
with a non-polar aromatic solvent could reduce the levels of chlorodibenzo-
p-dioxins, dibenzofurans, and hexachlorobenzene at the same time (Dodd,
Feb. 24, 1984).
Based on the information cited above, the Agency has concluded it is
technologically feasible to substantially reduce the stated impurities in
pentachlorophenol products.
The Agency also believes it would be economically feasible to reduce
the dioxih content in pentachlorophenol products. The Dow Chemical Company
produced and sold Dowicide EC-7 which contained less than 1.0 ppm HxCDD.
Dow discontinued the manufacturing of this product in part, as reported by
NIOSH (1983), because the purification process was too costly. However,
while it may not have been economical for one manufacturer in a competitive
market, the Agency believes that requiring all registrants to lower the
HxCDD content to levels not to exceed 1.0 ppm would eliminate that cost
disadvantage. Costs would be absorbed by the companies and/or passed on
to the consumer.
The Agency is aware that although it may be technologically and economically
feasible to produce pentachlorophenol and sodium pentachlorophenate products
containing no more than 1.0 ppm HxCDD, it will take time to modify the
manufacturing process to meet this requirement. During the time these
modifications are being made, the Agency requires that the HxCDD contaminant
does not exceed the current representative upper limit of 15 ppm. Chemical
analyses of HxCDD in pentachlorophenol and sodium pentachlorphenate indicate
that it is currently possible to meet a 15 ppm HxCDD upper limit without
"purifying" the product. This interim upper limit of 15 ppm will allow the
modifications to the manufacturing process to be completed without unwarranted
economic disruption.
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Rakshpai (1980) summarized data received from Dow Chemical, Reichold,
and Vulcan which showed that an upper limit of 15.0 ppm or less HxCDD
could be achieved.
The Science Advisory Board (SAB, 1978) and AWPI (Rebuttal to PD1, #30000/30,
Appendix 4, pp. 52-55) reported that HxCDD contamination found in a composite
sample (excluding the purified Dowicide EC-7) from pentachlorophenol producers
was 15.0 ppm or less. SAB (1978, Tables 2.1 and 2.2) also reported HxCDD
concentrations of less than 10.0 ppm for Dowicide 7, a commercial "non-purified"
pentachlorophenol product. Sodium pentachlorophenate was reported to contain
below 4.0 ppm HxCDD (SAB, 1978, Table 2.2). AWPI (#30000/30, 1979 pp. 53-55)
also reported HxCDD concentrations below 4.0 ppm for sodium pentachlorophenate.
Reichold Chemicals [83(30000/280] also cited data from the SAB report
(1978 Tables 3 and 4) showing that Dowicide 7, an "unpurified" product,
contained less than 10 ppm HxCDD and that a composite pentachlorophenol
sample contained 15.0 ppm HxCDD. This latter figure was also reported in
a submission by AWPI [|84 (30000/28C)].
Regarding pentachlorophenol manufacturers in Europe, Buser and Bosshardt
(1976) published results of analyses of HxCDD in several pentachlorophenol
products purchased in Switzerland. The HxCDD concentrations of all samples
were below 10.0 ppm. The Agency has received additional information that
two manufacturers of pentachlorophenol in Europe currently consistently
achieve below 8 ppm HxCDD contamination without any additional "purification"
steps (Dobbs, personal communication, 1984). The average concentration is
4.5 +_ 0.6 ppm HxCDD with 95% confidence limits.
The above cited data indicate it is currently technologically and
economically feasible to produce pentachlorophenol and sodium pentachloro-
phenate products containing 15.0 ppm as an upper limit for HxCDD contamination.
Therefore, the Agency has determined that registrants will be required to
amend their confidential statements of formula for technical pentachloro-
phenol and sodium pentachlorophenate products to indicate that the HxCDD
contamination does not exceed 15.0 ppm. The confidential statements of
formula must be amended within 30 days after the Notice concluding the
Wood Presevatives RPAR is published in the Federal Register or within 30
days after receipt of such Notice by the registrant, whichever occurs
later. Registrants must also periodically submit HxCDD analyses of their
products using an appropriate gas chromatography/mass spectrophotometry
method (e.g., Buser and Bosshardt, 1976) approved by the Agency.
Within the stated 30-day period, the registrant must also file an
application to amend the confidential statements of formula to reflect
that the HxCDD contamination does not exceed 1.0 ppm, effective 18 months
after publication of the Notice or receipt by the registrant, whichever
occurs later. The Agency believes this is a reasonable length of time for
the registrants to modify their manufacturing process to meet the HxCDD 1.0
ppm upper limit requirement. Furthermore, within 90 days of publication of
the Notice, registrants must submit to the Agency in writing their plan
for reducing the HxCDD contaminant to 1.0 ppm or lower.
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In addition to the chlorinated dibenzo-p-dioxins, chlorinated dibenzo-
furans have also been shown to be contaminants of pentachlorophenol products
(Position Document 1, 43 FR 48443 and PD 2/3, p. 16). Levels of contamina-
tion of the two chemicals parallel each other; i.e., high levels of dibenzo-
p-dioxin are associated with high levels of dibenzofuran (PD 1, 43 FR
48443, Baser and Bosshardt, 1976; Rappe, 1981; PD 2/3, p. 348). The
chlorinated dibenzofurans have been shown to be highly toxic in laboratory
animals (Moore et al., 1979; Baser and Bosshardt, 1976; Rappe, 1981).
Like the dioxins, they cause characteristic edema, weight loss and liver
toxicity in laboratory animals prior to death (McConnel and Moore, 1979)
In addition, tests of liver enzyme induction by chlorinated dibenzofurans
in hybrid mice (Poland et al., 1979) have shown that these chemicals are similar
to chlorinated dioxins in their response.
The chemical structures of the chlorinated dibenzo-p-dioxins and chlorinated
dibenzofurans are similar (Buser and Bosshardt, 1976).
Di benzo-p-dJroxi n
Dibenzofuran
Chlorine may be attached in various combinations, at the 1,2,3,4,6,
7,8, and 9 positions (Buser and Bosshardt, 1976).
Because of the structural similarity and because of their functional
similarity in short term testing, the Agency is concerned that, although
there are no chronic long term studies, chlorinated dibenzofurans
could be potential human oncogens as are the chlorinated dibenzodioxins.
Therefore, the Agency requires that the method used by registrants to
lower the HxCDD content mast not increase the chlorinated dibenzofuran
contamination.
Another contaminant in pentachlorophenol products is hexachlorobenzene
(HCB), shown in the PD 2/3 (p. 345} to be an oncogen in laboratory animals.
The potential oncogenic, reproductive, and teratogenic/fetotoxic risks
associated with exposure to HCB were presented in the PD 2/3 (pp. 345-346,
354-365).
Using the "one-hit" model of risk assessment, the oncogenic potency
(slope) was calculated to be 0.0027 (ug/kg/day)-1 (PD 2/3, p 365).
Though HCB is a less potent oncogen than HxCDD as indicated by the slope
calculated for HxCDD in the PD 2/3 [HxCDD slope=6.2 (ug/kg/day)'1], the
Agency is concerned about possible increases in this contaminant as well.
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Therefore, the Agency requires that the method used by registrants to
lower the HxCDD contamination must not increase the HCB contamination.
The Agency believes that it is prudent and reasonable to require that
registrants reduce HxCDD, and not increase the chlorinated dibenzofurans
and HCB contaminants in pentachlorophenol and sodium pentachlorophenate
products to protect the public from potential unreasonable adverse effects.
Theoretically, these three impurities can be reduced by the same purification
or extraction process during manufacturing (Dodd, 1984). By reducing the
HxCDD from 15 ppm to 1.0 ppm, the potential oncogenic risks to applicators
will be reduced by more than an order of magnitude.
The most highly toxic dioxin is 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)
(Nicholson and Moore, 1979). Although it has not been found in analyses of
samples of pentachlorophenol (Buser and Bosshardt, 1976; SAB, 1978; Rakshpal,
1980), the Agency has concluded that registrants must amend the confidential
statements of formula to indicate that 2,3,7,8-tetrachlorodibenzo-p-dioxin
(TCDD) is not found in pentachlorophenol products or products containing
salts of pentachlorophenol. TCDD must be below the limits of detection of
analytical methods acceptable to the Agency, such as that described by Buser
and Bosshardt (1976) using gas chromatography-mass spectrophotoraetry. This
regulatory action will ensure tht the public will not be exposed to TCDD
when applying pentachlorophenol or products containing pentachlorophenol
salts.
Because manufacturing process and product chemistry data are lacking
for technical pentachlorophenol and its salts, the Agency will require, in
a separate action, that registrants submit "additional data to support
existing registrations" pursuant to Section 3(c)(2)(B) of FIFRA, in order
to maintain in effect existing registrations.
To summarize, the Agency has concluded that, in order to avoid posing
an unreasonable adverse effect to the environment, registrants of products
containing technical pentachlorophenol or its salts must meet the following
two requirements (among others presented in this position document) within
30 days of publication of the Notice concluding the Wood Preservatives
RPAR in the Federal Register, or within 30 days of receipt of such Notice
by the registrant, whichever occurs later:
1. File an application to amend the confidential statements of formula
(CSF) for products containing technical pentachlorophenol or its
salts to indicate that the HxCDD contamination does not exceed 15
ppm and that 2,3,7,8-TCDD is below the limits of detection, using a
gas chromatography-mass spectrophotometry method acceptable to the
Agency (e.g., Buser and Bosshardt, 1976).
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2. File an application to amend the CSFs for products containing tech-
nical pentachlorophenol or its salts to indicate that effective 18
months after publication of the Notice or receipt by the registrant
(whichever occurs later) the HxCDD contamination does not exceed
1.0 ppm. (The method used to lower the HxCDD levels to 15.0 ppm or
1.0 ppm or lower must not increase the hexachlorobenzene or the
chlorinated dibenzofuran levels above the levels in products marketed
at the time of publication of the FR Notice.)
In addition to complying with the above requirements, the registrants
of products containing technical pentachlorophenol or its salts will be
required in an action separate from this PD 4, to submit the following
to maintain in effect existing registrations pursuant to FIFRA Section
3(c)(2)(B):
1. A description of the starting materials, manufacturing process and
reaction conditions including any steps to reduce HxCDD.
2. Information on product identity relative to identification of
ingredients, statement of composition and a discussion of the
formation of impurities.
3. Data on the analysis and certification of product ingredients
relative to preliminary analysis, certification of limits, and
analytical methods for the enforcement of limits. An analytical
method employing combined gas chromatography and mass spectrophoto-
metry is acceptable (e.g., Buser and Bosshardt, 1976).
4. HxCDD analyses every three1 months, the first analysis to be submitted
within the stated 90-day period.
5. A description of any changes in the manufacturing process used to
lower HxCDD to 15 ppm and/or 1.0 ppm or lower must also be submitted
within the stated period of 90 days. (The methods used to lower HxCDD
must not increase the chlorinated dibenzofurans and HCB contaminants
above the levels in products marketed at the time of publication
of the FR Notice.)
6. Information on the technical feasibility and costs of reducing the
HxCDD contamination further than the 1.0 ppm upper limit.
These requirements satisfy the SAP recommendation that "industry reduce
the dioxin contamination in penatachlorophenol to as low a level as is
technologically and economically feasible." These requirements and other
requirements presented throughout this document to reduce the risks (e.g.,
protective clothing and equipment, restricted use) fulfill the congressional
mandate as outlined in FIFRA to regulate the use of pesticides so that
there will be no unreasonable risk to man or the environment.
To recalculate the potential oncogenic risks without protective measures
for pentachlorophenol and sodium pentachlorophenol in this PD 4, the Agency
assumed that the upper limit of HxCDD contamination was 15 ppm; to recalculate
risks with protective measures (e.g., HxCDD reduction, protective clothing,
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respirators), the Agency assumed that the HxCDD upper limit was 1.0 ppm.
The recalculated PD4 risks presented throughout this document reflect this
assumption.
As reported in the PD 2/3 (pp. 16-17), the forms of chlorinated dibenzo-
p-dioxins most commonly found in pentachlorophehol (including its salts) are hexa,
hepta, and octachlorodibenzo-p-dioxins. A small amount of tetrachlorodibenzo-
p-dioxin (TCDD) has also been found, but this is not the highly toxic
2,3,7,8-TCDD. The chlorinated dibenzofurans found in pentachlorophenol are
the tetra, penta, hexa, hepta, and octachlorodibenzofurans. The Agency
believes that the requirements for exposure reduction described in this PD 4
with which the registrants must comply will serve to reduce the chlorinated
dibenzo-p-dioxins and the chlorinated dibenzofurans to levels which will
not pose unreasonable adverse effects to the environment.
B. Teratogenicity/Petotoxicity Warning on All Labels for Products Containing
Pentachlorophenol or Pentachlorophenol Salts.
Exposure/Risk; As described in the PD 1 (43 FR 48443) and PD 2/3 (pp.
347-356) studies have shown that administration of pentachlorophenol to
laboratory animals is associated with fetotoxic effects, HXCDD with teratogenic
and fetotoxic effects, and HCB with teratogenic, fetotoxic, and reproductive
effects. These studies are summarized in the paragraphs which follow.
Pentachlorophenol. The study of Schwetz et al. (1974) showed that
either commercial or purified pentachlorophenol, when administered by
gavage to rats on gestation days 6 through 15, caused statistically signi-
ficant increases in fetal resorptions, altered sex ratios, and decreases
in fetal body weight and crown-rump length at the higher doses tested.
Significant increases in fetal anomalies (compared to controls) were observed
for skeletal defects of the ribs, sternebrae, and vertebrae, at the two
highest dose levels of both purified and commercial penta. The lowest
dose of purified penta (5 mg/kg/day) caused an increase in delayed skull
ossification. The Agency believes the delayed skull ossification observed
at this level is significant.
Due to lack of an adequate NOEL in the study of Schwetz et al. (1974),
the Agency chose the one-generation study of Schwetz et al. (1978) for
purposes of risk assessment. In this study, parental rats were given dietary
administration at 3 and 30 mg/kg/day. At the 3 mg/kg/day level the data
show a trend toward decreased neonatal weight (consistent with the high
dose) which continues as the animals age. At any individual measurement
period, however, this neonatal weight decrease at 3 rag/kg/day is not
statistically significant. At the highest dose there was "a significant
decrease in the percent of pups born alive, as well as significant decreased
survival to days 7, 14, and 21 of lactation." The average litter size
after treatment at the highest dose also was significantly lower than
among controls on days 7, 14, and 21 of lactation. Treatment at the high
dose caused a significantly increased number of litters with variations in
lumbar spurs and vertebrae with unfused centra.
The data of Schwetz et al. (1978) are adequate to establish a provisional
NOEL for the fetotoxicity of the pentachloropenol studied.
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As more fully described in the PD-2/3, other toxicity parameters also
exhibit NOELs near or somewhat below 3 mg/kg/day. Female rats dosed
dietarily with 1.5 mg/kg/day of technical penta (Goldstein et al., 1977}
showed a 15-fold increase over controls in the activity of aryl hyrdocarbon
hydroxylase (AHH) and a significant elevation of glucuronyl transferase
activity. Although the toxicological meaning of these elevations is not
clear, an elevated AHH activity has been used as a "biochemical correlate"
for the presence in biological samples of some of the non-phenolic contaminants
of technical pentachlorophenol.
It is also noted in the PD 2/3 that at the level of 3 mg/kg/day (or
somewhat lower) there exist systemic or organ-specific NOELs in rats exposed
to chronic or subchronic treatment. The two-year study of Schwetz et al.
(1978) reports body weight and food consumption changes in the adults.For
subchronic toxicity, Kimbrough and Linder (1978) reported mild histopathologic
effects in the liver of rats treated at 1.5 mg/kg/day. The 90-day feeding
study of Kociba et al. (1973) reported decreased testes-to-body weight
ratios at all doses, including significantly lower ratios at 1.0 mg/kg/day.
In the 90-day rat feeding study of Knudsen et al. (1974), the liver-weight
increase in females was dose related and significant at 2.5 mg/kg/day. A
third 90-day rat feeding study (Johnson et al., 1973) reported a NOEL of 3
mg/kg/day, based on increased liver weight at higher doses. Results of 90-
day feeding studies are useful for comparison with fetotoxic effects which may
occur with relatively short exposure duration.
HxCDD; The teratogenicity and fetotoxicity of HxCDD is demonstrated in
the gavage study of Schwetz et al. (1973), in which pregnant rats were treated
on days 6 through 15 of gestation with two (unspecified) isomers of purified
HxCDD. At the upper doses there were significant increases above control
values in fetal resorptions, dilated renal pelvis, and cleft palate (top
dose), as well as decreases in fetal body weight and crown-rump length.
Subcutaneous edema was observed at all doses except 0.1 ug/kg/day (low dose),
which the Agency adopted as the fetotoxicity/teratogenicity NOEL for HxCDD.
HCB: Courtney et al. (1976) reported teratogenic effects in mice caused
by oral administration of 100 mg/kg/day HCB, including cleft palates, elevated
maternal liver-to-body weight ratios, and decreased fetal body weights.
Khera (1974) reported fetotoxic effects at 40 mg/kg HCB including sternal
defects and extra ribs. Simon et al. (1979) found reproductive effects in
the rat at 70 or 221 mg/kg/day HCB including a decrease in the number of
females inseminated and impregnated. Grant et al. (1977) , in a four genera-
tion rat reproduction study, found reproductive changes relative to pregnancy,
viability, lactation indices, neonatal weight gain, and relative liver weight
at a NOEL of 1.0 mg/kg/day dietary HCB.
The NOELs used in the PD 2/3 to calculate margins of safety were:
Pentachlorophenol: 3 mg/kg/day (Schwetz et al., 1978) .
HxCDD: 0.1 ug/kg/day (Schwetz et al., 1973).
HCB: 1.0 mg/kg/day (Grant et al., 1977).
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The Agency was concerned that applicators of pentachlorophenol in both
occupational and home and farm settings were being exposed to these potential
risks. By dividing the NOEL by the estimated exposure, the Agency calculated
the Margins of Safety (MOS) for these effects and found (PD 2/3, pp. 357-
359) that, with no protective measures taken into account, exposure to
pentachlorophenol during application posed the greatest potential hazard
with MOS's ranging from only 5.9 for dip/flow applicators to 650 for home and
farm use? MOS's for HxCDD ranged from only 13 (home and farm) to 330 (opening
cylinder door); and MOS's for HCB were all above 10,000.
PD 2/3 Proposal; To provide greater protection from the potential feto-
toxic, teratogenic, and reproductive effects of pentachlorophenol and its
contaminants, the PD 2/3 proposed requiring protective measures such as gloves,
protective clothing, protective equipment, and restrictions on use, depending
on the specific exposure situation. With these protective measures the
Margins of Safety were increased (PD 2/3, pp. 660-662) and thus the Agency
concluded that no unreasonable adverse effects would be posed to applicators
using pentachlorophenol products.
Final Agency Position and Rationale;
Since the publication of the PD 2/3, new information as described in
Section II of this document resulted in revisions in both exposure and risk
estimates for pentachlorophenol. For example, the Agency revised the rates
of dermal absorption of pentachlorophenol from 10% (PD 2/3) to 50%, and the
protection provided by gloves from 99% (PD 2/3) to 90%. These revisions
resulted in lower estimated Margins of Safety than had been calculated for
the PD 2/3. As summarized in Appendix B of this PD 4, the MOS for millwork/
plywood applicators (dip/flow) and home and farm applicators using protective
gloves is 12. The MOS for millwork/plywood spray applicators using gloves
and respirators is 23. Applicators in pressure treatment plants use a
much more concentrated pentachlorophenol solution (40% vs. 0.5 to 5%) and
therefore, though no dermal exposure could be estimated, it would be
expected that the Margin of Safety would be lower than 12 for applicators
wearing gloves and protective clothing in pressure treatment plants.
Therefore, the Agency has concluded, as described elsewhere in this
document for the various use/exposure situations, that all pentachlorophenol
and sodium pentachlorophenate products must be restricted to use only by
certified applicators and that appropriate impermeable protective clothing
must be worn by the certified applicators. In addition, the Agency requires
all registrants of products containing pentachlorophenol or its salts to
include the following information on the labels:
The U.S. EPA has determined that pentachlorophenol can produce
defects in the offspring of laboratory animals. Exposure to
pentachlorophenol during pregnancy should be avoided.
Because women of child-bearing age may be exposed to both occupational
and home/farm uses of pentachlorophenol the Agency has concluded it is
prudent and reasonable to include the label statement to inform women of
the potential teratogenic/fetotoxic hazards. Although no specific risk
reduction estimate can be made, the Agency assumes that potential risks
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from exposure to pregnant women using pentachlorophenol or sodium penta-
chlorophenate for wood preservation would be reduced if this information
is displayed prominently on the label and if use is restricted to certified
applicators who must wear impermeable protective clothing.
C. Pressure Treatment Uses: All Three Wood Preservatives
Wood may be preserved by the application of creosote, inorganic arsenicals,
and pentachlorophenol either by pressure treatment or non-pressure treatment
methods. This Section addresses pressure treatment uses of the three wood
preservatives, discusses the PD 2/3 regulatory proposals and the final
regulatory position, and presents the bases and rationale for the final
position.
Risks are estimated for each of several activities in the treatment
plant where applicators are exposed to the wood preservatives. If one
applicator performs several activities, the total potential risks to that
individual will be higher. Wherever it was possible to estimate both dermal
and inhalation risks, the Agency has done so. These estimated risks
represent the increased risk of cancer due to exposure to wood preservatives
above that of incidences of cancer from other causes.
1. Permissible Exposure Limit (PEL)/Respirators for Inorganic
Arsenical Treatment Plant Workers
Exposure/Risk; As discussed in the PD 2/3, applicators or other personnel
working outdoors in inorganic arsenical treatment plants are exposed to
potentially high air concentrations of arsenic which are distributed
throughout the treatment plants. The applicator's inhalation exposure to
the ambient arsenic increases when the treatment solution leaches, dries,
and flakes from the surface of the drying stacks of freshly treated wood,
producing a dust containing arsenic. The Agency was concerned that applicators
were inhaling small particles of the arsenic dust and that arsenic was being
absorbed in the lung. Larger particles are ingested and are absorbed in
the gastrointestinal tract. Based on an air arsenic level of 70 ug/m^,
the Agency estimated in the PD 2/3 (p. 245) that the teratogenic/fetotoxic
Margin of Safety (MOS) is 500. The total lifetime onccgenic risk from the
background arsenic air levels in the plant was estimated to be 1.9 x 10~2
(PD 2/3, pp. 582, 623, and 644).
PD 2/3 Proposal; To reduce this inhalation exposure, the Agency proposed
the following in the PD 2/3:
Applicators who work outdoors in arsenical wood treatment plants must
wear a dust mask capable of trapping 80% of particulates greater than
5 microns in size.
Wearing a dust mask while working outdoors in an arsenical wood treatment
plant reduces inhalation and ingestion exposure and results in a total
oncogenic risk from exposure to the inorganic arsenicals during this activity
of 3.8 x 10~3 (PD 2/3, pp. 624 and 645). The teratogenic/fetotoxic MOS
would be 2,500 (PD 2/3, pp. 624 and 653) if a dust mask were worn.
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Final Regulatory Position and Rationale: The Agency received new data
submitted by AWPI (|36: 30000/28C) in response to the PD 2/3 regarding the
arsenic levels to which workers are exposed in the treatment plant.
These data, as described in Section II of this document, as well as
data collected and evaluated by OSHA (48 FR 1864), indicated that a more
realistic estimate of airborne arsenic in a treatment plant environment
was 10 ug/m3 (PD 2/3 assumed 70 ug/m3).
The Agency recalculated the oncogenic risks based on the revised exposure
estimates for airborne arsenic in a treatment plant environment and revised
estimates for the inhalation absorption rate for particulate matter containing
arsenic. The Agency compared risks to applicators using dust masks with
risks to applicators using respirators. Without inhalation protection the
resulting total oncogenic risks, if an applicator is exposed to 10 ug/m3
(0.01 mg/m3) of ambient arsenic for an 8-hour work day are 4.1 x 10~3
(Rispin, April 18, 1984). The PD 2/3 estimate was 1.9 x 10-2 based on a
70 ug/m3 air concentration. If the inorganic arsenic level is unknown,
but assumed to be 10 ug/m3 and the employee wears a dust mask, the total
oncogenic risks are reduced to 8.2 x IQ~^, assuming 80% inhalation protection
(Kozak, 1980). No new MOS figures were calculated for inorganic arsenic
because the Agency has determined as discussed in Section III. B of this
document, that there are not adequate data to determine a NOEL.
If the inorganic arsenic level is unknown, but assumed to be 10 ug/m3
(averaged over 8 hours) and the employee wears a respirator, the total
oncogenic risks would be 4.1 x 10~-5 as compared with 8.2 x 10""4 if
dust masks are worn (Rispin, April 18, 1984) . Thus, a respirator gives
approximately five times more protection than a dust mask. Respirators are
assumed to provide 99% protection against arsenic inhalation (OSHA 29 CPR
1910.1018, Table 1) and dust masks are assumed to provide 80% inhalation
protection (Kozak, 1980).
See Appendix B for a comparison of the revised risk estimates with
those calculated for the PD 2/3. The risk model used for the calculations
was a human dose-response model whereby the risk is linearly related to
dose as described in the "Health Assessment Document for Inorganic Arsenic"
(U.S EPA, June 1983).
Taking into account the new data, the revised risks, the and the reduction
in exposure afforded by a respirator, the Agency has determined that inhalation
exposures will be sufficiently reduced such that there will be no unreasonable
adverse effects if a Permissible Exposure Limit (PEL) of 10 ug/m3 averaged
over 8 hours is adopted or if respirators are worn. As described in Section
II of this document, this is consistent with the Threshold Limit Value (TLV)
of 10 ug/m3 for arsenic adopted by the Occupational Safety and Health
Administration (OSHA). The Agency has concluded that registrants must
modify their labels to contain the following information:
Employees in the work area of an arsenical wood treatment
plant must wear properly fitting, well-maintained high
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efficiency filter respirators MSHA/NIOSH-approved for
inorganic arsenic if the level of inorganic arsenic in
the plant is unknown or exceeds 10 micrograms per cubic
meter of air (10 ug/m^) averaged over an 8-hour work
period. Air monitoring programs, procedures and record
retention and submission must be conducted in accordance
with the instructions on the attached labeling material.
Employers who elect to monitor air levels (to avoid having workers
wear respirators at all times if arsenic air levels are unknown) must
complete air monitoring to determine initial levels of airborne arsenic
exposure within one year of publication of the final determination con-
cluding the wood preservatives RPAR in the Federal Register, and must
repeat monitoring if the initial or subsequent monitoring reveals exposure
above 5 ug/m^ or if certain other conditions exist. The Agency expects
that this monitoring requirement may also serve as an incentive for opera-
tors of wood treatment facilities to make sure that the ambient air levels
of arsenic do not exceed 5 ug/m3. For a more complete explanation of the
implementation of the monitoring program required, see Section VIII.B.3
of this document.
The Agency has chosen the PEL of 10 ug/m^ average over an 8-hour period
as an alternative to requiring respirators to be worn at all times by all
applicators who work outdoors in arsenical wood treatment plants because:
1) the option of monitoring to determine ambient levels of arsenic would
relieve the workers of the burden of wearing respiratory protection un-
necessarily; and 2) the PD 2/3 proposal did not take into account esta-
blishments in which the levels of inorganic arsenic were known to be below
a specified upper limit. In addition, OSHA based the upper limit of 10
ug/m-3 on both oncogenic risk assessment and technical feasibility consi-
derations .
2. Protective Clothing and Respirators/Entering Treatment Cylinders.
Exposure/Risk; As discussed in the PD 2/3, it is occasionally necessary
for a treatment plant applicator to enter a pressure cylinder (e.g., for
manual cleaning or releasing a wood jam). During such activity, there is
an opportunity for both dermal and inhalation exposure. This potential
exposure to the treatment solution exists in all treatment plants, whether
creosote, pentachlorophenol, or the inorganic arsenicals are being used for
wood preservation.
The risks to applicators resulting from exposure to any of the three
wood preservatives during this activity have not been quantified due to a
lack of exposure data. However, in the PD 2/3, the Agency assumed for the
inorganic arsenicals that the total oncogenic risk to personnel entering
the cylinders would be greater than the risks from the background inhalation
exposure (1.9 x 10~2) and the dermal exposure from coming into contact with
the diluted solutions (2.6 x 10~2).
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PD 2/3 Proposal; To reduce these risks the Agency proposed for each of the
three chemicals that:
Applicators who enter pressure treatment cylinders and other
related equipment wear a neoprene-coated cotton or rubberized
overall, jacket, gloves and boots, and a properly maintained
half-mask canister or cartridge respirator designed for pesticide
use.
An applicator wearing this protective clothing and a respirator while
performing these activities will have a significantly reduced inhalation
exposure (by 90%) and total dermal exposure (by 80%) resulting in significantly
reduced risks.
Final Regulatory Position and Rationale for Creosote and Pentachlorophenols
The Agency received information from the wood preserving industry (AWPI,
June 17, 1982) about the types of protective gloves, clothing and equipment
suitable for applicator protection from creosote and pentachlorophenol, though
no actual data were submitted on the permeability of the various protective
materials. Data by Silkowski (1982) indicated "break-through" times for
certain materials in contact with a pentachlorophenol solution. The data
indicated how long the materials could be in contact with the solutions
before leaks in the material developed.
As a result of evaluating this information the Agency has revised the
PD 2/3 proposal to require additional detail concerning types of respirator
and specific materials for protective clothing to be included on the labels.
However, this is an interim measure. The Agency, in a separate action pur-
suant to PIFRA Section 3(c)(2)(B), will require that the registrants provide
data on the impermeability of these recommended materials when in contact with
creosote. The Agency is requiring certain materials for protective clothing
for workers when contacting pentachlorophenol solutions, based on the study
by Silkowski (1982). Upon receipt of the permeability data on creosote, the
Agency will reevaluate its recommendations for materials considered appro-
priate for protection against contact with creosote formulations.
The Agency has concluded that, in order that the benefits of pressure
treatment uses of creosote and pentachlorophenol exceed the risks, the
labels must be modified to contain the following information:
Applicators who enter pressure treatment cylinders and other
related equipment that is contaminated with the wood treatment
formulation (e.g., cylinders that are in operation or are not free
of the treatment formulation) must wear protective clothing (including
overalls, jacket, gloves and boots) impervious to the wood treatment
formulation and respirator.
Respirators acceptable for use by applicators of creosote must be
properly fitting, well-maintained, half-mask canister or cartridge
respirators which are MSHA/NIOSH-approved for polynuclear aromaties
and organic vapors. Examples of acceptable materials for protective
clothing (e.g., gloves, overalls, jackets, and boots) required
during application and handling of creosote are polyvinyl acetate
(PVA), polyvinyl chloride (PVC), neoprene, and NBR (Buna-N).
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Respirators acceptable for use by applicators of pentachlorophenol
must be properly fitting, well-maintained, half-mask canister or
cartridge respirators which are MSHA/NIOSH-approved for organic
vapors and acid gases. Examples of acceptable materials for
protective clothing (e.g., gloves, overalls, jackets, and boots)
required during application and handling of pentachlorophenol are
polyvinyl acetate (PVA), polyvinyl chloride (PVC), neoprene, NBR
(Buna-N), and nitrile. In addition, plastic-coated disposable
coveralls impervious to dust are acceptable for dust protection.
An applicator who enters treatment cylinders and who wears protective
clothing resistant to penetration by these pesticide solutions would have
a significantly reduced (80%) total dermal exposure (Kozak, 1980). Although
no specific risk estimate can be calculated due to the absence of exposure
data in this situation, an applicator wearing a respirator would have a
significantly reduced (90%) inhalation exposure, resulting in reduced
risks (Kosak, 1980). When data are submitted on the permeability of protective
materials when in contact with creosote formulations, the Agency will
evaluate the data and will take further regulatory action if it is deemed
appropriate.
Final Regulatory Position and Rationale for the Inorganic Arsenicals; The
Agency received information from the wood preserving industry (AWPI, June 17,
1982) on the types of protective clothing reportedly suitable for applicator
protection from the inorganic arsenicals. As a result of evaluating this
information, the Agency has revised the PD 2/3 proposal to include additional
detail about the types of materials for the protective clothing. This is
an interim measure, however, because the Agency will, as stated above for
creosote, require the registrants to submit data on the permeability of
various materials used for gloves and protective clothing in contact with
arsenic formulations. The registrants will be notified as to the specifics
of this requirement in a separate action pursuant to PIFRA Section 3(c)(2)(B).
The Agency has also reevaluated the proposal that a respirator should
be worn by applicators who enter arsenical pressure treatment cylinders.
The Agency believes that the arsenic levels inside a cylinder will not
exceed the background air arsenic dust levels of the plant because inorganic
arsenical formulations are water-based solutions which do not typically
produce vapors (USDA, 1981). Also, these formulations are applied at
ambient temperatures at which vapors are not formed (PD 2/3, pp. 584 and
621).
The Agency believes, therefore, that the requirements for respiratory
protection for applicators entering cylinders should be consistent with
the requirements for employees in other work areas of the treatment plant;
i.ee, applicators entering cylinders should wear respirators if the back-
ground air arsenic dust levels are unknown or exceed 10 ug/m3, averaged
over an 8-hour period.
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The Agency has concluded that in order for the benefits of pressure
treatment uses of the inorganic arsenicals to exceed the risks, the labels
must be modified to contain the following information:
Applicators who enter pressure treatment cylinders and other
related equipment that is contaminated with the wood treatment
solution (e.g., cylinders that are in operation or are not free
of the treatment solution) must wear protective clothing (including
overalls, jacket, gloves and boots) impervious to the wood treat-
ment formulation.
In addition, employees who enter pressure treatment cylinders
must wear properly fitting, well maintained high efficiency filter
respirators MSHA/NIOSH-approved for inorganic arsenic if the level
of inorganic arsenic in the plant is unknown or exceeds 10 micro-
grams per cubic meter of air (10 ug/m3), averaged over an 8-hour
work period. Air monitoring programs, procedures and record
retention and submission must be conducted in accordance
with the instructions on the attached labeling material.
Examples of acceptable materials for protective clothing (e.g.,
gloves, overalls, jackets, and boots) required during application
and handling of inorganic arsenicals are vinyl, polyvinyl chloride
(PVC), neoprene, NBR (Buna-N), rubber, and polyethylene.
The requirement of wearing gloves during these activities will reduce the
hand dermal exposure by 99% and use of coveralls will reduce the total dermal
exposure by 80%, resulting in reduced risks. If the measured arsenic air level
exceeds 10 ug/m3 or is unknown and respirators become necessary, as described
in the proceeding section, the risks due to inhalation exposure (assume 10
ug/m3) will be 4.1 x 10~5 (with respirators) (Rispin, April 18, 1984).
Use of respirators reduces arsenic inhalation exposure by 99%. These risk
figures are based on new epidemiological and exposure data developed since
the PD 2/3 was issued as discussed in Section II of this document. A
comparison of the PD 2/3 risks (with and without protective measures) and
recalculated risks (with protective measures) is contained in Appendix B.
3. Closed Mixing Systems for Prilled or Flaked Pentachlorophenol
Exposure/Risk; The Agency was concerned about the high inhalation and
dermal exposure situations during the manual opening and emptying of bags of
prilled (granular) formulations of pentachlorophenol or prilled or powder
formulations of sodium pentachlorophenate in the preparation of the treatment
solutions. The total oncogenic risk for this operation was estimated to range
from 7.3 x 10~3 to 1.5 x 10~2 without protective clothing and equipment, and
the fetotoxic MOS ranged from 6.4 to 13 (PD 2/3, p. 587). These estimates
were based on 2.4 mg/m3 airborne pentachlorophenol concentration due to bag
emptying and mixing operations (PD 2/3, p. 317). The dermal exposure was
assumed to be 40 to 400 mg/hr (PD 2/3, p. 319) and the rate of dermal
absorption was assumed to be 1% (PD 2/3, p. 205).
PD 2/3 Proposal; To reduce the inhalation and dermal exposures during
this activity, the Agency proposed in the PD 2/3:
A closed emptying and a closed mixing system must be used
for all prilled (granular) formulations of pentachlorophenol
and prilled (granular) and powder formulations of sodium
pentachlorophenate.
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An example of an acceptable closed emptying and mixing system for
handling large quantities of preservative is one in which the prilled or
powder formulations are unloaded by pneumatic equipment from a hopper
truck or railroad car directly into the closed (dissolving) mixing tanks.
This requirement was expected to reduce the applicator exposure to penta-
chlorophenol and sodium pentachlorophenate to a level comparable to the
background (ambient) air levels in the plant (PD 2/3, p. 628). The Agency
assumed (PD 2/3, p. 561) that risks would be greatly reduced where closed
systems are used for emptying and mixing activities on both a large scale
and small scale (emptying bags).
The Agency's final regulatory position regarding closed systems for
pentachlorophenol is discussed in the paragraphs which follow. The position
for sodium pentachlorophenate, a non-pressure use, is the same and is
presented in Section VI. F of this PD 4.
Final Regulatory Position and Rationale; The SAP recommended that the
Agency investigate ways to reduce exposure to the dry formulations of
pentachlorophenol and sodium pentachlorophenate other than by imposing the
requirement of closed systems because "...such a requirement would impose
an unfair burden on small operators in terms of additional capital investment."
AWPI (#36:30000/28C) commented that the Agency had overestimated the
time spent opening and emptying bags of prilled and flaked pentachlorophenol
and mixing pentachlorophenol solutions, as discussed in Section II of this
document. After evaluating this submission, the Agency revised the PD 2/3
exposure analysis from an estimate of 4 hours/day for 5 days/week to a
maximum of 2 hours/day for 2 days/week for bag emptying and mixing.
In light of the SAP recommendation and reduced time of exposure resulting
in a lower risk to applicators, the Agency reevaluated the PD 2/3 proposal
regarding the mandatory use of closed systems for dry pentachlorophenol and
sodium pentachlorophenate formulations.
If closed systems are used, exposure will be reduced to ambient levels
at 0.028 mg/m- based on Arsenault (1976) and thus risks would be significantly
decreased. For general operations in a treatment plant, the exposure to
pentachlorophenol at ambient levels is 4.1 ug/kg/day (Rispin, April 18,
1984). The Margin of Safety for teratogenic/fetotoxic effects is 730
(Rispin, April 18,1984). The oncogenic risk due to inhalation exposure is
estimated to be negligible because of the low vapor pressure of HxCDD at
6.6x10"? mm Hg (U.S.S.P.A Science Advisory Board, 1978).
The cost of installing closed systems for bag emptying would be approxi-
mately $10,000. If closed systems are not used, the alternative of wearing
gloves and coveralls during the emptying of bags prilled or flaked penta-
chlorophenol would reduce total dermal exposure by 80% and a respirator would
reduce inhalation exposure by 90%. If this protective clothing and equipment
are used, the total oncogenic risks range from 4.3 x 10-4 to 4.3 x 10"5 and
the fetotoxic MOS ranges from 400 to 160 (Rispin, April 18, 1984). The recal-
culated inhalation risk estimates were based on an airborne pentachlorophenol
concentration of 2.4 mg/m3, the highest level that can be tolerated by persons
conditioned to exposure (PD 2/3, p. 317). Pentachlorophenol concentrations
higher than 2.4 mg/m3 cause severe respiratory distress (PD 2/3 p. 317).
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The recalculated dermal risk estimates were based on the dermal exposure
of the insecticide Guthion in powdered form (40 mg/hr) and the fertilizer
disulfoton as a dry mix (400 mg/hr) (Rispin, April 18, 1984). The risks
were not based on actual prilled/flaked pentachlorophenol exposure data.
Pentachlorophenol manufacturers are presently producing "glazed-flaked"
forms of dry pentachlorophenol in an effort to reduce the amount of small
particulates that may become airborne (AWPI, Aug. 18, 1982). Therefore,
the actual dermal and inhalation exposure for current dry pentachlorophenol
products is likely to be somewhat less, and the risks to applicators due
to exposure to dry pentachlorophenol when emptying and mixing bags are
also likely to be somewhat lower than those stated above (Day, Jan. 31,
1984). The current dermal absorption assumptions for dry pentachlorophenol
are the same as those of the PD 2/3, except that the HXCDD dermal absorption
rate is assumed to be 50% based on data from a dermal absorption study in
rats using TCDD by Poiger and Schlatter (1980) (Rispin, April 24, 1984).
While oncogenic risks may be somewhat lower than the stated range of
4.3x10-4 to 4.3x10-5, the Agency has no exposure data to determine how much
lower. Therefore, because closed systems are expected to significantly
reduce exposure to pentachlorophenol, the Agency has determined that closed
systems must be used when emptying and mixing bags of prilled or flaked
pentachlorophenol for pressure treatment uses. Because the Agency realizes
this may present a financial hardship to the smaller wood treatment operators,
the Agency will require that the closed systems be "phased in" over a
period of 3 years. This will enable the smaller operators to plan for the
financial investment.
During the three-year period before closed systems are in place, the
Agency has concluded that respirators and protective clothing must be worn,
if closed systems are not in place, in order to protect applicators while
empyting and mixing bags of prilled or flaked pentachlorophenol.
Therefore the Agency will require that 30 days after publication of
the Notice concluding the Wood Preservatives RPAR in the Federal Register
or 30 days after receipt of the Notice by the registrant, whichever occurs
later, registrants must file an amended application to include the following
information on labels of prilled or flaked pentachlorophenol formulations:
Until August 31, 1987, a closed emptying and mixing
system must be used or protective clothing (including
respirator, gloves and tightly woven, long-sleeved
cotton or disposable coveralls) must be worn when
emptying and mixing prilled or flaked formulations of
pentachlorophenol. After September 1, 1987, a closed
system must be used when emptying and mixing prilled
or flaked formulations of pentachlorophenol. A closed
system is defined as any containment which prevents the
release of subject chemicals into the surrounding exter-
nal environment.
Respirators acceptable for use by applicators of pentachlorophenol and
examples of acceptable materials for gloves required during application and
handling of pentachlorophenol are described in Section VI.C.5 of this
document. This information must also be included on the labels.
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The same label statements will be required for prilled and flaked penta-
chlorophenol for millwork and plywood use (Section VI.H) and for powdered
sodium pentachlorophenate (Section VI.G). This protective measure will re-
duce pentachlorophenol exposure to 0.024 mg/m3, the concentration in ambient
air at treatment plants (Arsenault, 1976). The potential inhalation oncogenic
risk will then be negligible and the MOS for teratogenic/fetotoxic effects
will be 730 (Rispin, April 18, 1984).
4. No Visible Surface Deposits for Arsenicals
Exposure/Risk; Workers in treatment plants that apply inorganic
arsenical formulations are exposed to the background (ambient) arsenic
dust via inhalation exposure. This dust results from the leaching, drying
and subsequent flaking off of the inorganic arsenical formulations from
the surface of the treated wood which is drying in the yards. The contribution
this dust makes to the ambient levels of arsenic is related to the levels
of surface residues of the inorganic arsenic formulations.
Treatment plant applicators are also exposed to residues of arsenic via
handling of dry treated wood. Thus, the Agency was concerned that treatment
plant applicators, as well as end-users of arsenical-treated wood, were
exposed to arsenic through ambient air levels and through dermal contact
with the surface residues.
PD 2/3 Proposal; To reduce this source of inhalation and dermal exposure
to the treatment plant applicators, the Agency proposed in the PD 2/3 the
requirement that:
The inorganic arsenical treatment solutions must be
filtered prior to use in the treatment cylinders and an
additional vacuum step must be used prior to the removal
of the treated wood from the treatment cylinders. In
addition to these requirements, recommended control
technologies to reduce the surface levels of arsenic on
the treated wood include the use of wood that is free of
heavy resins ("clean" wood), the post-treatment rinsing
of the treated wood, and the installation of protective
sheds or covers over the drying treated wood.
Reducing surface residues of arsenic on the treated wood was expected to
reduce the inhalation and dermal exposure to the end-users of the treated
wood. Although the reduction in arsenic residues achieved by the use of the
technologies proposed in the PD 2/3 could not be accurately quantified until a
standardized sampling method became available, the Agency believed that
significant reduction in residues would result from implementation of these
specific technology measures during the application process, and hence a
significant reduction in risks.
Final Regulatory Position and Rationale; AWPI (February 9, 1982) stated
that there are industrial methods currently used to reduce surface residues
of arsenic on treated wood and that these methods include several process
control technologies available to the wood treater. The effective use of
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any one or more of tftese steps to reduce surface residues depends upon a
number of variables including the season and climate, size of the plant,
type of wood, and the solution being used. The various technologies include
controls on the wood used, maintenance of clean facilities, draining excess
solutions from the wood after treatment, filtering solutions, improving
the purity of treating solutions, pH control of treatment solutions, an
additional vacuum step in the treatment process, post-treatment washing of
treated wood, and varying drying processes. AWPI also stated that steps
which effectively reduce surface residues under one set of conditions will
not yield similar results under different conditions and that judgments as to
which steps are necessary to reduce surface residues should be left to the
individual applicators.
USDA (1981) also stated in its comments to the Agency that industry
should be allowed to meet a clean-wood standard in ways that best suit
their specific situations.
The Agency has evaluated the industry standards and methods of
achieving clean wood and has determined that surface residues of arsenic
will be effectively reduced if the labels are modified to include the
following information:
Processes used to apply inorganic arsenical formulations shall
leave no visible surface deposits, as defined by AWPA Standard
C-l and AWPB Standards LP2 and LP22. Visible surface deposits
mean a surface residue or crystallization on the treated wood.
Small isolated or infrequent spots of chemical on otherwise clean
wood may be allowed.
The Agency has concluded that this requirement will reduce surface
residues of arsenic on the treated wood and will significantly reduce the
inhalation and dermal exposure and resultant risk to an applicator and to
end-users of treated wood. This requirement will allow the applicator the
choice of several treatment technologies to reduce the surface residues of
arsenic on the treated wood.
5. Use of Protective Gloves
Exposure/Risk; The Agency expressed concern in the PD 2/3 that the
treatment plant applicators may be dermally exposed to the wood treatment
solutions when mixing the wood preservatives and when cleaning and maintaining
treatment equipment, such as pressure cylinders (all three chemicals) and vats
(pentachlorophenol or sodium pentachlorophenate). Applicators may also be
exposed to the treatment solutions when handling freshly treated lumber, when
emptying and mixing bags of powder formulations, or when applying the
preservative solution.
Due to insufficient data, the Agency was unable to quantify the dermal
exposure from hand contact for 1) all activities in which contact with creo-
sote solution is likely to occur, 2) activities such as entering cylinders and
opening cylinder doors in which dermal contact with the inorganic arsenicals
solution is likely to occur, and 3) those activities such as opening cylinder
doors, cleaning of equipment, and handling pentachlorophenol-treated wood in
which dermal contact with the pentachlorophenol solutions is likely to occur.
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The Agency, however, was able to estimate the total inorganic arsenical
exposure while handling wet freshly treated wood and diluted solutions.
The total oncogenic risk, without gloves, was 2.6 x 10~2 (PD 2/3, p. 217)
and the teratogenic/fetotoxic Margin of Safety (MOS) was 417 (PD 2/3, p. 245).
The risk estimate for arsenic also includes the inhalation exposure due to
the treatment plant (background) arsenic levels.
PD 2/3 Proposal; To reduce risks the- Agency proposed the following
requirement:
All applicators wear gloves impervious to the wood treatment
solution (e.g., rubber) in all situations where dermal
contact with creosote, pentachlorophenol, or the inorganic
arsenicals is possible (e.g., handling treated wood and
opening cylinder doors).
Although adequate experimental data were not available on the permeability
of gloves to these wood preservatives, the Agency estimated (PD 2/3, p. 556)
that an applicator wearing gloves resistant to penetration by these wood
preservatives would have significantly reduced (by 99%) exposures to these
pesticides via the hands alone. The reduction in total dermal exposure
is about 30%.
As stated in the PD 2/3 (p. 615), wearing gloves while handling freshly-
treated inorganic arsenical-treated wood and diluted solutions results in
a reduction of total (dermal and inhalation) oncogenic risk from 2.6 x
10~2 (without gloves) to 1.91 x 10~2 (with gloves) and a teratogenic/
fetotoxic Margin of Safety (MOS) increase from 417 to 499. Although the
total inorganic arsenical risk has not been significantly reduced in this
situation due to the inclusion of the risk from inhalation exposure, the
dermal exposure to the inorganic arsenicals via the hands is significantly
reduced (by 99%). The risk probability of skin cancer to an individual
would be reduced from 7.0 x IQ"^ to 1.0 x 10~4 by wearing gloves for this
activity (PD 2/3,, p. 615).
Final Regulatory Position and Rationale; Based on rebuttal comments
(AWPI #36:3QOOO/28C) to the PD 2/3, the Agency revised some of the inorganic
arsenical exposure assumptions for inhalation as discussed in Section II of
this document. The estimate of airborne arsenic in a treatment plant
environment has been lowered to 0.01 mg/n»3 from 0.07 mg/ra^. in the
absence of inhalation absorption data for arsenic laden dust in the ambient
air of treatment plants, the Agency assumes 100% inhalation absorption as
in the PD 2/3.
The recalculated inhalation oncogenic risk to applicators handling freshly
treated wood in inorganic arsenical treatment plants would be 4.1 x 10~5
(assume 10 ug/m^) if respirators are worn (Rispin, April 18, 1984) . The
recalculated dermal risk is 6.2 x 10""4 with gloves, assuming 90% protection
(Rispin, April 18, 1984).
The Agency also received information on the types of materials appropriate
for protective clothing to reduce exposure to the various wood preservative
formulations (AWPI, June 17, 1982), but, as described previously in Section
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VI.C.2 of this PD 4, will require registrants to provide permeability data
for various glove materials in contact with arsenic and creosote formulations.
The Agency will revise the assumption of 90% protection by gloves if the
data indicate otherwise.
The Agency has revised the PD 2/3 proposal and has determined that, in
order for the benefits to exceed the risks for pressure treatment uses of
all three wood preservatives, the following information must appear on the
wood preservative labels:
Applicators must wear gloves impervious to the wood treatment
formulation [e.g., inorganic arsenicals; vinyl, polyvinyl
chloride (PVC), neoprene, NBR (Buna-N), rubber, and polyethylene?
creosote: polyvinyl acetate (PVA), polyvinyl chloride (PVC),
neoprene, and NBR (Buna-N); pentachlorophenol; polyvinyl acetate
(PVA), polyvinyl chloride (PVC), neoprene, NBR (Buna-N), and
nitrile] in all situations where dermal contact is expected (e.g.,
handling freshly treated wood and manually opening cylinder doors).
The Agency has revised the language of this requirement ("wearing
gloves where dermal contact is expected" rather than "where dermal contact
is possible") because the word "expected" provides clearer guidance to
the applicator. The word "possible" is overly broad and does not limit the
requirement to the situation of concern.
6. Disposal of Protective Clothing and Pesticide Formulation
Exposure/Risk; The Agency expressed concern in the PD 2/3 that, although
not quantified, there are potential risks from creosote, the inorganic
arsenicals and pentachlorophenol containing pesticide-laden dust or treatment
solutions which adhere to protective clothing and workshoes and are transported
from the treatment plant into the home. This practice of bringing contaminated
protective clothing and workshoes into the home creates a potential exposure
to the workers' families. The Agency sought to eliminate or greatly reduce
this potential source of wood preservative exposure in treatment plant
workers' homes.
PD 2/3 Proposal; The PD 2/3 proposal for a label modification to reduce
this type of exposure was:
All applicators must leave all protective clothing, workshoes
or boots, and equipment at the plant at the end of the day.
Worn-out protective clothing must be disposed of in accordance
with the instructions for pesticide container disposal.
Final Regulatory Position and Rationale; The PD 2/3 proposal stated
that disposal of worn-out protective clothing be in accordance with the
instructions on the label for pesticide container disposal. The direction
on the labels of the wood preservatives regarding disposal of the containers
states that the containers should be triple-rinsed prior to disposal accord-
ing to Subtitle C of the Resource Conservation and Recovery Act (RCRA).
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The Agency did not intend by the PD 2/3 proposal that protective clothing
be triple-rinsed prior to disposal and therefore has revised the wording
of the statement for clarification. The revised language describes exactly
how the worn-out protective clothing and worn-out workshoes or boots must be
disposed of.
The International Woodworkers of America (68:30000/280 commented that
the PD 2/3 proposal was not clear about the cleaning of protective clothing
and were concerned that applicators might come into contact with the pesti-
cides from their contaminated protective clothing. Based on this comment,
the Agency has concluded that there should be a statement on the label
indicating that there should be a change of protective clothing when such
clothing shows signs of contamination. This label language was also recom-
mended in a NIOSH report (1983).
The Agency has determined that registrants must revise their pressure-
treatment pesticide labels for products containing inorganic arsenicals to
include the following information:
Protective clothing must be changed when it shows signs of
contamination. Applicators must leave protective clothing,
workshoes or boots, and equipment at the plant. Worn-out
protective clothing and work shoes or boots must be left
at the plant and disposed of in a manner approved for
pesticide disposal and in accordance with State and
Federal regulations.
For products containing creosote or pentachlorophenol for pressure
treatment, labels must be modified to include the following information:
Protective clothing must be changed when its shows signs
of contamination. Applicators must leave protective
clothing, workshoes or boots, and equipment at the plant.
Worn-out protective clothing and workshoes or boots must
be left at the plant and disposed of in a general land-
fill, in the trash, or in any other manner approved for
pesticide disposal.
The Agency has adopted the revised requirement because it reduces
potential exposure to the workers' families from these wood preservatives
and because it is more specific regarding the method of disposal than
the PD 2/3 proposal. The new language clarifies the Agency's intention
regarding disposal of protective clothing includes "work shoes or boots"
which, when worn-out, must be disposed of as well as protective clothing,
and is more specific about the sites for disposal than the ED 2/3 proposal
for pentachlorophenol and creosote. Protective clothing contaminated with
the inorganic arsenicals may be a hazardous waste as defined by 40 CFR
261.24 under the Resource Conservation and Recovery Act (RCRA) if an
extract from the waste contains arsenic at a concentration equal to or
greater than 5.0 milligrams per liter. Therefore, protective clothing
contaminated with the inorganic arsenicals must be disposed of appropriately
in accordance with State and Federal regulations.
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On March 29, 1983, the Agency notified all manufacturers, formulators
and registrants of pesticides that the labels for all pesticide products
must include updated storage and disposal statements (U.S. EPA, PR Notice
83-3, March 29, 1983). The Notice indicated that, for arsenic formulations,
labels must bear the following pesticide disposal statement:
Pesticide wastes are acutely hazardous. Improper disposal of
excess pesticide, spray mixture, or rinsate is a violation
of Federal law. If these wastes cannot be disposed of by use
according to label instructions, contact your State Pesticide
or Environmental Control Agency, or the Hazardous Waste
representative at the nearest EPA Regional Office for guidance.
Although not all wastes containing arsenical compounds are listed under
RCRA as acute hazardous wastes, the inorganic arsenicals used as wood
preservatives are listed as acute hazardous wastes under 40 CFR 261.33(e).
The Notice (PR 83-3) indicated that, for pentachlorophenol and creosote
products, except those intended solely for household use, the labels must
bear the following pesticide disposal statement:
Pesticide wastes are toxic. Improper disposal of excess
pesticide, spray mixture, or rinsate is a violation of Federal
law. If these wastes cannot be disposed of by use according to
label instructions, contact your State Pesticide or Environmental
Control Agency, or the Hazardous Waste representative at the
nearest EPA Regional Office for guidance.
In addition to other label amendments required in this PD 4, the Agency
has concluded that labels of wood preservative formulations must be amended
as stated in PR Notice 83-3 regarding disposal of unused or spent formulations
containing pentachlorophenol, creosote, or inorganic arsenicals.
7. Warnings Regarding Eating, etc., during Application
Exposure/Risk; It is not unusual for treatment plant workers to eat their
lunches and smoke in the yard around stacks of treated wood or when handling
freshly treated wood, thus creating a potential for accidental ingestion
through contamination of food, drinks, and inhalation during smoking. Although
the risks of accidental contamination of food, drink, or tobacco products with
wood preservatives through oral exposure have not been quantified, the Agency
believes there is a potential risk from these activities.
PD 2/3 Proposal; The Agency proposed in the PD 2/3 the following label
modification:
Eating, drinking and smoking are prohibited during
the application of creosote, pentachlorophenol, and the
inorganic arsenical wood preservative pesticides by
pressure treatment.
The Agency proposed the stated prohibitions in order to achieve a
reduction in the applicator's oral exposure.
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Final Regulatory Position and Rationale; The Agency has concluded
that the following information must be included on the labels for pressure-
treatment uses of pentachlorophenol, creosote, and the inorganic arsenicals:
Applicators must not eat, drink, or use tobacco products during
those parts of the application process which may expose them to
the treatment formulation (e.g., manually opening/closing cylinder
doors, moving trams out of cylinders, mixing chemicals and handling
freshly treated wood). Wash thoroughly after skin contact, and
before eating, drinking, use of tobacco products, or using restrooms.
The Agency has revised the PD 2/3 proposal because the revised version
broadens the scope of prohibiting the use of all tobacco products (e.g.,
chewing tobacco) in the treatment area. It also further defines the specific
exposure situations when eating, drinking, and smoking should be prohibited
and thus provides clearer guidance to the applicator than the PD 2/3 recommen-
dation. This label instruction will accomplish the Agency's goal of reducing
accidental exposure to applicators via eating, drinking, and smoking. The
final requirement is also more specific than the PD 2/3 proposal in that
it requires washing after skin contact.
8. Risk Reduction Measures Regarding Opening Treatment Cylinder Doors
Exposure/Risk; During a brief time (about 1 hour per day), an applicator
may be manually opening cylinder doors following the pressure treatment of
wood. While the cylinder door is being opened, it is possible to dermally
contact^ the treatment solutions that have splashed and dried around the
cylinder door. In addition, immediately after the door is opened, hooks
are manually attached to the charge of wood for its removal from the cylinder.
During this operation the applicator may dermally contact the treatment
solutions.
The Agency was concerned that treatment plant applicators may be more
extensively and significantly exposed (dermal and inhalation) to creosote
and pentachlorophenol solutions and vapors while performing this particular
activity than during other activities around and about the treatment plant.
In the case of creosote, although the Agency has no quantitative data
demonstrating that workers involved in the opening of cylinder doors following
treatment are exposed to higher levels of the pesticide than in other work
situations, it seems reasonable to assume that in this particular situation
a greater exposure could occur.
For pentachlorophenol, the Agency has data on the applicator's
inhalation exposure only, but lacks information on the dermal exposure
occuring during the opening of cylinder doors. The oncogenic risk resulting
from inhalation alone under these circumstances was estimated to be 6.4 x
10~4; the MOS for fetc%oxic effects is estimated to be 150 in this situation
(PD 2/3, pp. 587, 588).
Because inorganic arsenical formulations are water-based solutions
which do not typically produce vapors, the Agency determined that the air
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arsenic concentrations while opening the cylinder door following treatment
will not exceed the background air arsenic dust levels of the plant {PD
2/3, p. 584). Thus, the inhalation exposure would not be higher than that
of any other applicator activity.
PD 2/3 Proposal; In the PD 2/3, the Agency proposed requiring that all
applicators who open pentachlorophenol or creosote treatment cylinder doors
wear gloves and a properly maintained half-mask canister or cartridge res-
pirator designed for that pesticide's use. An applicator wearing gloves
resistant to penetration by these pesticide solutions would have a signifi-
qantly reduced hand dermal (by 99%) (Kosak, 1980) exposure. An applicator
wearing a respirator while performing this activity with creosote or
pentachlorophenol will have a significantly reduced inhalation exposure
(by 90%) , resulting in significantly reduced risks.
For pentachlorophenol the oncogenic risk would be decreased from 6.4 x
10~4 to 6.4 x 10~5 and the fetotoxic MOS would be increased from 150 to 1,500
if these protective measures were taken (PD 2/3, pp. 657, 661).
As discussed in Section VI.C.5 of this document, the PD 2/3 proposed
that gloves be worn by arsenic applicators when opening clyinder doors.
As discussed in Section VI.C.I of this document, the PD 2/3 proposed that
all workers in arsenical treatment plants must wear dust masks.
Final Regulatory Position and Rationale; The Agency has concluded that
the following information must be included on the label for pressure treatment
uses of pentachlorophenol and creosote;
Pressure-treatment pentachlorophenol and creosote
applicators who manually open cylinder doors must wear
gloves and a respirator.
The types of gloves and respirators acceptable for creosote and penta-
chlorophenol which must be included on the label were described previously
in Section VI.C.2 of this document. As discussed in Section II of this
document, this requirement will also reduce hand dermal exposure by 90%
(Rispin, April 18, 1984) and inhalation exposure by 90% to these wood
preservatives, but is more specific than the PD 2/3 about the type of
respirator and materials appropriate for gloves.
The oncogenic risk due to exposure to pentachlorophenol was recalculated
using the multi-stage model, as discussed in Section II of this document.
An applicator wearing a respirator while opening cylinder doors would have
an inhalation oncogenic risk of 3.1 x 10-6 an
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three wood preservatives as compared with trained applicators. By prevent-
ing untrained or unsupervised applicators from using these pesticides, the
risk of human exposure due to misuse or carelessness would be significantly
reduced.
PD 2/3 Proposal; The Agency proposed in the PD 2/3 to classify pressure
treatment uses of the three wood preservatives for "Restricted Use" only.
Under FIFRA, hazardous pesticides may be classified for restricted use and
be limited to use only by or under the direct supervision of certified
applicators. To become certified, the applicators must enroll in a certification
program, which teaches the safe use and disposal of restricted use pesticides.
Upon completion of these programs, the applicators are certified for a
particular restricted use pesticide or pesticides* Therefore, the Agency
proposed the following label modification for pressure treatment uses of
all three wood preservatives:
Restricted for sale to and use only by certified applicators
or by persons under their direct supervision and only for
those uses covered by the certified applicator's certification.
Final Agency Position and Rationale; The Agency has adopted the PD 2/3
proposal as the final regulatory position because it will assure that
applicators will be properly trained in the safe handling of the three wood
preservatives. The Agency has concluded that labels for pressure-treatment
uses of pentachlorophenol, creosote, and the inorganic arsenicals must be
modified to include the following information:
Restricted Use Pesticide;. Restricted for sale to and use
only by certified applicators or by persons under their
direct supervision and only for those uses covered by the
certified applicator's certification.
The Agency believes that this restriction will reduce the opportunity
for misuse of the pesticides and will therefore decrease exposure and
potential risks to applicators and is, therefore, necessary to prevent
unreasonable adverse effects.
10. Closed System/Arsenical Powders
Exposure/Risk; The PD 2/3 assummed that treatment plant workers who empty
bags containing inorganic arsenical powder formulations in the preparation
of the treatment solutions contact up to 10 grams of arsenic dust via the
skin. The amount of inhaled arsenic dust is also increased over background
levels as a result of this activity. The Agency assumed in the PD 2/3
that all ambient dust resulting from bag emptying will be respirable and
will reach the "lungs, rather than the gastrointestinal tract, due to the
small particle size. The Agency estimated that a total lifetime oncogenic
risk of 3.4 x 10~2 and a teratogenic/fetotoxic MOS of 294 would result
from bag emptying of inorganic arsenical powder formulations (PD 2/3, p. 582).
PD 2/3 Proposal; The Agency proposed in the PD 2/3 to require closed
systems for the emptying and mixing of powder formulations of the inorganic
arsenicals to reduce inhalation and dermal exposures during this activity. An
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example of an acceptable closed emptying and mixing system was described
previously in Section VI.C.3 of this document. This requirement was expected to
reduce the applicator exposure to the inorganic arsenicals to a level that is
comparable to the background (ambient) air levels in the plant. The Agency
assumed dermal exposure is negligible where closed systems are used for emptying/
mixing activities.
Final Agency Position and Rationalet As discussed in Section II of
this document, the Agency based the recalculated dermal exposure estimate
on monitoring data obtained with Guthion powder and dry mix fertilizer.
The Agency estimated a dermal exposure of 3.8 to 142 mg/hr and 0.1% absorption
or 0.0038 to 0.142 mg/hr while dumping bags of FCAP for 1 hour/day for 5
days/week for 240 days/year over a working lifetime.
For inhalation exposure, the Agency assumed an upper limit of 10 ug/m3,
because if it were higher respirators would be required and inhalation
exposure would be reduced by 99% as previously discussed (Section VI.C.1).
The recalculated dermal risk for opening bags of FCAP is 7.3 x 10~3
without protective measures; the recalculated inhalation risk is 4.1x10~3,
assuming 10 ug/m3 exposure to arsenic (Rispin, April 18, 1984).
Since the PD 2/3 was published there were no comments received from
the public disagreeing with the PD 2/3 proposal to require closed systems
for emptying and mixing powdered forms of the inorganic arsenicals. It is
the Agency's understanding that closed systems are already being used in
the workplace for this exposure situation. Therefore, in light of the
potential risk to applicators and lack of additional data/comments from
the public to alter the position presented in the PD 2/3, the Agency has
concluded that labels for powder formulations of the inorganic arsenicals
must be modified to include the following information:
A closed emptying and mixing system must be used for
all powder formulations of the inorganic arsenicals.
A closed system is defined as any containment which
prevents the release of subject chemicals into the
surrounding external environment.
This requirement is identical to the Agency's proposal in the PD 2/3
and will significantly reduce exposure to the powdered inorganic arsenicals
to levels which are not above ambient air levels in the plant. It is assumed
that closed systems result in minimal exposure.
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0. Poles-Groundline Uses: Pentachlorophenol and Creosote
Sections VI.D through VI.H of this document discuss non-pressure treatment
uses of the three wood preservatives.
This section (VI.D) discusses uses of creosote and pentachlorophenol
which are for wood preservative treatment of utility poles (e.g., telephone
or electrical) 6 inches above and 16 inches below the groundline (poles-
groundline}.
1. Use of Protective Gloves
Exposure/Risk; Creosote poses potential oncogenic and mutagenic risks
to humans, however this risk has not been quantified for the poles-ground-
line use. There are very little data available regarding workers' exposure
to all of the specific oncogenic or mutagenic components of creosote.
However, there are many reports of incidences of skin cancer among wood
treaters and other workers who apply creosote.
Dermal exposure to the workers who apply pentachlorophenol for poles-
groundline use occurs during the handling and application of the wet paste.
The Agency believes this exposure will occur primarily through the hands.
Due to the nature of the operation, however, some splattering of treatment
solution onto other areas of exposed skin may also occur<
PD 2/3 Proposal; To reduce the risk caused by dermal exposure, the
Agency proposed in the PD 2/3 that all applicators using pentachlorophenol
and/or creosote for poles-groundline uses wear gloves impervious to these
pesticides. The wearing of gloves was expected to reduce the dermal
exposure from hand contact with these chemicals (pentachlorophenol and/or
creosote) by 99%. Specifically, the PD 2/3 proposed:
All applicators must wear gloves impervious to the
creosote and pentachlorophenol poles-groundline
formulations (e.g., rubber) in all situations where
dermal contact with pentachlorophenol and/or creosote
is possible.
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Final Agency Position and Rationale; The Agency has concluded that
labels for pentachlorophenol and/or creosote formulations for poles-
groundline use must contain the following information:
Applicators must wear gloves impervious to the wood
treatment formulation (e.g., polyvinyl acetate,
polyvinyl chloride or neoprene) in all situations
where dermal contact is expected (e.g., during the
actual application process and when handling freshly
treated wood).
The differences between the PD 2/3 proposal and the final requirement
are: a change from "wearing gloves where contact is possible" to "wearing
gloves where contact is expected" (for rationale, see Section VI.C.5 of
this document); the description of the types of gloves which are appropriate
(AWPI, June 17, 1982, and Silkowski, 1982); and addition of the exposure
situation of "during the actual application process" for clarification.
As indicated in Section VI.C.2 and VI.C.5, the Agency will require
registrants to provide permeability data for contact of various protective
materials with creosote formulations.
The Agency has adopted this requirement because it provides for the
reduction in dermal exposure from hand contact (by 90%), with clearer
guidance to the applicator.
2. Use of Coveralls
Exposure/Risk; It is likely, during the treatment of poles at groundline
with creosote and/or pentachlorophenol, that some spillage or splattering may
occur on the arms and legs as well as the hands. The Agency proposed in the
PD 2/3 to require that applicators of creosote and/or pentachlorophenol wear
other protective clothing, such as disposable coveralls, to reduce risks to a
greater degree than the risk reduction resulting from gloves alone. The
Agency, however, did not quantify the extent to which exposure would be
reduced.
PD 2/3 Proposal; The PD 2/3 proposal stated:
All applicators must wear disposable coveralls (e.g.,
nitrile or polyethylene) or similar protective
clothing during the application process.
Final Agency Position and Rationale; The Agency has determined that the
labels for pentachlorophenol and/or creosote formulations for poles-groundline
use must be modified to include the following information:
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Applicators must wear disposable coveralls (e.g., for
creosote: nitrile or neoprene; for pentachlorophenol:
nitrile or polyethylene) or other suitable impermeable
protective clothing during the application and mixing
processes in all situations where dermal contact is
expected.
The changes from the PD 2/3 proposal are a clarification of the acceptable
materials for the coveralls (AWPI, June 17, 1982), and a clarification of the
exposure situation from "during the application process" (PD 2/3) to
"application and mixing processes in all situations where dermal contact is
expected."
These requirements will reduce the applicator's total dermal exposure
from the splattering of the pesticide during the application process.
Additional data on permeability of recommended materials, however, are
required as discussed in Section VI.C.2 of this PD 4.
3. Disposal of Protective Clothing and Pesticide Formulations
Exposure/Risk: Although not quantified by the Agency, there are
potential risks resulting from pentachlorophenol and/or creosote ad-
hering to clothing and shoes and not being disposed of properly.
PD 2/3 Proposal; To reduce risks from this potential exposure, the
Agency proposed in the PD 2/3 that:
All applicators must dispose of worn-out protective
clothing in accordance with the instructions for
pesticide container disposal.
Final Regulatory Position and Rationale; The Agency has determined that
the following information must be included on the labels for the poles-
groundline uses of pentachlorophenol and/or creosote formulations:
Protective clothing must be changed when it shows
signs of contamination. Launder non-disposable
protective clothing separately from other household
clothing. Dispose of worn-out protective clothing
and workshoes or boots in any general landfill, in
the trash, or in any other manner approved for
pesticide disposal.
As previously explained in Section VI.C.6 of this document, this
label modification clarifies the Agency's intent regarding proper disposal,
so that the requirements for container disposal, which included three
rinses, are not imposed. It includes the disposal of worn-out "workshoes
or boots" and is more specific about where disposal may take place than
the PD 2/3 proposal. Also, instructions are provided regarding changing
protective clothing and laundering any non-disposable protective clothing
belonging to the applicator.
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The final requirement also accomplishes the reduction of exposure to
the workers' families from these wood preservatives and clarifies the
Agency's intention about disposal procedures and sites.
As explained in Section VI.C.6 of this PD 4, The Agency will also re-
quire that labels of poles-groundline formulations containing creosote
and pentachlorophenol be amended to include the following information as
stated in PR Notice 83-3 (U.S. EPA, March 29, 1983):
Pesticide wastes are toxic. Improper disposal of
excess pesticide, spray mixture, or rinsate is a
violation of Federal law. If these wastes cannot
be disposed of by use according to label instructions,
contact your State Pesticide or Environmental Control
Agency, or the Hazardous Waste representative at the
nearest EPA Regional Office for guidance.
4. Warnings about Eating, etc., During Application
Exposure/Risk; Although the risks due to accidental ingestion of wood
preservatives by smoking, drinking, or eating during poles-groundline
treatment have not been quantified, the Agency has determined (PD 2/3) that
there is potential for adverse human health effects in these use situations.
PD 2/3 Proposal; To eliminate risks from this potential exposure, the
Agency proposed the following prohibition:
Eating, drinking and smoking is prohibited during the
application of creosote and pentachlorophenol products
for the poles-groundline use.
Final Regulatory Position and Rationale; As previously described for
pressure treatment uses of the wood preservatives (Section VI.C.7), the
Agency has determined that the labels for poles-groundline uses of penta-
chlorophenol and/or creosote formulations must be modified to include the
following information:
Applicators must not eat, drink, or use tobacco
products during those parts of the application process
which may directly expose them to the wood treatment
formulation. Wash thoroughly after skin contact,
and before eating, drinking, use of tobacco products
or using restrooms.
This label language will greatly reduce the applicator's exposure
during the application process. The rationale for revising the PD 2/3
proposal regarding this issue has been discussed previously in this
document in Section VI.C.7. To summarize, it broadens the scope of
prohibiting the use of all tobacco products (e.g., chewing tobacco),
further defines the exposure situations of concern, and requires washing
after skin contact. The requirement also satifies the Agency's concerns
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because it reduces the potential for accidental exposure during the
application of these wood preservatives.
5. Restricted Use
Exposure Risk; The Agency was concerned about the possibility of the
high risk of exposure to applicators who had not been properly trained
in the safe handling and disposal of the poles/groundline formulations
of pentachlorophenol and/or creosote.
PD 2/3 Proposal; In order to reduce the probability of exposure due
to misuse or carelessness as discussed previously for pressure treatment
uses of wood preservatives, the Agency proposed in the PD 2/3 the follow-
ing label amendment for poles-groundline formulations of pentachlorophenol
and/or creosote:
Restricted Use Pesticide: For sale to and use only
by certified applicators or by persons under their
direct supervision and only for those uses covered
by the certified applicator's certification.
Final Agency Position and Rationale; The Agency has determined that
poles-groundline formulations of pentachlorophenol and/or creosote must
contain the following label information:
Restricted Use Pesticide; For sale to and use only by
certified applicators or by persons under their direct
supervision and only for those uses covered by the
certified applicator's certification.
This requirement is the same as that proposed in the PD 2/3 and will
assure that applicators will be properly trained in the safe handling of
these formulations. Thus, risk of exposure will be reduced.
E. Home and Farm Uses (Including Railroad Tie Repair)—Pentachlorophenol
and Creosote
This Section presents this Agency's position for "home and farm"
uses of pentachlorophenol and creosote products which may be applied by
non-pressure methods, for example, by brushing, dipping, or spraying the
wood. The "home and farm" uses also include applications by railroad workers
to preserve railroad ties? therefore all the requirements stated in this
Section will apply to products used for non-pressure applications by railroad
workers also.
1. Creosote: Restricted Use
Exposure/Risk; The Agency is concerned about the possibility of
high exposure to home and farm applicators who have not been properly
trained in the safe handling procedures for formulations of creosote
products which could be obtained "over-the-counter." The Agency is
concerned about the potential for high exposure to products requiring
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spraying and to products requiring mixing and/or diluting where there
could be some splashing of the formulation resulting in dermal and
inhalation exposure.
PD 2/3/Proposal; To protect the home and farm applicator from these
potentially high exposures to creosote products, the Agency proposed the
following in the PD 2/3.
Restricted Use Pesticides; For sale to and use only
by certified applicators or by persons under their
direct supervision and only for those uses covered
by the certified applicator's.certification.
Final Regulatory Position and Rationale;
For home and farm use creosote products, including those products for railroad
tie repair, the Agency will require that the labels be modified to include
the following information:
Restricted Use Pesticide; For sale to and use only
by certified applicators or by personnel under their
direct supervision and only for those uses covered by
the certified applicator's certification.
Although the SAP recommended that the Agency find ways of enabling farmers
with small farming operations to use creosote without becoming certified,
the Agency continues to be concerned about the potential risk of oncogenicity
and mutagenicity for 3 to 6 million home and farm users applying 2.0 million
pounds of creosote [46 FR 13020]. Registered alternatives which are available
include copper naphthenate, copper-8-quinolinolate, zinc napthenate and
tributyltin oxide, though there may be various drawbacks for certain use
situations. Other alternative measures include untreated wood, non-wood
materials (e.g., aluminium and concrete), pressure-treated wood, or a naturally
resistant wood species, though the latter are in short supply. In light of
the Agency's continued concern about risk and because of the availability of
alternative chemicals or materials, the Agency has determined that restricting
the use of creosote products is necessary to significantly reduce exposure
due to misuse or carelessness by an applicator not properly trained in safe
handling procedures. Although this change in classification of creosote for
the home and farm use may increase the burden of using these products, the
Agency has determined that the burden is outweighed by the benefits of assuring
that these products are used only by applicators adequately trained to use
them. Other protective measures described below in this Section include use
of protective gloves, protective clothing, proper instructions for disposal
of protective clothing, and warnings about eating during applications.
2. Pentachlorophenol: Restricted Use
Exposure/Risk; As with creosote, the Agency was concerned about the
potentially high exposure to home and farm applicators, including those
repairing railroad ties with pentachlorophenol, from use of pentachlorophenol
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products. In particular the Agency was concerned about those pentachloro-
phenol products requiring spraying, and products having a pentachlorophenol
concentration greater than 5%.
PD 2/3 Proposal: In order to reduce the risks due to these exposures,
the Agency proposed the following in the PD 2/3 for home and farm products
containing a pentachlorophenol concentration greater than 5%:
Restricted Use Pesticide; For sale to and use only
by certified applicators or by persons under their
direct supervision and only for those uses covered by
the certified applicator's certification.
The Agency also proposed the cancellation and denial of registration
of the spray method of application of pentachloropnenol products which
are available for retail sale in concentrations of 5% or less.
Final Regulatory position and Rationale;
As with creosote, the Agency continues to be concerned about exposure
to applicators who apply, mix or dilute pentachlorophenol products,
because of the exposure inherent in the application process and because
there could be some accidental splashing of the formulation resulting in
dermal and inhalation exposure. As described in Section II of this PD 4,
there has been an increase in the estimated rate of dermal absorption
for pentachlorophenol from 10% (PD 2/3) to 50%, and a decrease in the
estimated amount of protection afforded by gloves from 99% (PD 2/3) to
90%. This has resulted in a decrease in the estimated margins of safety
for teratogenic effects from 560 (PD 2/3) to 12, assuming the applicator
wears gloves. The Agency is concerned that the Margin of Safety for
fetotoxic effects is 12 and has determined that the risks to untrained
applicators from exposure to pentachlorophenol by brushing on 5% penta-
chlorophenol formulations are not outweighed by the benefits unless the
applicator is educated in safe handling procedures in a certification program.
Regarding the proposed cancellation of registrations of pentachloro-
phenol spray products in concentrations of less than 5% pentachlorophenol,
the Agency now realizes that if certified applicators wished to spray
pentachlrophenol concentrations at less than 5%, they would have to buy
a more concentrated formulation, mix it and dilute it. Because this
adds another possible source of exposure, the Agency will not cancel
registrations of the pentachlorophenol spray products of less than 5%
pentachlorophenol. The Agency will require that applicators be certified
to use all pentachlorophenol spray products.
Thus, all labels of pentachlorophenol home and farm products, including
those pentachlorophenol products for railroad tie repair, must be modified
to contain the following information:
Restricted Use Pesticide; For sale to and use only
by certified applicators or by persons under their
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direct supervision and only for those uses covered by
the certified applicator's certification.
As described above for creosote formulations, applicators who repair
railroad ties using pentachlorophenol formulations also should be trained in
the proper handling of wood preservatives, even for situations where the
application is automated. Thus applicators must be certified or work under
the direct supervision of a certified applicator. In addition, because of
concerns about the low Margin of Safety of 12 for fetotoxic effects, the
Agency will require that certified applicators must wear certain protective
clothing and/or equipment as described below in this section. For application
of pentachlorophenol by a spray method, these protective measures include
gloves, protective clothing, head covering, respirators and eye protection.
For the other methods of application of pentachlorophenol products (e.g.,
brushing), the protective measures include gloves and disposable coveralls
or other suitable impermeable protective clothing. The exposure and risks
for the home and farm applicators using restricted pentachlorophenol products
are described below in this section for the various exposure situations.
The Agency has determined that the registrations of home and farm use
pentachlorophenol products may be continued only if these products are
classified as restricted. The additional training and experience required
of the applicator of a restricted use pesticide should help to assure that
these products are applied only when indicated and with the appropriate
safeguards. In addition, as discussed in Section VLB of this document, the
Agency will also require that all pentachlorophenol labels include a statement
warning users of the potential fetotoxic effects.
The Agency considered cancelling registrations of pentachlorophenol for
home and farm use. The acute toxic effects of chemical alternatives, which
home and farm users might choose, were discussed in the PD 2/3 (pp. 367-379).
However, long term potential toxic effects of exposure to the alternative
chemicals have not yet been studied. It is possible that these chemicals
might be just as toxic or more toxic for chronic effects than pentachloro-
phenol. The Agency will request data from the registrants on all the chemical
alternatives for home and farm uses of pentachlorophenol. (See Section VIII
of this document.) Also, the alternative chemicals cost more, some have not
been shown to be as efficacious as pentachlorophenol, some may impart an
objectionable color to the wood, and some do not allow for subsequent painting
of the treated surfaces (PD 2/3 pp. 498-512).
When the studies on the chronic toxicity of alternative chemicals are
received, the Agency will evaluate the data and will then determine if further
regulatory action is necessary.
Because the Agency is concerned about potential hazards due to cresote
exposure to applicators using creosote for railroad tie repair, the Agency
is also requiring creosote products for this use to be for restricted use
also under the category of home and farm use. Even where this frequent
process of applying creosote by brushing or spraying is automated, the
applicator may still be involved, for example, in mixing, cleaning equipment
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or repairing equipment which fails or jams. In all situations involving
application, the applicator should be trained in the safe use and handling
of these toxic pesticides. The applicator may also work under the supervision
of a certified applicator. The Agency has concluded that only with these
restrictions and other restrictions presented in this PD 4 for home and farm
use will the benefits of use of home and farm products containing creosote,
including those for railroad tie repair, outweigh the risks.
3. Interior Application Prohibited
Exposure/Risk; The Agency expressed concern in the PD 2/3 about the
potentially high inhalation exposure to individuals from home and farm
use of creosote and pentachlorophenol applied indoors. Dermal exposure
to creosote and pentachlorophenol was assumed to be the same for indoor
as for outdoor application.
Due to insufficient data, the Agency did not evaluate the risks due to
creosote exposure, but assumed the risk could be significant.
Regarding exposure to pentachlorophenol, the extent of dermal exposure
during home and farm applications is dependent upon the care with which
the product is applied. The Agency estimated that homeowners may spill
amounts of pentachlorophenol formulation ranging from 1 drop (0.05 ml)
to 6.0 ml on their skin during one brush-on application period (PD 2/3,
p. 655). The Agency estimated that the total lifetime oncogenic risks
to the home and farm applicators from~dermal exposure to the pentachloro-
phenol formulation ranged from 1.0 x 10-6 to 1.3 x 10-4 for intermittent
indoor application (PD 2/3 pp. 330 and 672). For dermal exposure and
for exposure to pentachlorophenol vapors, the MOS for teratogenic/fetotoxic
effects ranged from 6 to 400 (PD 2/3, pp. 660 and 672).
PD 2/3 Proposal; To eliminate this particular exposure from interior
application of creosote and pentachlorophenol, the Agency proposed the
following prohibition on interior home and farm use of these products:
The application of creosote and pentachlorophenol
products indoors is prohibited.
Final Regulatory Position and Rationale; Based on acute animal studies
(Gaines, 1969) discussed in Section II of this document, the Agency
reassessed the dermal absorption rate for pentachlorophenol in organic
solvents (Zendzian, 1981) and determined that the dermal absorption rate
was 50% rather than the previously assumed 10% (PD 2/3f p. 337). Based
on inhalation exposure data submitted by USDA (1981) and discussed in
Section II of this document, the ambient air concentration levels during
the application of pentachlorophenol were estimated to be 34 to 140
ug/m3 instead of the previously assumed 40 ug/m3 (PD 2/3, p. 330). Also,
the estimate of the protection afforded by gloves has decreased from 99%
(PD 23/3) to 90% as described in Section II of this document.
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These changes in pentachlorophenol dermal absorption rate and inhala-
tion exposure significantly increase the oncogenic and fetotoxic risks
from exposure to pentachlorophenol from indoor application by home and
farm users as compared to that calculated in the PD 2/3.
Therefore, in order to protect the home and farm applicator, the Agency
has concluded that labels for home and farm uses of creosote and of
pentachlorophenol must, in addition to the statement regarding restricted
use, include the following information allowing outdoor application but pro-
hibiting indoor application.
Avoid inhaling vapors. If inhalation of vapors
cannot be avoided, appicators must wear a properly
fitting well-maintained half-mask canister cartridge
respirator which is MSHA/NIOSH-approved for organic
vapors and acid gases (pentachlorophenol) or for
polynuclear aromatics and organic vapors (creosote).
Do not apply in interiors.
If a certified applicator wears gloves (as required below) and a
respirator while applying pentachlorophenol formulations (assume 5%) outside
but in small crawl spaces under homes, the potential oncogenic risk is 6.2 x
10-6 and the potential teratogenic/fetotoxic Margin of Safety is 12 (Rispin,
April 18, 1984). It is assumed that the home and farm applicator applies
pentachlorophenol for a 2-week period once every 3 years (Burnam, 1983). If,
however, the applicator is employed doing odd jobs and uses pentachlorophenol
more frequently (assume 120 days per year for a 30-year working lifetime),
the estimated oncogenic risk is 2.1 x 10-4 (wearing gloves) and the Margin
of Safety for fetotoxic effects is 12 (Saito, June 6, 1984).
The Agency is concerned about these potential oncogenic and fetotoxic
riskes, but has concluded that requiring applicators to be trained in the
handling of these pesticides and requiring a statement on the pesticide label
that pregnant women should not use pentachlorophenol products will protect
the public such that continued use of home and farm products will not result
in the risks of use outweighing the benefits. The prohibitions and the
protective measures presented throughout this Section (VI.E) are necessary
to assure that exposure of individuals to all formulations of creosote and
pentachlorophenol and their vapors will be reduced to levels such that the
risks of use do not outweigh the benefits. When toxicity studies on chemical
alternatives to pentachlorophenol are received, the Agency will evaluate the
data and will take further regulatory action if it is deemed necessary.
4. Use of Protective Gloves
Exposure/Risk; Risks associated with exposure to all of the oncogenic or
mutagenic components of creosote could not be quantified. Athough there are
many reports of incidences of human skin cancer among creosote applicators
(PD 2/3, p. 36), there are no studies available which can be used for a
quantitative risk extrapolation of low levels of exposure.
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The Agency estimated in the PD 2/3 (p. 672) that the total lifetime
oncogenic risks to the home and farm applicators from dermal exposure to
pentachlorophenol ranged from 1.0 x 10-6 to 1.3 x 10-4 for both indoor
and outdoor application; the fetotoxic MOS ranged from 6 to 400 for indoor
application and from 6 to 650 for outdoor application.
PD 2/3 Proposal; To reduce the risk caused by dermal exposure, the Agency
proposed the following in the PD 2/3:
All applicators using pentachlorophenol and creosote
for home and farm uses must wear gloves impervious to
these pesticides (e.g., rubber) in all situations when
dermal contact with them is possible (e.g., handling
treated wood).
Implementation of this modification for home and farm application would
reduce the dermal exposure from hand contact by 99%. Using gloves, the
oncogenic risk from dermal exposure for both indoor and outdoor applications
of pentachlorophenol was in a range of 1.0 x 10~8 to 1.3 x 10~6, the MOS for
fetotoxicity for dermal and inhalation exposure to pentachlorophenol ranged
from 360 to 900 for indoor application, and 560 to 7,100 for outdoor appli-
cation (PB 2/3, pp. 660 and 672).
Final Regulatory Position; As explained previously (Section VI.B.3),
the Agency will prohibit application of pentachlorophenol and creosote in
residential interiors, but will allow outdoor application providing the
labels indicate that certain precautions are to be taken. The Agency has
recalculated the risks to home and farm users from outdoor exposure to penta-
chlorophenol and has found, if gloves are worn, that the oncogenic risk will
be 6.2 x 10-6, assuming the home and farm user applies pentachlorophenol for
a period of two weeks once every three years (Burnam, 1983). The MOS for
teratogenic/ fetotoxic effects is 12 (Rispin, April, 18, 1984). If the home
and farm user does odd jobs and applies the pentachlorophenol 120 days per
year for a 30-year working lifetime, the potential oncogenic risk is estimated
to be 2.1 x 10"4 (with gloves); the MOS is 12 (Saito, June 6, 1984). The
increased dermal absorption rate and increased inhalation exposure (Section
II) were taken into account in this calculation. No data were available to
calculate risks due to creosote exposure.
In order to reduce dermal absorption and protect the home and farm
applicator, the Agency has concluded that labels of all formulations of
creosote and pentachlorophenol must be amended to include the following
information:
Applicators must wear gloves impervious to the wood
treatment formulation in all situations where dermal
contact is expected (for example, during the actual
application process and when handling freshly treated
wood).
Acceptable materials for gloves for pentachlorophenol
and creosote products for home and farm use are polyvinyl
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chloride, polyvinyl acetate, neoprene, NBR (Buna-N),
nitrile (pentachlorophenol only).
This required label language states "where dermal contact is expected"
instead of "where dermal contact is possible" (PD 2/3 proposal), recommends
various types of glove materials instead of rubber (Silkowski, 1982), and
describes the additional exposure situation as "during the actual application
process." This requirement will, as would the PD 2/3 proposal, reduce
dermal exposure from hand contact with pentachlorophenol and creosote by
90% (Rispin, April 24, 1984). The rationale for the changes in wording from
the PD 2/3 proposal was discussed in section VI.C.5 of this document.
Acceptable materials for gloves for pentachlorophenol were recommended by
the wood preserving industry (AWPI, June 17, 1982) and by the University of
Washington (Silkowski, 1982). Rubber gloves are not now recommended for the
home and farm formulations of creosote and pentachlorophenol based on this
information. As discussed in Section VI.C.2 of this PD 4, the Agency will
require that the registrants submit data on the effectiveness of protection
of certain materials in contact with creosote formulations.
The Agency has concluded that benefits of home and farm use of pentachlo-
rophenol and creosote outweigh the risks of use only if modifications to the
terms and conditions of registration are made by the registrants as outlined
in Section VIII of this document. When studies on the toxicity of chemical
alternatives are submitted by the registrants, the Agency will evaluate the
data and take further regulatory action if deemed necessary.
5. Protective Clothing
Exposure/Risks; Home and farm products containing creosote or penta-
chlorophenol are typically applied by brush, dip or spray methods. The
Agency assumed (PD 2/3 p. 665) that the manual spray operation presents, by
far, the greatest opportunity for exposure to the applicator. However, the
risks associated with spraying these wood preservatives cannot be quantified,
because of the lack of quantitative exposure data.
PD 2/3 Proposal; To reduce exposure and risk from the brush, dip, or
spray methods of application of creosote or pentachlorophenol for home and
farm use, the Agency proposed in the PD 2/3 that certain protective clothing
be worn by the certified applicators:
All certified applicators who apply creosote or penta-
chlorophenol by the spray method must wear a neoprene-
coated cotton or rubberized overall, jacket, gloves and
boots, and a properly maintained half-mask canister or
cartridge respirator designed for pesticide use, and all
certified applicators who apply creosote or pentachloro-
phenol by other application processes (e.g., brush-on)
must wear disposable coveralls (e.g., nitrile or polyethy-
lene) or similar protective clothing.
As assumed in the PD 2/3, the use of the protective clothing would reduce
the total dermal exposure by 80%; the use of a respirator would reduce the
inhalation exposure by 90%, resulting in a significantly reduced risk.
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Final Regulatory Position and Rationale; Regarding protective clothing
for certified applicators, the Agency has determined that labels of creosote
and pentachlorophenol formulations must be amended to include the following
information:
Spray applicators must wear protective clothing (in-
cluding overalls, jacket/ gloves and boots) impervious
to the wood treatment formulation, and a respirator,
head covering and goggles when spraying. Applicators
who apply creosote and pentachlorophenol by other appli-
cation processes (e.g., brush-on) must wear disposable
coveralls or other suitable impermeable protective
clothing. Launder non-disposable protective clothing
separately from other household clothing
Respirators acceptable for spray applicators of creosote and penta-
chlorophenol were described in Section VI.C.2 of this document. Examples
of acceptable materials for protective clothing required during application
and handling of restricted use formulations of creosote and pentachlorophenol
are polyvinyl acetate (PVA), polyvinyl chloride (PVC), neoprene NBR (Buna-N),
and nitrile (pentachlorophenol only). Nitrile is also assumed to be accept-
able for disposable coveralls for creosote applications. This information
about respirators and materials for protective clothing must also be stated
on the label.
This requirement will reduce risks to certified applicators by providing
instructions regarding protective clothing and a respirator to certified
applicators who are allowed to apply the Restricted Use formulations of
creosote and pentachlorophenol. The types of materials for the protective
clothing are more clearly delineated in this final determination than in the
PD 2/3 proposal, based on information provided by the wood preserving industry
and evaluated by the Agency (AWPI, June 17, 1982). The additional protective
clothing of "head covering and goggles when spraying" is expected to reduce
exposure even further.
Without these label modifications the Agency has concluded that the
benefits of use of the Restricted Use formulations of pentachlorophenol
and creosote would not outweigh the risks.
The use of this protective clothing will reduce total dermal exposure by
80% and inhalation exposure by 90%, resulting in a reduced risk. Because the
Agency has no exposure data for this spray application activity, registrants
will be required to submit data on inhalation and dermal exposure from home
and farm spray applications of pentachlorophenol at several pentachlorophenol
concentrations. These data will enable the Agency to quantitate the risk
associated with this activity and take further regulatory action if deemed
necessary.
As discussed in Section VI.C.2, the Agency will reevaluate the appropriate-
ness of recommending certain materials for protection from creosote formulations
upon receipt of data required to be submitted by the registrants on the
permeability of materials to creosote formulations.
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6. Disposal of Clothing and pesticide Formulations
Exposure/Risk; As previously mentioned in this document, although the
Agency has not quantified the risks, there are potential risks resulting from
pentachlorophenol and creosote adhering to clothing and shoes and being
transported into the home following home and farm uses. This exposure
could pose a risk to the applicators' families.
PD 2/3 Proposal; To reduce risks from this potential exposure, the Agency
proposed in the PD 2/3 that applicators applying creosote or pentachlorophenol
solutions (home and farm use) follow certain instructions regarding disposal
of clothing.
Specifically, the Agency proposed the following:
All applicators must dispose of worn-out protective
clothing in accordance with the instructions for
pesticide container disposal.
Final Regulatory Position and Rationale; The Agency has concluded that
the labels of all formulations of creosote and pentachlorophenol for home and
farm use must be amended to include the following information:
Protective clothing must be changed when it shows
signs of contamination. Dispose of worn-out
protective clothing and workshoes or boots in any
general landfill, in the trash or in any other
manner approved for pesticide disposal.
This wording will reduce exposure to the worker by providing instructions
for changing protective clothing. The rationale for the more specific
directions for disposal of worn-out protective clothing was described in
Section VI.C.6 of this document.
This requirement will accomplish the reduction of exposure to applycators1
families from these wood preservatives such that the benefits of use will
exceed the risks.
As described in Section VI.C.6 of this PD 4, the Agency published PR Notice
83-3 (March 29, 1983) informing registrants of proper instructions to include
on pesticide labels regarding storage and disposal of pesticide formulations.
The Agency therefore requires, as part of this conclusion to the wood preser-
vatives RPAR, that registrants amend the labels of formulations containing
pentachlorophenol and cresote which are for farm use or railroad tie repair
use only to include the following information:
Pesticide wastes are toxic. Improper disposal of excess
pesticide, spray mixture, or rinsate is a violation of
Federal Law. If these wastes cannot be disposed of by
use according to label instructions, contact your state
Pesticide or Environmental Control Agency, or the
Hazardous Waste representative at the nearest EPA Regional
Office for guidance.
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That notice as well as PR Notice 84-1 (Feb. 17, 1984} addressed disposal of
formulations for household/domestic use. The Agency will require, as part
of the regulatory action, that labels of formulations containing pentachloro-
phenol and creosote for household/domestic use be amended to include the
following information:
Securely wrap original pesticide container in
several layers of newspaper and discard in
the trash. Do not reuse empty container.
7. Warnings about Eating, etc., during Application
Exposure/Risk; Although the risks due to accidental ingestion of wood
preservatives by smoking, drinking or eating during home and farm applications
for pentachlorophenol and creosote have not been quantified, the Agency
has, however, determined that there is a potential for adverse human
health effects in these use situations.
PD 2/3 Proposal; To eliminate risks from this potential exposure, the
Agency proposed the following in the PD 2/3:
Eating, smoking and drinking are prohibited during the
application of creosote or pentachlorophenol products.
FinalRegulatory Position and Rationale; The Agency has concluded that
labels for these home and farm pentachlorophenol products must be amended
to include the following information:
Applicators must not eat, drink or use tobacco
products during those parts of the application process
which may expose them to the treatment formulation.
Wash thoroughly after skin contact, and before eating,
drinking, use of tobacco products, or using restrooms.
This requirement will greatly reduce or eliminate the applicators'
exposure during the application process.
The rationale for adopting this wording was discussed previously in
Section VI.C.7 of this document.
8. Contamination of Food, Feed, and Water
Exposure/Risk; The Agency was concerned that food, feed, and water may
become contaminated from home and farm use of pentachlorophenol or creosote
products and that there could be direct contact with domestic animals or
livestock.
PD 2/3 Proposal; The PD 2/3 proposed the following label amendment:
Do not use creosote or pentachlorophenol in a manner
which may result in direct exposure of domestic animals
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or livestock, or in the contamination of food, feed, or
drinking or irrigation water (e.g., food crates, irrigation
flumes, vegetable stakes, feed lot bins, and watering
troughs).
Final Regulatory Position and Rationale; Upon review of the PD 2/3
proposed label language, the Agency has concluded that the examples of
food crates, irrigation flumes, etc. should be deleted, not only because
the label language is self-explanatory but also because the Agency does
not want the application prohibitions to be limited to those particular
wood products. There may be other wood items to which pentachlorophenol or
creosote could be applied and thereby cause direct exposure to animals or
result in the contamination of food, feed, or water.
Taking these considerations into account, the Agency has concluded
that labels must be amended on all creosote and pentachlorophenol products
for home and farm use to include the following information.
Do not apply where there may be direct contact
with domestic animals or livestock, and where
there may be contact with food, feed, or drinking
and irrigation water.
This requirement will eliminate the possibility of the liquid formulations
coming into direct contact with food, feed, or water during application.
Precautions regarding intended uses of wood or wood products which have been
treated with pesticides are discussed below in Section VI.E.9.
The Agency has determined that this label amendment is necessary so
that benefits associated with home and farm use of pentachlorophenol and
creosote will not be outweighed by the risks.
9. Other Restrictions on Application and Intended Use of Treated Wood
Exposure/Risk; Human exposure to wood preservative chemicals from
contact with the wood which has been treated is also of concern to EPA.
Construction workers, home repairmen, and residents of homes containing
treated wood may all be exposed to wood preservatives from a variety of
treated products, often without being aware of exposure to the pesticides.
Although the Agency is not able to quantify the risk to the general
public from all exposure to treated wood products, such exposure is likely
to be significant.
PD 2/3 Proposal; To protect persons who would be exposed from wood
treated by a home and farm use product, the Agency proposed that the
following be included on pentachlorophenol and creosote labels.
The application of creosote and pentachlorophenol products
to wood intended for interior use is prohibited, except for
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those support structures (e.g., foundation timbers, pole
supports and the bottom six inches of stall skirtboards)
which are in contact with the soil in barns, stables, and
similar sites and millwork (pentachlorophenol only) which
has outdoor surfaces (e.g., doorframes, windows, and patio
frames).
Limitations on the use of treated wood were considered as part of a TSCA
rule. The Agency recommended that a rule be promulgated to require labeling
of the treated wood product. The label information under consideration in-
cluded additional warnings concerned regarding use of gloves when handling
treated wood, protective measures to be taken when sawing treated wood, a
prohibition on use of treated wood which may contact domestic animals, food,
feed, or water, and a prohibition on burning treated wood (PD 2/3, p.720).
Final Regulatory Position and Rationale; Regarding use of treated
wood in interiors, AWPI (#36H:30000/28C) commented that EPA lacks the
authority under FIFRA to regulate the end uses of treated wood, that
the restriction is an attempt to control end uses of treated wood through
FIFRA labeling, and that Congress did not intend that the end product,
whether an agricultural product or wood after being treated with the
preservative, continue to be regulated under FIFRA.
The Agency has determined that FIFRA gives the Agency broad authority
to regulate pesticides such that their use does not cause unreasonable
adverse effects (FIFRA Sections 3(c)(5), 3(c)(6), and 12). Pursuant to that
authority, the Agency may require that use restrictions be included on the
labels of pesticide products addressing precautions to be taken regarding
appropriate limitations on the use of products treated with pesticides.
AWPI (*36H:30000/28C) further commented that EPA has failed to show
that a hazard to human or animal health has been demonstrated from interior
uses of creosote or pentachlorophenol treated wood.
As discussed in Section VII.A.4 and VII.A.5 of this PD 4, acute
effects to man and domestic animals from interior use of these chemicals
have been adequately demonstrated; the potential for chronic effects also
is discussed in these sections. As indicated by USDA (1981) two coats of an
effective sealer reduces vaporization of pentachlorophenol by 85% (Day,
December 9, 1983). This reduction is consistent with data submitted by Dr.
Levin of the University of California (70:30000/28C) and Jackson and Stratton
of the California Department of Health Services (87:30000/280 on the reduction
of vaporization of pentachlorophenol by the use of two coats of a sealer (Day,
Aug. 16, 1983). Therefore the Agency will require that, for limited interior
use of treated wood, two coats of an effective sealer should be applied.
Because the Agency is concerned about potential unreasonable adverse
effects from exposure to wood products treated with pesticides, the
Agency has determined that certain actions must be taken to limit exposure
of the general public to wood preservatives released from wood after it is
treated. To assure that adequate warnings and use restrictions for treated
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wood are presented on labels of home and farm use products containing penta-
chlorophenol or creosote, the registration of these products must be amended
to require the following information on the label:
Do not apply to wood intended for use in interiors
except for those support structures which are in
barns, stables, and similar sites and which are
subject to decay and insect infestation; and
millwork (pentachlorophenol only) which has outdoor
surfaces (e.g., door frames, windows and patio frames).
Interior surfaces of the treated wood should be
sealed with two coats of an appropriate sealer.
Do not apply pentachlorophenol or creosote to wood
intended for farrowing or brooding facilities. Do
not apply pentachlorophenol or creosote to wood
intended to be used in the interiors of farm
buildings where there may be direct contact with
domestic animals or livestock which may crib (bite)
or lick the wood. Pentachlorophenol or creosote
may be used to treat wood intended to be used in
interiors of farm buildings where domestic animals
or livestock are unlikely to crib or lick the wood,
if two coats of an appropriate sealer will be applied.
DO not apply to wood intended to used in a manner
in which the preservative may become a component
of food or animal feed. Examples of such sites
would be structures or containers for storing silage
or food.
Do not use this product to treat wood intended to be
used for cutting boards or counter tops.
Do not use this product to treat wood intended for
construction of those portions of beehives which may
come into contact with the honey.
Do not use this product to treat wood intended to be
used where it may come into direct or indirect contact
with public drinking water, except for those uses
involving incidental contact such as docks and bridges.
Do not use this product to treat wood intended to be
used where it may come into direct or indirect contact
with drinking water for domestic animals or livestock,
except for uses involving incidental contact such as
docks and bridges.
Wood to be treated with this product should be cut to
size before treatment. If it is necessary to saw or
machine wood after treatment, wear goggles to protect
the eyes from flying particles and a dust mask to
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avoid inhaling sawdust from the treated wood. If oily
preservative or sawdust accumulate on clothes, launder
before reuse. Wash work clothes separately from other
household laundry.
Contact with treated surfaces should be avoided even
after the preservative has dried. When handling treated
wood, wear tightly woven coveralls and gloves which are
impervious (e.g., vinyl coated) to the pesticide.
Wash exposed skin thoroughly after contact with treated
wood, and before eating, drinking or using tobacco
products.
Wood which has been treated with this product should be
disposed of by burial or ordinary trash collection. Do
not burn treated wood in an outdoor fire or in stoves or
fireplaces, because toxic chemicals may be produced as
part of the smoke and ashes.
This product should not be used to treat wood which will
be in frequent or prolonged contact with skin, unless the
wood will be treated with an effective sealer.
Orethane, epoxy, and shellac are acceptable sealers for
all creosote-treated wood. Urethane, shellac, latex
expoxy enamel and varnish are acceptable sealers for
pentachlorophenol-treated wood.
These use restrictions should provide substantial protection from
exposure to creosote and pentachlorophenol through use of a home and
farm use product. The Agency has determined that such additional protec-
tion is necessary to avoid unreasonable adverse effects to the population.
Detailed discussion of the reduced exposure which can be expected from
implementation of these restrictions can be found in Section VILA, of
this PD 4, which discusses the Consumer Awareness Program.
F. Brush-on Treatments of Inorganic Arsenicals
Brush-on application refers to the commercial application of the inorganic
arsenicals to the cut-ends of treated wood, an activity which usually occurs
only at construction sites. These inorganic arsenical formulations have not
been generally available for purchase by the homeowner or farmer because of
current marketing practices.
1. Unclassified Use
Exposure/Risk; The Agency was concerned about exposure to applicators
from improper handling of the inorganic arsenicals during brush-on treatments.
However, the Agency had no means of quantifying the risk attributable to
careless handling procedures.
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PD 2/3 Proposal; To assure the proper and safe handling of inorganic
arsenical formulations for brush-on treatments, the Agency proposed the
following labeling modification on the PD 2/3:
Restricted Use Pesticide; For sale to and use only by
certified applicators or by persons under their direct
supervision and only for those uses covered by the
certified applicator's certification.
Final Regulatory position and Rationale; Based on comments by USDA
(1980) that restricted use classification for brush-on treatments of the
inorganic arsenicals was not necessary, the Agency reevaluated the exposure
situation for this activity. For the brush-on application of inorganic
arsenical products, the Agency has concluded that these products will
remain unclassified only if the labels are modified to indicate that
mixing and diluting are prohibited and that they are only for commercial
construction application to the cut ends of pressure-treated wood.
Specifically, the Agency has determined that in order for the benefits of
use to exceed the risks, formulations of the inorganic arsenicals for brush-on
treatments must have the labels amended to include the following statements:
For application to the cut ends of pressure-treated
wood only. Do not dilute or mix with other products.
For commercial construction use only. Not for household
use.
The Agency believes that with proper labeling, the ready-to-use products
for the brush-on application of the inorganic arsenicals can be handled
safely. The labels would also be modified to include the listing of pro-
tective measures that must be taken as described in the sections that
follow (gloves, protective clothing, etc.). The calculated potential risks
are also presented below in those sections.
2. Materials for Protective Gloves
Exposure/Risk; The exposure to the inorganic arsenicals by brush-on
treatment applications is caused by spilling or otherwise coming into con-
tact with the liquid formulations. The dermal exposure in this situation
was estimated to be 3 ug/kg/day, and the lifetime dermal oncogenic risk to
brush-on applicators is 1.2 x 10~2? the teratogenic/fetotoxic MOS was esti-
mated to be 1,667 (PD 2/3, p. 666). The Agency has assumed that inhalation
exposure would be negligible because aqueous solutions (with low vapor
pressure) are used and brush-on treatments are applied outdoors using
very small volumes of treatment solution (PD 2/3, p. 666).
PD 2/3 Proposal; To reduce the risk caused by dermal exposure, the A
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During commercial brush-on treatments of the inorganic arsenicals to
wood, there is a potential for dermal exposure to the pesticide. It was
calculated in the PO 2/3 that wearing gloves will reduce the dermal exposure
and thus oncogenic risk 99% from 1.2 x 10-2 to 1.2 x 10—* and increase
the teratogenic/fetotoxic MOS from 1,667 to 170,000 (PD 2/3, p. 672).
Final Regulatory Position and Rationale; The Agency has concluded that
labels for brush-on formulations of the inorganic arsenicals must be amended
to include the following information:
Applicators must wear gloves (e.g., rubber, vinyl, or
neoprene) impervious to the wood treatment solution in
all situations where dermal contact is expected (e.g.,
during the application process and handling freshly
treated wood).
The recalculated risk based on the assumptions discussed in Section
II for brush-on applications of inorganic arsenic is 2.8 x 10~4 (with
gloves) (Rispin, April 18, 1984).
The required language is more specific about the types of materials
appropriate for gloves and describes more specifically the exposure situa-
tions of concern.
This requirement for the use of gloves provides for the reduction in hand
dermal exposure as did the PD 2/3 proposal. The rationale for the changes
in the wording of the PD 2/3 proposal was discussed in Section VI.C.5 of this
document. The types of materials appropriate for gloves were based on informa-
tion submitted by the wood preserving industry (AWPI, June 17, 1982) and eval-
uated by the Agency. As previously mentioned (section VI.C.2 of this PD 4),
additional data will be required on the effectiveness of various materials
used for gloves and protective clothing in preventing exposure to arsenic
formulations.
3. Materials for Coveralls
Exposure/Risk: It is likely that, during the brush-on applications of
inorganic arsenicals, some spillage or splattering may occur on the arms and
legs as well as the hands. Although the Agency has not quantified the appli-
cator total dermal exposure during the brush-on application, there is the
likelihood that splattering of the pesticide may occur, hence the risk could
be significant.
PD 2/3 Proposal; To reduce total dermal exposure the Agency proposed
the following in the PD 2/3:
Applicators must wear disposable coveralls (e.g.., nitrile
or polyethylene) or similar protective clothing during the
application process.
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This modification would reduce risks to a greater degree than the risk
reduction resulting from gloves alone. Gloves alone reduce dermal expo-
sure from hand contact by 99% and total dermal exposure by 30%. If both
gloves and coveralls are worn, total dermal exposure is reduced by 80%.
Final Regulatory Position and Rationale; The Agency has concluded that
labels for brush-on formulations of the inorganic arsenicals must be modified
to include the following information:
Applicators must wear disposable coveralls (e.g., vinyl
or polyethylene) or other similar impermeable protective
clothing during the application process where dermal contact
is expected.
This requirement is different from the PD 2/3 proposal in that vinyl has
been substituted for nitrile as an appropriate material for the protective
clothing based on information from the wood preserving industry (AWPZ, June
17, 1982). The phrase "where dermal contact is expected" has been added to
further define the exposure situation. The recommended materials for protec-
tive clothing will be reevaluated when data are received from the registrants
on the permeability of materials when in contact with arsenic formulations.
4. Warnings about Eating, etc., during Application
Exposure/Risk; Although the risks due to accidential ingestion of wood
preservatives by smoking, drinking, or eating during commercial brush-on
applications of the inorganic arsenicals have not been quantified, the Agency
determined in the PD 2/3 that there is a. potential for adverse human health
effects in these use situations.
PD 2/3 Proposal; To eliminate risks from this potential exposure, the
Agency proposed (PD 2/3) the following:
Eating, drinking and smoking during the application of
the inorganic arsenical products are prohibited.
Final Regulatory Position and Rationale; The Agency has concluded that
brush-on formulations of the inorganic arsenicals must have the labels amended
to include the following information:
Applicators must not eat, drink, or use tobacco
products during those parts of the application
process which may directly expose them to the
treatment solution. Wash thoroughly after skin
contact, and before eating, drinking, use of
tobacco products, or using restrooms.
This restriction will greatly reduce or eliminate the applicators' accidental
exposure during the application process.
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The rationale for revising the PD 2/3 proposal was discussed in Section
VI.C.7 of this document.
5. Disposal of Clothing and Pesticide Formulations
Exposure/Risk; Although the Agency has not quantified the risks, there
are potential risks resulting from the inorganic arsenicals adhering to
clothing and shoes, and not being disposed of properly.
PD 2/3 Proposal; To reduce risks from this potential exposure, the
Agency proposed the following:
All applicators applying brush-on inorganic arsenicals
must dispose of worn-out protective clothing in
accordance with the instructions for pesticide
container disposal.
Final Regulatory Position and Rationale; The Agency has concluded that
labels of the brush-on formulations of the inorganic arsenicals must be
amended to include the following information;
Protective clothing must be changed when it shows
obvious signs of contamination. Launder non-disposable
protective clothing separately from other household
clothing. Dispose of worn-out protective clothing in a
manner approved for pesticide disposal and in accordance
with State and Federal regulations.
This requirement will reduce exposure to the workers and clarifies
the Agency's intention about pesticide disposal as described earlier in
Section VI.C.6 of this document. Also, additional instructions regarding
changing and laundering any non-disposable protective clothing belonging
to the applicator are provided.
In addition, as described in Section VI.C.6 of this PD 4, the Agency will
also require that labels of the brush-on formulation of the inorganic arsenicals
must be amended to include the following information as stated in the Agency's
PR Notice 83-3 (March 29, 1983):
Pesticide wastes are acutely hazardous. Improper disposal
of excess pesticide, spray mixture, or rinsate is a
violation of Federal law. If these wastes cannot be
disposed of by use according to label instructions,
contact your State Pesticide or Environmental Control
Agency, or the Hazardous Waste representative at the
nearest EPA Regional Office for guidance.
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6. Intended Interior Use and Pood/Feed/Water Issue
Exposure/Risk and PD 2/3 Proposal; The Agency was concerned about
exposure to individuals from brush-on uses of the inorganic arsenicals on
wood intended for interior use and proposed in the PD 2/3:
Do not apply brush-on inorganic arsenical solutions to
wood intended for indoor use, except for those support
structures (e.g., foundation timbers, pole supports and
the bottom six inches of stall skirtboards) which are
in contact with the soil in barns, stables and similar
sites, all weather wood foundations, sills and plates
and structural framing.
There were no exposure data available for these use situations, but
the Agency determined it prudent to propose this prohibition.
The Agency also proposed in the PD 2/3:
Do not use inorganic arsenicals in a manner which may
result in direct exposure to domestic annimals or
livestock or in the contamination of food, feed, or
drinking or irrigation water (e.g., food crates,
irrigation flumes, vegetable stakes, feed lot bins, and
watering troughs).
Final Regulatory Position and Rationale; The brush-on treatments
of the inorganic arsenicals will be permitted to be used by carpenters at
construction sites only for application to the cut-ends of arsenic pressure-
treated wood. The Agency has concluded, therefore, that labels for the
brush-on treatments of the inorganic arsenicals must be amended to include
the following information;
For application to the cut ends of pressure-treated
wood only. Do not dilute or mix with other products.
For commercial construction use only.
These prohibitions will effectively eliminate interior uses or other
uses in which the wood treated by brush-on applicators of the inorganic
arsenicals would come into* direct contact with domestic animals or livestock
or result in the contamination of food, feed, or drinking or irrigation
water.
With these label modifications the Agency has concluded that the benefits
of use of the brush-on formulations of the organic arsenicals will outweigh
the risks.
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6. Use of salts of Pentachlorophenol for Sapstain Control
This Section discusses the Agency's position for regulating uses of sodium
pentachlorophenate which is applied by non-pressure methods (spray or dip/flow)
for sapstain control. Infestation by sapstain fungi increases the capacity
of the wood to absorb moisture, making the wood more vulnerable to decay.
Moreover, the discoloration caused by the sapstain is objectionable to wood
users and reduces the market value of the wood (PD 2/3, p. 512).
1. Use Directions for Spray Applications of Sodium pentachlorophenate
Exposure/Risk; The Agency expressed concern in the PD 2/3 about the high
potential for dermal and inhalation exposure during the spray operations
using soditm pentachlorophenate for sapstain control in the non-pressure
treatment plants. The inhalation exposure occurs via inhalation of aerosoli-
zed sodium pentachlorophenate solution (PD 2/3, p. 589).
For spray operations, the total estimated lifetime oncogenic risk while
spraying sodium pentachlorophenate for sapstain control was 1.9 x 10~3; the
fetotoxic MOS was 50 (PD 2/3, p. 589). This estimate was based on the exposure
assumption that an applicator worked 8 hours per day near the spray booth
where the maximum air levels (69 ug/m3) of sodium pentachlorophenate were
measured (PD 2/3, p. 322).
PD 2/3 Proposal; To reduce the risks to spray applicators, the Agency
proposed in the PD 2/3 the following:
All applicators who apply sodium pentachlorophenate formulations by
the spray method must wear gloves and a properly maintained half-mask
canister or cartridge respirator designed for pesticide use.
An applicator wearing a respirator and gloves during the spray operation
will significantly reduce the hand dermal exposure by 99% and inhalation
exposure by 90%. The oncogenic risk during the spray operation of sodium
pentachlorophenate for sapstain control would be decreased from 1.9 x 10-3 to
4.8 x 10-5 (PD 2/3, p. 657); the fetotoxic MOS would be increased from 50 to
2,000 (PD 2/3, p. 662) if the protective clothing (gloves and respirator)
were worn during this activity.
The Agency assumed in the PD 2/3 that the applicators were being exposed
to a mist (aerosolized solution) of sodium pentachlorophenate resulting from
the spray application. Based on this assumption, the Agency concluded that
the applicator was also exposed to the contaminant HxCDD in the mist and
determined the applicator's exposure (worst case) to HxCDD based on measured
air levels of sodium pentachlorophenate near the spray booth (PD 2/3, p. 322).
Final Regulatory Position and Rationale; The Agency conducted field
investigations which established that the pesticide is mechanically applied to
the wood in an enclosed spray booth, so that a mist near the spray booth would
not normally be generated unless there were leaks in the system, in addition,
the applicators (e.g., about three to four workers) are usually about 30 to
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40 feet from the enclosed spray booth and, thus, would not be exposed to any
significant amount of generated mist of sodium pentachlorophenate. However,
the applicators may be exposed to sodium pentachlorophenate vapors (invisible
evaporated chemical) measured at 12 ug/m3 (PD/3, p. 322).
HxCDD has a low vapor pressure of 6.6x10"7 mm Hg (SAB, 1978), therefore
workers 30 to 40 feet from the enclosed spray booth would not be expected to
be exposed to HxCDD. Based on the fact that (1) the spray booth is enclosed
and (2) HxCDD has a low vapor pressure, the Agency now assumes that the
applicators 30 to 40 feet away from the spray booth are only exposed to the
sodium pentachlorophenate vapors. Based on these revised exposure assumptions,
the Agency recalculated the potential risks to applicators.
The sodium pentachlorophenate air concentration typically found in the area
where a worker spends the majority of the time (30 to 40 feet from the enclosed
spray booth) during an 8-hour work shift is 12 ug/m3 (PD 2/3, p. 322). Based
on this concentration the total inhalation exposure (without respirators)
is 1.3 ug/kg/day (Day, Exposure Assessment 1982 and Rispin, April 18, 1984)
and the MOS for fetotoxicity/teratogenicity effects from inhalation exposure is
approximately 1700 (MOS » NOEL = 3000 ug/kg/day). Therefore, it would
Exposure 1.8 ug/kg/day
not be necessary for workers not in the immediate vicinity of the apparatus
to wear respirators for protection against sodium pentaehlorophenate vapors,
because without them the margin of safety is adequate. However, gloves
would be necessary to reduce dermal exposure during the handling of _freshly
treated wood as discussed below in this Section (VI.G.4).
Applicators in the vicinity of the spray apparatus could be exposed to both
HxCDD and sodium pentachlorophenate mist and vapors. To estimate exposure,
the Agency assumed the dermal absorption rate was 1.0% (Day, Dec. 9, 1983 and
Rispin, April 18, 1984). The multi-stage risk model was used for risk estimation
instead of the one-hit model as explained in Section II of this document.
It was assumed that applicators used a 0.5% solution for spraying sodium
pentachlorophenate (Rispin, April 18, 1984). No estimate could be made for dermal
exposure to parts of the body other than the hands. However, it was assumed
protective clothing would reduce dermal exposure by 80%.
For sodium pentachlorophenate, the recalculated oncogenic risk with
gloves, protective clothing and a respirator (recalculated) is 3.8 x 10~5
and the fetotoxic risk is 2,000 as compared with 4.8 x 10-5 and 2,000,
respectively, calculated for PD 2/3.
Therefore, if the applicator is in the vicinity of the spray booth during
operation and a visible mist is present, the Agency has concluded that the
applicator must wear a respirator for protection against both sodium
pentachlorophenate and HxCDD. Gloves and protective clothing would also be
necessary to reduce dermal exposure.
The Agency has determined that labels of sodium pentachlorophenate for
sapstain control must be amended to include the following information:
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For the spray method of application, the spray apparatus
must (1) be operated so as to minimize overspray (i.e., no
visible mist) and (2) be free of leaks in the system. Should
there be a visible mist, spray applicators in the vicinity
of the apparatus (the zone in which the mist is visible)
must wear a respirator and protective clothing (including overalls,
jackets, boots, head covering impervious to the wood treatment
formulation and goggles). Respirators must be properly fitting,
we11-maintained half-mask canister or cartridge respirators, which
are MSHA/NIOSH-approved for organic vapors.
Examples of materials for protective clothing must be provided on the
label as described in Section VI.C.2 of this document.
The final requirement will achieve the same reduction in inhalation
exposure (by 90%) as the PD 2/3 proposed requirement. The proposed labeling
language accomplishes the Agency's desire to reduce applicators' exposures
while spraying sodium pentachlorophenate and requires the use of respirators
only when necessary for protection against the visible mist (aerosolized
solution) containing both the sodium pentachlorophenate and its HxCDO contami-
nate.
2. Use Directions for Emptying and Mixing
Exposure/Risk; In the PD 2/3, the Agency was concerned about the high
inhalation and dermal exposure situations during the manual opening and
emptying of bags of prilled (granular) or powder formulations of sodium penta-
chlorophenate in the preparation of treatment solutions.
PD 2/3 Proposal; The Agency proposed in the PD 2/3 to require closed
systems for the emptying and mixing of all prilled (granular) and powder
formulations of sodium pentachlorophenate to reduce inhalation and dermal
exposures during this activity.
Final Regulatory Position and Rationale; The Agency's regulatory position
and rationale for arriving at the final position is the same as that
discussed in detail for dry pentachlorophenol in Section VI.C.3 of this
document. The exposure and risk estimates are considered to be the same for
dry sodium pentachlorophenate products as for dry pentachlorophenol products;
i.e., airborne concentration is 2.4 mg/m3, dermal exposure is 40 to 400
mg/hr, rate of dermal absorption for dry pentachlorophenol or sodium penta-
chlorophenate formulations is 1% and for HxCDD is 50%.
There are no "prilled" or flaked formulations of sodium pentachlorophenate
presently registered. The Agency has determined that, within 30 days after
publication of the Notice concluding the wood preservatives RPAR or 30 days
after receipt of the Notice by registrant, whichever occurs later, the labels
for powder formulations of pentachlorophenate used for sapstain control must
be amended to include the following information:
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Until August 31, 1987, a closed emptying and mixing system
must be used or protective clothing (including respirator/
gloves and tightly woven, long-sleeved cotton or disposable
coveralls) must be worn when emptying and mixing powder
formulations of pentachlorophenate. After September 1,
1987, a closed system must be used when emptying and
mixing powder formulations of pentachlorophenate. A
closed system is defined as any containment which pre-
vents the release of subject chemicals into the sur-
rounding external environment.
Respirators must be properly fitting, well-maintained
half-mask canister or cartridge respirators which are
MSHA/NIOSH-approved for organic vapors.
Examples of acceptable materials for gloves and coveralls which must be
included on the labels are listed below in Section VI.G.5 "Use of Protective
Clothing."
As described in Section VI.C.3, the use of closed systems will reduced
exposure to ambient levels at 0.028 mg/m3 based on Arsenault (1976), and thus
risks will significantly be reduced, potential oncogenic risks will be
negligible and the MOS for teratogenic/fetotoxic effects will be 730 (Rispin,
April 18, 1984).
3. Food/Feed/Water Issue
Exposure/Risk; The Agency expressed concern in the PD 2/3 that use of sodium
pentachlorophenate for treating wood could result in direct exposure to domestic
animals or livestock and in the contamination of food, feed, and water.
PD 2/3 Proposal; The Agency proposed in the PD 2/3:
Do not use sodium pentachlorophenate in a manner which may
result in direct exposure to domestic animals or livestock,
or in the contamination of food, feed, or drinking and
irrigation water (e.g., food crates, irrigation flumes,
vegetable stakes, feedlot bins and watering troughs).
Final Regulatory Position and Rationale; since the PD 2/3, the Agency has
re-evaluated this PD 2/3 proposal regarding sapstain control. Sodium
pentachlorophenate is used for control of sapstain only for posts and poles
during air seasoning before they can be kiln dried and pressure-treated, and for
green lumber during storage and transportation (PD 2/3, p. 513). Therefore,
it would not be likely that the sodium pentachlorophenate would directly
contact domestic animals or livestock or would contaminate food, feed, or
drinking and irrigation water, in addition, because sodium pentachlorophenate
is applied in an aqueous solution of 0.3 to 0.9% (PD 2/3, p. 322), it is
expected that when the salt formulation evaporates the residues on the surface
on the wood would be insignificant.
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For these reasons the Agency has determined that it will not be necessary
for labels of sodium pentachlorophenate to be amended as proposed in the PD
2/3 for this exposure situation.
4. Materials for Protective Gloves
Expos tare/Risk; The Agency expressed concern that sodiun pentachlorophenate
treatment plant applicators may be dermally exposed to the wood treatment
solutions when mixing the wood preservative and when cleaning and maintaining
treatment equipment, such as vats. Applicators may also be exposed to the
treatment solutions when handling freshly treated lumber or when applying
(spraying, dipping) the preservative solution.
Although adequate experimental data are not available on the permeability
of gloves to sodium pentachlorophenate, the Agency estimated that an applicator
wearing gloves resistant to penetration would have significantly reduced (by
99%) exposures via the hands- Gloves would also provide some reduction in
total dermal exposure. The reduction in total dermal exposure when gloves
are worn, based on the reduction of skin area available to absorb the pesti-
cide, is estimated to be about 30%.
PD 2/3 Proposal; The PD 2/3 proposed the following:
All applicators using sodium pentachlorophenate for sapstain
control must wear gloves impervious to sodium penta-
chlorophenate (e.g., rubber) in all situations where dermal
contact with sodium pentachlorophenate is possible (e.g.,
handling treated wood).
For the dip/flow treatment, the oncogenic risk from dermal and inhalation
exposure was estimated to be reduced from 7.1 x 10~4 without gloves to 7.1
x 10~6 with gloves; the MOS was increased from 59 to 6,000 (PD 2/3, p. 617).
For the spray method the oncogenic risk from both dermal and inhalation
exposure was estimated to be reduced from 1.9 x 10**3 without gloves and
respirator to 4.8 x 10~5 with gloves and respirator (PD 2/3, p. 657); the
fetotoxic MOS was increased from 50 to 2,000 (PD 2/3, p. 662).
Final Regulatory Position and Rationale; The Agency has concluded that
sodiun pentachlorophenate labels must be amended to include the following
information:
All applicators must wear gloves impervious to the wood
treatment formulation in all situations where dermal contact
is expected (e.g., during the application process and when
handling freshly treated wood).
This requirement achieves reduction in hand dermal exposure as did the
PD 2/3 proposal. Examples of acceptable materials for gloves are found
below in Section VI.G.5 of this document ("Use of Protective Clothing11).
These examples are required on the label.
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Because of revised dermal absorption rates for sodion pentachlorophenate
aqueous solutions (1%) and the use of the multistage risk model (Section II
of this document), the Agency recalculated the risk due to exposure to the
dip/flow treatment and found the risk (using gloves) to be 4.3 x 10-4 and
the fetotoxic MOS to be 600. It was assumed aplicators were using a maximim
of 5% sodium pentachlorophenate solution (Rispin, April 18, 1984).
The risk reduction to spray applicators of sodium pentachlorophenate
when wearing gloves and a respirator was discussed previously in Section
VI.G.1 of this document. Wearing both gloves and a respirator, the oncogenic
risk is 3.8 x 10-5. the fetotoxic MOS is 2,000 for workers in the immediate
vicinity of the spray booth.
The required labeling language is expected to reduce the applicator's
dermal and inhalation exposure to sodium pentachlorophenate. The rationale
for the specific wording of the label statement is discussed in Section VI.C.5
of this document.
5. Use of Protective clothing
Exposure/Risk; The Agency was concerned that individuals who enter or
clean vats and other related equipment would be exposed (dermal and
inhalation) to the sodium pentachlorophenate solutions or vapors. Due to
insufficient data, risks were not quantified for applicators entering vats,
but some finite risk was assuaed.
PD 2/3 Proposal; The Agency proposed the following in the PD 2/3:
All individuals who enter or clean vats and other related
equipment must wear a neoprene-coated cotton or rubberized
overall, jacket, gloves, and boots and a properly maintained
half-mask canister or cartridge respirator designed for
pesticide use.
Final Regulatory Position and Rationale; The Agency has concluded that
labels of sodium pentachlorophenate for sapstain control must be amended
to include the following information:
Individuals who enter, clean, or repair vats, tanks or
other related equipment that is contaminated with the
treatment solution must wear a respirator. In addition,
where dermal contact is expected, these individuals must
wear overalls, jackets, boots, and head covering impervious
to the wood treatment formulation and goggles.
Respirators acceptable for use by applicators of sodium
pentachlorophenate must be properly fitting, well-maintained, -
half-mask canister or cartridge respirators, which are HSHA/
NIOSH-approved for organic vapors. Examples of acceptable
materials for protective clothing (e.g., overalls, jackets,
head covering, boots, disposable coveralls and gloves)
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required during application and handling of sodium
pentachlorophenate are polyvinyl acetate (PVA), polyvinyl
chloride (PVC), neoprene, NBR (Buna-N), and nitrile.
The Agency believes that an individual wearing this protective clothing
and a respirator while performing these activities will have a significantly
reduced inhalation (respirator will reduce inhalation exposure by 90%) and
dermal exposure (protective clothing will reduce total dermal exposure by
30%), resulting in significantly reduced risks.
This requirement provides the same reduction in exposures as the PD 2/3
proposal. The required label language also clarifies that the exposure
situation of concern is "contact with equipment that is contaminated
with the treatment solutions." The rationale for requiring the specific
type of respirator and materials for protective clothing was discussed in
Section VI.C.2 of this document.
6. Disposal of clothing and pesticide Formulations
Exposure/Risk; Although not quantified, as previously stated for other
types of application of wood preservatives, there are potential risks from
sodium pentachlorophenate pesticide-laden dust or treatment solutions which
adhere to protective clothing and workshoes, and are transported from the
treatment plant into the home. Bringing contaminated protective clothing and
workshoes into the home at the end of the work day creates a potential
exposure to the workers1 families.
PD 2/3 Proposal; To eliminate or greatly reduce a potential source of
wood preservative exposure in treatment plant workers' homes, the Agency
proposed the following in the PD 2/3:
All applicators must leave all protective clothing, workshoes
or boots, and equipment at the plant at the end of the day.
Worn-out protective clothing must be disposed of following the
instructions for pesticide container disposal.
Final Regulatory Position and Rationale; The Agency has concluded that
all labels of sodium pentachlorophenate for sapstain control must be amended
to include the following information:
Protective clothing must be changed when it shows signs of contamin-
ation. Applicators must leave all protective clothing, workshoes
or boots and equipment at the plant. Worn-out protective clothing
and workshoes or boots must be left at the plant and disposed of in
a general landfill, in the trash or in any other manner approved
for pesticide disposal.
This requirement will eliminate this potential source of exposure in
workers' homes.
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The rationale for the change in the PD 2/3 proposal was discussed in
Section VI.C.6 of this document.
In addition, as described in Section VI.C.6 of this document, the Agency
requires that registrants amend the labels of sodium pentachlorophenate labels
to include the following information as stated in the Agency's PR Notice 83-3
(March 29, 1983):
Pesticide wastes are toxic. Improper disposal of excess pesticide,
spray mixture, or rinsate is a violation of Federal law. If these
wastes cannot be disposed of by use according to label instructions,
contact your State Pesticide or Environmental Control Agency, or the
Hazardous Waste representative at the nearest EPA Regional Office
for guidance.
7. Warnings About Eating, etc., During Application
Exposure/Risk; As previously stated in this document, although the risks
due to accidental ingestion of wood preservatives by smoking, drinking, or
eating have not been quantified, the Agency has determined that there is a
potential for adverse human health effects in these use situations.
PD 2/3 Proposal; To eliminate risks from this potential exposure, the
Agency proposed the following in the PD 2/3:
Eating, drinking and smoking are prohibited during the
application of sodium pentachlorophenate for sapstain
control.
Final Regulatory Position and Rationale; The Agency has determined that
labels of sodium pentachlorophenate for sapstain contol must be amended to
include the following information:
Applicators must not eat, drink, or use tobacco products
during those parts of the application process which may
expose them to the treatment formulation. Wash thoroughly
after skin contact, and before eating, drinking, use of tobacco
products, or before using restrooms.
This requirement will greatly reduce or eliminate this type of accidental
exposure during the application process. The rationale for the specific
language in the requirement was discussed in Section VI.C.7 of this document.
8. Restricted Use
The Agency has adopted the PD 2/3 proposal regarding restricted use and
has concluded that labels of sodium pentachlorophenate products for sapstain
control must be amended to include the following information:
RESTRICTED USE PESTICIDE; For sale to and use only
by certified applicators or persons under their direct
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supervision and only for those uses covered by the
certified applicator's certification.
This requirement is the same as that proposed in the PD 2/3. The
rationale for the PD 2/3 proposal and final position is the same as
that discussed for pentachlorophenol, creosote and inorganic arsenicals
in Section VI.C.9 of this document.
H. Non-Pressure Treatment Plant Dip/flow and Spray Uses of
Pentachlorophenol
This Section presents the Agency's position for regulating non-
pressure uses of pentachlorophenol for protection of millwork and plywood,
particleboard and logs for log homes. Pentachlorophenol is applied to
millwork and plywood primarily by dipping or spraying the wood (PD 2/3,
p. 524). Dip treatment is also used to apply pentachlorophenol to logs
which may be used in the construction of log homes. During the manufacture
of particleboard, the pentachlorophenol solution, urea formaldehyde
resin, and wax emulsion are mixed with the wood particles at the same
time in a closed system (PD 2/3, p. 529).
1. Use Directions for Millwork and Plywood Spray Operations
Exposure/Risk; The Agency was concerned about a potential for high
inhalation exposure during the spray operations in the non-pressure
pentachlorophenol treatment plants for millwork and plywood. For non-pressure
spray operations for millwork and plywood the total estimated lifetime oncogenic
risk without protective measures from exposure to pentachlorophenol is 9.8 x 10~3
and the fetotoxic MOS is 10 (PD 2/3, p. 589).
PD 2/3 Proposal; To reduce the risks to millwork and plywood applicators,
the Agency proposed the following in the PD 2/3 for non-pressure spray operations
using pentachlorophenol for millwork and plywood:
All applicators who apply pentachlorophenol to millwork and
plywood by the spray method must wear gloves and a properly
maintained half-mask canister or cartridge respirator
designed for pesticide use.
Wearing a respirator during the spraying operation would significantly
reduce the applicator's inhalation exposure by 90%. During the spray
operation of pentachlorophenol on millwork and plywood, the oncogenic risk
would be decreased from 9.8 x 10-3 to 2.4 x 10-4 (pD 2/3, p. 657); the
fetotoxic MOS would increase from 10 to 400, if both gloves and a respirator
were worn (PD 2/3, p. 661).
Final Regulatory Position and Rationale; The Agency has determined that
labels of pentachlorophenol products used for spray application on millwork and
plywood must be amended to include the following information:
For the spray method of application: spray apparatus must
(1) be operated so as to minimize overspray (i.e., no visible
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mist) and .(2) be free of leaks in the system, should there be a
visible mist, spray applicators in the vicinity of the apparatus
(the zone in which the mist is visible) must wear a respirator and
protective clothing (including overalls, jackets, boots, head covering
impervious to the wood treatment formulation and goggles). Respirators
must be properly fitting, well-maintained half-mask canister or
cartridge respirators which are MSHA/NIOSH-approved for organic
vapors and acid gases.
Suggested materials for protective clothing must be included on the label
as discussed in Section VI.C.5 of this document.
Gloves are also required as described below in Section VI.H.5 of this
document.
The rationale for adopting this requirement for millwork and plywood and
not the requirement that all applicators must wear respirators as proposed in
the PD 2/3 is the same as that discussed in Section VI.G.1 of this document for
sodium pentachlorophenate spray operations. In summary, (1) the process is
automated and enclosed, and applicators are not continually exposed to a
mist (aerosolized solution) as was assumed in the PD 2/3, and (2) applicators
are not exposed to HxCDD vapors (invisible evaporated chemical) in the work
area due to the low vapor pressure of 6.6 x 10*~7 mm Hg (U.S. EPA, SAB, 1978).
Workers may, however, be exposed to pentachlorophenol vapors, since pentach-
lorophenol has a vapor pressure of 1.6 x 10~4 mm Hg (U.S. EPA, SAB, 1978).
The majority of the workers spend most of their time 30-40 feet away
from the apparatus and thus are not exposed to pentachlorophenol mist, but
may be exposed to pentachlorophenol vapors. The inhalation exposure at
28 ug/m3 pentachlorophenol air concentration for these workers is 4.1
ug/kg/day (Rispin, April 18, 1984) and the MOS for fetotoxic/teratogenic
effects is 726 (MOS = NOEL = 3000 ug/kg/day). Therefore, a respirator
Exposure 4.1 ug/kg/day
would not be necessary for these workers for protection against penta-
chlorophenol vapors, since the Margin of Safety for this exposure is adequate.
Gloves, however, would be necessary to reduce dermal exposure when handling
the freshly treated wood.
Applicators in the immediate vicinity of the apparatus may be exposed to
both pentachlorophenol mist (containing HxCDD) and pentachlorophenol vapors.
The Agency assumes that the applicator is using a 2.5% pentachlorophenol
solution (Rispin, April 18, 1984). The risks for this exposure were
recalculated based on the new exposure assumptions discussed in Section II
of this document. If there is a visible mist and workers are in the immediate
vicinity of the apparatus, the revised oncogenic risk (using gloves, protective
clothing, and a respirator) is 2.5 x 10~4 and the MOS is 23 (Rispin, April
18, 1984). Therefore, for these workers, protective gloves, clothing, and
respirators are necessary.
The final requirement will achieve the same reduction in inhalation
exposure (by 90%) as the PD 2/3 requirement, but will not impose the requirement
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for respirators in use situations where not warranted. If a visible mist is
present there is exposure to pentachlorophenol and its HxCDD contaminant;
therefore respirators would be necessary.
The Agency is concerned about the high potential oncogenic risks and low
margin of safety for potential fetotoxic effects to millwork and plywood
applicators exposed to pentachlorophenol. The Agency considered cancelling
registrations of pentachlorophenol for raillwork and plywood use and thus
reevaluated the benefits of use of these products, pentachlorophenol is
applied to millwork and plywood to prolong the life of the wood by protecting
the wood from decay. Pentachlorophenol is colorless, compatible with paints,
stains, sealers and primers, and does not interfere with the adhesion of
glazing compounds, caulkings or other sealants. The chemical alternatives
which millwork and plywood applicators might choose to purchase are not as
efficaceous as pentachlorophenol for all millwork and plywood use situations
and may be more expensive (PD 2/3, pp. 523-528).
The Agency also reevaluated the risk estimates for oncogenicity and
believes that a risk of 2.5x10~4 represents an extreme upper bound of
the actual risk because applicators may not contact the treatment solutions
dermally every day of their working life, nor would they receive inhalation
exposure from a visible mist everyday of their working life. Thus, the
estimated risk of 2.5x10~4 may be overstated, but, in the absence of infor-
mation to the contrary, the Agency continues to assume that this estimate
represents an upper limit of potential oncogenic risk.
Regarding the chemical alternatives to pentachlorophenol, the long-term
potential toxic effects of exposure to the chemicals have not yet been studied.
The Agency will therefore request data (chronic feeding, oncogenicity,
reproductive effects, and teratology studies) as outlined in Section VIII of
this document. When these studies are received, the Agency will evaluate the
data and determine if further regulatory action is necessary.
Regarding potential fetotoxic risks, while the Agency believes that few
women currently work as applicators in millwork and plywood treatment plants,
the Agency cannot ass one that no pregnant women are working or will work as
applicators in these plants.
For the present the Agency believes that in addition to other required
protective measures, (e.g., gloves, protective clothing, respirators),
requiring millwork and plywood applicators to be trained and certified for
the application of wood preservatives, and requiring a. statement on the pesti-
cide label that pregnant women should not use pentachlorophenol products
will protect the applicator such that continued use for millwork and plywood
applications will not result in fetotoxic risks outweighing the benefits of
use.
2. Use Directions for Mixing and Emptying
Exposure/Risk! In the PD 2/3, the Agency was concerned about the high
inhalation and dermal exposure situations during the manual opening and
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emptying of bags of prilled (granular) formulations of pentachiorophenol and in
mixing the treatment solutions for millwork, plywood, and particleboard use.
The risks due to exposure to pentachiorophenol during this activity were
discussed in Section VI.C.3 of this document.
No exposure data were available for the mixing operations for the non-
pressure application of pentachiorophenol in manufacturing particleboard.
However, the Agency assumed there would be negligible inhalation exposure,
because the application of pentachiorophenol to the wood particle mixture
takes place in an enclosed resin blender. Specifically, the pre-mixed
pentachiorophenol solution is pumped from its container directly into the
resin blender. Here the pentachiorophenol is mixed with the wood particles
along with the resin and wax (Esworthy, 1980).
PD 2/3 Proposal; The Agency proposed the following in the PD 2/3 regarding
the emptying and mixing of prilled (granular) pentachiorophenol formulations:
A closed emptying and a closed mixing systems must be used
for all prilled (granular) formulations of pentachiorophenol.
The Agency determined that this proposal would reduce inhalation and
dermal exposures during this activity for millwork and plywood, and particle-
board use. The Agency assumed that risks would be greatly reduced if closed
systems were used (PD 2/3, p. 561 ).
Final Regulatory Position and Rationale; For the reasons discussed in
Section VI.C.3, for pressure-treatment uses the Agency has concluded that
labels for prilled or flaked formulations of pentachiorophenol must be
amended, within 30 days after publication of the Notice concluding the
wood preservatives RPAR or 30 days after receipt of the Notice by the
registrants, whichever occurs later, to include the following information:
Until August 31, 1987, a closed emptying and mixing system must be
used or protective clothing (including respirator, gloves and tightly
woven, long sleeved cotton or disposable coveralls) must be worn
when emptying and mixing prilled or flaked formulations of
pentachiorophenol. After September 1, 1987, a closed system must be
used when emptying and mixing prilled or flaked formulations of
pentachiorophenol. A closed system is defined as any containment
which prevents the release of subject chemicals into the surrounding
external environment.
Acceptable respirators and materials for protective clothing were
discussed in Section VI.C.2 of this document. This information must also be
included on the labels.
The discussion of new exposure data received since the publication of the
PD 2/3, the reduction in exposure and risk if a closed system is used or if
protective clothing is worn, and the Agency's rationale for adopting this
final position were described previously in Section VI.C.3 of this document.
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3. Indoor Use of Pentachlorophenol-Treated Millwork and Plywood,
Particleboard, and Logs for Log Homes.
The Agency was concerned that there was exposure to humans and domestic
animals from interior uses of pentachlorophenol-treated millwork and plywood,
and particleboard, but that in a few situations the risks were estimated to be
sufficiently low, in light of the benefits, to warrant continuation of some
interior uses.
PD 2/3 Proposal: For millwork and plywood the Agency proposed in the PD 2/3:
The application of pentachlorophenol products to wood
intended for interior use is prohibited, except for wood
which has outdoor surfaces (e.g., door frames, windows and
patio frames).
For particleboard, the Agency proposed in the PD 2/3:
The application of pentachlorophenol to particleboard
intended for any interior use (e.g., kitchen cabinets) is
prohibited.
Final Regulatory Position and Rationale; The Agency reevaluated
this proposal and recognized that the exposure is likely to be low.
There is no alternative for pentachlorophenol-treated particleboard, and
the amount of pentachlorophenol-treated millwork, particleboard and plywood
that is likely to be in the interiors of residences is minimal.
Millwork use includes window frames, door frames, sash screens, and
molding in homes; pentachlorophenol water-repellent solutions (5%) are
applied to exterior millwork products to prevent decay and/or insect infesta-
tion (PD 2/3, p. 523). Millwork is normally coated with paint or varnish
(USDA, 1980), and, though exposure to the pentachlorophenol is unknown, it
is expected to be low (USDA, 1980, p. 102). Sealers are known to reduce
exposure by approximately 80% (Day, 1983).
Plywood is normally treated with a 5% pentachlorophenol solution (PD 2/3,
p. 524). The plywood is often stained or coated with shellac. Also, the
homeowner is not likely to invest the additional expense to buy pesticide-treated
plywood for interior use; pentachlorophenol-treated plywood is used mainly
as textured plywood siding to act as a water-repellant and mildewcide (PD
2/3, p. 524).
Treated particleboard represents about 0.005% of the particleboard produced
in the U.S. (PD 2/3, p. 529). Only 0.65% pentachlorophenol (0.65% pentachloro-
phenol solids based on the oven dry weight of the wood) is used in the mixture
of wood chips and resin (PD 2/3, p. 529). Therefore, though exposure to
pentachlorophenol vapors in interiors is unknown, it is expected to be low-
In addition, treated particleboard does not have widespread indoor use;
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it is mainly used for kitchen cabinets and outdoor furniture in Hawaii
where there is a high occurrence of above-ground termite attack.
As discussed in Section II of this document, instead of using the PD 2/3
estimate of 24 hours as the time spent in the home, the Agency revised the time
to 15 hours (8 hours resting, 1 hour heavy work, and 6 hours of light work).
This decrease in the time spent inside the home means decreased exposure and
risk.
Based on these considerations, the Agency will not prohibit interior
use of millwork, plywood, and particleboard treated with pentachlorophenol.
The benefits of use exceed the risks due to exposure in this situation.
However, the Agency continues to be concerned that the application of
pentachlorophenol on wood destined for interior use in enclosed residences,
other than the exceptions noted above, may result in unacceptable inhalation
and dermal exposure to residents of these dwellings. For example,
approximately half of a log which has been dipped in pentachlorophenol
for use in the construction of log homes intrudes into living areas. As
noted in the PD 2/3 (p. 333) , the Pesticide Incident Monitoring System
(PIMS, 1978) received numerous reports of human health effects following
the application of pentachlorophenol inside homes. Since the publication
of the PD 2/3, the Agency has received additional reports of acute toxicity
from interior use of pentachlorophenol-treated wood (Levin, Comment
160:30000/280; Friends of the Earth, Comment #70:30000/28C; and Center
for Disease Control, Comment #69:30000/28C), As discussed in Section
III.A {Pentachlorophenol Issue |3) Jackson and Stratton of the California
Department of Health Services (#87:30000/28C) reported increased pentach-
lorophenol concentrations in the urine of occupants of an office building
constructed with pentachlorophenol pressuretreated beams. Pentachloro-
phenol was also found in the air inside the building at 10 ug/m^ even
after the beams had been sealed.
While the application of a sealant was considered in the PD 2/3
(p. 335) as a potential measure by which the vaporization of pentachloro-
phenol from treated wood might be adequately reduced, Amburgey and Williams,
(Dec. 1982) who advise against the use of pentachlorophenol for log
homes, reported that film forming finishes or sealers, if applied before
one year after construction, may trap water in logs and lead to rapid
and widespread decay, especially if these materials are applied to both
the interior and exterior surfaces. Also, although OSDA (1981) reports
that sealers reduce vaporization by approximately 85%, there are no data
on the length of time that the sealers are effective. Sealers may have
to be reapplied at some later date.
Several alternatives to pentachlorophenol are cited in the literature:
dip treatment with copper-8-quinolinolate or zinc naphthenate are recom-
mended to protect log kits during transport and construction (Amburgey
and Williams, Dec. 1982). Seasoned logs could also be pressure-treated
with chromated copper arsenate (CCA) (Amburgey and Williams, Dec. 1982) .
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The Agency has not quantified the benefits derived from pentachloro-
phenol dip-treated logs. However, the Agency has determined that the
acute risks to inhabitants of log homes in which the interiors are treated
with pentachlorophenol are of such significance, particularly in light
of available alternatives, that risks exceed the benefits. Therefore,
the Agency requires that the following statement be included on the
labels intended for the dip/spray commercial application of pentachloro-
phenol:
Do not apply to logs which are intended for use in the
construction of log homes.
4. Food/Feed/Water Issue
Exposure/Risk: The Agency was concerned that use of pentachlorophenol-
treated millwork and plywood, and particleboard could result in direct exposure
to domestic animals or livestock or contaminate food, feed, or water.
PD 2/3 proposal; PD 2/3 proposed for millwork and plywood, and particleboard
use:
Do not use pentachlorophenol in a manner which may result
in direct exposure to domestic animals or livestock, or in
the contamination of food, feed or drinking and irrigation
water (e.g., food crates, irrigation flumes, vegetable
stakes, feedlot bins and watering troughs).
Final Regulatory Position and Rationale; The Agency has reexamined
these potential exposure situations for millwork and plywood, and particle-
board which have been treated with pentachlorophenol.
Millwork, which may have outdoor surfaces, is usually treated with a
5% pentachlorophenol solution (PD 2/3, p. 524), presumably resulting in a
minimal surface residue. According to USDA's "Biologic and Economic
Assessment" (1980), it is normally coated with paint or shellac. This
coating acts as a sealer, reducing exposure of hvmans or domestic
animals to pentachlorophenol. It would be unlikely for treated millwork
to be used in a way that pentachlorophenol would come into contact with
livestock or where it could contaminate food, feed, or water.
Plywood is also treated with a 5% solution of pentachlorophenol (PD 2/3,
p. 524) and is sometimes stained or coated with shellac if used in interiors,
thus reducing dermal or inhalation exposure. As stated above regarding
possible indoor exposure (Section VI.H.3) treated plywood is used mainly
for outdoor siding (PD 2/3, p. 524). While it would be unlikely that
consumers would use treated, unsealed plywood where it could come into
contact with animals, any exposure of the pentachlorophenol surface
residues to house pets, other domestic animals, or livestock would be
assuned to be low. It is also not likely that treated plywood would be
used in contact with food or animal feed. FDA has issued a regulation,
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however, stating that pentachlorophenol-treated wood may not contain
greater than 50 ppm pentachlorophenol for uses in contact with raw agri-
cultural products (21 CFR 178.3800). It is not likely that consuners would
use it where it would be in direct contact with drinking and irrigation
water, because the wood would decay, not having a sufficient concentration
of preservative.
As previously stated (Section VI.H.3), treated particleboard is mainly
used for kitchen cabinets and outdoor furniture in Hawaii where there is a
high incidence of above-ground termite attacks. The resin used in the
manufacture of particleboard acts as a sealant for the pentachlorophenol,
and thus dermal or inhalation exposure to domestic animals would be
expected to be low. It would not be likely to be used in situations
where it would come into contact with livestock. Consuners also would
not tend to use treated particleboard for construction of items which
might come into contact with drinking or irrigation water, because it
would decay, not having enough preservative. As stated above, FDA has
issued a regulation regarding contact of pentachlorophenol-treated
wood with raw agricultural products but not regarding contact of wood
preservatives with food or animal feed. However, any contamination of
food or animal feed from contact with treated particleboard is expected
to be low; consuners are not expected to use treated particleboard for
this use.
Based on the above considerations, the Agency will not require that
labels be amended as proposed in the PD 2/3 for these exposure situations
for millwork, plywood, and particleboard, as the Agency expects exposure
and risk to be low.
5. Use of Gloves
Exposure/Risk; The Agency was concerned that treatment plant applicators
of pentachlorophenol for raillwork and plywood, and particleboard may be
dermally exposed to the wood treatment solutions when mixing the wood preser-
vatives and when cleaning and maintaining treatment equipment, such as vats,
tanks, or other related equipment. Applicators may also be exposed to the
treatment solutions when handling freshly treated wood.
The Agency was unable to quantify the hand dermal exposure resulting from
most activities in which contact with these wood preservatives are likely to
occur but did have exposure data on the dip/flow treatments of millwork and
plywood. Although adequate experimental data are not available on the
permeability of gloves to these wood preservatives, the Agency estimated that
an applicator wearing gloves resistant to penetration by these wood
preservatives would have significantly reduced exposures (by 99%) to these
pesticides via the hands (Van Kozak, 1980). The reduction in total dermal
exposure, based on the reduction of skin area available to absorb the
pesticide, is about 30%.
For the dip/flow treatment of millwork and plywood, the risk (without
gloves) is 7.1 x 10~3 and the fetotoxic MOS is 5.9 (PD 2/3, pp. 617 and 660).
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PD 2/3 Proposal; To reduce dermal exposure, the Agency proposed fqr the
use of pentachlorophenol for millwork and plywood, and particleboard:
All applicators applying pentachlorophenol must wear gloves
impervious to the wood treatment solution (e.g., rubber) in
all situations where dermal contact with the treatment
solutions is possible (e.g., handling treated wood).
Wearing gloves would reduce the risk to 7.1 x 10-5 and increase the
fetotoxic MOS to 210 (PD 2/3, pp. 617 and 660). There were no dermal
exposure data for particleboard treatment using pentachlorophenol, but the
Agency assumed there would be a risk to workers handling the freshly treated
particleboard.
Final Regulatory position and Rationale; The Agency has determined that
labels of pentachlorophenol formulations used for millwork and plywood, and
particleboard must be amended to include the following information:
Applicators must wear gloves impervious to the wood
treattnent formulation in all situations where dermal
contact is expected (for example during the application
process and when handling freshly treated wood) .
As in the PD 2/3 (p. 576), the Agency will consider all workers associated
with the treatment process to be applicators, regardless of their individual
activities during the workday? all of the workers perform some aspect of
pesticide application during the workday.
Materials acceptable for gloves are discussed in Section VI.G.2 of this
document and will be required to be included in the label.
Wearing gloves will reduce dermal exposure from hand contact by 90% and
thus accomplishes the Agency's desire to reduce the applicator's risk from
exposure to these wood preservatives. The rationale for changing the wording
of the PD 2/3 proposal to that of the final requirement was discussed in
Section VI.C.5 of this document.
There were no dermal exposure data for application of pentachlorophenol
to particleboard, but the Agency assumed there would be a risk to workers if
they handled the fresh particleboard and that, therefore, gloves should be
worn.
If gloves are worn for the dip/flow pentachlorophenol (5%) treatment of
millwork and plywood, the risk (recalculated) is 4.3 x 10~4 and the fetotoxic
MOS is 12. These risks are higher than those previously calculated in the
PD 2/3 because of the new data, discussed in Section II. of this document,
showing increased dermal absorption of pentachlorophenol from 10% to 50%
(Zendzian, 1981) and a decrease in the protection afforded by gloves from
99% to 90% (Rispin, April 24, 1984). As was discussed above in Section VI.
H.1. for millwork and plywood spray operations, the Agency is concerned about
the potential oncogenic and fetotoxic risks associated with exposure to
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pentachlorophenol for these uses. However, the Agency has concluded that
other required protective measures such as protective clothing as discussed in
the next Section (VI.H.6) will further reduce total dermal exposure. The
Agency also has concluded that the Restricted Use classification and label
warning concerning potential fetotoxic effects will increase the margins of
safety by promoting careful use of the product, or avoidance of use, such
that there will be no unreasonable adverse effects. As discussed in Section
VI.H.1, the Agency will reevaluate the use of pentachlorophenol for millwork
and plywood when data on the potential toxicity asociated with the chemical
alternatives are submitted by the registrants. At that time, the Agency will
take further regulatory action if necessary.
6. Protective clothing
Exposure/Risk; As discussed in the previous section on gloves (Section
VI.G.5), the Agency was concerned about exposure to pentachlorophenol from
applications to millwork and plywood, and particleboard during cleaning
and maintaining equipment and handling freshly treated wood. Due to insuf-
ficient data, pentachlorophenol risks were not quantified for these
activities.
PD 2/3 Proposal; To reduce potential risks, however, the Agency proposed
the following in the PD 2/3:
All applicators who enter or clean vats and other related
equipment must wear a neoprene-coated cotton or rubberized
overall, jacket, gloves and boots, and a properly
maintained half-mask canister or cartridge respirator
designed for pesticide use.
The Agency believes that an applicator wearing this protective clothing
and a respirator while performing these activities will have a significantly
reduced inhalation exposure (by 90%) and total dermal exposure (by 80%),
resulting in significantly reduced risks.
Final Regulatory Positions and Rationale; The Agency has determined that
labels of pentachlorophenol formulations for millwork, plywood, and
particleboard must be amended to include the following information:
Individuals who enter, clean, or repair vats, tanks, or
other related equipment that are contaminated with the
treatment solution must wear a respirator. In addition,
when dermal contact is expected, these individuals must
wear overalls, jackets, boots, head covering impervious to
the wood treatment formulation, and goggles.
Acceptable respirators and materials for protective clothing to be
included on the label are listed in Section VT.C.2 of this document. As
stated in the previous section (VI.H.5), gloves must also be worn.
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This requirement for protective clothing, including head covering,
provides the same or greater reduction in exposures as the PD 2/3 proposal.
It further defines the possible exposures ("repair vats, tanks, or other
related equipment."). The label amendment also defines acceptable types of
respirators and gives examples of materials for protective clothing.
7. Disposal of Protective Clothing and Pesticide Formulations
Exposure/Risk; As previously stated, the Agency was concerned that,
although not quantified, there are potential risks from pentachlorophenol
containing pesticide-laden dust or treatment solutions which adhere to
protective clothing and workshoes, and are transported from the treatment
plant into the home. Bringing contaminated protective clothing and workshoes
into the home at the end of the work day creates a potential exposure to the
workers' families.
PP.2/3 Proposal; To eliminate or greatly reduce a potential source of
wood preservative exposure in treatment plant workers' homes, the Agency
proposed the following requirement in the PD 2/3 regarding protective
clothing used during the application of pentachlorophenol to millwork,
plywood, and particleboard:
All applicators must leave all protective clothing, work-
shoes or boots, and equipment at the plant at the end of
the day. Worn-out protective clothing must be disposed of
in accordance with instructions for pesticide container
disposal.
final Regulatory Position and Rationale; The Agency has determined that
labels of pentachlorophenol formulations for use on millwork, plywood, and
particleboard must be amended to include the following information;
Protective clothing must be changed when it shows obvious signs
of contamination. Applicators must leave all protective clothing,
workshoes or boots and equipment at the plant, worn-out protective
clothing and workshoes or boots must be left at the plant and dis-
posed of in a general landfill, in the trash or in any other manner
approved for pesticide disposal. »
This requirement will also eliminate this potential source of
exposure in workers' homes. The rationale for the wording of this final
requirement was discussed in Section VLB.6 of this docunent.
In addition, as described in Section VI.C.6 of this PD 4, the Agency
requires that registrants amend the labels of sodium pentachlorophenate labels
to include the following information as stated in the Agency's PR Notice 83-3
(March 29, 1983):
Pesticide wastes are toxic, improper disposal of excess pesticide,
spray mixture, or rinsate is a violation of Federal law. If these
wastes cannot be disposed of by use according to label instructions,
contact your State Pesticide or Environmental Control Agency, or the
Hazardous Waste representative at the nearest EPA Regional office
for guidance.
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8. Warnings about Eating, etc., during Application
Exposure/Risk; As previously stated, although the risks due to accidental
ingestion of wood preservatives by smoking, drinking, or eating have not been
quantified, the Agency determined that there is a potential for adverse human
health effects in these exposure situations.
PD 2/3 Proposal; To eliminate risks from this potential exposure, the
Agency proposed the following in the PD 2/3:
Eating, drinking and smoking are prohibited during the
application of pentachlorophenol to millwork, plywood, and
particleboard.
Final Regulatory Position and Rationale; The Agency has determined that
labels of pentachlorophenol formulatons for application on millwork and plywood,
and particleboard must be amended to include the following information:
Applicators must not eat, drink, or use tobacco products
during those parts of the application process which may
expose them to the treatment formulation. Wash thoroughly
after skin contact, and before eating, drinking, use
of tobacco products, or using restrooms.
This requirement will greatly reduce or eliminate this type of accidental
exposure during the application process. The rationale for the wording of
this final requirement was discussed in Section VI.C.7 of this document.
9. Restricted Use
Exposure/Risk; The Agency was concerned that applicators untrained in
the safe handling practices of pentachlorophenol for use on millwork and
plywood, and particleboard could have a greater exposure than trained appli-
cators due to misuse or carelessness. In order to reduce this potential
exposure, the Agency proposed in the PD 2/3 to restrict use of this pesticide.
PD 2/3 Proposal; Specifically, the Agency proposed the following label
modification:
RESTRICTED USE PESTICIDE; For retail sale to and use only
by certified applicators or persons under their direct
supervision and only for those uses covered by the
certified applicator's certification.
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Final Regulatory Position and Rationale; The Agency has determined that
in order for the benefits of use to exceed the risks, labels of pentach-
lorophenol for millwork and plywood, and particleboard uses must be amended
to include the following information:
RESTRICTED USE PESTICIDE; For retail sale to and use only
by certified applicators or persons under their direct super-
vision and only for those uses covered by the certified applicator's
certification.
This requirement is the same as that proposed in the PD 2/3. The Agency
expects that this protective measure will reduce exposure to applicators by
providing for training in safe use procedures.
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VII. MEASURES TO REDUCE END-USER'S RISK FROM EXPOSURE TO PRESSURE-TREATED
WOOD
The Agency believes that the majority of the population exposed to or
using pesticide-treated wood is not aware that the wood is treated with a
potentially hazardous pesticide and that individuals (including homeowners)
need to be alerted to the potential hazards of using pesticide-treated wood.
In the PD 2/3 several measures were considered for precautions concerning
use of the treated wood. One was to require warnings on the label of the
pesticide container itself. The Agency, however, has recognized that labeling
information, in many instances, could not be expected to reach the consumer
or purchaser of the commercially treated wood product, and in such circum-
stances the proposed pesticide label statements regarding treated-wood
would not be useful.
The Agency also recommended in the PD 2/3 (pp. 719-721) the implementation
of regulatory measures under Section 6 of TSCA to inform the end-user about
treated wood. The PD 2/3 recommended promulgating a rule under TSCA to
distribute labeling information to reduce the risks from the use of treated
wood. TSCA Section 6(a) (3) provides that the Agency can require that products
"be marked with or accompanied by clear and adequate warnings and instructions
with respect to its use, distribution in commerce, or disposal or with respect
to any combination of the activities." Promulgation of a rule under TSCA,
however, could take several years to complete. The Agency wanted to develop a
means of educating the public as soon as possible about the use of pesticide
treated wood. Therefore, the Agency has explored other means of informing
consumers of safe handling practices when using treated wood.
The wood preserving industry, as represented by the American Wood Preservers
Institute (AWPI) and the Society of American Wood Preservers (SAWP) , suggested
an alternative approach, the Consumer Awareness Program (CAP), to inform the
public about the proper use and handling of pressure-treated wood. In
support of their suggestion, they submitted a detailed description of a CAP
and a plan for its implementation (AWPI, Feb. 23, 1983). As part of their
proposal, a Consumer Information Sheet (CIS) would be distributed with every
purchase of pesticide-treated wood throughout the entire chain of commerce.
These CIS's would be designed to alert the consumer and commercial users to
the hazards and proper handling of wood products impregnated with wood preser-
vatives.
The Agency believes a Consumer Awareness Program, such as that proposed
by the industry, may be adequate to inform the users of treated wood of proper
handling and use precautions. The CAP as proposed by the pressure-treatment
industry representatives was intended to be completely voluntary. Because of
the importance of the effective implementation of the CAP to the Agency's reg-
ulatory decision, however, EPA has determined that the program should be legally
required as a condition of continued use of the wood preservatives for treating
wood or wood products. Requiring the commercial producers of wood wood or wood
products, which have been treated with wood preservatives, to participate in
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this effort to adequately inform the public of proper handling of treated wood
will most effectively assure the program's successful implementation.
The Agency will require that wood treaters using pressure-treatment
methods participate in a Consumer Awareness Program, but will not require
participation of wood treaters using non-pressure treatment methods because
the Agency does not expect use of wood commercially treated by non-pressure
methods to pose an unreasonable risk to end-users.
First, the Agency expects that the pesticide residues on non-pressure
treated wood will be low. For example, for millwork and plywood a 5% solution
of pentachlorophenol is used for surface application (PD 2/3, pp. 523 and
524; for particleboard there is a 0.65% concentration (pentachlorophenol
solids based on the oven-dried weight of the wood) in the wood-chip mixture;
and sodium pentachlorophenate is applied to lumber and freshly peeled poles
and posts at 6.3 to 6.9% for sapstain control (PD 2/3, p. 322, and p. 514).
Thus, dermal or inhalation exposure to end-users is expected to be low during
the handling or sawing/fabricating non-pressure treated wood.
Secondly, the patterns of use are such that exposure is also expected to be
low. For example, treated millwork, plywood, and particleboard are not used in
large amounts in residential interiors and are in some instances, sealed with
paint or shellac, thus significantly reducing dermal and inhalation exposure
(see Section V.H.3). While lumber treated with sodium pentachlorophenate could
be used in interiors, the Agency expects dermal exposure to be low because of
the low concentration used for treatment; inhalation exposure would be expected
to be minimal because sodium pentachlorophenate is not highly volatile as is
pentachlorophenol. The Agency did not propose in the PD 2/3 prohibiting interior
used of wood treated for sapstain control (PD 2/3, p. 720).
Another potential use pattern, contact of pentachlorophenol-treated
millwork and plywood and particleboard with domestic animals or food, feed,
or water, was discussed in Section VI.H.4 of this PD 4. Sapstain-treated wood
in contact with domestic animals or food, feed or water was discussed in
Section VI.G.3 of this document. In summary, the Agency believes that exposure
and risk for this use pattern are not significant.
Regarding proper disposal of non-pressure treated wood, the Agency believes
not only that the concentration of pentachlorophenol or sodium pentachlorophenate
residues will be low, but that consumers are unlikely to burn treated millwork
and plywood and particleboard and wood treated for sapstain control in
significant amounts.
In conclusion, upon consideration of the potential risks associated with
the above uses of non-pressure-treated-wood, the Agency has determined that
the risk potential to end-users of these non-pressure-treated wood items is
probably low. Therefore, the Agency will not require that commercial wood
treaters using non-pressure treatment methods participate in a Consumer
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Awareness Program for the following non-pressure treated wood-end-products:
millwood, plywood, particleboard, and wood treated for sapstain control.
Should data be brought to the Agency's attention which might alter this
conclusion, the Agency will act accordingly.
The risks associated with use of pressure-treated wood, however, compel
the Agency to require that wood treaters using pressure treatment methods
must participate in a Consumer Awareness Program to educate end-users of
pressure-treated wood or pressure-treated wood items about safe handling and
use procedures. To implement the Consumer Awareness Program, the Agency
requires that, the registration of every product, which may be used for
commercial pressure treatment of wood for distribution or sale and which
contains either creosote, pentachlorophenol, or inorganic arsenic, must be
amended to require the following statement to be prominently displayed on
the label:
This pesticide product may not be used for pressure-
treatment of wood or wood products for sale or distribu-
tion unless the wood treater is participating in or
affiliated with a program adequate to inform users of
the treated wood of proper precautions to be taken in
handling and using such treated wood.
At a minimum wood treaters must:
(1) distribute adequate consumer information sheets
(CIS) with each shipment of pressure-treated
wood so that at least one CIS will be securely
attached to each bundle or batch of treated-
wood as it leaves the treating plant;
(2) attach at least one CIS to each invoice for
sale of pressure-treated wood;
(3) make available to retailers, wholesalers and
distributors an adequate supply of CIS's and
signs or placards to inform consumers of the
existence of the CIS's; and
(4) encourage retailers to display signs or pla-
cards informing consumers of the availability
of the CIS's and to make the CIS's readily
available to the consumer.
The information which the United States Environ-
mental Protection Agency requires to be included
in the CIS is found in the attached labeling.
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See Section VII. C. for the exact language required by EPA to be included
in the Consumer Information Sheet for each of the three wood preservatives.
The Consumer Awareness Program can provide a reasonable approach to
educating the public and alerting it to the proper precautions to be taken
when handling treated wood. If the CAP is implemented and is effective in
reducing risks, the Agency will not need to promulgate a rule pursuant to
TSCA. TSCA rulemaking, however, remains a potential regulatory vehicle if
the CAP program fails to meet the Agency's expectations or if it is not
adequately implemented by distritutors of pressure-treated wood. In calcu-
lating the risks and benefits of continued registration of the wood preserva-
tives, the Agency has assumed that an effective Consumer Awareness Program
will be instituted. If such a program proves ineffective further regulating
actions may be needed.
A. Elements of an Adequate Consumer Awareness Program
The issues which should be covered in ah adequate Consumer Awareness
Program are discussed below. Following this section is required language
for Consumer Information Sheets for the three wood preservatives.
1. Use of Gloves
Exposure/Risk: Dermal exposure can result from contact with wood
which has been treated with creosote, pentachlorophenol, or the inorganic
arsenicals. Workers who handle (sawing and fabricating) the dry inorganic
arsenical-treated wood have an estimated increase in potential risk of
skin cancer, if not wearing gloves or other protective clothing, which ranges
from 7.9 x 10~3 to 3.9 x 1Q-2 (PD 2/3, p. 217). The dermal absorption
was assumed to be 0.01% (PD 2/3, pp. 199 and 205).
PD 2/3 Recommendation; In order to reduce dermal exposure through the
hands, the Agency recommended in the PD 2/3 that the following statement be
included on labeling information distributed with the treated wood to end-
users:
All individuals who handle pesticide-treated wood should wear
gloves impervious to the wood preservatives (e.g., rubber).
This measure would apply to all construction workers, individuals
installing fence posts, individuals climbing or working on utility poles, and
other exposed individuals. If gloves were worn by workers who handle (sawing
and fabricating) the dry inorganic arsenical-treated wood, the risk of skin
cancer to an individual would be reduced from a range of 7.9 x 10~3 to
3.9 x 10~2 without gloves (PD 2/3, p. 217) to a range of 8.0 x 10~5 to
4.0 x 10-4 with gloves (PD 2/3, p. 699). This latter risk estimate (with
gloves) included both dermal and inhalation exposure, but did not include the
gastrointestinal exposure which may result from sawing inorganic arsenical-
treated wood. The teratogenic and fetotoxic MOS for this activity would be
increased from approximately 300 to 500 (PD 2/3, p. 699) by wearing gloves.
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Although the dermal exposure to pentachlorophenol-treated wood and creosote-
treated wood was not quantified, wearing gloves was estimated in the PD 2/3
to reduce hand dermal exposure by 99% and would be expected to result in a
corresponding decrease in risk.
Final Agency Position and Rationale; New information on arsenic
absorption submitted by AWPI {#36: 30000/28C) was reviewed by the Agency.
Peoples (1979) studied the dermal absorption of arsenic in two dogs exposed to
sawdust from wood treated with ammoniacal copper arsenate (ACA) or chromated
copper arsenate (CCA) type C. One dog was exposed to 1.5 gm of ACA-treated
Douglas fir sawdust containing 6.7% arsenate which was spread on a pad
placed in intimate contact with the skin for 3 days. The second dog was
exposed to 1.5 gm of CCA-C treated fine southern pine sawdust containing
3.0% pentavalent arsenic applied in the same manner for 2 days. Orine from
each dog was collected for 2 days prior to treatment as well as after treat-
ment and was analyzed for arsenate (As V), arsenite (As III), methyl
arsente (MA) and dimethyl arsenate (DMA).
The Agency evaluated the results of this study and concluded that there
was no evidence of arsenic dermal absorption from treated wood. Although
only two dogs were used, th« Agency believes the results are sufficient, in
the absence of other data, to indicate that dermal absorption of arsenic from
the treated wood does not occur (Zendzian, 1982).
New information on dermal exposure from pentachlorophenol pressure-
treated wood was also submitted to the Agency (AWPI, Sept. 27, 1983). In a
study performed for AWPI by Ingram and McGinnis at Mississippi State University,
wood pressure-treated with pentachlorophenol in P-9 oil at 0.35 to 0.45
pounds per cubic foot was wiped with a cloth at 4.8 pounds pressure. The
residue was then converted to pentachlorophenol residue per square foot.
The Agency evaluated the results of this study and concluded that the upper-
limit exposure was 500 micrograms per square foot (Day, June 18, 1984).
Assuming the area of both hands to be 0.88 square feet, dermal contact with
pentachlorophenol could result in a dermal exposure of 440 ug. Assuming a
carpenter makes 25 hand contacts with the wood per day (for example, while
building a deck for a home) for 5 days per week, 20 weeks per year, for 30
years, the margin of safety for teratogenic/fetotoxic effects from hand
contact with pentachlorophenol pressure-treated wood is 1875 (Saito, June 19,
1984).
The potential oncogenic risk from hand dermal exposure to the HxCDD
contaminant of pentachlorophenol in the wood is 8.8 x 10""* (without gloves)
assuming 15 ppm HxCDD and is 8.8 x 10""5 if gloves are worn. The potential
oncogenic risk assuming 1 ppm HxCDD is 6.2 x 10"^ (without gloves) and is
6.2 x 10~6 if gloves are worn (Saito, June 19, 1984).
The Agency has concluded that gloves should be worn when handling wood
which has been pressure-treated with pentachlorophenol.
No new information was received on dermal exposure from handling dry
creosote-treated wood. The Agency assumes, as in the PD 2/3, that there is
some risk to anyone handling wood treated with this wood preservative.
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Based on the above information, the Agency has determined that, for
inorganic arsenical-treated wood, end-users would not need to wear gloves,
due to the negligible absorption rate demonstrated in the Peoples (1979)
study (Zendzian, 1982). However, the model CIS contains statements acceptable
to the Agency regarding gloves for handling pentachlorophenol-treated wood
and creosote-treated wood. The statements are as follows:
Avoid frequent or prolonged skin contact with penta-
chlorophenol-or creosote-treated wood; when handling
the treated wood, wear tightly woven coveralls and use
gloves impervious to the chemicals (for example, gloves
that are vinyl-coated).
The Agency has concluded that this precautionary statement on the model
CIS would inform the public about the necessary use of gloves when handling
treated wood. Gloves are expected to reduce creosote and pentachlorophenol
dermal exposure by 90% (Rispin April 24, 1984). The Agency will reevaluate
the acceptability of the materials recommended for protective clothing for
persons handling creosote-treated wood upon receipt of data from the reg-
istrants on permeability of materials in contact with creosote formulations.
2. Use of Coveralls, Gloves, and Dust Mask
Exposure/Risk; As discussed above, the Agency determined in the PD 2/3
that, during sawing operations with treated wood, preservative-bearing sawdust
tends to become airborne with resultant inhalation, gastrointestinal, and
widespread dermal exposure. During the sawing of inorganic arsenical-
treated wood, the total oncogenic risk without protective clothing was
estimated to range from 1.6 x 1.0-1 to 1.3 x 10~1 (PD 2/3, p. 217). The
teratogenic/fetotoxic MOS for arsenically treated wood ranges from 106 to
128 (PD 2/3, p. 245) . The creosote and pentachlorophenol risks have not
been quantified.
PD 2/3 Recommendation; To reduce the exposure created from the sawing
of pesticide-treated wood, the Agency recommended the following statements
be included on labeling information to be distributed with the treated
wood to end-users:
Individuals who saw such wood occupationally should wear
disposable coveralls (e.g., nitrile or polyethylene) or
similar protective clothing (for homeowners, tightly-woven
long sleeved cotton coveralls are acceptable). Individuals
who saw pesticide treated wood and fabricate structures
with treated wood should wear a dust mask capable of
trapping 80% of particulates greater than 5 microns in size.
The Agency determined (PD 2/3) that implementation of this modification
would reduce total dermal exposure to the wood preservatives by 80% if gloves
and coveralls were worn, and inhalation exposure of particulates by 80% if a
dust mask were worn by these workers. Wearing this protective clothing
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while working with inorganic arsenical-treated wood gives a total oncogenic
risk range of 2.7 x 10-3 to 3.0 x 10-3 for persons who are occupationally
exposed to sawdust from treated wood and a teratogenic/fetotoxic MOS
of 3,520 (PD 2/3, pp. 650 and 654). The dermal absorption for inorganic
arsenic from dry inorganic arsenic-treated wood was assumed to be 0.01%
(PD 2/3, pp. 199 and 205).
Final Agency Position and Rationale; The Agency believes there is some
risk to all persons handling and sawing treated wood. The model CIS addresses
this concern and states:
Avoid frequent or prolonged inhalation of sawdust from
treated wood. When sawing and machining treated wood wear a
dust mask. Whenever possible, these operations should be
performed outdoors to avoid indoor accumulations of
airborne sawdust from treated wood.
Avoid frequent or prolonged skin contact with pentachloro-
phenol- or creosote-treated wood: when handling the treated
wood, wear tightly woven coveralls and use gloves impervious
to the chemicals (for example, gloves that are vinyl coated).
When power sawing and machining, wear goggles to protect eyes
from flying particles. Wash thoroughly after skin contact,
and before eating, drinking, or use of tobacco products. If
oily preservatives or sawdust accumulate on clothes, launder
before reuse. Wash work clothes separately from other house-
hold clothing.
Although the risks from exposure to creosote and pentachlorophenol have
not been quantified, this modification would reduce total dermal exposure to
these preservatives by 80% if gloves and coveralls are worn, and inhalation
exposure of particulates by 80% if a dust mask is worn by these workers
(PD 2/3, p. 701). Wearing a dust mask while working with inorganic arsenical-
treated wood would result in a potential inhalation risk of 1.7x10~4 for CCA
and 4.2x10-4 for ACA. Wearing a dust mask would result in a potential risk
of skin cancer from oral/gastrointestinal exposure of 6.2x10-5 for CCA and
1.5x10-4 for ACA (Rispin, April 18, 1984). Therefore, the Agency has con-
cluded that dust masks should be worn by workers who saw arsenically treated
wood. As mentioned above under the Section on "gloves," the Agency will re-
evaluate the acceptability of recommended materials upon receipt of the data
submitted by the registrants.
3. Disposal of Treated Wood
Exposure/Risk; As stated in the PD 2/3 (p. 701), when creosote-treated
wood is burned, various oncogenic or mutagenic compounds may be formed.
When burned, wood treated with the inorganic arsenical compounds produces as
a residue arsenic trioxide ash, a teratogen, mutagen and potent oncogen.
PD 2/3 Recommendation; To reduce exposure to the toxic products that may
result from burning treated wood, the Agency recommended in the PD 2/3 that a
prohibition against the burning of this wood be included in the labeling to
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be distributed with treated wood. Although the Agency believes there could
be a. significant hazard to human health from burning treated wood the hazard
has not been quantified. However, implementation of this prohibition would
eliminate exposure to the potential risks from burning pesticide-treated
wood. Specifically, the PD 2/3 recommended:
Treated wood should not be burned, but should be
disposed of by methods, such as on-site burial, which
are in accordance with local and state laws, and
the Resource Conservation and Recovery Act.
Final Agency Position and Rationale; New information indicates that
pentachlorophenol-treated wood, when burned, produces dioxins (including
HxCDD) (Rappe and Marklund, 1978; and Jansson and Sundstrom, 1978). There-
fore, based on the fact that additional toxic chemicals may be produced
from burning treated wood, the Agency has included the following statement
in the model Consumer Information Sheet:
Dispose of treated wood by ordinary trash collection
or burial. Treated wood should not be burned in open
fires, or in stoves or fireplaces because toxic chem-
icals may be produced in the smoke and ashes. Large
quantities of treated wood from commercial or indus-
trial use (e.g., construction sites} may be burned in
commercial or industrial incinerators in accordance
with State and Federal Regulations.
The latter statement would permit an effective, efficient method of
disposing of large quantities of wood which may be commercially generated
at, for example, large construction sites (e.g., for piers, homes with all-
weather wood foundations).
This instruction would reduce improper disposal of pesticide-treated
wood and would therefore reduce exposure and potential risks from burning
pesticide-treated wood. Users would be informed that the treated wood should
not be burned but be disposed of by placing in trash collection or by burial.
The additional statement regarding burning in fireplaces and stoves, was
added because it had been brought to the Agency's attention from several
sources that some homeowners were burning treated wood in their home fire-
places and stoves.
The Agency believes that disposal of treated wood in this way will not
pose unreasonable risks to human health and the environment, because the
toxicants of concern are not likely to leach into the environment to any
significant degree. Arsenate forms insoluble compounds in soil and is
generally only moved by erosion. Arsenicals in treated wood have a very
low tendency to leach into the soil, because the compound fixes well in
the wood. Arsenic in water is adsorbed by sediments and becomes unavail-
able to aquatic plants or animals. (USDA, 1980, page xx, U.S. EPA, PD
1, p. 48448; Arsenault, 1975).
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Pentachlorophenol degrades rapidly (within days) in the soil, given
conditions of high moisture, temperature and organic matter. However, tinder
sub-optimal soil conditions, or in the presence of a solvent or fungicide,
pentachlorophenol degradation is slower (Day, 1980). Pentachlorophenol in
its salt form (high pH conditions) is subject to leaching. Leaching or
bleeding from pentachlorophenol-treated wood may result in low levels of
pentachlorophenol contamination in the immediate vicinity (several inches)
of the treated structure.
Creosote may be lost from treated wood by evaporation, exudation, or
leaching, depending on the kind of coal used to make coal tar and other
processing factors (U.S. EPA PD 1, p. 48159). While some of the lower
distilling fractions are lost very soon after the wood is treated, the
remainder is lost more slowly. Exuded liquid moves into soil a few
inches before biodegradation. The fate of creosote in the environment
is not known, but some components are rapidly biodegraded. Therefore,
the Agency expects that disposal of treated wood by ordinary trash collec-
tion or by burial should not pose unreasonable adverse effects to man or
the environment.
4. Indoor Use of Treated Wood
Exposure/Risk; The Agency concluded in the PD 2/3 that pesticide-treated
wood which is destined for interior use or enclosed structures will result in
inhalation and dermal exposure to the inhabitants of these dwellings or
structures. The Agency determined in the PD 2/3 that the oncogenic risk to
inhabitants in such enclosed areas from the interior uses (e.g., AWWF, plates
and sills, and structural framing) of arsenically treated wood was 9 x 10-6
(PD 2/3, p. 217); the MOS was 128,200 (PD 2/3, p. 654). In enclosed areas
treated with pentachlorophenol, inhalation exposures of about 8 ug/kg/day
may occur as a result of the vaporization of pentachlorophenol. This exposure
to pentachlorophenol results in a fetotoxic MOS of about 380; the exposure
to HxCDD is negligible (low vapor pressure) (PD 2/3, pp. 337 and 693).
For occupational interior use of wood which has been pressure-treated
with pentachlorophenol where there is poor ventilation, the exposure in
occupational or commercial settings is 5.9 ug/kg/day (PD 2/3, p. 337). The
oncogenic risk is negligible and the MOS is 510.
(MOS = NOEL = 3000 ug/kg/day)
Exposure 5.9 ug/kg/day
If the occupational setting is well ventilated, the exposure is 0.38
ug/kg/day (PD 2/3, p. 337). The oncogenic risk is negligible and the MOS is
7,900. (3000 ug/kg/day)
0.38 ug/kg/day
Sodium pentachlorophenate, used for sapstain control, is a salt in an
aqueous solution and thus has a very low vapor pressure. Consequently,
risks from the use of 0.5% sodium pentachlorophenate for control of sapstain
on wood which may be used indoors are not expected to be significant (PD 2/3,
p. 694).
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Although the Agency did not quantify the risks resulting from inhalation
or dermal exposure to interior wood to which creosote has been applied, the
Agency believes there is some degree of risk to individuals contacting
creosote-treated wood dermally or breathing fumes in enclosed areas.
PD 2/3 Recommendation; TO reduce these risks, the Agency recommended in the
PD 2/3 limiting the use of pesticide-treated wood to exterior and specific
indoor uses only. Under this limitation, treated wood which would ultimately
be used in the interiors of human and animal dwellings would be limited to
those posing a minimal risk.
Specifically, the Agency recommended (PD 2/3) the following statements be
included on labeling information distributed with the treated wood to end-users:
Treated wood should not be used indoors except for
those support structures (e.g., foundation timbers,
pole supports, and the bottom six inches of stall
skirtboards) which are in contact with the soil in
barns, stables and similar sites '(all three wood
preservatives); all weather wood foundations, sills
and plates, structural framing (inorganic arsenicals
only); millwork (pentachlorophenol only) which has
outdoor surfaces (e.g., doorframes, windows, and patio
frames); and wood treated for sapstain control with
0.5% sodium pentachlorophenate.
In addition to recommending that end-use labeling be distributed with
the treated wood, the Agency also proposed in the PD 2/3 that similar ,
prohibitions on interior uses of treated wood be enforced under FIFRA through
appropriate statements on the label of the pesticide formulation. Implemen-
tation of this modification was expected to reduce the risk resulting from
the use of treated wood in interior settings (e.g., paneling, cabinets,
interior surfaces of log homes) by placing the responsibility on the treater
not to treat wood intended for these uses.
Final Agency position and Rationale; Reichold chemicals Inc. recommended
that a sealer be used on pentachloropenol pressure-treated wood used in in-
teriors (Reichold, Aug. 3, 1981). OSDA (1981) and AWPI (Comment #36s 30000/28C)
provided data on the effectiveness of sealers to reduce vaporization of
creosote and pentachlorophenol from commercially treated wood at 20°C and
31°C and a relative humidity of 50%. The air-flow rate was 1.0 liter per
minute. Most sealers including stains, wood finishers, and varnishes were
70-100% effective in reducing these pesticide vapors with an average vapor
reduction of 85% if two coats were applied (Day, December 9, 1983):
Also, as discussed in Section II, new information has convinced the
Agency that the time a resident would spend in a home was overestimated in
the PD 2/3. Instead of using the PD 2/3 estimate of 24 hours, the Agency
revised the time spent to 15 hours (8 hours resting, 1 hour heavy work, and
6 hours of light work). Due to receipt of this new information, the Agency
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revised its exposure assumptions (Day, May 19, 1982 Exposure Analysis;
Day, 1982 Rebuttal Analysis, and Day, Dec. 9, 1983), and, thus, its risk
estimates.
USDA {1981) supplied data on the inhalation exposure resulting from the
vaporization of pentachlorophenol from commercially dipped wood and aged
pressure-treated Wood (Day, 1982). The Agency had assumed (PD 2/3, p.
335) that the concentration of pentachlorophenol in the air from treated
wood in residential interiors was 30 ug/m3. The revised inhalation
exposure levels are 4.8 - 20.4 ug/m3 (industrially dip treated wood) and
0.5 - 10 ug/m3 (aged treated wood) (Day, May 19, 1982 Exposure Analysis).
For wood intended for residential use which has been commercially
dip/pressure-treated with pentachlorophenol and has an effective sealer
applied, the fetotoxio MOS would range from 6,300 to greater than 10,000
(Van Ormer, 1982). The exposure to HxCDD would also be reduced by 85%.
However, the Agency considered exposure to HxCDD to be negligible due to its
lower vapor pressure relative to that of pentachlorophenol. The MOS range
without sealers is 940-4000 (Van Orraer, 1982). If the commercial penta-
chlorophenol-treated wood is aged and a sealer is used, the fetotoxic MOS
would be greater than 10,000 (Van Ormer, 1982).
For a well-ventilated occupational establishment with interiors consisting
of pentachlorophenol dipped or pressure-treated wood, the fetotoxic MOS
would range from 7,900 (if no sealer were used) to greater than 10,000 (if a
sealer was used); in a poorly ventilated occupational setting, the MOS is
510 if no sealer is used and would range from 6,700 to greater than 10,000
if a sealer is used (Van Ormer, 1982).
i
Although the risks from interior uses of creosote-treated wood have not
been quantified, the use of an effective sealer is assumed to reduce creosote
vapors by 85% and thus contribute to a significant reduction in risk.
For wood pressure-treated with the inorganic arsenical compounds which
may be used for some interior uses listed above (e.g., all-weather-wood-founda-
tions or homes constructed with arsenic pressure-treated wood), the recalculated
inhalation oncogenic risk to inhabitants of such an enclosed area without sealers
is 4.6 x 10"^. These risks are based on the new risk and exposure information
discussed in Section II of this document and are not significantly different
from background.
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However, while it is true that sealers reduce vaporization of pentachloro-
phenol by about 85%, the Agency has received many reports of acute toxicity
in enclosed areas where pentachlorophenol-treated wood has been used (Levin,
#60:30000/28C; Friends of the Earth, #70:30000/28C; Center for Disease Control,
#69:30000/28C; and U.S. EPA P1MS, 1981).
No data are available to indicate the length of time of effectiveness of
the sealers; Levin (#60:30000/28C) submitted information which indicated that
the wood preserving industry recommended continued air monitoring after
sealing pentachlorophenol treated wood "to establish that any trace vapors
remain at no-effect levels."
Also, AWPI (#36B;30000/28C, pp. 44) commented that in highly enclosed spaces
pentachlorophenol should not be used to preserve a large portion of wall space
and recommended use of pentachlorophenol-treated wood only for support structures
and other building components subject to decay or termite hazards but only if
appropriate sealer is applied.
Additional information submitted by the California Department of Health
Services to the Agency (Jackson and Stratton, #87:30000/28C) indicated that
occupants of an office building containing sealed pentachlorophenol pressure-
treated wood in Long Beach, California, continued to have increased levels
of free pentachlorophenol in their urine compared to the levels prior to
occupancy. Air levels of pentachlorophenol were 50 ug/m3) prior to sealing
the wood. Air levels in this range (40 - 50 ug/m3) were reported to be
associated with acute toxic effects by Jackson and Stratton (#87:30000/28c).
After sealing the wood, air levels decreased to 5 ug/m3, a level not known
to be associated with any direct adverse health effects (#87:30000/28c).
While sealers may provide an adequate Margin of Safety from potential
teratogenic/fetotoxic effects, in light of the information on acute toxic
effects tiie Agency has incorporated statements into the model CIS to discourage
use of pentachlorophenol-treated wood unnecessarily indoors, including
interiors of residences, and industrial and commercial buildings. The Agency
has also incorporated statements in the CIS regarding limitations on interior
use of creosote-treated wood and wood treated with the inorganic arsenicals.
The CIS states:
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Pentachlorophenol-treated wood should not be used in residen-
tial, industrial, or commercial interiors except for laminated
beams or building components which are in ground contact and are
subject to decay or insect infestation and where two coats of an
appropriate sealer are applied.
Creosote-treated wood should not be used in residential
interiors. Creosote-treated wood in interiors of indus-
trial buildings should only be used for wood-block flooring
and industrial building components which are in ground
contact and are subject to decay or insect infestation
and where two coats of an appropriate sealer are applied.
Coal tar pitch and coal tar pitch emulsion are effec-
tive sealers for creosote-treated wood-block flooring.
Urethane, epoxy, and shellac are acceptable sealers for
all creosote-treated wood. Urethane, shellac, latex
epoxy enamel, and varnish are acceptable sealers for
pentachlorophenol-treated wood.
The Agency will not advise against the interior use of arsenical -
treated wood, because the risks of use (4.6 x 10~6) have been shown not
to be above background. The arsenic air levels measured in homes con-
structed with arsenic treated wood are not significantly different from
background arsenic air levels when all dust is vacuumed from the wood
surfaces (Koppers, Nov. 15, 1983) .
Therefore, the Agency will require that the CIS contain in the
following statement:
Exposed wood pressure-treated with waterborne
arsenical preservatives may be used inside
residences as long as all dust is vacuumed from
the wood surface.
The Agency expects that the Consumer Awareness Program, when initiated
by the wood preserving industry, will adequately inform users as to the
proper use of pressure-treated wood. Based on the revised risks of the
sealed treated wood for interior uses, the Agency believes that limited interior
uses of sealed pentachlorophenol and creosote treated wood will not cause
unreasonable adverse effects to man or the environment. See Appendix B
for a comparison of the risks calculated in the PD 2/3 and the present
recalculated risks.
As stated above, the Agency had also proposed in the PD 2/3 that similar
prohibitions on interior uses of treated wood be stated on the labels of the
pesticide formulation and be enforced under FIFRA. The responsibility would
have been placed on the wood treater not to treat wood intended for use in
interiors. However, the Agency now recognizes that the treatment plant appli-
cator would not necessarily know how the treated wood might later be used.
Thus, it would be unreasonable to hold the treater responsible for a use occur-
ring after treatment. Therefore, the Agency will not require that such label
restrictions be stated on pesticide formulations which are used by applicators
who treat wood for commercial distribution.
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5. Animals/Food/Feed/Water Issue
Exposure/Risk; The Agency expressed concern in the the PD 2/3 that
pesticide-treated wood could come into contact with food/ feed, and water
resulting in some exposure to domestic animals and/or humans.
PD 2/3 Recommendation; To eliminate this route of exposure, the Agency
recommended that certain labeling information accompany the treated wood.
The recommended statement to be included on the label was as follows:
Treated wood should not be used in a manner which may
result in direct exposure to domestic animals or
livestock, or in the contamination of food, feed, or
drinking and irrigation water (e.g., food crates,
irrigation flumes, vegetable stakes, feedlot bins, and
watering troughs).
The Agency also proposed in the PD 2/3 that these prohibitions be en-
forced under FIFRA through appropriate statements on the label of the pesticide
fomulation. This regulatory action would place the responsibility on the
wood treater not to treat wood intended for those uses. The Agency now
recognizes that the treatment plant operator does not necessarily know how
the treated wood will be used. Therefore, it would be inappropriate to hold
the treater responsible for a later use, and this label change will not be
implemented.
Final Agency Position and Rationale: AWPI (Feb. 9, 1982) and USDA (1981)
objected to this recommended prohibition, stating that it was too wide-ranging
and that very little contamination, if any, would be expected.
Animal Contact
A report by USDA (1980) has indicated that several types of domestic animals
can be exposed to the pesticides in treated wood from breathing air containing
pesticide vapors or pesticide-laden dust particles, from oral contact, or
from dermal contact. The principal problem is chemical residues in food
products of animal origin which humans may consume rather than acute toxicity
in animals following direct exposure, though some toxicity has been reported.
Cattle, for example, can come into contact with pentachlorophenol by
breathing vapors or dust in a barn constructed in part from poles and boards
treated with pentachlorophenol or by licking or chewing on treated wood.
Horses may crib (bite) treated wood and thereby may ingest pesticides from
treated wood. Deaths in piglets and skin burns on the sow1s udder have been
reported when sows are farrowed (give birth) on pentachlorophenol-treated
wood that is bleeding (oozing pesticide). Problems with poultry have been
reported when sawdust/wood chips containing pentachlorophenol are used for
bedding (liiter) (USDA, 1980, and FDA, 1983).
Pentachlorophenol and HxCDD residues have been shown to accumulate in the
milk and blood of cows fed technical pentachlorophenol (Firestone, 1979).
Dioxin residues have been shown to accumulate in the meat and tissues of
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cattle fed technical grade pentachlorophenol with the largest HxCDD residue of
3 ppb being found in the liver (Zabik, 1980). A USDA meat/poultry sampling
showed pentachlorophenol residues in animals, with the highest concentration
of 2 ppm in hogs (Day, 1983). USDA (1980) also reports that pentachlorophenol
residues in blood of dairy cattle which have been housed in a barn containing
a feedbunk made of pentachlorophenol-treated wood are higher (0.279 mg/liter)
than residues in the blood of dairy cattle housed without a pentachlorophenol
treated feedbunk (0.050 mg/liter).
Based on the above information, the Agency believes it would be prudent to
prohibit the use of pentachlorophenol-treated wood in interiors of farm
buildings where it may come into contact with domestic animals or livestock
which may crib or lick the wood, in order to prevent any potential toxicity to
the animals or to humans who may consume food products of animal origin.
Though the Agency has no data on creosote residues in the tissues of
domestic animals following exposure, the Agency believes it is prudent to
prohibit the use of creosote-treated wood in interiors of farm buildings
where the treated wood may come into contact with domestic animals or live-
stock which may crib or lick the wood.
Regarding arsenic, studies have shown that arsenic is readily excreted
in cattle and does not biomagnify through the food chain and that dermal
absorption of arsenic from treated wood is negligible (Day, 1983; Zendzian,
1982; ; NIOSH, 1983; and PD2/3, p. 170). If domestic animals do crib or
lick the wood, exposure is expected to be limited (USDA, 1980) . Therefore,
the Agency will not require a statement in the CIS regarding direct contact
of domestic animals with arsenic-treated wood. However, as stated below
under "Pood and Feed," FDA has the responsibility for setting food additive
regulations where pesticides may contaminate food or animal feed; e.g.,
where the food or animal feed is in contact with pesticide-treated wood.
The Agency requires that the following statements be contained in the
CIS:
Do not use pentachlorophenol or creosote treated wood
for farrowing or brooding facilities. Wood treated with
pentachlorophenol or creosote should not be used in the
interiors of farm buildings where there may be direct
contact with domestic animals or livestock which may
crib (bite) or lick the wood. In interiors of farm buildings
where domestic animals or livestock are unlikely to crib
or lick the wood, pentachlorophenol or creosote treated
wood may be used for building components which are in ground
contact and are subject to decay or insect infestation and
where two coats of an appropriate sealer are applied.
Urethane, epoxy, and shellac are acceptable sealers for
all creosote-treated wood. Urethane, shellac, latex
epoxy enamel, and varnish are acceptable sealers for
pentachlorophenol-treated wood.
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Food and Feed
The Food and Drug Administration (FDA) has the responsibility for setting
food additive regulations. FDA has stated that preserved wood cannot be
used under circumstances where the pesticide may become a component of food
or feed unless a food additive regulation has been promulgated and prescribes
safe use (Hile, Aug. 4, 1983).
FDA has issued a regulation for the safe use of pentachlorophenol and
sodium pentachlorophenate on wooden articles at levels up to 50 ppm in wood
contacting raw agricultural products (21 CFR 178.3800). However, FDA
has expressed concern about the use of pentachlorophenol-treated wood
under other conditions where the pentachlorophenol would be likely to
migrate to other food or animal feed, such as silage, because chlorinated
phenols or their contaminants could become concentrated in the edible
tissue of animals (Hile, Aug. 4, 1983). No food additive regulation
permits pentachlorophenol, creosote or inorganic arsenicals from treated
wood in food or animal feed. Therefore, any food or animal feed which
contain residues from contact with treated wood will be adulterated
under the Food, Drug and Cosmetic Act. Accordingly, the EPA requires
that the following statement be included in the CIS to provide guidance
to the consumer who may be considering using the treated wood where it
may contact food or animal feed:
Do not use treated wood under circumstances where the
preservative may become a component of food or animal
feed. Examples of such sites would be structures or
containers for storing silage or food.
The Agency believes that it would also be prudent to include the following
statement in the model CIS:
Do not use treated wood for cutting boards or counter tops.
Drinking Water (Human)
The use of treated wood in drinking water systems includes interiors of
reservoir roofs, support beams, and truss structures above water levels, and
may involve either direct or indirect contact with drinking water. In both
situations migration of preservative chemicals at significant rates is possible,
by leaching when direct contact is involved and via condensation and other
mechanisms when treated wood is in indirect contact with drinking water.
Arsenic: The Agency believes that arsenic-treated wood should not be used
in contact with drinking water until studies are conducted to show that the
contribution of arsenic to drinking water via this source cannot be expected
to exceed 5.0 ppb in the water. This limit for arsenic is 10% of the Maximum
Contaminant Limit (MCL) of 50 ppb established under the National Interim
Primary Drinking Water Regulations (40 Federal Register, 59566, December 24,
1975). A 10% contribution limit of any given MCL or of a given Suggested
No-Adverse-Effect Level (SNARL), when no MCL exists, has been suggested by
the National Academy of Sciences (NAS) Committee on Water Treatment Chemicals
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(NAS, 1982) for intentional water quality degradation by a given impurity in
a water treatment chemical. As the intentional degradation during water
treatment is no different than degradation occurring during water storage,
(e.g., from contact with treated wood,) a 10% MCL contribution limit is
appropriate in both situations.
Creosote; Because components in creosote have been shown to be oncogenic
and mutagenic (PD 2/3) and because creosote and other coal tar based products
impart an objectionable taste and odor to water, the Agency recommends that
creosote-treated wood not be used where it may come in contact with drinking
water. The World Health Organization (1983) has recently recommended against
the use of coal tar-based and associated materials in drinking water contact.
Pentachlorophenol; Drinking water SNARL values for pentachlorophenol have
been calculated by the NAS assuming contributions from drinking water ranging
from 0-20%. Considering a conservative hypothetical situation where water
contributes as much as 20% of the total intake of pentachlorophenol, the NAS
SNARL for drinking water would be 0.021 ppm. With the NAS recommended 10%
contribution limit discussed above for arsenic, the acceptable level for
pentachlorophenol present in drinking water due to contact with pentachlorc—
phenol-treated wood would be 0.0021 ppm. In a study submitted by the wood
preservative industry, levels of pentachlorophenol in water which was in
contact with pentachlorophenol treated wood were significantly higher (4.2
and 4.7 ppra) (AWPI, 1983). Therefore, the Agency will recommend that the
CIS contain statements indicating that pentachlorophenol-treated wood should
not be used where it may come in contact with drinking water, except for
docks and bridges constructed from pentachlorophenol-treated wood.
The statement which the Agency requires be included in the Consumer
Information Sheet regarding pesticide-treated wood coming into contact with
drinking water is as follows:
Pesticide-treated wood should not be used where it
may come into direct or indirect contact with public
drinking water except for uses involving incidental
contact such as docks and bridges.
Drinking Water (Domestic Animals)
In order to determine whether wood preservatives migrate in water which
comes into contact with certain structures built of pressure-treated wood,
AWPI (1983) performed a study using water troughs made of arsenic, penta-
chlorophenol, and creosote pressure-treated wood. Pesticide residues in
the water in these structures were measured with samples taken (1) from an
area adjacent to the treated wood and (2) from the center of the structure.
Arsenic; The Agency reviewed the results of this study (Day, 1983). It was
found that, though arsenic was recovered from the water at levels as high as
40 ppb, the residues were below the 50 ppb upper limit for arsenic set by
EPA's National Interim Primary Drinking Water Regulations (40 FR 59566, Dec.
24, 1975). It is also below the 0.2 ppm (200 ppb) upper limit recommended
by NAS for domestic animal drinking water (NAS, 1972, p. 310).
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Therefore, the Agency has concluded that arsenic-treated wood could be
used for construction of containers for water for domestic animal or livestock
consumption.
Pentachlorophenol; The results of the study also showed transfer of penta-
chlorophenol from the wood to the water, with the pentachlorophenol (4.2
ppm) distributed homogeneously throughout. Normal city water contains up to
0.0001 ppm pentachlorophenol (PD 2/3, p. 341); therefore, domestic animals
could receive up to 42,000 times the normal intake of pentachlorophenol due
to direct contact of the water with the treated wood (Day, Jan. 18, 1983).
This could contribute to the pentachlorophenol levels found in livers of
domestic animals (PD 2/3, p.343). Therefore, the Agency will require
that pentachlorophenol treated wood should not be used where it may
come into direct contact with drinking water for domestic animals and
livestock.
Creosote; The water in contact with the creosote-treated wood showed
homogeneous contamination of creosote at 0.1 ppm. Because of the diverse
nature of creosote and the uncertainty of the significance of 0.1 ppm in
water, it is not possible to define these results in terms of hazard.
However, the World Health Organization, in its 1983 proposal entitled
"Guidelines for Drinking Water Quality," has recommended discontinuation
of the use of coal tar-based and associated materials in contact with
public drinking water (WHO, 1983).
Creosote and other coal tar-based products have been shown to be
mutagenic and oncogenic (PD 2/3) and can also impart an objectionable
taste and odor to water. The Agency believes, therefore, that it would
not be prudent to allow creosote-treated wood to come into direct contact
with drinking water for domestic animals and livestock.
To summarize, the Agency has concluded that inorganic arsenic (CCA salt
or oxide) treated wood can be used in direct contact with drinking water for
domestic animals, but pentachlorophenol and creosote treated wood cannot.
The Agency requires that the CIS contain the following statement:
Do not use pentachlorophenol or creosote treated wood
where it may come into direct or indirect contact with
drinking water for domestic animals or livestock, except
for uses involving incidental contact such as docks and
bridges.
6. Outdoor Uses of Pressure-Treated Wood
In the PD 2/3, possible exposures from patios, decks and walkways were not
considered. However, these potential exposures are now addressed in the CIS.
The statement in the CIS is:
Only treated wood that is visibly clean and free of
surface residue should be used for patios, decks and
walkways.
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The Agency has no monitoring data on exposure of persons to arsenically-
treated playground equipment or persons who inadvertently contact arsenically-
treated wood surfaces such as handrails, sun decks, park benches, stadium
seats, and boardwalks. As discussed previously in Section VII.A.I of this
document, dermal absorption of inorganic arsenic from dry treated wood is
considered to be negligible (Zendzian, 1982). The dermal absorption of
arsenic from treated wood which subsequently becomes wet with water is 0.1%
(Day, Oct. 27, 1983). The dermal absorption of pentachlorophenol from dry
pentachlorophenol treated wood or from pentachlorophenol-treated wood which
subsequently becomes wet with water is 1.0% (Day, Oct. 27, 1983). There are
no data on dermal absorption of creosote from creosote-treated wood, but the
Agency assumes that some absorption does occur.
Therefore, in order to reduce exposure to pentachlorophenol and creosote
treated wood, the CIS will state the following:
Wood treated with pentachlorophenol or creosote should
not be used where it will be in frequent or prolonged
contact with bare skin (for example, chairs and other
outdoor furniture), unless an effective sealer has been
applied.
7. Use of Treated Wood for Beehives and Hive Platforms
AWPI (Feb. 24, 1983) suggested that a statement be included in the CIS
informing users of treated wood that only acid copper chromate (ACC) and
chromated zinc chloride (CZC)-treated wood should be used in the construction
of beehives and hive platforms because creosote, pentachlorophenol, or
arsenically treated wood are acutely toxic to bees. No data were submitted
to substantiate this claim. This use had not been considered in the PD 2/3
and no other comments were received on this subject.
The Agency has researched this issue and has found that pentachlorophenol
is recommended widely as a preservative for hive stands and bottom boards of
hives (Ludvik, 1984). No data to support AWPI's claims of toxicity to bees
from using treated wood for beehives were found.
However, the Agency believes it would be prudent to caution users of
treated wood against using the treated wood in those parts of beehives which
are likely to come into contact with the honey and possibly result in pesticide
residues in the honey.
The Agency requires that the following statement be included
in the CIS:
Do not use treated wood for construction of those
portions of beehives which may come into contact
with the honey.
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B. Model Consumer Awareness Program
AWPI and SAWP developed a model Consumer Awareness Program (CAP)
and a model Consumer Information Sheet (CIS) containing use site precautions
and safe working practices which EPA has reviewed and has found to be generally
satisfactory to address its concerns. EPA, however, requires that other
statements be included in the model CIS. The CIS'would serve as the main
vehicle for conveying information about treated wood to purchasers of landscape
ties, fence posts, lumber and timber. The focus of the CAP would be on
ensuring the dissemination of the CIS at the time of sale or delivery to
these end-users.
Each wood treater will be able to customize its CIS. Thus, the individual
wood treater's CIS at a minimum, would contain in one section the information
included in the model CIS, in so far as it applies to the wood preserver's
product, but might also include in a separate section information not contra-
dictory to the statements required by EPA. Such additional information
might include the sealer's name, address and logo. Additional warnings may
also be added. In all cases, however, the use site precautions and the safe
handling practices information required by EPA would have to be distinct and
clearly legible, using Bodoni bold 12 pt type.
The wood treater will have primary responsibility for ensuring that the
CIS is disseminated to the consuming public. Wood treaters are expected to
distribute CIS's and signs or placards to their retailers, wholesalers and
distributors, attach a CIS to each bundle or batch of treated wood, and
attach a CIS to each invoice. The preservative manufacturers, formulators
and trade associations may also work to ensure the consumer receives the
necessary product information.
A yearly survey of member compliance and effectiveness of the distribution
of the CIS will be conducted by EPA.
The CAP must be implemented when the amended labels for the wood
preservatives appear on the market approximately 6 months to 1 year after the
Notice concluding the Wood Preservatives RPAR is published in the Federal
Register.
The obligation to implement an adequate Consumer Awareness Program is on
wood treaters who use wood preservatives to commercially pressure-treat wood.
To fulfill this obligation they must:
(1) distribute adequate consumer information sheets (CIS) with each
shipment of pressure-treated wood so that at least one CIS will be
securely attached to each bundle or batch of treated wood as it
leaves the treating plant;
(2) attach at least one CIS to each invoice for sale of pressure-treated
wood;
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(3) make available to retailers, wholesalers and distributors an adequate
supply of CIS1s and signs or placards to inform consumers of the
existence of the CIS's; and
(4) encourage retailers to display signs or placards informing consumers
of the availability of the CIS's and to make the CIS's readily
available to the consumer.
Although only the users of the wood preservatives are actually required
by the label instructions to implement the Consumer Awareness Program, EPA
expects the other organizations may participate as well.
Such additional organizations include the wood preserving industry
trade associations and the registrants of the affected wood preservative
products. These organizations may be able to implement parts of the program
more economically and efficiently by, for example, printng Consumer Informaton
Sheets in bulk for distribution or by serving as a centralized clearinghouse
for encouraging distributors and retailers of treated wood to fully implement
the CAP. Two wood preservative trade associations, the Society of American
Wood Preservers and the American Wood Preservers Institute, have submitted
to EPA a plan for implementing the CAP (36J:30000/28C). In this plan the
wood treaters, the trade associations and the registrants would work together
to attempt to assure the program is effective. EPA has reviewed this plan
and has found it to be a wholly satisfactory means of carrying out the
label requirement and encouraging the industry to fully implement it. The
ultimate obligation to carry out an adequate program to inform the public,
however, lies with users of the wood preservatives as a condition of their
legal use of the products.
C. Consumer Information Sheets
1. CREOSOTE
The following is the wording acceptable to EPA for the Consumer Infor-
mation Sheet (CIS) for creosote pressure-treated wood. This CIS is based on
the version proposed by AWPI and SAWP (Feb. 24, 1983) , but it has been
revised to reflect additional Agency concerns. These Consumer Information
Sheets must accompany each shipment of creosote pressure-treated wood.
CONSUMER INFORMATION SHEET
This wood has been preserved by pressure treatment with an EPA-registered
pesticide containing creosote to protect it from insect attack and decay.
Wood treated with creosote should be used only where such protection is
important.
Creosote penetrates deeply into and remains in the pressure-treated
wood for a long time. Exposure to creosote may present certain
hazards. Therefore, the following precautions should be taken both
when handling the treated wood and in determining where to use the
treated wood.
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USE SITE PRECAUTIONS FOR CREOSOTE PRESSURE-TREATEDWOOD
— Wood treated with creosote should not be used where it will be
in frequent or prolonged contact with bare skin (for example,
chairs and other outdoor furniture) unless an effective sealer
has been applied.
-- Creosote-treated wood should not be used in residential interiors.
Creosote-treated wood in interiors of industrial buildings should
only be used for wood-block flooring and industrial building
components which are in ground contact and are subject to decay or
insect infestation, and where two coats of an appropriate sealer
are applied.
— Wood treated with creosote should not be used in the interiors of
farm buildings where there may be direct contact with domestic
animals or livestock which may crib (bite) or lick the wood.
— In interiors of farm buildings where domestic animals or livestock
are unlikely to crib (bite) or lick the wood, creosote-treated
wood may be used for building components which are in ground contact
and are subject to decay or insect infestation and where two coats
of an effective sealer are applied.
— Do not use creosote treated wood for farrowing or brooding facilities.
— Do not use treated wood under circumstances where the preservative
may become a component of food or animal feed. Examples of such sites
would be structures or containers for storing silage or food.
— Do not use treated wood for cutting boards or countertops.
— Only treated wood that is visibly clean and free of surface
residues should be used for patios, decks and walkways.
— Do not use treated wood for construction of those portions of beehives
which may come into contact with the honey.
— Creosote-treated wood should not be used where it may come into
direct or indirect contact with public drinking water, except for
uses involving incidental contact such as docks and bridges.
— Do not use creosote-treated wood where it may come into direct
or indirect contact with drinking water for domestic animals
or livestock, except for uses involving incidental contact such as
docks and bridges.
HANDLING PRECAUTIONS FOR CHEOSOTE PRESSURE-TREATED WOOD
Dispose of treated wood by ordinary trash collection or burial.
Treated wood should not be burned in open fires or in stoves or
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fireplaces because toxic chemicals may be produced as part of the
smoke and ashes. Large quantities of treated wood from commercial
or industrial use (e.g., construction sites) may be burned in
commercial or industrial incinerators in accordance with state and
Federal regulations.
Avoid frequent or prolonged inhalation of sawdust from treated wood.
When sawing and machining treated wood, wear a dusk mask. Whenever
possible, these operations should be performed outdoors to avoid
indoor accumulations of airborne sawdust from treated wood.
Avoid frequent or prolonged skin contact with creosote-treated
wood; when handling the treated wood, wear tightly woven coveralls
and use gloves impervious to the chemicals (for example, gloves
that are vinyl-coated).
When power-sawing and machining, wear goggles to protect eyes from
flying particles.
Wash exposed areas thoroughly after skin contact, and before
eating, drinking or use of tobacco products.
If oily preservatives or sawdust accumulates on clothes, launder
before reuse. Wash work clothes separately from other household
clothing.
Coal tar pitch and coal tar pitch emulsion are effective sealers
for creosote-treated wood block flooring, urethane, epoxy,
and shellac are acceptable sealers for all creosote-treated wood.
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2« PENTACHLOROPHENOL
The following is the wording required for the Consumer Information Sheets
(CIS) which must accompany each shipment of pentachlorophenol pressure-treated
wood.
CONSUMER INFORMATION SHEET
This wood has been preserved by treatment with an EPA-registered pesticide
containing pentachlorophenol, to protect it from insect attack and decay.
Wood treated with pentachlorophenol should be used only where such pro-
tection is important.
Pentachlorophenol penetrates deeply into and remains in the pressure-
treated wood for a long time. Exposure to pentachlorophenol may present
certain hazards. Therefore, the following precautions should be taken
both when handling the treated wood and in determining where to use the
treated wood.
USE SITE PRECAUTIONS FOR PEMTACHLOROPHEHOL PRESSURE-TREATED WOOD
— Wood treated with pentachlorophenol should not be used
where it will be in frequent or prolonged contact with bare skin
(for example, chairs and other outdoor furniture), unless an
effective sealer has been applied.
— pentachlorophenol-treated wood should not be used in residential,
industrial, or commercial interiors except for laminated beams or
building components which are in ground contact and are subject to
decay or insect infestation and where two coats of an appropriate
sealer are applied.
— Wood treated with pentachlorophenol should not be used in the
interiors of farm buildings where there may be direct contact with
domestic animals or livestock which may crib (bite) or lick the
wood.
— In interiors of farm buildings where domestic animals or livestock
are unlikely to crib (bite) or lick the wood, pentachlorophenol-
treated wood may be used for building components which are in ground
contact and are subject to decay or insect infestation and where
two coats of an appropriate sealer are applied.
~ Do not use pentachlorophenol-treated wood for farrowing or brooding
facilities.
~ Do not use treated wood under circumstances where the preservative
may become a component of food or animal feed. Examples of such sites
would be structures or containers for storing silage or food.
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— Do not use treated wood for cutting boards or countertops.
— Only treated wood that is visibly clean and free of surface residue
should be used for patios, decks and walkways.
—• Do not use treated wood for construction of those portions of beehives
which may come into contact with the honey.
— Pentachlorophenol-treated wood should not be used where it may come
into direct or indirect contact with public drinking water, except
for uses involving incidental contact such as docks and bridges.
— Do not use pentachlorophenol-treated wood where it may come into
direct or indirect contact with drinking water for domestic animals
or livestock, except for uses involving incidental contact such as
docks and bridges.
HANDLING PRECAUTIONS FOR PENTACHLOROPHENOL PRESSURE-TREATED WOOD
— Dispose of treated wood by ordinary trash collection or burial.
Treated wood should not be burned in open fires or in stoves or
fireplaces because toxic chemicals may be produced as part of the
smoke and ashes. Large quantities of treated wood from commercial
or industrial use (e.g., construction sites) may be burned in
commercial or industrial incinerators in accordance with state and
Federal regulations.
— Avoid frequent or prolonged inhalation of sawdust from treated wood.
When sawing and machining treated wood, wear a dusk mask. Whenever
possible, these operations should be performed outdoors to avoid
indoor accumulations of airborne sawdust from treated wood.
— Avoid frequent or prolonged skin contact with pentachlorophenol-
treated wood; when handling the treated wood, wear tightly
woven coveralls and use gloves impervious to the chemicals (for
example, gloves that are vinyl-coated).
— When power-sawing and machining, wear goggles to protect eyes from
flying particles.
— Wash exposed areas thoroughly after skin contact, and before
eating, drinking or use of tobacco products.
— If oily preservatives or sawdust accumulates on clothes, launder
before reuse. Wash work clothes separately from other household
clothing.
— Urethane, shellac, latex epoxy enamel and varnish are acceptable
sealers for pentachlorophenol-treated wood.
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3. INORGANIC ARSENICALS
The following is the wording required for the Consumer Information Sheets
(CIS) which must accompany each shipment of inorganic arsenical pressure-treated
wood.
CONSUMER INFORMATION SHEET
This wood has been preserved by treatment with an EPA-registered
pesticide containing inorganic arsenic to protect it from insect attack
and decay. Wood treated with inorganic arsenic should be used only where
such protection is important.
Inorganic arsenic penetrates deeply into and remain in the pressure-
treated wood for a long time. Exposure to inorganic arsenic may present
certain hazards. Therefore, the following precautions should be taken
both when handling the treated wood and in determining where to use the
treated wood.
USE SITE PRECAUTIONS FOR INORGANIC ARSENICAL PRESSURE-TREATED WOOD
— Exposed wood pressure treated with waterborne arsenical
preservatives may be used inside residences as long as all
dust is vacummed from the wood surface.
— Do not use treated wood under circumstances where the preservative
may become a component of food or animal feed. Examples of such sites
would be structures or .containers for storing silage or food.
— Do not use treated wood for cutting boards or countertops.
-- Only treated wood that is visibly clean and free of surface residue
should be used for patios, decks and walkways.
— Do not use treated wood for construction of those portions of beehives
which may come into contact with the honey.
— Treated wood should not be used where it may come into direct or
indirect contact with public drinking water, except for uses involving
incidental contact such as docks and bridges.
HANDLING PRECAUTIONS FOR INORGANIC ARSENICAL PRESSURE-TREATED WOOD
— Dispose of treated wood by ordinary trash collection or burial.
Treated wood should not be burned, in open fires or in stoves or
fireplaces because toxic chemicals may be produced as part of the
smoke and ashes. Large quantities of treated wood from commercial
or industrial use (e.g., construction sites) may be burned in
commercial or industrial incinerators in accordance with state and
Federal regulations.
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Avoid frequent or prolonged inhalation of sawdust from treated wood.
When sawing and machining treated wood, wear a dusk mask. Whenever
possible, these operations should be performed outdoors to avoid
indoor accumulations of airborne sawdust from treated wood.
When power-sawing and machining, wear goggles to protect eyes from
flying particles. •
Wash exposed areas thoroughly after skin contact, and before eating,
drinking or use of tobacco products.
If preservatives or sawdust accumulates on clothes, launder before
reuse. Wash work clothes separately from other household clothing.
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VIII. MODIFICATIONS TO THE TERMS AND CONDITIONS OF REGISTRATION OF WOOD
PRESERVATIVE PRODUCTS J/
A. Upper Limits for Hexachlorodibenzo-p-dioxin (HxCDD) Contamination
In order to avoid cancellation, registrants of the wood preserving
chemicals technical pentachlorophenol and pentachlorophenol salts
must meet the following requirements within 30 days of publication
of the Final Notice of Determination concluding the Wood Preservatives
RPAR or within 30 days of receipt of such Notice, whichever occurs
later:
1. File an application to amend the Confidential Statements of
Formula (CSF) for products containing technical pentachlorophenol
or its salts to indicate that the HxCDD contamination does not
exceed 15 ppra, and that 2,3,7,8-TCDD is below the limits of
detection using a gas chromatography-mass spectrophotometry
method acceptable to the Agency (e.g., Buser and Bosshardt, 1976).
2. File an application to amend the Confidential Statements of
Formula for products containing technical pentachlorophenol or
its salts to indicate that, effective 18 months after publication
of the Notice or receipt by the registrant (whichever occurs
later), the HxCDD contamination does not exceed 1.0 ppm. (The
method used to lower HxCDD levels to 15 ppm or 1.0 ppm or lower
must not increase the hexachlorobenzene or the chlorinated
dibenzofuran levels above those in products marketed at the
time of publication of the PR Notice.)
B. Label Modifications
In order to avoid cancellation, registrants of the wood preserving
chemicals (inorganic arsenicals, pentachlorophenol and pentachlorophenol
salts, and creosote) must—file an amended application to modify the terms
and conditions of registration to include certain information on their product
labels.
The amended application must be filed within 30 days after publication
of the Final Notice of Determination concluding the Wood Preservative RPAR or
within 30 days of receipt of such Notice, whichever occurs later.
The labels must be amended for the various uses of the wood preserving
chemicals to include the following information.
The worker protection requirements specified in this document are estab-
lished pursuant to FIFRA, which provides no means of regulating occupational
safety and health hazards except insofar as they are directly associated
with the use of a registered pesticide. EPA has made no attempt to regulate
any workplace hazard except those associated with the use of pesticide
products containing creosote, pentachlorophenol (and its salts) and the
inorganic arsenicals as wood preservatives. EPA in developing these worker
protection requirements has only considered the hazards directly attributed to
the use of these pesticides.
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1. All uses of pentachlorophenol or pentachlorophenol salts
- The U.S. EPA has determined that pentachlorophenol can produce
defects in the offspring of laboratory animals. Exposure to
pentachlorophenol during pregnancy should be avoided.
2- All creosote, pentachlorophenol and inorganic arsenical products
which are used for the commercial pressure-treatment of wood
This pesticide product may not be used for treatment of wood or
wood products for sale or distribution unless the wood treater is
participating in or affiliated with a program adequate to inform
users of the treated wood of proper precautions to be taken in
handling and using such treated wood.
At a minimum wood treaters must:
a. distribute adequate consumer information sheets (CIS) with each
shipment of pressure-treated wood so that at least one CIS will be
securely attached to each bundle or batch of treated wood as it
leaves the treating plant;
b. attach at least one CIS to each invoice for sale of pressure-treated
wood;
c. make available to retailers, wholesalers and distributors an adequate
supply of CIS's and signs or placards to inform consumers of the
existence of the CIS's; and
d. encourage retailers to display signs or placards informing consumers
or the availability of the CIS's and to make the CIS's readily available
to the consumers.
The information which the United States Environmental Protection
Agency requires to be included in the CIS is found in the attached
labeling.
3. Pressure Treatment Uses for Inorganic Arsenicals
a. Restricted Use Pesticide:
For sale to and use only by certified applicators or by persons
under their direct supervision and only for those uses
covered by the certified applicator's certification.
b. Applicators must wear gloves impervious to the wood treatment
formulation in all situations where dermal contact is expected
(e.g., handling freshly treated wood and manually opening
cylinder doors).*
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c. Applicators who enter pressure treatment cylinders and other
related equipment that is contaminated with the wood treatment
solution (e.g., cylinders that are in operation or are not free
of the treatment solution) must wear protective clothing (including
overall, jacket, gloves and boots) impervious to the wood treatment
formulation.* In addition, employees who enter pressure-treatment
cylinders must wear properly fitting, well-maintained, high
efficiency filter respirators MSHA/NIOSH-approved for inorganic
arsenic if the level of inorganic arsenic in the plant is unknown
or exceeds 10 micrograms per cubic meter of air (10 ug/m^)
averaged over an 8-hour work period. Air monitoring programs,
procedures and record retention and submission must be conducted
in accordance with the instructions on the attached labeling
material.
d. Protective clothing must be changed when it shows signs of
contamination. Applicators must leave protective clothing and
workshoes or boots and equipment at the plant. Worn-out protec-
tive clothing and workshoes or boots must be left at the plant
and disposed of in a manner approved for pesticide disposal
and in accordance with State and Federal regulations.
e. Pesticide wastes are acutely hazardous. Improper disposal of
excess pesticide, spray mixture, or rinsate is a violation of
Federal law. If these wastes cannot be disposed of by use
according to label instructions, contact your State Pesticide or
Environmental Control Agency, or the Hazardous Waste representative
at the nearest EPA Regional Office for guidance.
f. Applicators must not eat, drink, or use tobacco products during
those parts of the application process that may expose them to
the wood treatment formulation (e.g., manually opening/closing
cylinder doors, moving trams out of cylinders, mixing chemicals,
and handling freshly treated wood).
g. Wash thoroughly after skin contact, and before eating, drinking,
use of tobacco products, or using restrooms.
h. A closed emptying and mixing system must be used for all powder
formulations of the inorganic arsenicals. A closed system is
defined as any containment which prevents the release of subject
chemicals into the surrounding external environment.
i. Processes used to apply inorganic arsenical formulations shall
leave no visible surface deposits on the wood, as defined by AWPA
Standard C-1 and AWPB Standards LP2 and LP22. (Visible surface
deposits means a. surface residue or crystallization on the
treated wood. Small isolated or infrequent spots or chemical
on otherwise clean wood shall be allowed.)
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j. Employees in the work area of an arsenical wood treatment plant
must wear properly fitting, well-maintained high efficiency
filter respirators MSHA/NIOSH-approved for inorganic arsenic if
the level of inorganic arsenic in the plant is unknown or exceeds
10 micrograms per cubic meter of air (10 ug/m3) averaged over
an 8-hour work period. Air monitoring programs, procedures and
record retention and submission must be conducted in accordance
with the instruction on the attached labeling material.
*Note to user: Examples of acceptable materials for protective clothing
(e.g., gloves, overalls, jackets, and boots) required during application and
handling of inorganic arsenicals are vinyl, polyvinylchloride (PVC), neoprene,
NBR (Buna-N), rubber and polyethylene.
ATTACHED LABELING
IMPLEMENTATION - Each arsenical wood treatment plant employer shall require
all employees potentially exposed to airborne inorganic arsenic to wear properly
fitting, well maintained high efficiency filter respirators MSHA/NIOSH-approved
for inorganic arsenic for the entire period that the employees are in the
treatment application work area or engaged in any activity associated with
the treatment process. Alternatively, to potentially relieve employees from
the burden of wearing respirators, the employer may implement a Permissible
Exposure Limit (PEL) monitoring program.
All wood treatment plant employers who elect to implement the PEL monitoring
program must determine the current levels of airborne arsenic, averaged over
an 8-hour period, to which their employees are exposed. Monitoring data
obtained one year prior to this implementation date may be used to determine
the initial levels of airborne exposure to employees, if the data were obtained
in the same manner as described below in the "Monitoring and Measurements
Procedures" section, and if the employer can certify that no changes have
been made since the time of monitoring that could have resulted in new or
additional employee exposure to inorganic arsenic including events on the
PEL Checklist (see PEL Checklist, below).
If the initial or subsequent monitoring demonstrates that airborne
inorganic arsenic in a work area is greater than 10 ug/m3, all employees
working in that area are required to wear properly fitting, well maintained
high efficiency filter respirators MSHA/NIOSH approved for inorganic arsenic.
If in subsequent monitoring, at least two consecutive measurements taken at
least seven (7) days apart, the inorganic arsenic levels are below 10 ug/m3,
employees in those areas may discontinue the wearing of the respirators,
except as discussed in the section "PEL Checklist" below. However, if the
employee exposure is above 5 ug/m3 and below 10 ug/m3, the employer shall
repeat monitoring at least every six months until at least two consecutive
measurements, taken at least seven days apart, are below 5 ug/m3. The employer
may then discontinue monitoring, except as discussed in the section "PEL
Checklist" (below).
*
If the monitoring reveals employees are exposed to airborne arsenic levels
below 5 ug/m3, monitoring need not be repeated, except as discussed in the
section "PEL Checklist" (below).
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PEL CHECKLIST - In all cases where there has been a change in production,
process, control, or employee handling procedures, or if any events in the
PEL Checklist occurred, or if for any other reason an employer should suspect
new or additional airborne inorganic arsenic, additional monitoring that
complies with the requirements for initial monitoring shall be completed.
Responses to the Checklist will become part of the monitoring records.
Monitoring is required within 2 months if any of the following events/questions
on the check list can be answered in the affirmative with respect to any
events which may have occurred since the last monitoring report submitted to
the Agency:
1. After the wood has been treated, have you changed from hand stacking
to mechanical stacking or from mechanical stacking to hand stacking?
If yes, when?
2. Has your production capacity increased significantly? If yes, when?
3. Have you changed from a ready-to-use or dilute concentrate to a mix-
it-yourself formulation? Has the proportional amount of arsenic in
the solution increased, e.g., have you shifted from CCA type A or C
to type B? If yes, when?
4. Has a significant, i.e., reportable under the "Comprehensive
Environmental Response, Compensation, and Liability Act of 1980"
(Superfund), 42 U.S.C. 9601 et seq., spill occurred? If yes, when?
5. Is treated wood being retained on the drip pad for less time? If
yes, wfien?
6. Have there been any other production, process, control or employee
handling procedure changes which could result in new or additional
airbone inorganic arsenic? Identify change, and when it occurred.
MONITORING AND MEASUREMENT PROCEDURES - The employer shall collect personal
air samples, including at least one sample which is adequate to represent
typical conditions for a full work shift (at least 7 hours) for each job
classification in each work area. Sampling should be done using a personal
sampling pump calibrated at a flow rate of 2 liters per minute. Samples
should be collected on 0.8 micrometer pore size membrane flter (37 mm diameter)
The method of sampling analysis should have an accuracy of not less than £25%
(with a confidence limit of 95%) for 10 micrograms per cubic meter of air
(10 ug/m3) and + 35% (with a confidence limit of 95%) for concentrations of
inorganic arsenic between 5 and 10 ug/m3.
Monitoring may be conducted through a request made to the Occupational
Safety and Health Administration (OSHA) for monitoring assistance which may
be provided free of charge under the terms of the OSHA consultation program
as provided under Section 7(c)(1) of the OSHA Act, or by employees or
contractors of the employer's choosing.
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The Environmental Protection Agency (EPA) may direct that remonitoring
take place at statistically selected establishments to assure that the Check-
list is effective in identifying events which increase airborne arsenic.
Selected employers will be notified by EPA/State enforcement representatives.
The employer will be responsible for obtaining current air monitoring data
within the time specified in the remonitoring notification and for submitting
these data and reports to the EPA as described below.
DATA SUBMISSION AND CERTIFICATION - The employer shall establish and maintain
accurate records which include responses to the PEL Checklist and all monitoring
reports. The annual records or copies thereof shall be submitted to the
U.S. Environmental Protection Agency
Office of Pesticides and Toxic Substances
Compliance Monitoring Staff (EN-342)
401 M Street, SW.
Washington, D.C. 20460
All records submitted will be certified by the employer as accurate and in
compliance with all calibration, analytical and sampling requirements outlined
in this program, if the employer received assistance from an OSHA 7(c)(1)
consultant, that consultant's report to the employer will be an acceptable
record of calibration, analysis, and monitoring requiring no additional
certi fic ation.
CONSUMER INFORMATION SHEET
This wood has been preserved by treatment with an EPA-registered pesticide
containing inorganic arsenic to protect it from insect attack and decay. Wood
treated with inorganic arsenic should be used only where such protection is
important.
Inorganic arsenic penetrates deeply into and remains in the pressure-treated
wood for a long time. Exposure to inorganic arsenic may present certain
hazards. Therefore, the following precautions should be taken both when
handling the treated wood and in determining where to use the treated wood.
USE SITE PRECAUTIONS FOR INORGANIC ARSENICAL PRESSURE-TREATED WOOD
~ Exposed wood pressure - treated with waterborne arsenical
preservatives may be used inside residences as long as all
dust is vacuumed from the wood surface.
— Do not use treated wood under circumstances where the preservative
may become a component of food or animal feed. Examples of such sites
would be structures or containers for storing silage or food.
— Do not use treated wood for cutting boards or countertops.
—- Only treated wood that is visibly clean and free of surface residue
should be used for patios, decks and walkways.
— Do not use treated wood for construction of those portions of beehives
which may come into contact with the honey.
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— Treated wood should not be used where it may come into direct or
indirect contact with public drinking water, except for uses involving
incidental contact such as docks and bridges.
HANDLING PRECAUTIONS FOR INORGANIC ARSENICAL PRESSURE-TREATED WOOD
— Dispose of treated wood by ordinary trash collection or burial.
Treated wood should not be burned in open fires or in stoves or
fireplaces because toxic chemicals may be produced as part of the
smoke and ashes. Large quantities of treated wood from commercial
or industrial use (e.g., construction sites) may be burned in
commercial or industrial incinerators in accordance with state and
Federal regulations.
— Avoid frequent or prolonged inhalation of sawdust from treated wood.
When sawing and machining treated wood, wear a dusk musk. Whenever
possible, these operations should be performed outdoors to avoid indoor
accumulations of airborne sawdust from treated wood.
— When power-sawing and machining, wear goggles to protect eyes from flying
particles.
—- Wash exposed areas thoroughly after skin contact, and before eating,
drinking or use of tobacco products.
— If preservatives or sawdust accumulate on clothes, launder before reuse.
Wash work clothes separately from other household clothing.
4. Pressure Treatment Uses for Creosote
a. Restricted Use Pesticide:
For sale to and use only by certified applicators or by persons
under their direct supervision and only for those uses covered by
the certified applicators' certification.
b. Applicators must wear gloves impervious to the wood treatment
formulation in all situations where dermal contact with creosote
is expected (e.g., handling freshly treated wood and manually
opening cylinder doors).*
c. Applicators who manually open cylinder doors must wear gloves and
a respirator.*
d. Applicators who enter pressure treatment cylinders and other
related equipment that is contaminated with the wood treatment
formulation (e.g., cylinders that are in operation or are not free
of the treatment formulation) must wear protective clothing
(including overalls, jacket, gloves and boots) impervious to the
wood treatment formulation and a respirator.*
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e. Pesticide wastes are toxic. Improper disposal of excess pesticide,
spray mixture, or rinsate is a violation of Federal law. If
these wastes cannot be disposed of by use according to label
instructions, contact your State Pesticide or Environmental
Control Agency, or the Hazardous Waste representative at the
nearest EPA Regional Office for guidance.
f. Protective clothing must be changed when it shows signs of
contamination. Applicators must leave protective clothing and
workshoes or boots and equipment at the plant. Worn-out protective
clothing and workshoes or boots must be left at the plant and
disposed of in any general landfill, in the trash, or in any
other manner approved for pesticide disposal.
g. Applicators must not eat, drink, or use tobacco products during
those parts of the application process that may expose them to the
wood treatment formulation (e.g., manually opening/closing
cylinder doors, moving trams out of cylinders, mixing chemicals,
and handling freshly treated wood),
h. Wash thoroughly after skin contact, and before eating, drinking,
use of tobacco products, or using restrooms.
*NOTE TO USER;
Respirators acceptable for use by applicators of creosote must be properly
fitting, well-maintained, half-mask canister or cartridge respirators
which are HSHA/NIOSH-approved for polynuclear aromatics and organic vapors.
Examples of acceptable materials for protective clothing (e.g., gloves,
overalls, jackets, and boots) required during application and handling of
creosote are polyvinyl acetate (PVA), polyvinyl chloride (PvC), neoprene,
and NBR (Buna-N).
CONSUMER INFORMATION SHEET
This wood has been preserved by pressure treatment with an EPA-registered
pesticide containing creosote to protect it from insect attack and decay.
Wood treated with creosote should be used only where such protection is
important.
Creosote penetrates deeply into and remains in the pressure-treated
wood for a long time. Exposure to creosote may present certain hazards.
Therefore, the following precautions should be taken both when handling
the treated wood and in determining where to use the treated wood.
USE SITE PRECAUTIONS FOR CREOSOTE PRESSURE-TREATED WOOD
— Wood treated with creosote should not be used where it will be
in frequent or prolonged contact with bare skin (for example,
chairs and other outdoor furniture), unless an effective sealer
has been applied.
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Creososte-treated wood should not be used in residential interiors.
Creosote-treated wood in interiors of industrial buildings should
only be used for wood-block flooring and industrial building
components which are in ground contact and are subject to decay or
insect infestation and where two coats of an appropriate sealer
are applied.
— Wood treated with creosote should not be used in the interiors
of farm buildings where there may be direct contact with domestic
animals or livestock which may crib (bite) or lick the wood.
— In interiors of farm buildings where domestic animals or livestock
are un^-ifceiy to crib (bite) or lick the wood, creosote-treated wood
may be used for building components which are in ground contact and
are subject to decay or insect infestation and where two coats of
an appropriate sealer are applied.
— Do not use creosote-treated wood for farrowing or brooding facilities.
— Do not use treated wood under circumstances where the preservative
may become a component of food or animal feed. Examples of such sites
would be structures or containers for storing silage or food.
— Do not use treated wood for cutting boards or countertops.
— Only treated wood that is visibly clean and free of surface residues
should be used for patios, decks, and walkways.
— Do not use treated wood for construction of those portions of beehives
which may come into contact with the honey.
— Creosote-treated wood should not be used where it may come
into direct or indirect contact with public drinking water, except
for uses involving incidental contact such as docks and bridges.
— Do not use creosote-treated wood where it may come into direct or
indirect contact with drinking water for domestic animals or livestock,
except for uses involving incidental contact such as docks and
bridges.
HANDLING PRECAUTIONS FOR CHEOSOTE PRESSURE-TREATEDWOOD
— Dispose of treated wood by ordinary trash collection or burial.
Treated wood should not be burned in open fires or in stoves or
fireplaces because toxic chemicals may be produced as part of the
smoke and ashes. Large quantities of treated wood from commercial
or industrial use (e.g., construction sites) may be burned in
commercial or industrial incinerators in accordance with state
and Federal regulations.
— Avoid frequent or prolonged inhalation of sawdust from treated wood.
When sawing and machining treated wood, wear a dusk mask. Whenever
possible, these operations should be performed outdoors to avoid
indoor accumulations of airborne sawdust from treated wood.
239
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-- Avoid frequent or prolonged akin contact with creosote-treated wood;
when handling the treated wood, wear tightly woven coveralls and use
gloves impervious to the chemicals (for example, gloves that are
vinyl-coated).
— When power-sawing and machining, wear goggles to protect eyes from
flying particles.
— Wash exposed areas thoroughly after skin contact/ and before
eating, drinking or use of tobacco products.
— If oily preservatives or sawdust accumulate on clothes, launder
before reuse. Wash work clothes separately from other household
clothing.
— Coal tar pitch and coal tar pitch emulsion are effective sealers
for creosote-treated wood-block flooring. Urethane, epoxy, and
shellac are acceptable sealers for all creosote-treated wood.
5. Pressure Treatment Uses for Pentachlorophenol
a. Restricted Use: For sale to and use only by certified applicators
or by persons under their direct supervision and only for those
uses covered by the certified applicators' certification.
b. Applicators must wear gloves impervious to the wood treatment
formulation in all situations where dermal contact is expected
(e.g., handling freshly treated wood and manually opening cylinder
doors).*
c. Applicators who manually open cylinder doors must wear gloves and
a respirator.*
d. Applicators who enter pressure treatment cylinders and other
related equipment that is contaminated with the wood treatment
formulation (e.g., cylinders that are in operation or are not
free of the treatment solution) must wear protective clothing
(including overalls, jacket, gloves and boots) impervious to the
wood treatment formulation and a respirator.*
e. pesticide wastes are toxic. Improper disposal of excess pesticide,
spray mixture, or rinsate is a violation of Federal law. If
these wastes cannot be disposed of by use according to label
instructions, contact your State Pesticide or Environmental
Control Agency, or the Hazardous Waste representative at the
nearest EPA Regional Office for guidance.
f. Protective clothing must be changed when it shows signs of con-
tamination. Applicators must leave protective clothing and
workshoes or boots and equipment at the plant. Worn-out protec-
tive clothing and workshoes or boots must be left at the plant
and disposed of in any general landfill, in the trash, or in any
other manner approved for pesticide disposal.
240
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9* Applicators must not eat, drink, or use tobacco products during
those parts of the application process that may expose them to the
wood treatment formulation (e.g., manually opening/closing
cylinder doors, moving trams out of cylinders, mixing chemicals,
and handling freshly treated wood).
h. Wash thoroughly after skin contact, and before eating, drinking,
use of tobacco products, or using restrooms.
i. Until August 31, 1987, a closed emptying and mixing system must
be used or protective clothing (including respirator, gloves and
tightly woven, long-sleeved cotton or disposable coveralls) must
be worn when emptying and mixing prilled or flaked formulations
of pentachlorophenol. After September 1, 1987, a closed system
must be used when emptying and mixing prilled or flaked formula-
tions of pentachlorophenol. A closed system is defined as any
containment which prevents the release of subject chemicals into
the surrounding external environment.
*NOTE TO OSER;
Respirators acceptable for use by applicators of pentachlorophenol must be
properly fitting, well-maintained, half-mask canister or cartridge respirators
which are MSHA/NIOSH-approved for organic vapors and acid gases.
Examples of acceptable materials for protective clothing (e.g., gloves,
overalls, jackets, and boots) required during application and handling of
pentachlorophenol are polyvinyl acetate (PVA), polyvinyl chloride (PVC),
neoprene, NBR (Buna-N), and nitrile. In addition, plastic-coated disposable
coveralls impervious to dust are acceptable for dust protection.
CONSUMER INFORMATION SHEET
This wood has been preserved by treatment with an EPA-registered pesticide,
containing pentachlorophenol, to protect it from insect attack and decay.
Wood treated with pentachlorophenol should be used only where such pro-
tection is important.
Pentachlorophenol penetrates deeply into and remains in the pressure-
treated wood for a long time. Exposure to pentachlorophenol may present
certain hazards. Therefore, the following precautions should be taken
both when handling the treated wood and in determining where to use the
treated wood.
USE SITE PRECAOTIOliS FOR PEMTACHLOROPHENOL PRESSURE-TREATED WOOD
— Wood treated with pentachlorophenol should not be used
where it will be in frequent or prolonged contact with bare skin
(for example, chairs and other outdoor furniture), unless an
effective sealer has been applied.
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— Pentachlorophenol-treated wood should not be used in residential,
industrial, or commercial interiors except for laminated beams or
building components which are in ground contact and are subject to
decay or insect infestation and where two coats of an appropriate
sealer are applied.
— Wood treated with pentachlorophenol should not be used in the
interiors of farm buildings where there may be direct contact with
domestic animals or livestock which may crib (bite) or lick the
wood.
— In interiors of farm buildings where domestic animals or livestock
are unlikely to crib (bite) or lick the wood, pentachlorophenol-
treated wood may be used for building components which are in ground
contact and are subject to decay or insect infestation and where
two coats of an appropriate sealer are applied.
— Do not use pentachlorophenol-treated wood for farrowing or brooding
facilities.
— Do not use treated wood under circumstances where the preservative
may become a component of food or animal feed. Examples of such sites
would be structures or containers for storing silage or food.
— Do not use treated wood for cutting boards or countertops.
— Only treated wood that is visibly clean and free of surface residue
should be used for patios, decks and walkways.
— Do not use treated wood for construction of those portions of beehives
which may come into contact with the honey.
— Pentachlorophenol-treated wood should not be used where it may come
into direct or indirect contact with public drinking water, except
, for uses involving incidental contact such as docks and bridges.
— Do not use pentachlorophenol-treated wood where it may come into
direct or indirect contact with drinking water for domestic animals
or livestock, except for uses involving incidental contact such as
docks and bridges.
HANDLING PRECAUTIONS FOR PENTACHLOROPHENOL PRESSURE-TREATED WOOD
— Dispose of treated wood by ordinary trash collection or burial.
Treated wood should not be burned in open fires or in stoves or
fireplaces because toxic chemicals may be produced as part of the
smoke and ashes. Large quantities of treated wood from commercial
or industrial use (e.g., construction sites) may be burned in
commercial or industrial incinerators in accordance with state and
Federal regulations.
242
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— Avoid frequent or prolonged inhalation of sawdust from treated wood.
When sawing and machining treated wood, wear a dusk mask. Whenever
possible, these operations should be performed outdoors to avoid
indoor accumulations of airborne sawdust from treated wood.
— Avoid frequent or prolonged skin contact with pentachlorophenol-
treated wood; when handling the treated wood, wear tightly
woven coveralls and use gloves impervious to the chemicals (for
example, gloves that are vinyl-coated).
— When power-sawing and machining, wear goggles to protect eyes from
flying particles.
— Wash exposed areas thoroughly after skin contact, and before
eating, drinking or use of tobacco products.
—- If oily preservatives or sawdust accumulates on clothes, launder
before reuse* Wash work clothes separately from other household
clothing.
— Urethane, shellac, latex epoxy enamel and varnish are acceptable
sealers for pentachlorophenoI-treated wood.
6. Groundline Treatment of Poles with Creosote and Pentachlorophenol
a. Restricted Use Pesticide: For sale to and use only by certified
applicators or by persons under their direct supervision and
only for those uses covered by the certified applicators'
certification.
b. Applicators must wear gloves impervious to the wood treatment
formulations (e.g., polyvinyl acetate, polyvinyl chloride or
neoprene) in all situations where dermal contact is expected
(e.g., during the actual application process and when handling
freshly treated wood).*
c. Applicators must wear disposable coveralls (eeg., nitrile or
neoprene for creosote; nitrile or polyethylene for pentachloro-
phenol) or other suitable impermeable protective clothing during
the application and mixing processes and all situations where
dermal contact is expected.
d. Protective clothing must be changed when it shows signs of
contamination. Launder non-disposable protective clothing
separately from other household clothing. Dispose of worn-out
protective clothing and workshoes or boots in any general
landfill, in the trash, or in any other manner approved for
pesticide disposal.
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e. Pesticide wastes are toxic. Improper disposal of excess
pesticide, spray mixture, or rinsate is a violation of Federal
law. If these wastes cannot be disposed of by use according to
label instructions, contact your State Pesticide or Environmental
Control Agency, or the Hazardous waste representative at
the nearest EPA Regional office for guidance.
f. Applicators must not eat, drink, or use tobacco products during
those parts of the application process that may directly expose
them to the wood treatment formulation.
g. Wash thoroughly after skin contact, and before eating, drinking,
use of tobacco products or using restrooms.
7* Home and Farm Uses (Including Railroad Tie Repair) of Creosote-Restricted
Use
a. RESTRICTED USE PESTICIDE: For sale to and use only by certified
applicators or persons under their direct supervision and only for
those uses covered by the certified applicators' certification.
b. Applicators must wear gloves impervious to the wood treatment
formulation in all situations where dermal contact is expected
(for example, during the actual application process and when
handling freshly treated wood).
c. Spray applicators must wear protective clothing (including
overalls, jackets, gloves and boots) impervious to the wood
treatment formulation, and a respirator,* head covering, and
goggles when spraying.
d. Applicators who apply creosote by other application processes
(e.g., brush-on) must wear disposable coveralls or other suitable
impermeable protective clothing.* Launder non-disposable pro-
tective clothing separately from other clothing.
e. Protective clothing must be changed when it shows signs of
contamination. Dispose of worn-out protective clothing and
workshoes or boots in a general landfill, in the trash, or in
any other manner approved for pesticide disposal.
f. For products for farm use or for railroad tie repair farm use:
Pesticide wastes are toxic. Improper disposal of excess
pesticide, spray mixture, or rinsate is a violation of Federal
Law. If these wastes cannot be disposed of by use according
to label instructions, contact your State Pesticide or Environ-
mental Control Agency, or the Hazardous Waste representative
at the nearest EPA Regional Office for guidance.
For household domestic use products: Securely wrap original
pesticide container in several layers of newspaper and discard
in the trash. Do not reuse empty container.
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g. Applicators must not eat, drink, or use tobacco products those
parts of the application process that may expose them to the
treatment formulation.
h. Wash thoroughly after skin contact, and before eating, drinking,
use of tobacco products, or using restrooms.
i. Avoid inhaling vapors. If inhalation of vapors cannot be
avoided, applicators must wear a properly fitting, well-
maintained half-mask canister or cartridge respirator which is
MSHA/ NIOSH - approved for pclynuclear aromatics and organic
vapors.
j. Do not apply where there may be direct contact with domestic
animals or livestock, and where there may be contamination of
food, feed, or drinking and irrigation water.
k. Do not apply in interiors. Do not apply to wood intended for
use in interiors except for those support structures which are
in contact with the soil in barns, stables, and similar sites
and which are subject, to decay or insect infestation. Interior
surfaces of the treated wood should be sealed with two coats of
an appropriate sealer.
1. Do not apply creosote to wood intended for farrowing or brood-
ing facilities. Do not apply creosote to wood intended to be
used in the interiors of farm buildings where there may be
direct contact with domestic animals or livestock which may
crib (bite) or lick the wood. Creosote may be used to treat
wood intended to be used in interiors of farm buildings where
domestic animals or livestock are unlikely to crib or lick the
wood, if two coats of an appropriate sealer will be applied.
m. Do not apply wood intended to be used in a manner in which
the preservative may become a component of food or animal
feed. Examples of such sites would be structures or containers
for storing silage or food.
n. Do not use this product to treat wood intended to be used
for cutting boards or counter tops.
o. Do not use this product to treat wood intened for construction
of those portions of beehives which may come into contact with
the honey.
p< Do not use this product to treat wood intended to be used
where it may come into direct or indirect contact with public
drinking water, except for those uses involving incidential
contact such as docks and bridges.
q. Do not use this product to treat wood intended to be used where
it may come into direct or indirect contact with drinking
245
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water for domestic animals or livestock, except for uses involving
incidental contact such as docks and bridges.
r. Wood to be treated with this product should be cut to size
before treatment. If it is necessary to saw or machine
wood after treatment, wear goggles to protect the eyes from
flying particles and a dust mask to avoid inhaling sawdust
from the treated wood. If oily preservatives or sawdust
accumulate on clothes, launder before reuse. Wash work clothes
separately from other household laundry.
s. Contact with treated surfaces should be avoided even after
the preservative has dried. When handling treated wood
wear tighly woven coveralls and gloves which are impervious
(e.g., vinyl coated) to the pesticide. Wash exposed skin
thoroughly after contact with treated wood and before eating,
drinking or using tobacco products.
t. Wood which has been treated with this product should be
disposed of by burial or ordinary trash collection. Do
not burn treated wood in an outdoor fire or in stoves or
fireplaces because toxic chemicals may be produced as part of
the smoke and ashes.
u. This product should not be used to treat wood which will
be in frequent or prolonged contact with skin, unless the
wood will be treated with an effective sealer.
*NOTE TO USER;
Respirators acceptable for use by applicators of creosote must be properly
fitting, well-maintained, half-mask canister or cartridge respirators which
are MSHA/NIOSH-approved for polynuclear aromatics and organic vapors.
Examples of acceptable materials for protective clothing (e.g., gloves,
overalls, head covering, jackets, and boots) required during application and
handling of creosote are polyvinyl acetate (PVA), polyvinyl chloride (PVC),
neoprene, and NBR (Buna-N). in addition to these materials, nitrile is also
acceptable for disposable coveralls.
Urethane, exoxy, and shellac are acceptable sealers for all creosote-treated
wood.
8. Home and Farm Uses (Including Railroad Tie Repair) of Pentachlorophenol
(Restricted Use)
a. RESTRICTED USE PESTICIDE; For retail sale to and use only by
certified applicators or persons under their direct supervision
and only for those uses covered by the certified applicators'
certification.
b. Applicators must wear gloves impervious to the wood treatment
formulation in all situations where dermal contact is expected
246
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(for example, during the actual application process and when
handling freshly treated wood).
c. Spray applicators must wear protective clothing (including overalls,
jackets, gloves and boots) impervious to the wood treatment
formulation, and a respirator, head covering, and goggles
when spraying.*
d. Applicators who apply pentachlorophenol by other application
methods (e.g., brush-on) must wear disposable coveralls or other
suitable impermeable protective clothing.* Launder non-dispos-
able protective clothing separately from other clothing.
e. Protective clothing must be changed when it shows signs of
contamination. Dispose of worn-out protective clothing and work-
shoes or boots in any general landfill, in the trash, or in any
other manner approved for pesticide disposal.
f. For products for farm use or railroad tie repair:
Pesticide wastes are toxic. Improper disposal of excess
pesticide, spray mixture, or rinsate is a violation of Federal
Law. If these wastes cannot be disposed of by use according
to label instructions, contact your State Pesticide or Environ-
mental Control Agency, or the Hazardous Waste representative
at the nearest EPA Regional Office for guidance.
For household/domestic use products: Securely wrap original
pesticide container in several layers of newspaper and discard in
the trash. Do not use empty container.
g. Applicators must not eat, drink, or use tobacco products during
those parts of the application process which may expose them to
the treatment formulation.
h. Wash thoroughly after skin contact, and before eating, drinking,
use of tobacco products, or using restrooms.
i. Avoid inhaling vapors. If inhalation of vapors cannot be avoided,
applicators must wear a properly fitting, well-maintained half-mask
cannister or cartridge respirator which is MSHA/NIOSH approved
for organic vapors and acid gases.
j. Do not apply where there may be direct contact with domestic animals
or livestock, and where there may be contamination of food, feed,
or drinking and irrigation water.
k. Do not apply in interiors. Do not apply to wood intended for use
in interiors except for those support structures which are in
contact with the soil in barns, stables, and similar sites and
which are subject to decay or insect infestation; and millwork
which has outdoor surfaces (e.g., doorframes, windows and patio
frames). Interior surfaces of the treated wood should be sealed
with two coats of an appropriate sealer.
247
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1. Do not apply pentachlorophenol to wood intended for farrowing or
brooding facilities. Do not apply pentachlorophenol to wood
intended to be used in the interiors of farm buildings where
there may be direct contact with domestic animals or livestock
which may crib (bite) or lick the wood. Pentachlorophenol may be
used to treat wood intended to be used in interiors of farm buildings
where domestic animals or livestock are unlikely to crib or lick
the wood, if two coats of an appropriate sealer will be applied.
m. Do not apply to wood intended to be used in a manner in which the
preservative may become a component of food or animal feed.
Examples of such sites would be structures or containers for
storing silage or food.
n. Do not use this product to treat wood intended to be used
for cutting boards or counter tops.
o. Do not use this product to treat wood intended for construction of
those portions of beehives which may come into contact with the
honey.
p. Do not use this product to treat wood intended to be used where
it may come into direct or indirect contact with public drinking
water, except for those uses involving incidental contact such
as docks and bridges.
q. Do not use this product to treat wood intended to be used where
it may come into direct or indirect contact with drinking water
for domestic animals or livestock, except for uses involving
incidental contact such as docks and bridges.
r. Wood to be treated with this product should be cut to size before
treatment. If it is necessary to saw or machine wood after
treatment, wear goggles to protect the eyes from flying particles
and a dust mask to avoid inhaling sawdust from the treated wood.
If oily preservatives or sawdust accumulate on clothes, launder
before reuse. Wash work clothes separately from other household
laundry.
s. Contact with treated surfaces should be avoided even after the
preservative'has dried. When handling treated wood wear tightly
woven coveralls and gloves which are impervious (e.g., vinyl
coated) to the pesticide. Wash exposed skin thoroughly after
contact with treated wood, and before eating, drinking or using
tobacco products.
t. Wood which has been treated with this product should be disposed
by burial or ordinary trash collection. Do not burn treated
wood in an outdoor fire or in stoves or fireplaces because
toxic chemicals may be produced as part of the smoke and ashes.
248
-------
u. This product should not be used to treat wood which will be in
frequent or prolonged contact with skin, unless the wood will be
treated with an effective sealer.
*MOT1 TO USER;
Respirators acceptable for use by applicators of pentachlorophenol must be
properly fitting, well-maintained half-mask canister or cartridge respirators
which are MSHA/NIOSH-approved for organic vapors and acid gases.
Examples of acceptable materials for protective clothing (e.g., overalls,
jackets, head covering, boots, disposable coveralls, and gloves) required
during application and handling of pentachlorophenol are polyvinyl acetate
(PVA), polyvinyl chloride (PVC), neoprene, NBR (Buna-N), and nitrile.
Urethane, shellac, latex epoxy enamel and varnish are acceptable sealers for
pentachlorophenol-treated wood.
9- Brush-On Treatments of Inorganic Arsenicals (Unclassified Use)
a. Applicators must wear gloves (e.g., rubber, vinyl or neoprene)
impervious to the wood treatment solution in all situations
where dermal contact is expected (e.g., during the application
process and handling freshly treated wood).
b. Applicators must wear disposable coveralls (e.g., vinyl or
polyethylene) or other similar impermeable clothing during the
application process where dermal contact is expected.
c. Applicators must no't eat, drink, or use tobacco products during
those parts of the application process that may directly expose
them to the treatment solution.
d. Wash thoroughly after skin contact, and before eating, drinking,
use of tobacco products, or using restrooms.
e. Protective clothing must be changed when it shows signs of
contamination. Launder non-disposable protective clothing
separately from other household clothing. Dispose of worn-out
protective clothing in a manner approved for pesticide disposal
and in accordance with State and Federal regulations.
f. Pesticide wastes are acutely hazardous. Improper disposal of
excess pesticide, spray mixture, or rinsate is a violation of
Federal law. If these wastes cannot be disposed of by use
according to label instructions, contact your State Pesticide
or Environmental Control Agency, or the Hazardous Waste
representative at the nearest EPA Regional Office for guidance.
g. For application to the cut ends of pressure-treated wood
only. Do not dilute or mix with other products.
h« For commercial construction use only. Not for household use.
249
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10. Sapstain Use of Sodium Pentachlorophenol Salts
a. RESTRICTED USE PESTICIDE; For retail sale to and use only by
certified applicators or persons under their direct supervision
and only for those uses covered by the certified applicator's
certification.
b. All applicators must wear gloves* impervious to the wood treatment
formulation in all situations where dermal contact is expected
(for example, during the application process and when handling
freshly treated wood).
c. Until August 31, 1987, a closed emptying and mixing system must
be used or protective clothing (including respirator, gloves and
tightly woven, long-sleeved cotton or disposable coveralls) must
be worn when emptying and mixing powder formulations of penta-
chlorophenate. After September 1, 1987, a closed system must be
used when emptying and mixing powder for formulations of penta-
chlorophenate. A closed system is defined as any containment
which prevents the release of subject chemicals into the surround-
ing external environment.
d. For the spray method of application: spray apparatus must (1) be
operated so as to minimize overspray (i.e., no visible mist) and
(2) be free of leaks in the system, should there be a visible mist,
spray applicators in the vicinity of the apparatus (the zone in
which the mist is visible) must wear a respirator* and protective
clothing (including overalls, jackets, boots, head covering
impervious to the wood treatment formulation, and goggles).*
e. Individuals who enter, clean, or repair vats, tanks or other
related equipment that is contaminated with the treatment solution
must wear a respirator. In addition, where dermal contact is
expected, these individuals must wear overalls, jackets, boots,
head covering impervious to the wood treatment formulation and
goggles.*
f. Protective clothing must be changed when it shows signs of con-
tamination. Applicators must leave all protective clothing,
workshoes or boots, and equipment at the plant. Worn-out protec-
tive clothing, and workshoes or boots, must be left at the
plant and disposed of in any general landfill, in the trash, or
in any other manner approved for pesticide disposal.
g. Pesticide wastes are toxic. Improper disposal of excess pesticide,
spray mixture, or rinsate is a violation of Federal law. If
these wastes cannot be disposed of by use according to label
instructions, contact your State Pesticide or Environmental
Control Agency, or the Hazardous Waste representative at the
nearest EPA Regional Office for guidance.
250
-------
h. Applicators must not eat, drink, or use tobacco products during
those parts of the application process which may expose them to
the treatment formulation.
i. Wash thoroughly after skin contact, and before eating, drinking,
use of tobacco products, or using restrooms.
*MOTE TO USER;
Respirators acceptable for use by applicators of sodium pentachlorophenate
must be properly fitting, well-maintained half-mask canister or cartridge
respirators which are MSHA/NIOSH-approved for organic vapors.
Examples of acceptable materials for protective clothing (e.g., overalls,
jackets, head covering, boots, disposable coveralls, and gloves) required
during application and handling of sodium pentachlorophenate are polyvinyl
acetate (PVA), polyvinyl chloride (PVC), neoprene, and NBR (Buna-N), and
nitrile.
11. Non-Pressure Treatment Plant Dip/Flow and Spray Uses of Pentachlorophenol
a. RESTRICTED USE PESTICIDE; For sale to and use only by certififed
applicators or persons under their direct supervision and only for
those uses covered by the certififed applicator's certification.
b. Applicators must wear gloves impervious to the wood treatment
formulation in all situations where dermal contact is expected
(for example, during the application process and when handling
freshly treated wood).*
c. Until August 31, 1987, a closed emptying and mixing system must
be used or protective clothing (including respirator, gloves and
tightly woven, long-sleeved cotton or disposable coveralls) must
be worn when emptying and mixing prilled or flaked formulations
of pentachlorophenol. After September 1, 1987, a closed system
must be used when emptying and mixing prilled or flaked formula-
tions of pentachlorophenol. A closed system is defined as any
containment which prevents the release of subject chemicals into
the surrounding external environment.
d. For the spray method of application: spray apparatus must (1) be
operated so as to minimize overspray (i.e., no visible mist) and
(2) be free of leaks in the system. Should there be a visible mist,
spray applicators in the vicinity of the apparatus (the zone in
which the mist is visible) must wear a respirator* and protective
clothing (including overalls, jackets, boots, head covering
impervious to the wood treatment formulation, and goggles).*
e. Individuals who enter, clean, or repair vats, tanks or other
related equipment that are contaminated with the treatment solution
must wear a respirator. In addition, where dermal contact is
expected, these individuals must wear overalls, jackets, boots,
head covering impervious to the wood treatment formulation and
goggles.*
251
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f. Protective clothing must be changed when it shows signs of
contamination. Applicators must leave all protective clothing,
workshoes or boots, and equipment at the plant. Worn-out pro-
tective clothing, and workshoes or boots, must be left at the
plant and disposed of in any general landfill, in the trash, or
in any other manner approved for pesticide disposal.
g. Pesticide wastes are toxic, improper disposal of excess pesticide,
spray mixture, or rinsate is a violation of Federal law. If
these wastes cannot be disposed of by use accoring to label
instructions, contact your State Pesticide or Environmental
Control Agency, or the Hazardous Waste representative at the
nearest EPA Regional Office for guidance.
h. Applicators should not eat, drink, or use tobacco products
during those parts of the application process which may
expose them to the treatment formulation.
i. Wash thoroughly after skin contact, and before eating, drinking,
use of tobacco products, or using restrooms.
j. Do not apply to logs which are intended for use in construction
of log homes.
*HOTE TO THE USER;
Respirators acceptable for use by applicators of pentachlorophenol must be
properly fitting, well-maintained half-mask canister or cartridge respirators
which are MSHA/NIOSH-approved for organic vapors and acid gases. Examples
of acceptable materials for protective clothing (e.g., overalls, jackets,
head covering, boots, disposable coveralls, and gloves) required during
application and handling of pentachlorophenol are polyvinyl acetate (PVA),
polyvinyl chloride (PVC), neoprene, and NBR (Buna-N), and nitrile. In addition,
plastic-coated disposable coveralls impervious to dust are acceptable for
dust protection.
C. Data Requirements.
In an action separate from this PD4, registrants will be required to
submit certain data within 90 days after notification to maintain existing
registrations in effect pursuant to FIFRA Section 3(c)(2)(B).
1. Registrants of products containing technical pentachlorophenol or
its salts will be required to submit the following:
a. A description of the starting materials, manufacturing process
and reaction conditions including any steps to reduce HxCDD.
b. Information on product identity relative to identification of
ingredients, statement of composition and a discussion of the
formation of impurities.
252
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c. Data on the analysis and certification of product ingredients
relative to preliminary analysis, certification of limits, and
analytical methods for the enforcement of limits. An analytical
method employing combined gas chromatography and mass spectro-
phatometry is acceptable (e.g., Buser and Bosshardt, 1976).
d. HxCDD analyses every three months, the first analysis to be
submitted within the stated 90 day period.
e. A description of any changes in the manufacturing process used
to lower HxCDD to 15 ppm and/or 1.0 ppm or lower must also be
submitted within the stated time period of 90 days. The methods
used to lower HxCDD must not increase the chlorinated dibenzo-
furans and HCB contaminants above the levels in products marketed
at the time of publication of the FR Notice.
f. Information on the technical feasibility and costs of reducing
HxCDD contamination further than the 1.0 ppm upper limit.
2* Registrants of creosote will be required to submit the following:
a. Epidemiology study on workers at creosote treatment plants.
b. Mr monitoring and dermal exposure data from creosote treatment
plants.
3. Registrants of creosote and arsenic will be required to submit
the following:
a. Data on permeability of glove and protective clothing materials
indicating degree of protection for creosote and inorganic
arsenical formulations.
4. Registrants of bis (tri-n-butyltin) oxide, copper-8-quinolinolate,
copper-naphthenate, acid copper chromate, chromated zinc chloride,
sodium tetrachlorophenate, zinc naphthenate 3-iodo-2-propynyl butyl-
carbamate, and barium metaborate will be required to submit the
following:
a. Chronic feeding studies
b. Oncogenicity studies
c. Reproduction studies
d. Teratology studies
5. Registrants of pentachlorophenol will be required to submit dermal
and inhalation exposure data on the home and farm spray application
of pentachlorophenol.
253
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Comments on the PD 2/3 and April 14, 1983 Public Meeting
Allied Chemical, Morristown, NJ. July 21, 1983. 79(30000/280
American Institute of Timber Construction, Englewood, CO. April 9, 1981.
10(30000/280
American Wood Preservers Institute, Mclean, VA. May 20, 1981. 36A(30000/28C)
American Wood Preservers Institute, McLean, VA. and National Forest Products
Association, Washington, D.C. May 20, 1981. 36B(30000/28C)
American Wood Preservers Institute, McLean, VA. May 20, 1981. 36C(30000/28C)
American Wood Preservers Institute, Mclean, VA. c/o Steptoe and Johnson,
Washington, D.C. May 29, 1981. 36D(30000/28C)
American Wood Preservers Institute, McLean, VA. c/o Steptoe and Johnson
Washington, D.C. June 10, 1981. 36E(30000/28O
American Wood Preservers Institute, McLean, VA. and National Forest Products
Association, Washington, D.C. c/o Steptoe and Johnson, June 12, 1981.
36F(30000/28C)
American Wood Preservers Institute, McLean, VA, c/o Steptoe and Johnson,
Washington, D.C. August 31, 1981. 36G(30000/28O
American Wood Perservers Institute, McLean, VA. February 9, 1982.
36H(30000/28C)
American Wood Perservers Institute, Society of American Wood Preservers, Inc.,
and National Forest Products Association. February 15, 1982. 36K30000/28C)
American Wood Perservers Institute, Society of American Wood Preservers,
Inc. National Forest Products Association. February 24, 1983. 36J(30000/28O
American Wood Preservers Institute, McLean, VA. July 14, 1983. 78(30000/280
American Wood Preservers Institute, McLean, VA. August 23, 1983. 81(30000/280
American Wood Preservers Institute, McLean, VA. November 14, 1983. 84(30000/28c)
American Wood Preservers Institute, McLean, VA. Jan. 30, 1984. 86(30000/280
American Wood Preservers Institute, Vienna, Va. March 21, 1984. 88(30000/280
Arneson Timber Company, Steeville, MO. May 15, 1981. 46(30000/280
254
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Association of American Railroads, Washington, DC. May 20, 1981. 34(30000/280)
Association of American Railroads, Washington, DC. June 24, 1981. 71(30000/280
Burdell, Charles, A., Spartanburg, SC. September 6, 1983. 82(30000/280)
C.A. Niece Company, Lambertville, N.J. April 24, 1981. 19(30000/280
California Division of Occupational Safety and Health, April 25, 1983.
San Francisco, CA. 67(30000/280
Carson's Hardware, Hellertown, PA. May 12, 1981. 29(30000/280
Ceder Fence Distributors Company, Inc., Greenbrook, N.J. April 16, 1981.
9(30000/280
Center for Disease control, public Health Service, Atlanta, GA. May, 1983.
69(30000/280
Consumers Power Company, Jackson, MI. May 14, 1981. 3K30000/28C)
Coopers Creek Chemical Corporation, West Conshohocken, PA. April 6, 1981.
4(30000/28C)
Department of the Army, Kingsport, TH. March 5, 1981. K30000/28C)
Detroit Idison, Detroit, MI- May 18, 1981. 40(30000/280
Dow Chemical Company, Midland, NJ. May 15, 1981. 32(3000/280
Doylestown Lumber and Millwork, Doylestown, PA. April 22, 1981. 18(30000/280
Dries Building Supply Co., Macungie, PA. April 20, 1981. 1K30000/28C)
Ecological and Speciality Products, Paterson, NJ. May 12, 1981.
47(30000/280
Edison Electric Institute, Washington, DC. May 20. 1981. 35(30000/280
Friends of the Earth, Washington, DC. June 30, 1981. 55(30000/280
Friends of the Earth, Washington, DC. May 11, 1983. 64(30000/280
255
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Friends of the Earth, Washington, DC. May 19, 1983. 70(30000/280
GAF Supply Center, Baltimore, MD. May 5, 1981. 2K30000/28C)
Georgia Department of Agriculture, Atlanta, GA. May 5, 1983. 62{30000/2SC)
Gibson-Homans Company, Twinsburg, OH. April 2, 1981. 3(3000/28C)
G.M., Deck & Sons, Amber, PA. May 18, 1981. 45(30000/280
Good-Life, Inc., Effingham, IL. April 17, 1981- 58(30000/280
Hatboro Lumber & Fuel Co., Hatboro, PA. April 21, 1981. 16(30000/280
Health Research Group, Washington, DC. May 4, 1983. 65(30000/280
Herric & Smith, c/o Samuel Cabot Inc., Washington, DC. May 22, 1981.
38(30000/280
Illinois Power Co., Decatur, IL. April 6, 1981. 5(30000/280
International Woodworkers of America, Local 38, Shelton, WA. May 12, 1983.
63(30000/280
International Woodworkers of America, Portland, OR. April 29, 1983.
68(30000/280
Iowa-Illinois Gas & Electric Co., Davenport, IA. June 4, 1981.
50(30000/280
J.H. Baxter & Co., San Mateo, CA. July 11, 1983. 76(30000/280
James Haggis & Sons, Maiden, MA. May 6, 1981. 57(30000/280
Jenison-Wright Corporation, Toledo, OH. May 15, 1981. 37(30000/280
Kerr-McGee Company, Oklahoma City, OK. May 15, 1981. 33(30000/280
Koppers Company, Pittsburgh, PA. July 13, 1983. 72(30000/280
Koppers Company, Pittsburgh, PA. July 13, 1983. 77(30000/280
Koppers Company, Pittsburgh, PA. December 12, 1983. 85(30000/280
Koppers Company, Pittsburgh, PA. November 15, 1983. 89(30000/28C)
Levin, H., University of California, May 9, 1983. 60(30000/280
Lloyd H. Daub, Inc=, Bridgeport, PA. April 16, 1981. 15(30000/280
Louisiana-Pacific Corp., Red Bluff, CA. May 17, 1981. 43(30000/280
256
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Louisiana-Pacific Corp., Samoa, CA. July 7, 1983. 73(30000/280)
McFarland Cascade, Sandpoint, ID. July 6, 1983. 74(30000/280
McPhillips Manufacturing Co., Mobile, AL. June 3, 1981. 49(30,000/280
Michlin Chemical Corporation, Detroit, MI. May 8, 1981. 25(30000/280
Michlin Chemical Corporation, Detroit, MI. May 5, 1981. 25A(30000/28C)
Missouri Department of Agriculture, May, 18, 1981. 25A(30000/28C)
Missouri Forest Products Assoc., Jefferson City, MO. May 19, 1981.
39(30000/28C)
Monona Grove Clinic, Madison, WI. May 11, 1981. 27(30000/280
Monsey Products, Kimberton, PA. May 7, 1981. 23(30000/280
National Forest Products Association, Washington, DC. July 11, 1983.
75(30000/280
National Paint Center, Lansdale, PA. April 15, 1981. 7(30000/280
National Solvent Corporation,.Medina, OH. April 10, 1981. 6(30000/280
National Woodworks, Inc., Birmingham, AL. May 6, 1981. 24(30000/280
Nebraska Cooperative Extension Service, Lincoln, NE. June 12, 1981.
5K30000/28C).
N.Y. Power Pool, Schenectady, NY. May 20, 1981. 30(30000/280
Niagara Mohawk Power Corp, Syracuse, NY. May 20, 1981. 42(30000/280
OSMOSE, Buffalo, NY. May 18, 1981. 4K3000Q/28C)
OSMOSE, Buffalo, NY, April 27, 1983. 61(30000/280
Philadelphia Reserve Supply Company, Croyden, PA. April 24, 1981. (17:30000/28C)
Portland Cement Association, Skokie, IL. May 4, 1981. 26(30000/280
Portland Cement Association, Skokie, IL. May 6, 1983. 66(30000/28C)
Publishers Paper, Oregon City, OR. June 23, 1981. 54(30000/280
RAECO Products, Rochester, NY. April 30, 1981. 22(30000/28C)
Reichold Chemicals, Inc. and Vulcan Materials Company, c/o Paul Hastings,
Janofsky and Walker, Washington, DC. June 3, 1983. 83(30000/28C)
Reliance Company, Brood Brook, CT. May 15, 1981. 59(30000/280
257
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Roberts Consolidated Industries, Kalamazoo, MI. April 24, 1981. 20(30OOO/28C)
Sampson Paint Manufacturing Company, Inc., Richmond, VA. April 16, 1981.
12(30000/28C)
Sentinel Wood Treating, Inc., Ashland, MO. March 18, 1981. 2(30000/28C)
Seymour Chemicals Inc., Bannockburn, IL. June 3, 1981. 52(30000/280
Society of American Wood Preservatives, Arlington, VA. June 15, 1981.
53(30000/280
Soult Wholesales Company, Clearfield, PA. April 16, 1981. 8(30000/280
Standard Concrete Company, York, PA. April 15, 1981. 13(30000/280
State of California, Department of Health Services. October 19, 1983.
87(30000/280
Structural Wood Systems, Greenville, AL. April 17, 1981. 14(30000/280
U.S. Department of Energy, Washington, DC. May 20, 1981. 44(30000/280
Walpole Woodworkers, Walpole, MA. May 11, 1981. 56(30000/280
Weyerhaeuser Company, Tacoma, WA. June 1, 1981. 48(30000/280
Witco Chemical, New York, NY. July 28, 1983. 80(30000/280
258
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EPA for the assessment of carcinogenic risks. J. Natl. Cancer Inst.,
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Altaian, P.L., S.R. Gibson and C.C. Wang. Respiratory Rate, Handbook of
Respiration. W.B. saunders Co., Philadelphia and London 41 pp. 1958.
American Wood Preservers Institute. Response of AWPI to U.S. EPA's PO 1,
OPP 30000/29: RPAR Inorganic Arsenicals, Pg. 154-192. 1979.
Amburgey, T. L. and Williams, L. H. Constructing Log Homes in the South.
Miss. St. Univ., December 10, 1982.
American Wood Preservers Institute. Evaluation of Pentachlorophenol Treated
Lumber for Potential Dermal Exposure. Study conducted at Mississippi
State University by L. Ingram and G. McGinnis, dated June 30, 1983.
Submitted by AWPI to EPA by W. Talarek, dated September 27, 1983.
American Wood Preservers Institute. PD 1 Rebuttal, 30000/30 Vol. I.
February 12, 1979.
Ames, B. N. The detection of chemical mutagens with enteric bacteria.
Chemical Mutagens; Principles and Methods for Their Detection, A.
Hollaender (ed.). Vol. 1. Hew York: Plenum Pres, pages 267-282. 1971.
Andelman, Julian B. Feasibility Study to Resolve Questions on the Relation-
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Anderson, G. L., Memo to Edwin L. Johnson (EPA) concerning the transmittal
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June 16, 1983.
Arsenault, R.D. Pentachlorophenol and contained chlorinated dibenzodioxins
in the environment. A study of environmental fate, stability and signif-
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Association of American Railroads, Analysis of Railroad Personnel Occupational
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Ataullakhandu, F.I., Vitvitskii, V.M., and Platouova, D.V. Biofizika 23:
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Woolson, E. Letter to Dr. Lederer. August 13, 1982.
World Health Organization (WHO). Guidelines for Drinking Water Quality.
Vol. 1. Recommendations, Pg. 80. 1983.
Wyllie, J. A., J. Gociba, W. W. Benson, and J. Yoder. Exposure and
contamination of the air and employees of a pentachlorophenol plant,
281
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Idaho, 1972. Pesticides Monitoring Journal. 9(3)(150-153. 1975.
Yamauchi and Yamamura. Urinary inorganic arsenic and methyl arsenic
excretion following arsenate-rich seaweed ingestion. Jap. J. Ind.
Health. 21:47-54. 1979 (Engl. Summary, Tables and Figures).
Yoder, J. B., Metals Analysis of Mushrooms, April 7, 1981.
Zabik, M. E. and Zabik, M. J. Dioxin Levels in Raw and Cooked Liver,
Loin Steaks, Round, and Patties from Beef Fed Technical Grade
Pentachlorophenol. Environ. Contain. Toxicol. 24:344-349, 1980.
Zendzian, R. p. PD 2/3 Rebuttal Analysis. February 26. 1982.
Zendzian, R. P. EPA Memorandum to Paul Cammer concerning the dermal
penetration of pentachlorophenol pellets. January 22, 1981.
Zendzian, R. P. Adsorption estimates wood preservatives: pentachlorophenol,
inorganic arsenicals and creosote-coal tars. EPA Memo to H. Day
April 16, 1982.
282
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Appendix A
Comparison of PD 2/3 Proposals with the
Agency's Final Regulatory Me as tores
283
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1. All Uses of Technical Pentachlorophenol
and Pentachlorophenol Salts
Cancellation and denial of registrations of technical pentachlorophenol and salts of pentachlorophenol unless
registrants modify the terms and conditions of registration to include the following information within 30 days
after publication in the Federal Register of the Notice concluding the Wood preservatives RPAR, or within 30
days of receipt of such Notice, whichever occurs later:
PD 2/3 Proposal
Final Regulatory Measures
No requirement proposed.
1. File an application to amend the confidential statements of Formula
(CSF) to indicate that the hexachlorodibenzo-p-dioxin (HxCDD)
contamination does not exceed 15 ppm and that 2,3,7,8-TCDD is below
the limits of detection using a gas chromatography-mass spectro-
photometry method of analysis acceptable to the Agency (e.g.,
Buser and Bosshardt, 1976).
2. File an application to amend the Confidential Statements of Formula
for technical pentachlorophenol and pentachlorophenol salts to
indicate that, effective 18 months after publication of the Notice or
receipt by the registrant, whichever occurs later, the HxCDD
contamination does not 1.0 ppm. (The method used to lower the
HxCDD to 15.0 ppm or 1.0 ppm or lower must not increase the
hexachlorobenzene or chlorinated dibenzofurans above the levels in
products marketed at the time of publication of the FR Notice.)
284
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2. All Uses of Pentachlorophenol
and Pentachlorophenol Salts
Cancellation and denial of registrations of all products containing pentachlorophenol and salts of pentachloro-
phenol unless registrants modify the terras and conditions of registration to include the following information
within 30 days after publication in the Federal Register of the Notice concluding the Wood Preservatives RPAR,
or within 30 days of receipt of such Notice, whichever occurs later:
PD 2/3 Proposal Final Regulatory Measure
Label Statement;
No requirement proposed. 1. The U.S. EPA has determined that pentachlorophenol can produce
defects in the offspring of laboratory animals. Exposure to
pentachlorophenol during pregnancy should be avoided.
285
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3. Pressure-treatment Uses
Cancellation and denial of registrations of creosote, pentachlorophenol and inorganic arsenical products used for
commercial pressure-treatment of wood unless the registrants modify the labeling of those creosote, pentachloro-
phenol and inorganic arsenical products to include the following information:
PD 2/3 Proposal Final Agency Position ___
Not proposed This pesticide product may not be used for treatment of
wood or wood products for sale or distribution unless
the wood treater is participating in or affiliated with
a program adequate to inform users of the treated wood
of the proper precautions to be taken in handling and
using such treated wood.
At a minimum wood treaters must:
(1) distribute adequate consumer information sheets
(CIS) with each shipment of pressure-treated wood so
that at least one CIS will be securely attached to
each bundle or batch of treated wood as it leaves
the treating plant;
(2) attach at least one CIS to each invoice for sale of
pressure-treated wood;
(3) make available to retailers, wholesalers and distri-
butors an adequate supply of CIS1s and signs or
placards to inform consumers of the existence of the
CIS's; and
(4) encourage retailers to display signs or placards in-
forming consumers of the availability of the CIS's and
to make the CIS's readily available to the consumer.
The information which the United States Environmental
Protection Agency requires to be included in the CIS
is found in the attached labeling.
286
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3. Pressure-Treatment lises (Cont'd)
PD 2/3 Proposal
Final Agency Position
(1) All individuals who handle pesticide-treated wood
should wear gloves impervious to the wood pre-
servatives (e.g., rubber).
(1)
{2) Individuals who saw pesticide-treated wood should
wear disposal coveralls (e.g., nitrile or polyethyl-
ene) or similar protective clothing (for homeowners
tightly-woven cotton coveralls are acceptable).
(3) Individuals who saw pesticide-treated wood and
fabricate structures with treated wood should wear
a dust mask capable of trapping 80% of participates
greater than 5 microns in size.
Model Consumer information Sheets (CIS) to be distri-
buted with each shipment of pressure-treated wood
(Actual CIS will be separate for each chemical.)
& (2) Avoid frequent or prolonged skin contact
with pentachlorophenol or creosote-treated wood;
when handling the treated wood, wear tightly woven
coveralls and use gloves impervious to the chemicals
(for example, gloves that are vinyl-coated. When power
sawing and machining, wear goggles to protect eyes from
flying particles. Wash thoroughly after skin contact,
and before eating, drinking, or use of tobacco products.
If oily preservatives or sawdust accumulate on clothes,
launder before reuse. Wash work clothes separately
from other household clothing.
(3) Avoid frequent or prolonged inhalation of
sawdust from treated wood. When sawing and
machining treated wood, wear a dust mask.
Whenever possible, these operations should be
performed outdoors to avoid indoor accumulations'
of airborne sawdust from treated wood.
(4) Treated wood should not be used indoors except (4) & (5)
for those support structures (e.g., foundation
timbers, pole supports and the bottom six inches
of stall skirt-boards) which are in contact with
the soil in barns, stables, and similar sites
(all three wood preservatives); all-weather wood
foundations, sills and plates, structural framing
(inorganic arsenicals only); millwork
(pentachlorophenol only) which have outdoor
USE SITE PRECAUTIONS
— Wood treated with pentachlorophenol or creosote
should not be used where it will be in. frequent
or prolonged contact with bare skin (for example,
chairs and other outdoor furniture), unless an
effective sealer * has been applied.
* Coal tar pitch and coal tar pitch emulsions are effective sealers for creosote-treated wood block flooring.
Urethane, expoxy and shellac are acceptable sealers for all creosote-treated wood, urethane, shellac, latex
epoxy enamel and varnish are acceptable sealers for pentachlorophenol-treated wood.
287
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PD 2/3 Proposal
3. Pressure-Treatment Uses (Cont'd)
Final Agency Position
surfaces (e.g., doorframes, windows and patio frames);
and wood treated for sapstain control with 0.5% sodium
pentachlorophenate.
(5} Treated wood should not be used in a manner which
may result in direct exposure to domestic animals or
livestock, or in the contamination of food, feed, or
drinking and irrigation water (e.g., food creates,
irrigation flumes, vegetables stakes, feedlot bins
and watering troughs).
pentachlorophenol-treated wood should not be used in
residential, industrial, or commercial interiors,
except for laminated beams or building components
which are in ground contact and are subject to decay
or insect infestation and where two coats of an
appropriate sealer are applied.*
Creosote-treated wood should not be used in residen-
tial interiors, creosote-treated wood in interiors
of industrial buildings should only be used for wood-
block flooring and industrial building components
which are in ground contact and are subject to decay
or insect infestation and where two coats of an
appropriate sealer are applied.*
Exposed wood pressure-treated with waterborne
arsenical preservatives may be used inside residences
as long as all dust is vacuumed from the wood surface.
Wood treated with pentachlorophenol or creosote should
not be used in the interiors of farm buildings where
there may be direct contact with domestic animals or
livestock which may crib (bite) or lick the wood.
In interiors of farm buildings where domestic animals
or livestock are unlikely to crib (bite) or lick the
wood, pentachlorophenol or creosote-treated wood
may be used for building components which are in
ground contact and are subject to decay or insect
infestation and where two coats of an appropriate
sealer are applied.*
* Coal tar pitch and coal tar pitch emulsions are effective sealers for creosote-treated wood block flooring.
Urethane, expoxy and shellac are acceptable sealers for all creosote-treated wood. Urethane, shellac, latex
epoxy enamel and varnish are acceptable sealers for pentachlorophenol-treated wood.
288
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3. Pressure-Treatment Uses (Cont'd)
PD 2/3 Proposal Final Agency Position
—- Do not use pentachlorophenol or creosote-treated wood
for farrowing or brooding facilities.
— Only treated wood that is visibly clean of surface
residue should be used for patios, decks and
walkways.
— Do not use treated wood under circumstances where the
preservative may become a component of food or animal
feed. Examples of such sites would be structures or
containers for storing silage or food.
-- Do not use treated wood for cutting boards or
countertops.
— Do not use treated wood for construction of those
portions of beehives which may come into contact
with the honey.
-- Pesticide-treated wood should not be used where it may
come in to direct or indirect contact with public
drinking water, except for uses involving incidental
contact, such as docks and bridges.
— Do not use pentachlorophenol or creosote treated wood
where it may come into direct or indirect contact
with drinking water for domestic animals or livestock,
except for uses involving incidental contact, such
as docks and bridges.
(6) Treated wood should not be burned, but should be (6) Dispose of treated wood by ordinary trash collection
disposed of by methods, such as on-site burial, or burial. Treated wood should not be burned in open
which are in accordance with local and state laws, fires or in stoves or fireplaces because toxic chemi-
and/or the Resource Conservation and Recovery Act. cals may be produced in the smoke and ashes. Large
quantities of treated wood from .commercial or indus-
trial use (e.g., construction sites) may be burned
in commercial or industrial incinerators in accordance
with state and Federal regulations.
289
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4. Pressure-Treatment Uses
Cancellation and denial of registrations of creosote, pentachlorophenol and inorganic arsenical products for
wood preservatives use on railroad ties, lumber, timber and plywood, pilings, posts, crossarms, and poles unless
the registrants modify the labeling of creosote, pentachlorophenol, and inorganic arsenicals products to include
the following information:
PD 2/3 Proposal
a. Restricted Use Pesticide: For sale to
and use only by certified applicators or by
persons under their direct supervision and
only for those uses covered by the certified
applicator's certi fication.
b. Protective Clothing and Equipment.
(1) All applicators must wear gloves
(e.g., rubber) in all situations where dermal
contact with creosote, pentachlorophenol or
inorganic arsenical is possible (e.g.,
handling treated wood and opening cylinder
doors).
(2) Creosote and Pentachlorophenol. All
applicators who open treatment cylinder doors
must wear gloves and a properly maintained
half-mask canister or cartidge respirator
designed for pesticide use.
Final Regulatory Measures
a. Restricted Use Pesticide: For sale to and use only by
certified applicators or by persons under their direct
supervision and only for those uses covered by the
certified applicator's certification.
b. Protective Clothing and Equipment. (1) Applicators
must wear gloves* impervious to the wood treatment for-
mulation in all situations where dermal contact is
expected (e.g., handling freshly treated wood and
manually opening cylinder doors).
(2) Creosote: Applicators who manually open cylinder
doors must wear gloves* and a respirator (properly fitting,
well-maintained, half-mask canister or cartridge respirator
which is MSHA/NIOSH-approved for polynuclear aromatics and
organic vapors).
Pentachlorophenol: Applicators who manually open cylinder
doors must wear gloves* and a respirator (properly fitting,
well-maintained, half-mask canister or cartridge respirator
which is MSHA/NIOSH-approved for organic vapors and acid gases).
290
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4. Pressure Uses, Cont'd.
PD 2/3 Proposal
Final Regulatory Measures
c. Applicators who enter pressure treatment
cylinders and other related equipment must
wear a neoprene-coated cotton or rubberized
overall, jacket, gloves and boots, and a
properly maintained half-mask canister or
cartridge respirator designed for pesticide
use.
c. (1) Creosote & Pentachlorophenol. Applicators who enter
pressure treatment cylinders and other related equipment that
is contaminated with the wood treatment formulation (e.g.,
cylinders that are in operation or are not free of the treatment
formulation) must wear protective clothing (including overalls,
jacket, gloves and boots)* impervious to the wood treatment
formulation and a respirator as described in b(2) above.
c. (2) Inorganic Arsenicals. Applicators who enter pressure
treatment cylinders and other related equipment that are con-
taminated with the wood treatment solution (e.g., cylinders
that are in operation or are not free of the treatment solution)
must wear protective clothing (including overalls, jackets, glove
and boots)* impervious to the wood treatment formulation.
In addition, employees who enter pressure-treatment cylinders
must wear properly fitting, well-maintained high efficiency
filter respirators MSHA/NIOSH-approved for Inorganic arsenic if
the level of inorganic arsenic in the plant is unknown or exceeds
10 micrograms per cubic meter of air ( 10 ug/m3), averaged over
an 8-hour work period. Air monitoring programs, procedures,
and record retention and submission must be conducted in accor-
dance with the instructions on the attached labeling
material.
^Examples of acceptable materials for protective clothing (e.g., gloves, overalls, jackets, and boots) required
during application and handling of creosote are polyvinyl acetate (PVA), polyvinylchloride (PVC), neoprene, and
NBR (Buna-N); for pentachlorpphenol, acceptable materials are polyvinyl acetate (PVA), polyvinyl chloride (PVC),
neoprene, NBR (Buna-N), and nitrile. In addition, plasticated disposable coveralls impervious to dust are
acceptable for dust protection (pentachlorophenol). Examples of protective clothing (e.g., gloves, overalls,
jackets, and boots) required during application and handling of inorganic arsenicals are vinyl, polyvinyl chloride
(PVC), neoprene, NBR (Buna-N), rubber, and polyethylene.
291
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Pressure Use Cont'd
PD 2/3 Proposal
Final Regulatory Measures
d. Applicators who work outdoors in
arsenical wood treatment plants must wear
a dust: mask capable of trapping 80% of
particulates greater than 5 microns in
size.
e. A closed emptying and a closed mixing
system must be used for all powder formul-
tions of the inorganic arsenicals.
f. A closed emptying and a closed mixing
system must be used for all prilled
(granular) formulations of pentachloro-
phenol.
g. The inorganic arsenical treatment
solutions must be filtered prior to
use in the treatment cylinders and an
additional vacuum step must be used
prior to the removal of the treated
wood from the treatment cylinders.
In addition to these requirements,
recommended control technologies to
reduce the surface levels of arsenic
on the treated wood include the use
of wood that is free of heavy resins
("clean" wood), the post-treatment
rinsing of the treated wood, and
the installation of protective sheds
or covers over the drying treated
wood.
d. Employees in the work area of an arsenical wood treatment
plant must wear properly fitting, well maintained high efficiency
filter respirators MSHA/NIOSH-approved for inorganic arsenic
if the level of inorganic arsenic in the plant is unknown or
exceeds 10 micrograms per cubic meter of air (10 ug/m3) averaged
over an 8-hour work period. Air monitoring programs, procedures
and record retention and submission must be conducted in accor-
dance with the instructions on the attached labeling material.
e. A closed emptying and mixing system must be used for all
powder formulations of the inorganic arsenicals. A closed system
is defined as any containment which prevents the release of
subject chemicals into the surrounding environment.
f. Until August 31, 1987, a closed emptying and mixing system
must be used or protective clothing (including respirator, gloves
and tightly woven, long-sleeved cotton or disposable coveralls)
must be worn when emptying and mixing prilled or flaked formula-
tions of pentachlorophenol. After September 1, 1987, a closed
system must be used when emptying and mixing prilled or flaked
formulations of pentachlorophenol. A closed system is defined as
any containment which prevents the release of subject chemicals
into the surrounding external environment. Examples of accept-
able respirators and protective clothing materials for penta-
chlophenol applicators are found in b(2) and c(1) above.
g. Processes used to apply inorganic arsenical formulations shall
leave no visible surface deposits on the wood, as defined by AWPA
Standard C-1 and AWPB Standards LP2 and LP22. (Visible surface
deposits means a surface residue or crystallization on the
treated wood. Small isolated or infrequent spots of chemical on
otherwise clean wood shall be allowed.)
292
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4. Pressure Uses, Cont'd.
PD 2/3 Proposal
Final Regulatory Measures
h. All applicators must leave all protective
clothing, work shoes or boots, and equipment
at the plant at the end of the day. Worn-out
protective clothing must be disposed of in
accordance with the instructions for
pesticide container disposal.
i. Eating, drinking and smoking are
prohibited during the application of
creosote, pentachlorophenol, and inorganic
arsenical wood preservative pesticides
by pressure treatment.
j. (1) The application of creosote, penta-
chlorophenol, or inorganic arsenicals to
wood which is intended for interior
use is prohibited, except for those
support structures (e.g., foundation
timbers, pole supports and the bottom
six inches of stall skirtboards) which
are in contact with the soil in barns,
stables and similar sites; inorganic
arsenical-treated all-weather wood
foundations, sills and plates, and
structural framing.
(2) Do not apply inorganic arsenicals,
pentachlorophenol, or creosote to wood
which will be used in a manner which may
result in direct exposure to domestic
animals or livestock, or in the contami-
nation of food, feed, or drinking and
irrigation water (e.g., food crates,
irrigation flumes, vegetable stakes,
feedlot bins and watering troughs).
h. Pentachlorophenol and Creosote; Pesticide wastes are toxic.
Improper disposal of excess pesticide, spray mixture, or
rinsate is a violation of Federal law. If these wastes cannot
be disposed of by use according to label instructions, contact
your State Pesticide or Environmental Control Agency, or the
Hazardous Haste representative at the nearest EPA Regional
Office for guidance.
Protective clothing must be changed when it shows signs
of contamination. Applicators must leave protective
clothing and equipment at the plant. Worn-out protective
clothing and workshoes or boots must be left at the plant
and disposed of in a general landfill, in the trash or in
any other manner approved for pesticide disposal.
Arsenic; Protective clothing must be changed when it shows
signs of contamination. Applicators must leave protective
clothing and equipment at the plant. Worn-out protective
clothing and workshoes or boots must be left at the plant
and disposed of in a manner approved for pesticide disposal
and in accordance with State and Federal regulations. Pesti-
cide wastes are acutely hazardous. Improper disposal of
excess pesticide, spray mixture, or rinsate is a violation
of Federal law. If these wastes cannot be disposed of by use
according to label instructions, contact your State Pesticide
or Environmental Control Agency, or the Hazardous Waste
representative at the nearest EPA Regional Office for guidance.
i. Applicators must not eat, drink, or use tobacco products
during those parts of the application process which may expose
them to the wood treatment formulation (e.g., manually opening
closing cylinder doors, moving trams out of cylinders, mixing
chemicals and handling freshly treated wood). Wash thoroughly
after skin contact, and before eating, drinking or use of tobacco
products, or using restrooms.
j. (1) and (2) Not practical to enforce under FIFRA, because it
would not be reasonable to expect the wood treater to know how
the wood being treated and sold would be used. Instead,
consumers will be informed about the proper use of treated wood
by the Consumer Information Sheet distributed under the Consumer
Awareness Program. (See Item 3 of Appendix.)
293
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5. Groundline Treatment of Poles
Cancellation and denial of registration of creosote and pentachlorophenol products for wood preservatives
use for groundline treatment of poles unless the registrants modify the labeling of creosote and penta-
chlorophenol products for the poles-groundline use to include the following information:
PD 2/3 Proposal
Final Regulatory Measures
a. Restricted Use Pesticide; For sale to
and use only by certified applicators or by
persons under their direct supervision and
only for those uses covered by the certified
applicator's certification.
b. Protective Clothing and Equipment.
(1) All applicators must wear gloves
impervious to the pentachlorophenol and
creosote poles-groundline formulations
(e.g., rubber) in all situations where
dermal contact with pentachlorophenol
and/or creosote is possible.
(2) All applicators must wear disposable
coveralls (e.g., nitrile or polyethylene)
or similar protective clothing during the
application process.
c. All applicators must dispose of worn-
out protective clothing in accordance with
the instructions for pesticide container
disposal
d. Eating, drinking and smoking are
prohibited during the application of
creosote and pentachlorophenol products
for the poles-groundline use.
a. Restricted Use Pesticide; For sale to and use only by
certified applicators or by persons under their direct super-
vision and only for those uses covered by the certified
applicator's certification.
b. Protective Clothing and Equipment
(1) Applicators must wear gloves impervious to the wood treat-
ment formulation (e.g., polyvinyl acetate, polyvinyl chloride or
neoprene) in all situations where dermal contact is expected
(e.g., during the actual application process and when handling
freshly treated wood).
(2) Applicators must wear disposable coveralls (e.g., creosote:
nitrile or neoprene; pentachlorophenol: nitrile or polyethelene)
or other suitable impermeable protective clothing during the
application and mixing processes in all situations where dermal
contact is expected.
c. Protective clothing must be changed when it shows signs of
contamination. Launder non-disposable protective clothing
separately from other household clothing. Dispose of
worn-out shoes or boots in any general landfill, in the trash
or in a other manner for pesticide disposal.
Pesticide wastes are toxic. Improper disposal of excess
pesticide, spray mixture, or rinsate is a violation of Federal
Law. If these wastes cannot be disposed of by use according to
label instructions, contact your State Pesticide or Environmental
Control Agency, or the Hazardous Waste representative at the
nearest EPA Regional Office for guidnace.
d. Applicators must not eat, drink, or use tobacco products
during those parts of the application process which may directly
expose them to the wood treatment formulation.
Wash thoroughly after skin contact, and before eating, drinking,
use of tobacco products, or before using restrooms.
294
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6. Home and Farm
Cancellation and denial of registration of creosote and pentachlorophenol for non-pressure wood preservative
home and farm use (including non-pressure use on railroad ties) unless the registrants modify the labeling
of creosote and pentachlorophenol products for home and farm use to include the following information:
Home and Farm Use (Restricted)
PD 2/3 Proposal
a. (1) For all creosote products and those
pentachlorophenol products containing a penta-
chlorophenal concentration greater than 5%:
Restricted Use Pesticide: For retail sale to
and use only by certified applicators or by
persons under their direct supervision and
only for those uses covered by the certified
applicator's certification.
Final Regulatory Measures
a. (1) and (2) For creosote and pentachlorophenol products
registered for home and farm use (including use on railroad
ties).
Restricted Use Pesticide; For retail sale to and use
only by certified applicators or persons under their
direct supervision and only for the uses covered by
the certified applicator's certification.
(2) Cancellation and denial of registration
of the spray method of pentachlorophenol
products which are available in concentration
of 5% or less.
b. Protective Clothing and Equipment
(1) All applicators must wear gloves
impervious to the creosote and pentachloro-
phenol treatment solutions (e.g., rubber) in
all situations when dermal contact with these
pesticides is possible (e.g., handling
treated wood).
b. Protective Clothing and Equipment
{1) For Restricted Use Products; Applicators must wear
glove's impervious to the wood treatment formulation [e.g.,
pentachlorophenol; polyvinyl acetate (PVA), polyvinyl chloride
(PVC), neonprene HER (Buna-N), and nitrile; creosote;
polyvinyl acetate (PVA), polyvinyl chloride (PVC), neoprene,
and NBR (Buna-N)] in all situations where dermal contact is
expected (for example, during the actual application process
and when handling freshly treated wood).
295
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PD 2/3 Proposal
6. Home and Farm Use (Cont'd)
Final Regulatory Measures
(2) All certified applicators who apply
creosote and pentachlorophenol by the spray
method must wear a neoprene-coated cotton or
rubberized overall, jacket, gloves and boots,
and a properly maintained half-mask canister
or cartridge respirator designed for pesti-
cide use, and all certified applicators who
apply creosote and pentachlorophenol
by other application processes (e.g.,
brush-on) must wear disposable coveralls
(e.g., nitrile or polyethylene) or
similar protective clothing.
All non-certified applicators must wear
tightly-woven, long sleeved cotton cover-
alls or similar protective clothing during
the application process.
(2) Restricted Uses; Spray applicators must wear protective
clothing* (including overalls, jacket, gloves and boots) impervious
to the wood treatment formulation and a respirator**, head covering,
and goggles when spraying. Applicators who apply creosote and
pentachlorophenol by other application processes (e.g., brush-on)
must wear disposable coveralls or other suitable impermeable pro-
tective clothing. Launder non-disposable protective clothing
separately from other clothing.
* Examples of protective clothing for restricted uses of creosote and pentachlorophenol are polyvinyl
acetate (PVA), polyvinyl chloride (PVC), neoprene, NBR (Buna-N), and nitrile (pentachlorophenol only),
Nitrile is also acceptable for disposable coveralls for creosote applicators.
** Respirators acceptable for use by applicators must be properly fitting, well-maintained half-mask
canister or cartridge respirators which are MSHA/NIOSH-approved for polynuclear aromatics and organic
vapors (creosote applicators) or for organic vapors and acid gases (pentachlorophenol applicators).
296
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6. Home and Farm Use (Cont'd)
PP 2/3 Proposal
Final Regulatory Measures
c. All applicators applying creosote
or pentachlorophenol solutions must dispose
of worn-out protective clothing in accordance
with the instruction for pesticide disposal.
d. Eating, smoking, and drinking are pro-
hibited during the application of
creosote or pentachlorophenol products.
e. The application of cresote and penta-
chlorophenol products indoors is prohibited.
The application of creosote and penta-
chlorophenol products to wood intended for
interior use is prohibited, except for
those support structures (e.g., foundations
timbers, pole supports, and the bottom six
inches of stall skirtboards) which are in
contact with the soil in barns, stables and
similar sites, and millwork (pentachlorophenol
only) which has outdoor surfaces (e.g., door
frames, windows, and patio frames).
c. Restricted Uses; Protective clothing must be changed when
it shows signs of contamination. Dispose of worn-out protective
clothing and workshoes or boots in any general landfill, in the
trash, or in any other manner approved for pesticide disposal. For
farm use or railroad tie repair: Pesticide wastes are toxic. Improper
disposal of excess pesticide, spray mixture, or rinsate is a viola-
tion of Federal Law. If these wastes cannot be disposed of by use
according to label instructions, contact your State Pesticide or
Environmental Control Agency, of the Hazardous Haste representative
at the nearest EPA Regional Office for guidance. For products for
household/domestic use; Securely wrap original pesticide container
in several layers of newspaper and discard in the trash. Do not re-
use empty container.
d. Restricted Uses; Applicators must not eat, drink,
or use tobacco products during those parts of the application
process which may expose them to the treatment formulation.
Wash thoroughly after skin contact, and before eating,
drinking, use of tobacco products, or using restrooms.
e. Restricted Uses; Pentachlorophenol and creosote; Avoid
inhaling vapors. If inhalation of vapors cannot be avoided,
applicators must wear a properly fitting, well-maintained half-
mask or cartridge respirator which is MSHA/NIOSH-approved for
organic vapors and acid gases (pentachlorophenol) or for poly-
nuclear aromatics and organic vapors (creosote).
Do not apply in interiors. Do not apply to wood intended for
use In interiors, except for those support structures which are in
contact with the soil in barns, stables and similar sites, and
which are subject to decay or insect infestation; and millwork (pen-
tachlorophenol only) which has outdoor surfaces (e.g., door-
frames, windows, and patio frames). Interior surfaces of the
treated wood should be sealed with two coats of an appropriate
sealer. Urethane, epoxy, and shellac are acceptable sealers for
all creosote-treated wood. Ur«thane, shellac, latex epoxy enamel
and varnish are acceptable sealers for pentachlorophenol-treated
wood.
297
-------
6. Home and Farm Use (Cont'd)
PD 2/3 Proposal
Final Regulatory Measures
f. Do not use creosote or pentachloro-
phenol in a manner which may result in direct
exposure to domestic animals or livestock,
or in the contamination of food, feed, or
drinking and irrigation water (e.g., food
crates, irrigation flumes, vegetable stakes,
feedlot bins, and watering troughs.)
f. Restricted Uses; Do not apply where there may be direct
contact with domestic animals or livestock, and where there may
be contamination of food, or drinking and irrigation water.
Do not apply to wood intended for farrowing or brooding
facilities. Do not apply to wood intended to be used in
the interiors of farm buildings where there may be direct
contact with domestic animals or livestock which may crib
(bite) or lick the wood. Pentachlorophenol or creosote
may be applied to wood intended to be used in interiors
of farm buildings where domestic animals or livestock
are unlikely to crib or lick the wood, and if two coats
of an appropriat sealer will be applied.
Do not apply to wood intended to be used in a manner in
which the preservative may become a component of food or
animal feed. Examples of such sites would be structures
or containers for storing silage or food.
Do not use this product to treat wood intended to be
used for cutting boards or counter tops.
Do not use this product to treat wood for construction
of those portions of beehives which may come into contact
with the honey.
Do not use this product to treat wood intended to be used
where it may come into direct or indirect contact with
public drinking water, except for those uses involving
incidental contact such as docks and bridges.
298
-------
6. Home and Farm Use (Cont'd)
PD 2/3 Proposal Final Regulatory Measures
Do not: use this product to treat wood intended to be used
where it may come into direct or indirect contact with
drinking water for domestic animals or livestock, except
for uses involving incidental contact such as docks and
bridges.
g. Other Precautions
Wood to be treated with this product should be cut to
size before treatment. If it is necessary to saw or
machine wood after treatment, wear goggles to protect the
eyes from flying particles and a dust mask to avoid inhaling
sawdust from the treated wood. If oily preservatives or
sawdust accumulate on clothes/ launder before reuse.
Wash work clothes separately from other household laundry.
Contact with treated surfaces should be avoided even after
the preservative has dried. When handling treated wood
wear tightly woven coveralls and gloves which are impervious
(e.g., vinyl coated) to the pesticide.
Wash exposed skin thoroughly after contact with treated wood,
and before eating, drinking or using tobacco products.
Wood which has been treated with this product should be
disposed of by burial or ordinary trash collection. Do
not burn treated wood in an outdoor fire or in stoves or
fireplaces, because toxic chemicals may be produced in the
smoke and ashes.
This product should not be used to treat wood which will be
in frequent or prolonged contact with skin, unless the wood
will be treated with an effective sealer.
299
-------
7. Brush-on Treatments of Inorganic Arsenicals
Cancellation and denial of registration of brush-on treatments of the inorganic arsenicals unless the registrants
modify the labeling of the inorganic arsenical products to include the following information.
PD 2/3 Proposal
Final Regulatory Measures
a. Restricted-Use Pesticide; For sale to and
use only by certified applicators or by
persons under their direct supervision and
only for those uses covered by the certified
applicator's certification.
b. Protective Clothing and Equipment
(1 ) All applicators must wear gloves impervious to
the inorganic arsenical solutions (e.g., rubber)
in all situations where dermal contact with the
pesticide solution is possible (e.g., handling
treated wood).
(2) All applicators must wear disposable coveralls
(e.g., nitrile or polyethylene) or similar protective
clothing during the application process.
c. Eating, drinking and smoking during the
application of the inorganic arsenical products
is prohibited.
d. All applicators applying brush-on inorganic
arsenicals solution must dispose of worn-out
protective clothing in accordance with the
instructions for pesticide container disposal.
a. Unclassified Use
300
k- Protective Clothing and Equipment
(1) Applicators must wear gloves (e.g.,
rubber, vinyl or neoprene) impervious to the
wood treatment solution in all situations where
dermal contact is expected (e.g., during the
application process and handling freshly treated
wood).
(2) Applicators must wear disposable coveralls
(e.g., vinyl or polyethelene) or other suitable
impermeable protective clothing during the appli-
cation process where dermal contact is expected.
c. Applicators must not eat, drink or use tobacco
products during those parts of the application process
which may directly expose them to the treatment solution.
Wash thoroughly after skin contact, and before eating,
drinking, use of tobacco products, or using restrooms.
d. Protective clothing must be changed when it shows
signs of contamination. Launder non-disposable
protective clothing separately from other household
clothing. Dispose of worn-out protective clothing
in a manner approved for pesticide disposal and in
accordance with State and Federal regulations.
Pesticide wastes are acutely hazardous. Improper
disposal of excess pesticide, spray mixture, or rinsate
is a violation of Federal law. If these wastes cannot be
disposed of by use according to label instructions,
contact your State Pesticide or Environmental Control
'Agency; or the Hazardous Haste representative at the
nearest: EPA Regional Office for.guidance."
-------
7. Brush-on Treatments of Inorganic Arsenicals (Cont'd)
PD 2/3 Proposal Final Regulatory Measures
e. Do not apply brush-on inorganic arsenical solution e. & f. For application to the cut ends of pressure-
to wood intended for indoor use, except for those treated wood only. Do not dilute or mix with other
support structures (e.g., foundation timbers, pole products. For commercial construction use only.
supports and the bottom six inches of stall skirtboards) Not for household use.
which are in contact with the soil in barns, stables and
similar sites, all-weather wood foundations, sills and
plates and structural framing.
f. Do not use the inorganic arsenicals in a manner which
may result in direct exposure to domestic animals or live-
stock, or in the contamination of food, feed, or drinking
or irrigation water (e.g., food crates, irrigation flumes,
vegetable stakes, feedlot bins and watering troughs).
301
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8. Non-Pressure Uses of Pentachlorophenol Salts for Sapstain Control
Cancellation and denial of registration of sodium pentachlorophenate products for sapstain control
unless the registrants modify the labeling of sodium pent ach lor ophenate products to include the following
information:
PD 2/3 Proposal
Final Regulatory Measures
a. Restricted Use Pesticide; For sale to and use
only by certified applicators or by persons under
their direct supervision and only for those uses
covered by the certified applicator's certification.
b. Protective Clothing and Equipment; (1) All
applicators using sodium pentahchlorophenate for
sapstain control must wear gloves impervious to
sodium pentachlorophenate (e.g., rubber) in all
situations where dermal contact with sodium
pentachlorophenate is possible (e.g., handling
treated wood).
(2) All applicators who apply sodium penta-
chlorophenate formulations by the spray method
must wear gloves and a properly maintained
half-mask canister or cartridge respirator
designed for pesticide use.
(3) All individuals who enter or clean vats and other
related equipment must wear a neoprene-coated cotton
or rubberized overall, jacket, gloves and boots and a
properly maintained half-mask canister or cartridge
respirator designed for pesticide use.
a. Restricted Use Pesticide; For sale to and
use only by certified applicators or by persons
under their direct supervision and only for
those uses covered by certified applicator's
certi fication.
b. Protective Clothing and Equipment
(1) All applicators must wear gloves impervious
to the wood treatment formulation in all situa-
tions where dermal contact is expected (for example,
during the application process and when handling
freshly treated wood) *
(2) For the spray method of application: spray
apparatus must (1) be operated so as to minimize
overspray (i.e., no visible mist) and (2) be free
of leaks in the system, should there be a visible
mist, spray applicators in the vicinity of the appara-
tus (the zone in which the mist is visible)
must wear a respirator* and protective clothing
(including overalls, jacket, boots, head covering
impervious to the wood treatment formulation, and
goggles).
(3) Individuals who enter, clean, or repair vats,
tanks or other related equipment that are
contaminated with the treatment solution must
wear a respirator.* In addition, when dermal
contact is expected, these individuals must wear
overalls, jackets, boot, head covering impervious
to the wood treatment formulation and goggles.*
* Respirators must be properly fitting, well-maintained, half-mask canister or cartridge respirators,
which are MSHA/NIOSH-approved for organic vapors. Examples of acceptable materials for protective clothing
(e.g., overall, jackets, head covering, boots, disposable coveralls, and gloves) required are polyvinyl
acetate (PVA), polyvinyl chloride (PVC), neoprene, NBR (Buna-N), and nitrile.
-------
8. Non-Pressure Uses of Pentachlorophenol Salts for Sapstain Control (Cont'd)
PD 2/3 Proposal
c. A closed emptying and a closed mixing system
must be used for all prilled (granular) and powder
formulations of sodium pentachlorophenate.
Final Regulatory Measures
d. All sapstain control applicators must leave
all protective clothing, work shoes or boots and
at the plant. Worn-out protective
clothing must be disposed of following the
instructions for pesticide container disposal.
e. Bating, drinking and smoking is prohibited during
the application of sodium pentachlorophenate for
sapstain control.
c. Until August 31, 1987, a closed emptying and
mixing system must be used or protective clothing
(including respirator*, gloves* and tightly woven,
long-sleeved cotton or disposable coveralls*)
must be worn when emptying and mixing powder for-
mulations of pentachlorophenate. After September 1,
1987, a closed system must be used when emptying
and mixing powder formulations of pentachlorophenate.
A closed system is defined as any containment which
prevents the release of subject chemicals into the
surrounding external environment.
d. Protective clothing must changed when it shows
signs of contamination. Applicators must equipment
leave all protective clothing, work shoes or boots
and equipment at the plant. Worn-out protective
clothing and work shoes or boots must be left at
the plant and disposed of in any general landfill
in the trash, or in any other manner approved for
pesticide disposal.
Pesticide wastes are toxic. Improper disposal of
excess pesticide, spray mixture, or rinsate is a
violation of federal law. If these wastes cannot
be disposed of by use according to label instructions,
contact your State Pesticide or Environmental Control
Agency, or the Hazardous Waste representative at the
nearest EPA Regional Office for guidance.
e. Applicators must not eat, drink, or use
tobacco products during those parts of the
application process which any expose them to
the treatment formulation.
f. Do not use sodium pentachlorophenate for sapstain
control in a manner which may result in direct
exposure to domestic animals or livestock, or in the
contamination of food, feed, or drinking and irrigation
water (e.g., food crates, irrigation flumes, vegetable
stakes, feed lot bins and watering troughs),
*«/ \J ^/
Wash thoroughly after skin contact, and before
eating, drinking, use of tobacco products or using
restrooms.
f. No regulation (minimal exposure).
-------
9. Millwork and Plywood & Particleboard and Logs for Log Homes
Cancellation and denial of registration of the wood preservative use of pentachlorophenol for mi 11 work,
plywood, and particleboard and logs for construction of log homes unless the registrants modify the labeling
of pentachlorophenol products for the millwork, plywood, and particle board uses to include the following
information:
PD 2/3 Proposal Final Regulatory Measures
a. Restricted Use Pesticide; For sale to and use
only by certified applicators or by persons under
their direct supervision and only for those uses
covered by the certified applicator's certification.
b. Protective Clothing and Equipment; (1) All
applicators applying pentachlorophenol must wear
gloves impervious to the wood treatment solution
(e.g., rubber) in all situations where dermal contact
with the treatment solutions is possible (e.g.,
handling treated wood).
(2) All applicators who apply pentachlorophenol
to millwork and plywood by the spray method must wear
gloves and a properly maintained half-mask canister
or cartridge respirator designed for pesticide use.
(3) All individuals who enter or clean vats and other
related equipment must wear a neoprene-coated cotton
or rubberized overall, jacket, gloves and boots and
a properly maintained half-mask canister or cartridge
respirator designed for pesticide use.
a. Restricted Use Pesticide; For sale to and
use only by certified applicators or by persons
under their direct supervision and only for those
uses covered by certified applicator's certification.
b. Protective Clothing and Equipment
(1) Applicators must wear gloves impervious
to the wood treatment formulation in all
suitations where dermal contact is expected
(for example, during the application process
and when handling freshly treated wood).*
(2) For the spray method of application, spray
apparatus must (1) be operated so as to minimize
overspray (i.e., no visible mist) and (2) be free of
leaks in the system. Should there be a visible mist,
spray applicators in the vicinity of the apparatus
(the zone in which the mist is visible) must wear a
respirator* and protective clothing (including over-
alls, jackets, boots, head covering impervious to the
wood treatment formulation, and goggles).
(3) Individuals who enter, clean or repair vats,
tanks, or other related equipment that are
contaminated with the treatment solution must wear
a respirator.* In additition, when dermal contact
is expected, these individuals must wear overalls
jacket, boots, head covering impervious to the wood
treatment formulation, and suitable eye goggles.
Respirators must be properly fitting, well-maintained half-mask canister or cartridge respirators, which
are MSHA/NIOSH-approved for organic vapors and acid gases. Examples of acceptable materials for protective
clothing (e.g., overalls, jackets, head covering, boots, disposable coveralls and gloves) required during
the application and handling of pentachlorophenol are polyvinyl acetate (PVA), polyvinylchloride (PVC),
neoprene, NBR (Buna-N), and nitrile. In addition, plastic-coated disposable coveralls impervious to dust
are acceptable for dust protection. •? ~ .
-------
9. Millwork and Plywood & Particleboard
and Logs for Log Homes (Cont'd)
PD 2/3 Proposal
Final Regulatory Measures
c. A closed emptying and a closed mixing system
must be used for all prilled (granular) formulations
of pentachlorophenol.
d. All applicators who apply pentachlorophenol to
millwork, plywood and particleboard must leave all
protective clothing, work shoes or boots, and
equipment at the plant at the end of day. Worn-out
protective clothing must be disposed of following
the instructions for pesticide container disposal.
e. Eating, drinking and smoking is prohibited during
the application of pentachloropenol to millwork,
plywood, and particleboard.
c. Until August 31, 1987, a closed emptying and
mixing system must be used or protective clothing
(including respirator, gloves and tightly woven,
long-sleeved cotton or disposable coveralls)*
must be worn when emptying and mixing prilled or
flaked formulations of pentachlorophenol. After
September 1, 1987, a closed system must be used when
emptying and mixing prilled or flaked formulations of
of pentachlorophenol. A closed system is defined as
any containment which prevents the release of subject
chemicals into the surrounding external environment.
d. Protective clothing must be changed when it shows
signs of contamination. Applicators must leave
all protective clothing, workshoes or boots, and equip-
ment at the plant. Horn-out protective clothing and
work-shoes or boots must be left at the plant and dis-
posed of in any general landfill, in the trash, or in
any other manner approved for pesticide disposal.
Pesticide wastes are toxic. Improper disposal of
excess pesticide, spray mixture, or rinsate is a vio-
lation of Federal law. If these wastes cannot be dis-
posed of by use according to label instructions, con-
tact your State Pesticide or Environmental Control
Agency, or the Hazardous Waste representative at the
nearest EPA Regional office for guidance.
e. Applicators must not eat, drink, or use tobacco
products during those parts of the application process
which may expose them to the treatment formulation.
Wash thoroughly after skin contact, and before eating,
drinking, use of tobacco products or using restrooms.
Respirators must be properly fitting, well-maintained half-mask canister or cartridge respirators, which
are MSHA/NIOSH-approved for organic vapors and acid gases. Examples of acceptable materials for protective
clothing (e.g., overalls, jackets, head covering, boots, disposable coveralls and gloves) required during
the application and handling of pentachlorophenol are polyvinyl acetate (PVA), polyvinyl chloride (PVC),
neoprene, NBR (Buna-N), and nitrile. In addition, plastic-coated disposable coveralls impervious to dust are
acceptable for dust protection.
305
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9. Millwork and Plywood & Particleboard (Cont'd)
PD 2/3 Proposal Final Regulatory Measures
f. Interior Use f. & g. No regulation for mi 11 work, plywood and
Millwork and Plywood: The application of penta- particleboard (minimal exposure).
chlorophenol products to wood intended for interior
use is prohibited, except for wood which has outdoor - Do not apply to logs which are intended for use
surfaces (e.g., doorframes, windows and patio frames). in the construction of log homes.
Particleboard: The application of pentachlorophenol
to particleboard intended for any interior use
(e.g., kitchen cabinets) is prohibited.
g. Do not use pentachlorophenol in a manner which may
result in direct exposure to domestic animals or
livestock, or in the contamination of food, feed, or
drinking and irrigation water (e.g., food crates,
irrigation flumes, vegetable stakes, feedlot bins
and watering troughs).
306
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10. Data Requirements [FIFRA 3(c)(2)(B)]
In an action separate from this PD 4, registrants will be required to submit certain data to maintain existing
registrations in effect pursuant to FIFRA 3(c)(2)(B).
PD 2/3 Proposal Final Regulatory Measures
No proposal. a. Registrants of products containing technical
pentachlorophenol or pentachlorophenol salts
will be required to submit the following:
1. A description of the starting materials, manu-
facturing process and reaction conditions includ-
ing any steps to reduce HxCDD.
2. Information on product identity relative to
identification of ingredients, statement of
composition and a discussion of the formation
of impurities.
3. Data on the analysis and certification of
product ingredients relative to preliminary
analysis, certification of limits, and analy-
tical methods for the envorcement of limits.
An analytical method employing combined
gas chromatography and mass spectrophoto-
metry is acceptable (e.g., Buser and
bosshardt, 1976).
4. HxCDD analyses every three months, the first
analysis to be submitted within the stated
90-day period.
5. A description of any changes in the manu-
facturing process used to lower HxCDD to 15
ppm and/or 1 ppm or lower must also be sub-
mitted within the stated time period of 90
days. The methods used to lower HxCDD must
not increase the chlorinated dibenzofurans and
.HCB contaminants above the levels in products
marketed at the time of publication of the
FR Notice.
-Zf\-j 6. Information on the technical feasibility and
•5U I costs of reducing HxCDD contamination further.
-------
10. Data Requirements [FIFRA 3(c)(2)(B)] (Cont'd)
In an action separate from this PD 4, registrants will be required to submit certain data to maintain existing
registrations in effect pursuant to FIFRA 3(c)(2)(B).
PP 2/3 Proposal Final Regulatory Action
b. Registrants of creosote will be required to submit the
following:
1. Retrospective epidemiology study on workers at
creosote treatment plants.
2. Air monitoring and dermal exposure data from
cresote-treatment plants.
c. Registrants of creosote and arsenic will be
required to submit the following:
1. Data on permeability of glove and protective
clothing materials indicating degree of
protection for creosote and inorganic
arsenical formulations.
d. Registrants of bis(tri-n-butyltin) oxide, acid
copper chromate, chromated zinc chloride, sodium
tetrachlorophenate, copper-8-quinolinolate,
copper naphthenate, zinc naphthenate and 3-iodo-2-
propynyl butylcarbamate, and barium metaborate
will be required to submit the following:
1. Chronic feeding studies
2. Oncogenicity studies
3. Reproduction studies
4. Teratology studies.
6. Registrants of pentachlorophenol will be required
to submit inhalation and dermal exposure data
for spray applications of pentachlorophenol prod-
ucts for home and farm use.
308
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APPENDIX B
Comparison of Risks for pentachlorophenol and the
Inorganic Arsenicals Calculated in the PD 2/3,
with and without Proposed Protective Measures,
with the recalculated Risks with and without
Required Protective Measures (Final Regulatory Measures)
309
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Appendix B
Pentachlorophenol (Penta)
Note; The estimates for the oncogenicity and fetoxicity/teratogenic risks for pentachlorophenol for the PD4 were
summarized from Rispin (1984). PD 2/3 pentachlorophenol and sodium pentachlorophenate risks were based on a
dermal absorption rate of 10%} the 1-hit oncogenic risk model was used. The PD4 risks for HxCDD were based on
a dermal absorption rate of 50% (Rispin April 24, 1984). The multi-stage oncogenic risk model was used for the
PD4 risk estimates (Rispin, April 18, 1984, and McGaughy, April 24, 1984). MOS (Margins of Safety) estimates
for teratogenic/fetotoxic risks are rounded off to two significant figures and assume a 50% dermal absorption
rate for liquid pentachlorophenol and 1% for dry formulations. For a detailed summary of exposure assump-
tions, see Appendix C.
Expos ure
Situation
Initial Risk (PD 2/3)
(Without Protective
Measures)
HxCDD(15 ppm) Penta
(onco) MOS
Risk with Protective
Measures (PD 2/3)
HxCDD( 15 ppm) Penta
(onco) MOS
Initial Risk
(PD/4) Without
Protective Measures
HxCDD(15 ppm) Penta
(onco) MOS
Risk with Protective
Measures
(Final PD4 Requirement)
HxCDD( 1 ppm) Penta
(onco) MOS
1. Pressure treat-
ment plants
a. Opening
cylinder
doors [1] 6.4 x 10
-4
Require gloves
and respirator
150
6.4 x 10
-5
1,500
4.3 x 10
-4
b. Entering121 Not Not
cylinders determined deter-
mined
Wear protective clothing Not
and respirator. (Reduce deter-
dermal exposure by 80% & mined
inhalation exposure by 90%.)
Require gloves and a respi-
rator (total dermal risk
150 reduced 80%)
3.1 x 10~6 1500
Not Wear protective clothing
deter- and a respirator. (Reduce
mined total dermal exposure by
80% and inhalation exposure
by 90%.)
[1] Dermal exposure not determined.
[2] The PD 2/3 and PD4 information for applicators entering cylinders also applies to millwork and plywood
applicators who enter, clean, or repair vats or other related equipment that is contaminated with the
treatment solution.
310
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Appendix B (Continued)
Pentachlorophenol (Penta)
Initial Risk (PD 2/3)
(Without Protective
Measures)
Risk with Protective
Measures {PD 2/3)
Initial Risk
(PD4) Without
Protective Measures
Risk with protective
Meas ures
(Final PD4 Requirement)
Exposure HxCDD( 15 ppm)
Situation ( onco )
c. bag 1.5 x 10~2
emptying* to
7 x 10~3
Penta HxCOD( 15 ppm) Penta
MOS (onco) MOS
227 Require closed
to emptying and mixing
470 systems. Assume minimal
exposure and risk.
HxCDD( 15 ppm) Penta HxCDD( 1 ppm) Penta
(onco) MOS (onco) MOS
4.3 x 10~^ 43 In three years,
to to require closed emptying
3.5 x 10~2 23 and mixing systems.
(Assume minimal exposure
and risk. )
In the meantime, require
protective clothing and
a respirator.
4.3 x 10~4 400
to to
4.3 x 10~5 160
* The PD4 risks were calculated based on the assumption that an applicator empties/mixes the formulation a maximum
of 2 hrs/day for 2 days/week. The PD 2/3 and PD4 information for bag emptying also applies to millwork and plywood
applicators who empty and mix bags of prilled or flaked formulations of pentachlorophenol and to applicators empty-
ing and mixing bags of powdered sodium pentachlorophenate for use in sapstain control.
31 1
-------
Appendix B (continued)
Pentachlorophenol (Penta)
Exposure
Situation
Initial Risk (PD 2/3)
(Without Protective
Measures)
HxCDD(15 ppm) Penta
(onco) MOS
Risk with protective
Measures (PD 2/3)
HxCDD(15 ppm) Penta
(onco) MOS
Initial Risk
(PD 4) Without
Protective Measures
HxCDD(15 ppm) Penta
(onco) MOS
Ri.sk with Protective
Measures
(Final PD 4 Requirement)
HxCDD(1 ppm) Penta
(onco) MOS
2. Non-pressure
treatment uses
a. Poles/
Groundline
Not
determined
Not Require gloves and pro-
deter- tective clothing. (Re-
mined duce total dermal exposure
by 80%.)
Not
determined
Not
deter-
mined
b. Millwork/plywood [4]
i.) Dip/flow
(5.0%)
7.1 x 10
-3
5.9
Require gloves
7.1 x 10"*5
6.6 x 10
-2
1.2
Require gloves and protective
clothing. (Reduce total der-
mal exposure 80%.)
Require gloves
4.3 x 10~4
12
ii.) Spray Require gloves
(2.5%) and respirator
[2J9.8 x 10~3 [2]10 2.4 x 10~4[2]
40012] [3]3.3 x 10~2 [3J2.4
Require gloves
[3]1.9 x 10"4 [3] 23
In addition require respirator and
protective clothing if visible mist
present in the vicinity of the
apparatus.
[213.4 x 10~2 [2]2.3 [2]2.5 x 10~4
[2] 23
[1] Van Ormer (1982d) has corrected this PD 2/3 MOS number to 590.
[2] Assuming the applicator is in the vicinity of the enclosed spray apparatus and is exposed to both HxcDD and
Pentachlorophenol (dermal and inhalation).
[3] Assuming the applicator is 30 to 40 feet away from the enclosed spray apparatus, is only exposed to pentachloro-
phenol vapors, not HxCDD, but is exposed dermally (hand contact) with the treatment solutions.
[4] The Agency considered cancelling registrations of pentachlorophenol for mi11work and plywood use because of the
potential oncogenic and teratogenic/fetotoxic risks. While the economic impacts of a cancellation are considered
to be minor in terms of absolute dollars (Section II.C.2.d. of this PD 4), the impact would be significant for
users who would not have an equally efficacious alternative chemical to apply. Section VI.H.I. of this PD 4 dis-
cusses in detail the bases for not cancelling pentachlorophenol registrations for this use.
312
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Appendix B (continued)
Pentachlorophenol (Penta)
Exposure
Situation
Initial Risk (PD 2/3)
(Without Protective
Measures)
HxCDD(15 ppm) Penta
(onco) MOS
Risk with Protective
Measures (PD 2/3)
HxCDD(15 ppm) Penta
(onco) MOS
Initial Risk
(PD/4) Without
Protective Measures
HxCDD(15 ppm) Penta
(onco) MOS
Risk with Protective
Measures
(Final PD4 Requirement)
HxCDD(1 ppm) Penta
(onco) MOS
c. Sapstain
(Sodium penta-
chlorophenate)
i.) Dip/flow[3]
(5%)
ii.) Sapstain
Spray
(0.5%
Solution)
7.1 x 10
-4
59
Require gloves
7.1 x 10 "
-6
6,000
6.6 x 10
-2
Require gloves
60
4.3 x 10
-4
600
x 10"3 [1]50
Require gloves
and respirator
[1]4.8 x 10~5 [112,000
Require gloves.
[2}6.8 x 10~3 [2J440 [214.3 X 10 ~5 [2]1300
In addition require
respirator and protective
clothing if visible mist
present in the vicinity
of the apparatus
[1J6.8 x 10~3 [1]200 [1J3.8 x lO"5
[112000
[1] Assuming the applicator is in the vicinity of the apparatus and is exposed to both HxCDD and pentachlorophenol
(dermal and inhalation).
[2] Assuming the applicator is 30 to 40 feet away from the enclosed spray apparatus, is only exposed to pentachlorphenol
vapors (not HxCDD), but is exposed dermally (hand contact) to the treatment solutions. The Agency assumed that an
applicator may spill 6.0 mis of a 5% sodium pentachlorophenate solution to cover the hands (Day, 1982).
[3] Assume a. 5% solution of sodium pentachlorophenate, a 50% dermal absorption rate for HxCDD and a 1% dermal absorption
rate for sodium pentachlorophenate in an aqueous solution (Rispin, 1984).
313
-------
Appendix B (continued)
Pentachlorophenol (Penta)
Exposure
Situation
Initial Risk (PD 2/3)
(Without Protective
Measures)
HxCDD(15 ppm) Penta
(onco) MOS
Risk with Protective
Measures (PD 2/3)
HxCDD(15 ppm) Penta
(onco) MOS
Initial Risk
(PD/4) Without
Protective Measures
HxCDD(15 ppm) Penta
(onco) MOS
Risk with Protective
Measures
(Final PD4 Requirement)
HxCDDd ppm) Penta
(onco) MOS
d. Home and Farm
i.) Brush-on*
-Indoor
Application
1 x 10~4
Prohibit indoor
appl i c a tio n.
No risk.
6.2 x 10""4 1.2 Prohibit indoor applica-
tion. No risk*
-Outdoor
Application
1 x 10~4
ii. Spray
Application
Not
determined
Not
determined
Require gloves
1.3 x 10
-6
560
Require respirator
and protective
clothing. (Reduce
total dermal ex-
posure by 80% and
inhalation exposure
by 90%.)
6.2 x 10'
1.2
Not Not
determined determined
Require gloves. Use respira-
tors during application
if inhalation of vapors cannot
be avoided.
6.2 x 10~6 12
Reduce acute toxicity due to
inhalation of vapors by 90%.
Require respirator and pro-
tective clothing. (Reduce
total dermal exposure 80%
and inhalation exposure
90%.)
* The PD4 oncogenicity risks for brush-on home and farm applications were calculated based on the assumption that an
applicator applies the formulation once every three years for 2 weeks duration (Burnam, 1983). The Agency also
assumed that an applicator may spill 6.0 mis of a 5% pentachlorophenol solution to cover the hands (Day, 1982).
For a home and farm user who does odd jobs outdoors and who may use pentachlorophenol more frequently, the Agency calcu-
lated the potential risks as follows: if a worker applies a 5% pentachlorophenol solution 120 days per year for a 30
year working lifetime the oncogenic risk is 2.6 x 12~2( 15 ppm HxCDD) and 2.1 x10~3 (1 ppm HxCDD) if no gloves are
worn. The risk is 2.1 x 10~4 (1 ppm HxCDD) if impermeable gloves are worn. The MOS for fetotoxic effects is 12.
31 4
-------
Appendix B (continued)
Pentachlorophenol (Penta)
Exposure
Situation
Initial Risk (PD 2/3}
(Without Protective
Measures)
HxCDD(15 ppm) Penta
(onco) MOS
Risk with Protective
Measures (PD 2/3)
HxCDD(15 ppm) Penta
(onco) MOS
Initial Risk
(PD/4) Without
Protective Measures
HxCDD(15 ppm) Penta
(onco) MOS
Interior Use of
treated wood.
Occupational
End-Use.
Poorly Ven-
Negligible
510
Prohibit interior
use. No risk
Negligible 4300
to
1000
Acute toxicity
b.
Occupational
End-Use.
Well
ventilated.
Negligible
7,900
Prohibit interior
use.
No risk.
Negligible 7,900
Acute toxicity
Risk with Protective
Measures
(Final PD4 Requirement)
HxCDD(1 ppm) Penta
(onco) MQS
Prohibit interior use except
for support structures where
necessary.
Require Sealers 7,500 to
Negligible >10,000
Reduce acute toxicity 80%*
Prohibit interior use except
for support structures where
necessary.
Require sealers.
Negligible >10,000
Reduce acute toxicity 80%
315
-------
Appendix B (continued)
Pentachlorophenol (Penta)
Exposure
Situation
Initial Risk (PD 2/3)
(Without Protective
Measures)
HxCDD(15 ppm) Penta
(onco) MOS
Risk with protective
Measures (PD 2/3)
HxCDD(15 ppm) Penta
(onco) MOS
Initial Risk
(PD/4) Without
Protective Measures
HxCDD(15 ppm) Penta
(onco) MOS
Risk with protective
Measures
(Final PD4 Requirement)
HxCDD(1 ppm) Penta
(onco) MOS
Residential
end-use of
commercial
dip/pressure
treated wood
Not determined
prohibit interior Use
d.
Residual
end-use of
aged treated
Not Determined
Prohibit interior use
Negligible 940 Prohibit interior use except
to for support structures where
4000 necessary. Require sealers.
Negligible. 6,300
to
>10,000
Acute toxicity Reduce acute toxicity by 80%.
Prohibit use of nonpressure
penta treated logs for log
homes.
No
risk
Negligible 1,900 Prohibit interior use except
to for support structures where
38,000 necessary. Require Sealers.
Negligible. >10,000
Acute toxicity
Reduce acute toxicity by 80%.
316
-------
Appendix B (continued)
Inorganic Arsenic
NOTEs
The estimates for oncogenicity risks for inorganic arsenic were summarized from Rispin (April 18, 1984). Data were in-
adequate to allow calculation of a NOEL for teratogenic/fetotoxic effects; thus, MOS risks were not estimated (Sochard,
1983). The PO 2/3 inhalation and dermal oral risks were calculated using linear dose-response risk models based on epidi-
miological data (PD 2/3, p. 215). The PD4 inhalation risks were also calculated using a linear dose response model but
were based on new epidimiological data (U.S. EPA, June 1983; McGaughy, April 24, 1984; and Rispin, April 18, 1984). The
PD4 dermal/ oral risks were calculated using a linear dose response model different from that of the PD 2/3, but using the
same epidimiological data (U.S. EPA, June 1983; McGaughy, April 24, 1984; and Rispin, April 18, 1984). For a detailed
summary of exposure assumptions, see Appendix C.
Initial Risk (PD 2/3) Risk with protective
Exposure
Situation
Without Protective
Measures
Oncogenic
Measures (PD2/3)
Oncogenic MOS
MOS
1. Pressure treatment plant
Initial Risks (PD/4) Risk with Protective
Without Protective Measures (Final PD4 Requirement
Measures Oncogenic
(Onco)
Exposure to
ambient
arsenic*
Require dust masks
1.9 x 10
-2
500
3.8 x 10
-3
2,500
4.1 x 10
Require respirators if the
arsenic level is unknown or
~3* exceeds 10 ug/m3.
4.1 x 10"5*
b. Opening cylinder
doors
Not determined
c. Entering cylinder Not determined
Require gloves (Reduce Not Determined
dermal exposure by 99%)
Require protective Dermal risk
clothing and respirator not determined.
(Reduce inhalation ex-
posure by 90% and dermal
exposure by 80%.)
4.1 x 10
-3*
Require gloves
(reduce dermal exposure by 90%)
Require protective clothing to
reduce total dermal exposure by
80%.
If 10 ug/m3 exceeded or unknown
require respirators.
4.1 x 10~5*
* Inhalation risks based on an assumed exposure of 10 ug/m3 inorganic arsenic levels in the air averaged over an 8-hour
workday (Rispin, April 18, 1984).
317
-------
Appendix B (continued)
Inorganic Arsenic
Exposure
Situation
Initial Risk (PD 2/3)
Without Protective Risk with protective
Measures Measures (PD 2/3)
Oncogenic MOS _ Oncogenic _ MOS
d. Handling freshly
treated wood
and mixing (d + i)
dilute formu- 2.6 x 10~2
e. Bag emptying
3.4 x 10
-2
(d + i)
417
Require gloves
(d + i) (d + i)
1.9 x 10~2 499
294
Require closed systems.
(minimal risk)
Initial Risk (PD/4)
Without Protective
Measures
(onco)
6.2 x 10
-3
(d)
4.1 x 10~3 (i)*
7.3 x 10~3 (d)
4.1 x ID"3 (i)*
Risk with Protective
Measures (Final PD4 Require-
ment) Oncogenic
Require gloves
(reduce dermal exposure 90%)
6.2 x 10~4 (d)
Require gloves and respi-
rator if 10 ug/m3 arsenic is
exceeded or unknown.
4.1 x 10~5 (i)*
Require closed systems.
(minimal risk)
Brush-on
Applications
Interior Uses
1.2 x 10~2 1,667
9.0 x 10
-6
128,000
Require gloves and
coveralls
1.2 x 10~4 170,000
Prohibit interior uses
except for all-weather
wood foundations, plates,
sills, structural
framing, timbers, and
pole supports.
2.8 x 10"3 (d)
4.7 x 10~5(i)
i**
Require gloves and
coveralls
2.8 x 10
-4
(d)
Allow interior uses of
arsenic pressure - treated
wood.
4.6 x 10~6 (i)***
* Inhalation risks based on an assumed exposure of 10 ug/m3 arsenic in ambient air averaged over an 8-hour work
day (Rispin, April 18, 1984).
** Based on 0.031 ug/m3 arsenic air levels (PD 2/3, p. 200).
*** Based on 0.004 ug/m3 arsenic air levels (Koppers, Nov. 15, 1983) where wood surfaces were vacuumed to be free
of dust.
318
-------
Inorganic Arsenic
Exposure
Situation
4• Sawing/
fabricating
treated wood.**
Initial Risk (PD 2/3)
Without: Protective Risk with Protective
Measures Measures (PD 2/3)
Oncogenic MOS Oncogenic MOS
Initial Risk (PD/4)
Without Protective
Measures
(onco)
Require dust masks
and coveralls
1.3 x 10~1
to
1.6 x 10~1
128
to
106
2.7 x 10~3
to
3.0 x 10~3
>3,000
3.1 x 10~4 CCA (g)
7.6 x 10~4 ACA (g)
8.6 x 10"4 CCA (i)
2.1 x 10~3 ACA (i)
Risk with protective
Measures (Final PD4 Require-
ment) Oncogenic
Require dust masks
6.2 x 10~5 CCA (g)
1.5 x 10~4 ACA (g)
1.7 x 10~4 CCA (i)
4.2 x 10~4 ACA (i)
**
PD 2/3 risks (p. 701) based on dermal, inhalation, and gastrointestinal exposure. PD 4 risks based on inhalation
and gastrointestinal exposure, assuming negligible exposure from dermal contact with arsenic treated wood
(Zendzian, 1982).
d = dermal; i = inhalation; g = gastrointestinal exposure
319
-------
APPENDIX C
Comparison of the Recalculated Exposures
for Pentachlorophenol and Inorganic Arsenic
With and Without Protective Measures
(Final Regulatory Position)
320
-------
Exposure Assumptions for Appendix C
Inorganic Arsenic
1. The dermal absorption for inorganic arsenic solutions (1.7% ACA
solution for pressure treatments) and treated wood which subsequently
becomes wet with water is 0.1%. six mis are assumed to contact the
hands.*
2. The dermal absorption for dry inorganic arsenic (powder or arsenic-
laden dust) is 0.1%.** FCAP (Fluor chrome arsenic phenol) is assumed
to contain 9.59% arsenic as metal.*
The dermal exposure for 1 hour of bag emptying is estimated to range
from 3.8 to 142 mg/hr,* based on Comer (1975), Jegier (1964), and Wolfe
(1978).
3. The dermal absorption for inorganic arsenic from dry treated wood and
arsenic-laden sawdust is negligible.***
4. The inhalation and gastrointestinal absorption rates and depositon
rates for sawdust from nailing, sawing, or fabricating arsenic-treated
wood are:*
27% for CCA (chromated copper arsenate)
65% for ACA (ammoniacal copper arsenate)
10% of the sawdust particles are respirable
90% of the sawdust particles will be ingested
5. For brush-on application, the arsenic concentration is assuned to be
3.3%.* Inhalation risk is assumed to be minimal (PD 1, 43 FR 48267)
because it is applied as a viscous liquid and vapor pressure is low.
The PD 2/3 (p. 211) stated that this exposure was "intermittent." When
risks were calculated in this PD 4, it was assumed that 6.0 mis covers
both hands during an accidental exposure and that this may occur 60 days
per year (Smale, May 11, 1984).
6. The inhalation and gastrointestinal absorption rate for arsenic from
arsenic-laden dust and for water soluble salts of inorganic arsenic
is 100%,* because there are no data to indicate otherwise.
7. The time a resident spends at home is 15 hours a day.*
8. The estimated concentration of inorganic arsenic in the air at
treatment plants is 10.0 ug/m3,* based on measured levels reported
in the PD 1 (43 FR 48267) and data submitted by AWPI (36C:30000/28C).
9. The estimated inhalation exposure in homes with all-weather-wood
foundations is 0.004 ug/m^ based on data submitted by Koppers
(Nov. 15, 1983).
10. The estimated inorganic arsenic air concentration while nailing,
sawing, or fabricating with arsenic-treated wood is 0.024 mg/m3,*
based on a study submitted by AWPI (#36C: 30000/28C) from the Uni-
versity of Minnesota.
* Day, May 19, 1982; revised January 25, 1984; and Rispin, 1984.
** Day, December 9, 1983; and Rispin, 1984.
***Zendzian, April 16, 1982; and Rispin, 1984.
321
-------
11. For pentachlorophenol surface spray treatments, the inhalation exposure
in the vicinity of the spray booth is estimated, in the absence of other
data, to be 5 times that of sapstain spray treatments as per PD 2/3
(p. 322), because the pentachlorophenol solution (2.5%) is 5 times
as concentrated as the sodium peatachlorophenate solution (0.5%).*
12. With sealants, the indoor pentachlorophenol air concentration is
reduced about 85%.*
13. Home and farm applicators use pentachlorophenol for a two-week
duration once every three years.*** This time estimate was taken into
account when the risks were calculated. Six mis of a 5% soution is
assumed to cover both hands during an accidental spill.
14. As in the PD 2/3 (p. 316), the Agency assumes the pentachlorophenol
inhalation exposure while opening cylinder doors is 1.0 mg/m3 based
on data from Arsenault (1976)• It was assumed that workers engage
in this light activity 1 hour per day. HxCDD inhalation exposure was
estimated also,* since mist formation is likely to occur (PD 2/3,
p. 299 and p. 338).
* Day, May 19, 1982; amended January 25, 1984; and Rispin, April 18,
1984.
** Day, December 9, 1983; and Rispin, 1984.
***Burnam, Dec. 2, 1983; and Rispin, 1984.
322
-------
Exposure Assumptions for Appendix C
Inorganic Arsenic
1. The dermal absorption for inorganic arsenic solutions (1.7% ACA
solution for pressure treatments) and treated wood which subsequently
becomes wet with water is 0.1%. Six mis are assumed to contact the
hands.*
2. The dermal absorption for dry inorganic arsenic (powder or arsenic-
laden dust) is 0.1%.** FCAP (Fluor chrome arsenic phenol) is assumed
to contain 9.59% arsenic as metal.*
The dermal exposure for 1 hour of bag emptying is estimated to range
from 3.8 to 142 rag/hr,* based on Comer (1975), Jegier (1964), and Wfolfe
(19J8).
3. The dermal absorption for inorganic arsenic from dry treated wood and
arsenic-laden sawdust is negligible.***
4. The inhalation and gastrointestinal absorption rates and depositon
rates for sawdust from nailing, sawing, or fabricating arsenic-treated
wood are:*
27% for CCA (chromated copper arsenate)
65% for ACA (ammoniacal copper arsenate)
10% of the sawdust particles are respirable
90% of the sawdust particles will be ingested
5. For brush-on application, the arsenic concentration is assumed to be
3.3%«* Inhalation risk is assumed to be minimal (PD 1, 43 FR 48267)
because it is applied as a viscous liquid and vapor pressure is low.
The PD 2/3 (p. 211) stated that this exposure was "intermittent." When
risks were calculated in this PD 4, it was assumed that 6.0 mis covers
both hands during an accidental exposure and that this may occur 60 days
per year (Smale, May 11, 1984).
6. The inhalation and gastrointestinal absorption rate for arsenic from
arsenic-laden dust and for water soluble salts of inorganic arsenic
is 100%,* because there are no data to indicate otherwise.
7. The time a resident spends at home is 15 hours a day.*
8. The estimated concentration of inorganic arsenic in the air at
treatment plants is 10.0 ug/m3,* based on measured levels reported
in the PD 1 (43 FR 48267) and data submitted by AWPI (36C;30000/28C).
9. The estimated inhalation exposure in homes with all-weather-wood
foundations is 0.004 ug/m3 based on data submitted by Koppers
(Nov. 15, 1983).
10. The estimated inorganic arsenic air concentration while nailing,
sawing, or fabricating with arsenic-treated wood is 0.024 mg/m3,*
based on a study submitted by AWPI (#36C: 30000/28C) from the Uni-
versity of Minnesota.
*" 0ay, May 19, 1982;"revised January 25, 1984; and Rispin, 1984.
** Day, December 9, 1983; and Rispin, 1984.
***Zendzian, April 16, 1982; and Rispin, 1984.
323
-------
PENTACHLOROPHENOL
Comparison of Exposures in Various Situations Without and With Protective Measures
(Summarized from Day, May 19, 1982, revised January 25, 1984; and Rispin, 1984)
Dermal + Inhalation in ug/kg/day)
Exposure
Situation
1 . Pressure Treat-
ment Plants
a. Opening cylin-
der doors
b. Entering
cylinders*
c. Bag emptying*
2 « Non-pr es s ur e
Treatment plants
a . Poles/ ground-
line
Without Protective Measures
Total
Penta
exposure/day
20
(inhalation)
Not determined
69 to 129
Not determined
Average daily
HXCDD (15 ppm)
exposure/
lifetime
0.00007
(inhalation)
Not determined
0.0007 to
0.0057
Not determined
With Protective Measures
Total
Penta
expo sure/ day
v
2.0 (1)
(inhalation)
(2)
minimal (3a)
7.5 to 19 (3b)
(4) Dermal ex-
posure reduced
80%
Average daily
HXCDD ( 1 ppm)
exposure/
lifetime
0.0000005 (1)
(inhalation)
(2)
minimal (3a)
0.000007 to
0.00007 (3b)
(4) Dermal ex-
posure reduced
80%
Required Protective Measures
(Final Regulatory Position)
( 1 ) With gloves ( reduce hand
dermal exposure 90%) and
respirator (reduce inhala-
tion exposure 90%) •
(2) Protective clothing and
respirator reduces dermal
exposure by 80% and in-
halation exposure by 90%.
(3a) Require closed emptying
and mixing systems
(Assume minimal exposure)
or
(3b) Protective clothing and
a respirator
(4) Require gloves and
protective clothing
Information also applies to millwork/plvwood applicators and applicators using sodium pentachlorophenate for
sapstain control.
324
-------
PENTACHLOROPHEHOL
Comparison of Exposures in Various Situations (cont'd)
Without and With Protective Measures
Exposure
Situation
b. Millwork/Plywood
i ) dip/flow
ii) spray
c. Saps tain (sodium).
pentachlorophenate )
i) dip/flow
ii) spray
d. Home and Farm
i ) Brush-on
- indoor***
application
Without Protective Measures
Total
Penta
exposure/day
2504
1254*
1300**
50
6.8*
15.1**
2512
Average daily
HXCDD (15 ppm)
exposure/
lifetime
0.0107
0.0054*
0.0055**
0.0107
0.0011*
0.0011**
0.0001
With Protective Measures
Total
Penta
exposure/day
254 (5)
129 (6a)
130 (6b)
5.0
2.3* (7a)
1.5** (7b)
(11a)
Minimal exposure
(11b) 251
Average daily
HXCDD (1 ppm)
exposure/
lifetime
0.00007 (5)
0.00003* (6a)
0.00004** (6b)
0.00007 (6)
0.000007* (8a)
0.000006** (8b)
(11a)
Minimal exposure
(11b) 0.000001
Required Protective Measures
(Final Regulatory Position)
(5) Require gloves.
(6) (a) Gloves required.
(b) Require gloves, protec-
tive clothing and respirator
only if visible mist present
in the vicinity of the
apparatus .
(7) Require gloves.
(8) (a) Require gloves.
(b) Require gloves, pro-
tective clothing and
respirator only if visible
mist present in vicinity
of spray apparatus.
(11a) Prohibit indoor application.
(11b) Allow application with
gloves where vapors cannot
permeate to interiors. Wear
respirators during appli-
cation if inhalation of
vapors cannot be avoided.
**
30 to 40 feet away from the enclosed spray apparatus. (Assume no exposure to HxCDD vapors due to low vapor pressure
but assume dermal contact with treatment solutions.)
In the immediate vicinity of the enclosed spray apparatus. Assume both dermal and inhalation exposure for penta-
chlorophenol and HxCDD.
*** Exposure estimates assume 6.0 mis solution covering the hands.
325
-------
PENTACHLOROPHENOL
Comparison of Exposures in Various Situations (cont'd)
Without and With Protective Measures
Exposure
Situation
- outdoor
appl ic ation* *
ii) Spray Appli-
cation
3 • Interior Use of
Treated Wood
a . Occupational
End-Use. Poorly
Ventilated
b . Occupational
End-Use. Well
Ventilated
c. Residential end-
use of commercial
dip/pressure treated
wood
d. Residential end-
use of treated wood
Without Protective Measures
Total
Penta
exposure/ day
2500
Not determined
0.7 to
3.0
( inhalation)
0.38
(inhalation)
0.8 to 3.0
(inhalation)
0.1 to 1.6
( inhalation )
Average daily
HXCDD (15 ppm)
exposure/
lifetime
0.0001
Not determined
*
*
*
*
With Protective Measures
Total
Penta
expos ure/day
251(12)
(13)
0.1 to
0.4 (9)
(inhalation)
0.06 (10)
(inhalation)
(14a) 0.11 to
0.48
(14b) No ex-
posure
(15) 0.01 to
0.23
Average daily
HXCDD ( 1 ppm)
exposure/
lifetime
0.000001 (12)
(13)
(9) *
(10) *
(14a) *
(14b) No ex-
posure
(15) *
Required Protective Measures
(Final Regulatory Position)
(12) Require gloves .
(13) Require respirator (reduce
inhalation exposure 90%)
and protective clothing
(reduce total dermal ex-
posure 80%)
(9) Prohibit interior use
except where necessary.
Sealers required.
(10) Prohibit interior use except
where necessary.
Sealers required.
{ 14a) Prohibit interior use
except where necessary.
Require sealers .
(14b) prohibit use of non-pressure
treated logs for log homes.
(15) Prohibit interior use
except where necessary.
Require sealers.
*
**
It is assumed that HxCDD exposure is negligible, due to its low vapor pressure.
Exposure estimates assume 6.0 mis solution covering the hands.
326
-------
INORGANIC ARSENIC
Comparison of Exposures in Various Situations
Without and With protective Measures (Summarized from Day, May 19, 1982, amended Jan
Exposure
Situation
1. Pressure Treatment
a. Ambient air
levels*
b. Opening cylinder
doors
c. Entering
cylinders*
d. Handling
freshly treated
wood or mixing
dilute solutions
e. Bag emptying
FCAP**
Without Protective Measures
mg/kg/day
0.0015 (inhalation)
Dermal exposure not deter-
mined
Dermal exposure not deter-
mined
0.0015 (inhalation)
0.0017 (dermal)
0.002 (dermal)
0.0015 (inhalation)*
With Protective Measures
rag/kg/day
0.000015 (1)
(2)
Dermal exposure not deter-
mined (3a)
0.000015 (inhalation) (3b)
0.00017
Minimal exposure (5)
25, 1984. and Rispin IS
Required Protective Measures
(Final Regulatory Positiojn)
(1) Require respirators if the
arsenic level is unknown
or exceeds 10 ug/m3. (Reduce
inhalation exposure 99%.)
(2) Require gloves to reduce hand
dermal exposure by 9p%.
(3a) Require protective (clothing.
This reduces total dermal
exposure by 80%.
(3b) Require respirators if the
arsenic level is unknown or
exceeds 10 ug/m3.
(4) Require gloves.
(5) Require closed systems.
* Assume 10 ug/m3 inorganic arsenic to estimate inhalation exposure (Rispin, April 18, 1984)
** Fluor Chrome Arsenic Phenol
327
-------
INORGANIC ARSENIC
Comparison of Exposures in Various Situations
Without and With Protective Measures
(cont'd)
Exposure
Situation
Without Protective Measures
mg/kg/day
With Protective Measures
mg/kg/day
Required Protective Measure
(Final Regulatory position)
2. Non-pressure treat-
ment brush-on
applications
(outdoors)
3. Interior uses of wood
pressure-treated
with inorganic
arsenic
4. Handling/fabricating
treated wood
0.003 (dermal)
(inhalation negligible)
0.0000006 (inhalation)
(dermal negligible)
0.000086 CCA*
0.00021 ACA*
0.000095 CCA**
0.00023 ACA**
(6) 0.0003
(6) Require gloves and
coveralls.
(7) Allow interior use if
wood surfaces are
vacuumed.
0.0000172* (8)
0.000042* (8)
0.000019** (8)
0.00046** (8)
(8) Wear dust masks; reduce
inhalation and gastro-
intestinal exposure
by 80%.
* Gastrointestinal exposure as a result of inhaling arsenic-laden sawdust particles which become deposited in
bronchial passageways, are brought up by ciliary action and then swallowed. (Rispin, April 18, 1984).
** inhalation exposure as a result of inhaling arsenic-laden sawdust (Rispin, April 18, 1984).
328
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APPENDIX D
Scientific Advisory Panel (SAP) Comments
329
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Oi.Tito i. ••,;-- -.?• , in-;,i-^.; *± rr.'STZC'HGtf'TiGZtl CY
\*
July 13, 1981
HQfflKAKDUH
SUSJSCT: SL^Tlev of FEF3A Section 6(1)) (1) Accion on
Inorgaakc Arsenicals, and Creosoca (Vood Preserracives)
rSOMi Philip E. Gray, Jr.
Executive Secretary
HP8A Sci«acif ic
TOt Deputy Assistant. Adalnistratar
for Pesticide Programs (TS-766)
Ifie FTT2A Scientific. Advisory Panel has completed reriew of the
Hocice of Deterainatiott eaneludiag- the Refaurtabla Prasnaption Agaiasc
lagistratiou. (1PAS.) of pentacalorophenol, inorganic arsenic a Is and
creosote (Wood Preservatives). The review was completed in an. open.
n»eting held. ia. Arlington, Virginia, during the period June 17-13,
1981.
Attached. Is a. report of findings- by Che Panel-
Report
cer- Mr. Conlon
Ks-. Marcia ffilli^&s
Or. Hcflrath
Ms* Susan Sheraan
Ms. Joan Sarshawsky
Us. Beatty
Mr. Clark:
Mr. Smith - 17S2A
Hz. Ashmors
Panel Members
330
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F2DESAL IHSECnCXBi, FUNGICIDE,. AND aODEXTICIDE ACT (FITSA)
SCIENTIFIC ADVISOST PAHSL
Review of Preliminary Sociee of 3«terainaeion
Concludi-flg che Rebuctaale Presumption Against
Registration. (IPAS.) on, Wood Preservative
Uses of Pentachlerophenol,
Inorganic ArsenicaIs, and Creasoce
The Federal Insecticide, Fungicide, and Rodencicide Ace (TTT2A) Scientific
Advisory Panel has compleced reviev of plans by the Environmental Protection
Agency (EPA) for initiation of regulatory action on pesticide products
containing pentachlorophenol, inorganic arsenicals, and 'creosote under
Che provisions- of Session. 6(b)(l) of. FIT1U as amended, 'the review was
completed in open meetings held, in Arlington, Virginia, during che period
June 17-19, 1931.. The following Panel meabers participated la the reviev:
.. Torgeson, Davis, Saucklar, Oavies, and Jietealf (June, 17. and. 13).
public participation vas encotsraged for Che reviev. Public
notice of che. oeecing vaa published Is the Federal Register on
Tuesda7, June 1, 1981* In. addition, telephone calls were received
from and. special oailings seas co che general .public expressing ao.
inter esc la aesivities of the Panel- Written and. oral statements were
received .from the technical staff: of che Snvironsental Protection Agency,
froa representatives of- che American Wood Preservers Institute, Cherokee
Industries, Inc.., and from1 several private Individuals.
The Panel wishes to express its appreciation TO Special Pesticide Reviev
Division and Hazard Evaluation Division staff for their informative
briefings. In particular, she Panel wishes co thank Dr. Kinnie Sochard
far an -outstanding scientific briefing on the sutageniciry of the
inorganic, arsenical compounds. On che other hand, che. Panel deplores
die lack, of scientific objectivity of the presentations by industry
concerning biological hazards of wood preservatives, and finds the
industry's denial of scientific data concerning the sutagenicity and
cardnogenicity of the wood preservatives co be disturbing.
la, consideration of all matters brought, out during the oeeting and
careful reviev of *j,i documents presented by che Agency and other
parties, the Panel unanimously submits the following report:*
page numbers In che report refer so the SPA Position Document 2/3
331
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Report- of Scientific Advisor* Panel Reeoaaendations_
The Agency requested the Panel to focus ic* attention upon a see
of issues relating to. each of che three vood preservatives Cor groups
of wood preservatives) under consideration* There follows a list of
the issues and the Panel's response thereto:
PEKTAC5LOROPHEHOL
1. la PD-1, margins of safety were calculated based on a no
observable effect level (NOEL) of 5.3 eg/leg/day (commercial peacs)
ia a rat teratology study- However, since 2.0 tag/kg/day purified
penta. produced delayed skull ossification in the same study and this
was the lowest dose tested, the Agency stated in the PD-2/3 that no
HOEL could be accurately deterained. Does the Panel agree that the
occurrence of delayed skull ossification indicates an adverse effect
which precludes the establishment of a NOEL at that level?
Panel Responsei
The Panel believes thac one muse assume some effect on. ia utero
growth, gives the. considerable loss of litters ia the rat teratology
study. Therefore, the Panel agrees that establishment of a No Effecr
Level (HOEL) at 5.3 mg/kg/day is precluded both by the litter loss
phenomenon, and by the delayed skull ossification which occurred at the
above level ia the rar study -
2. Although the fetatoxic margin of safety for homeowner applica-
tion, was estiaated to be as low as 5 (see p. 327) and the oncogenie
risk was estimated to be as low as 1.3 x 10"4" (see p. 364), the Agency
did not propose to restrict the sale of over-the-counter products
containing 5Z or less penta (i.e., ready-to-use penta products). These
upper bounds of the risk, estimates were based on the assumption, that
the individual say spill an amount of commercial penta on himself equiva-
lent to the amount that would cover both .hands ti«e. , 5 ai; see pp. 331-
332), a situation thac the Agency does sbc consider likely. Does the
Panel believe the Agency is adequately protecting human health by
permitting the over-che-eouater sales of. 51 or less penta. to continue?
Panel Response;
The Panel believes thac the Agency is adequately protecting human
health by permitting the over-the-counter sales of 51 or less penta
to continue, provided that the label requires: 1) use of protective
clothing, including rubberised gauntlets, goggles and coveralls; and
2) that all uses take place in a well ventilated area.
332
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3. The Agency's estisaee of risk Co log home residents is currently
based on ehe ehree aeasuresents of airborne penta la- penta-creaced log
hoses (0.77, 0.38, and 0.20 ug/a 3-. Although the Agency has proposed
Che. prohibition of future use of- penta on che incerior surfaces of living
quarters, does- ehe Panel have any opinions, regarding che aeed for further
exposure studies of log homes?
Panel. Response t
The lade of- data on human exposure ca penca suggests chat a sore
critical review of che fate of* penca and its pathways in ehe environment-
is badly needed. A. full assessment of human, urinary excretion of penca,
which appears co be, widespread la Che U.S. population is aosc important.
Additional exposure and epideaiological studies should be conducted*
Any future decisions regarding- penta should, be based on che additional
data.
4» The Agency has information; suggesting chat penta is photo—
lytically converted, co hesachiorodibenso'-p-dioxin. and hesachlarobeazener
Does the Panel believe che Agency* should investigate this subject
further in order Co adequately assess che risk co individuals exposed Co
peata—treated wood?
*
Panel Response;
Tea,
5- On. pages 273-27.4- of FD-2/3, ehe Agency addresses ehe role of
the wood preserviag industry as a source- of ambient background levels
of- penta. in. che environment:. In Che absence of data co ehe contrary, • .
Che Agency's eommonsense approach assumed chat che amount: of ambient.
penta levels contributed by an industry is related co che amount of penta
used by chat industry' The wood preserving industry uses about 80Z
of Che penta. produced la che ff.S. Dees che Panel agree with chis
approach? If not, can. che Panel suggest a. feasible/appropriate method
of aore accurately addressing che question of. che source of environmental
penta? '
Panel Response:
The Panel believes chat it is essentially che Agency's responsibility
to develop a method of determining che source of environmental penta.
Zs general, che Agency's- reasoning appears co be sound. However, che.
Panel wishes co stress.che need..for determining che use(s) of che
remaining 20 per cent of che penta produced in che U.S., in. order chat
an- accurate exposure assessment can be oade.
333
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The- A;ene? also presented the Panel with a. see of proposed regula-
tory actions and codifications relating co peata. "These actions are
listed below followed by cha Panel's recommendation:
1*. Require Protective Clothing: GlovesT Panel concurs, with Che
proviso that elbow length rubberised gauntlets be required, noe
merely gloves.
2* Seqqire Protective Clothing: Disposable Coveralls: Panel
concurs.
3. jj-equirg Gloves and: aespirators- During Spraying (non-praasure)
and. Opening Cylinder Doors (Pressure Ireaeaenc Planes):
Panel concurs, with Che proviso chac coveralls be required
as veil as gloves and respirators.
4. Require Dusf Masks; Hoc applicable Co- penta.
5». Seaulre Proper- Distioaal of Procaettlve Clothln'g: Panel caacars.
G»- Prohibig Zaeing-. Orlaklny, and Smoking During Agplieatipn!
Panel concurs-
7.. Require Closed System During Sao eying and Mijeiag Q-peraglons:
Panel concurs,, with cha proviso chac such systess be reeotagended
foe use wherever practicable,, racher than required. The Panel
believes suck a requirement: would iapoae an >mf?,lr burden, on
saall operators- in ceras- of additional capital laves taenc, and
it encourages- cha Agency to search, for less cos elf alternatives.-
3* Classifr for- Restricted Use: Panel concurs; however, sea also
Pan* I response to Issue •/ 2, page 2.
?.• Liaic. ApoLieacion of- Pesticide or Use of Treated J7ood Co Outdoors:
Panel concurs, out 'wishes also to express its"coacern over cha
pro blast of disposal of created wood.
0^ Prohibit CTses Likely to Result in- Coata"-1 nation of Food., ?eed or*
Potable Wacar: Panel concurs.
Hoc applicable co- penta.
12. Cancel. .Spray Application for Homeowner Use; Panel concurs.
13. Require Protective dothiag: Neoprene Suit and Slesniracor:
Panel concurs.
334
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Ia. concluding -its review of penta,- the Panel wishes eo stress evo
further points;. (1) EPA should iapose aw ibniroring- reqyiresents ia
order eo establish eie sources of penta. in~che environaenc; and (2)
EPA shauld require industry eo reduce the. dioxia. contenc of penta. to
•slow a level, as is eechnolosically and economically feasible.-
TSORGAfflC
There follows a set of issues relating to the inorganic arsenicals
posed to the Panel, by 2PA and Che Panel's response ehereto:
1* Gives, cnar arsenic occurs predominantly in the pentavalent
oxidation, state ia craacad wood, pro bless still remain, in Che speciation
of arsenic, in """T? T s and the environment and in the determination. of
the effective-, toxicological ageat.
a) Ho« caa. analrciaal problaas of determining the species of.
arsenic ia, the Taiwanese vell-vater study be besc. resolved
for* risk assessment? (CAff, 19?8b)
b) If peatavalenfi arsenic is absorbed, vill is convert in. the.
body eb trlvalenc 'arsenic? (pp. 95-101)
Panel response :
The Panel, does., noe believe chare is-, sufficient scientific, inf oraa—
eiott to resolve this question: ar. che, present, time.
2. The estimated oncogenic risks associated vich che use of arsenic
as a wood preservative are very high. The regulatory options are not
correspondingly stringent. (Chapter 5). Consequently,
a) Are the Agency's exposure calculations for workers and'
consumers realistic: (pp. -135-210)
b) Is the ieraal absorption factor used to estiaate huaan.
exposure to arsenic from treated wood appropriate? (p. 199)
c) Is it appropriate to use cfae Taiwanese study,, the smelters
study and other epidemiology studies (ia which total
arsenic levels, are used, regardless of oxidation state)
to estimate exposure co (pentavaleat) arsenic in treated
«jod2 (pps- 214-217)
d>* Are. there other factors affecting che oncogenic potency
of arsenic in che epideaiology studies on which che risk.
aadel is- based?
335
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Panel Response;
The Panel chaoses aoc co respond, directly co Che fouc pares o£
Question 12. However, Che, Panel does, believe; thac wish Che additional
rscesnnendations- vttich it is. taking la connection with che Agency's
proposed regulatory options and. modifications» Sjuch options and modifi—
cations are sufficiently stringent to reduce risk, due to arsenic exposure
to- a, satisfactory level*
3~ If additional sampling needed, to determine exposure to arsenic
ia allrveataer wood, foundations? The Agency Is conceded because,
a) Exposure ranges- from. the. Rational Bureau of Standards
(HBS), American. Wood Preservers Institute (AK?T), and.
National Concrete and Masonry studies vary siguificantly,
(p- 189)
b) Toe. air sampling techniques, used, may aoc have been.
appropriate,. !.«., air volume of samplers,, filter oaterials,.
absence of arsine gas- aeasuremencs.
Panel response:
•The. Panel, does aoc believe that, additional oeasureaents. are necessary -
4.. Should the Agency reconsider* the. present teratology and. zaco—•
toxLciST triggers- for- the inorganic arsenicals?
Fanel response:
The Panel does aoc believe chac the teratology and. f etotosicicy
triggers-need, ta be reconsidered''- However, additional exposure data
on. the- arsenicals is needed, and. the Panel encourages S?A. to develop
and. izipleaenc. aonicpriag studies- to obtain such.,data*
With- regard to the sec of proposed regulatory options, and modifi-
cations for the inorganic arsenicals, the Panel concurs in. 4!! the
proposed actions applying- to. both penta and arsenic, with the same
provisos as indicated, above- With regard to the options pertaining-
ta arsenic alone„ che. Panel recomaends as follows:
4. Reg-airs- Duse Masks;. Panel concurs.
10. Prohibit Uses Likely co. Result in Contamination of Food,
Feed, or Potable Water (also applicable to penta. ana, craosaeal
Following discussion af the apparent need for arsenic treatment
of grape stakes, a. use I3A has proposed car selling, the Fanel
chooses to defer to EPA's judgaenc on this issue.
336
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Arsenic Surface Residues on ^Treated good.
The Panel recommends, seducing arsenical, (residues as created
wood by wins clean, wood cor treatment. The Panel, also notes-
the need far developing- a good sealant for outdoor wood, created.
with arsenic*
There follows a- sec of issues- relating co creosote posed co the-
Banel by ETA. and. che Panel's response thereto:
I* The Agency decerainacinn. chat creosote Is. a aucagen is. based
oa consideracioa oc the following issues (see pp. 75-81):
a) Creosote is a. coaplexr aisure- exhibiting toxicity as veil
as sretageaicity: Cseosote SI and ?2 are.'denonstrablj
*me4_/* lt^ m< /•^nM $\_ »^
-------
3. The Agency perforned a qualitative evaluation, rather thaa
* quantitative risk assessment, for oncogeaicity of creosote (se«
pp. 85-94} because of the variable composition of-creosote due to
source and industrial preparation, synefsism aaong its chaaical
components, insufficient exposure iafornatioa and. lack of an appro-
priate tpideaioiogy study for. direct, estimation, or human.risks* Does
the Panel advise the. Agency to- ask. for:
a.) Rodent inhalation studies- using- creosote aerosols?
b) Epidemiology studies- of wood, preservative treataenr plant,
workers?
e) More extensive- exposure studies is. wood preservative pressure-
treatment plants in- which, creosote vapor and polycyclic parties—
late organic natter (?POH) are sampled quantitatively and.
qualitatively (the-Lac tar to. identify cheaical profiles of air—
borne material)?
Panel res-ponser.
The Panel, believes- there- is- enough rodent data available- on. creosote-
Hovever, ic. does recoamend, additional epideoological studies- of wood
preservative- creataenc plane, workers, and. more, extensive ecposure- studies
ia, such, plants.
4. It has- been, brought, to: the Agency's attention chat, some, creosote-
is used ia coaaercial acre-pressure- operations. Does the Panel, advise
thac the Agency seek: exposure data, forr estimation or hazard ta workers-
ia- non-pressnre creacaent, plantsT
Panel res-ponse:
The Panel believes: ie logical chat EPA. seek, such information.
5«> Creosote for* hone and fara use* railroad tie repair-, and
groundliae treataent of ,po-les is being proposed as restricted to certified
applicators- only* In, light- of the lack; of exposure data, other than
isolated case studies, does the Panel chink this restriction is justified?
Page! response:
The Panel believes che- certified applicator requirement justified
except in. che case of fara use where it- appears to be coo restrictive.
The Panel suggests the Agescy examine ways to alleviate this situation.
338
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tflch regard co- Che Agency's proposed regulatory options and modifications
pertaining co craosoca, che Panel concurs In-all of. the Agency's recoo-
mendacious visit one excepciotu As. indicated above, Che Panel believes
it unfair co ssall £araars eo require, chea, co seek certification ia order-
to. use creosote and. recommends char ways be found of enabling f araers
to use cals- coapound wichouc becoaiag cerrified.
Th* Panel also recommends ehac SPA examine further ehe possible use of
sealants is conneccioa «lch indoor uses of creosote, some of whieix cixe
industry claims are essential.
Certif led as aar accurate report of Findings :
Eaecacive Secpecary
IITSA. Sciencif ic. Advisory Panel.
tr
339
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APPENDIX E
United States Department of Agriculture (USDA) Comments
340
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/S£>0 United States Office of Washington,
•U^;-' Depart"1*"^ Environmental O.C.
'?>*" Agriculture Quality 20250
May 29, 1981
Honorable Anne M. Gorsuch
Administrator HIM j
-------
Secretary of Agriculture's
Specific Comments to
the Wood Preservatives Notice of Determination PO 2/3
We agree with the recommended label modifications requiring protective
clothing and equipment with one exception. The use of half-mask canister or
cartridge^respirator is not necessary when entering arsenical pressure
treatment'cyTinders. Since these wood preservatives'are inorganic salts
which have no measurable vapor pressure, there are no fumes that need to be
trapped. A dust mask which would prevent inhalation of arsenate particles
or mist would be sufficient.
Clarification is needed regarding the requirements for protective clothing
for certified and noncertified applicators of creosote and pentachlorophenol
for home and farm uses. For applications of creosote, or pentachlorophenol
concentrations of greater than 5 percent, no differentiation in clothing
requirements should exist; that is, both certified and noncertified
applicators (who may be applying the chemical under the supervision of a
certified appl icator)" should wear the same protective clothing. Once
pentachlorophenol is diluted to 5 percent or less, or in the case of
products sold in a 5-percent or less formulations, long-sleeved shirts and
trousers offer adequate protection,
The use of wood preservatives for industrial uses should be restricted where
the worker has the risk of exposure on a daily basis. However, the
restrictions on homeowner use and on those contractors doing construction
work for the homeowner appear to be extreme given the limited risk of
exposure for persons in these categories. For example, classifying the
brush-on use of inorganic arsenicals as restricted-use pesticides would mean
that carpenters who want to treat the end cuts during fabrication of a
structure must be certified pesticide applicators. We are also concerned
that the proposed restricted-use classification will require certification
of entirety new groups of workers who do not fit into the classification of
commercial forestry, or farm-oriented certified applicators. We question
whether current certification programs apply to these new groups.
The proposed statements prohibiting the application of creosote, .
pentachlorophenol, or inorganic arsenicals to wood which is intended for
interior, except for those support structures which are in contact with soil
in barns, stables, similar sites and all weather wood foundations, sills and
plates, may cancel some uses for which there are no substitutes. Exposure
can be reduced for many of these uses, such as sealing creosote treated
woodblock flooring beneath a pitch wearing surface. Another important use
is that of penta treated wood for laminated timbers for warehouses, indoor
swimming pools, and other buildings where the type of use creates a high
decay hazard. Other preservatives are not practical. Creosote is an
342
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unsuitable preservative for esthetic reasons and arsenicals interfere with
gluing. Recent research has shown that the exposure from the use of penta
in enclosures is small, generally less than 1 microgram per cubic meter
which can be reduced by 80 to 90 percent by coatings or by surface
treatments that convert the penta to chemicals' with essentially zero vapor
pressure, (We are enclosing a research'paper about clear coatfngs.) A
solution formulated for the latter use is now commercially available. We
believe such formulations can be used safely, and these specialty uses
should notrbe limited where exposure can be effectively reduced.
The precautionary statements proposed in the Position Document which
prohibit the application of the inorganic arsenicals, creosote, or
pentachlorophenol to wood which will be used in a manner which may result in
direct exposure to domestic animals or livestock, or in the contamination of
food, feed, or drinking and irrigation water {e.g., food crates, irrigation
flumes, vegetable stakes, feedlot bins and watering troughs), could prohibit
virtually all agricultural uses of treated wood (such as fence posts, gates,
cattle guards, supports for feed bunks, retaining walls, etc.) since .it can
be argued that any of these uses could result in direct animal contact. A
strict interpretation of these restrictions could also prohibit the use of
treated wood in the construction of bridges or docks because in many cases
treated timbers are in direct contact with surface water or the subsurface
water table. Although more data are needed on residue levels of the wood
preservatives that result from such uses, available data- in the
USDA-States-EPA Assessment Report does not support the contention that these
uses will'result in significant exposure to the general public. A case in
point is the use of arsenical treated wood for vegetable stakes and grape
stakes, watering troughs, and feed bunks. If "visibly clean" ^treated wood
which contains not more than 0.1 mg. of soluble arsenic per 100 cm2, and
if it is assumed that all available arsenic is solubilized in the initial
fill of a watering trough 2 feet X 2 feet X 6 feet, the arsenic content in
that water would not exceed the maximum drinking water standards for humans
as established by the Department of Health, Education, and Welfare in 1962.
A strong data base (see Chapter 10, Report of the USOA-States-EPA
Preservative Assessment Team) supports the thesis that contact of plants
with. ar,s.enates does not increase the arsenic content of these plants.
While no food tolerances have been set specifically for the wood
preservative pesticides, there are tolerances for arsenic residues on a wide
variety of food crops. Normal residue levels for any crop could be used as
the tolerance level for that crop to insure that no increase in residue
resulted from the use of treated wood. The fact that "clean" salt pressure
treated wood would have essentially no residue which could be picked up by a
food crop must be taken into account, especially when considering the fact
that crops grow in a soil environment containing 2 to 5 parts per million
arsenic and that plants contain arsenic as a natural component of the fruit,
leaf, or root. The use of arsenic as a plant growth, regulator in grapefruit
production and the long-term use of arsenical treated wood for vegetable and
grape stakes—both without any Increase in arsenic levels of the
produce—are also strong arguments that the restrictions proposed for
arsenical treated wood for agricultural uses (greenhouses, mushroom flats,
support stakes for vegetables and.grapes, etc.) are inappropriate.
343
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The proposed label requirement that in-line filters must be used with
arsenical preservatives may not achieve the desired result of limiting
surface deposits of arsenical preservatives unless the filters are properly
maintained. The requirement that a post impregnation vacuum be applied is
poor technology, at least in the case o/ chromated copper arsenate (CCA)
preservatives, since this practice will introduce wood sugars into the
treating solutions and result in sludging of CCA solids in storage and
working tanks, thus aggravating the very problem the requirement is intended
to solve. ~A simple label requirement that arsenical treated wood must be
visibly clean would achieve-the result desired-and would not place EPA in
the position of dictating treatment methodology and fixing the
state-of-the-art. The post-treatment rinsing to remove surface residues
could be made mandatory for wood to be used in food contact applications.
However, the water used to wash the wood would have to be collected, stored,
and disposed of as a hazardous waste. Since few waste disposal sites will
take arsenic wastes, this process would greatly add to the cost of wood
treatment and add to the already critical waste disposal problem. We
believe it would be preferable-to set concentration or residue standards and
let industry meet the standard in ways that best suit their specific
situations.
The proposed requirement that treated wood either be disposed of by onsite
burial, or that if the pesticide-treated wood wastes exceed 1,000 kilograms
per site, disposal must comply with the provisions of the Resource
Conservation and Recovery Act, as amended, will result in significant costs
contrary to'EPA's expectation. There are over 4,000 bridges on National
Forest System lands which utilize treated timber piles, posts, and planks as
bridge components. The total weight of each bridge would exceed 1,000 kg in
about every case. Unusable materials from these bridges are often burned
when the bridges are replaced. The cost of dismantling, hauling, and
disposing of this material in approved disposal sites will be significant.
Such added costs would adversely impact the cost of road construction which
ultimately affects our ability to manage the forest resources. We believe
such requirements are premature because EPA admits that the hazards of
current disposal methods have not been quantified. We are willing to work
with the EPA in the development of scientific data designed to evaluate
workable disposal methods.
We are also concerned wi'th the proposal to require labels under the Toxic
Substances Control Act (TSCA) requiring impervious gloves to be worn by all
who handle preservative" treated wood, and requiring individuals who saw
pesticide treated wood to wear protective clothing and a dust mask. We feel
these regulations involve unrealistic and unenforceable restrictions.
344
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