PB87-178851
Coal Tar, Croosote, and Coal Tat Neutral 0l1
Non-Wood Preservative Uses
Position Document No. 2/3
(U,S.) Environmental Protection Agency
Washington, DC
Aug 84
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COAL TAR, CREOSOTE, AND COAL TAR NEUTRAL OIL:
NON-WOOD PRESERVATIVE USES
POSITION DOCUMENT NO. 2/3
Office of Pesticide Programs
Office of Pesticides and Toxic Substances
U.S. Environmental Protection Agency
401 M Street, SW
Washington, D.C. 20460
i. a-
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TABLE OF CONTENTS
PAGE NO.
TABLE OF CONTENTS i
EXECUTIVE SUMMARY iv
ACKNOWLEDGEMENTS viii
PART I. INTRODUCTION 1-1
A. General Background and Organization 1-1
B. Legal Background 1-2
C. Chemical Background - Creosote, Coal Tar, 1-3
Coal Tar Neutral Oils
1. Chemical and Physical Characteristics 1-3
2. Use and Production 1-4
3. Tolerances 1-4
PART II. RISK ANALYSIS AND ASSESSMENTS II-l
A. Basis of Presumption and Analysis II-l
of Rebuttal and Public Comments
Concerning Mutagenicity
1. Basis of Presumption II-l
2. Analysis of Specific Rebuttal II-3
and Public Comments
Concerning Mutagenicity
3. Summary of Rebuttal Comments 11-11
Concerning Mutagenic Effects
B. Basis cf Presumption and Analysis
of Kebuttal and Public Comments 11-12
Concerning Oncogenicity
1. Basis of Presumption 11-12
2. Analysis of Specific Rebuttal 11-12
and Public Comments Concerning
Oncogenicity
I. b
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C. Analysis of Rebuttal Comments Concerning 11-35
Human Exposure
D. Human Exposure Analysis 11-35
1. Chemistry 11-35
2. Summary of Application Practices 11-40
3. Human Exposure Analysis for Specific 11-44
Exposure Situations
C. Risk Assessment for Mutagenicity and 11-48
Oncogenicity
1. Risk Assessment for Mutagenicity 11-48
2. Risk Assessment for Oncogenicity 11-54
3. Conclusions 11-56
PART ITI. BENEFITS ANALYSIS III-l
A. Introduction III-l
B. OrnanamentaJ Flowering Plants and Ornamental III-l
Lawns
C. Product Storage Yards III-2
D. Agricultural Premises and Highway III-2
Rights-of-Way
B. Rope and Canvas Tarpaulins III-3
P. Seed Potato Storage Premises and Equipment II1-4
G. Livestock Premises III-5
H. Poultry Premises III-5
I. Home and Institutional Use III-6
J. Transportation Vehicles III-6
,K. Tree Wound Dressings II1-7
L. Metalworking Fluids III-7
M. Mosquito Larvicide III-8
N. Animal Repellent III-8
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O. Bird Repellent III-9
P. Insect Repellent 111-10
0. Screwworm Control III-11
R. Insect Control III—11
S. Gypsy Moth Control 111-12
T. Animal Dip 111-13
PART IV. DEVELOPMENT OP REGULATOR* OPTIONS IV-].
A. Introduction IV-1
B. Basis and Rationale for Developing IV-1
Options and Modifications
IV- 2
C. Discussion of Option 2, Modifications to
the Terms and Conditions of Registration
PART V. PROPOSED REGULATORY DECISION V-l
A. Risk/Benefit Analysis of Regulatory V-l
Options, Use by Use
B. Summary of Proposed Regulatory Decision V-13
PART VI. BIBLIOGRAPHY VI-1
APPENDIX
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EXECUTIVE SUMMARY
Creosote, Coal Tar, and Coal Tar Neutral Oils-
Non-wood Uses
Position Document 2/3
On October 18, 1978 EPA issued Notices of Rebuttable
Presumption Against Registration and Continued Registration
(RPAR) of pesticide products containing creosote, coal tar,
and coal tar neutral oils. The presumption against these
chemicals was based on validated studies showing that these
compounds are oncogenic and mutagenic. In January, 1981 a
Position Document 2/3 was issued that addressed the risks and
benefits and proposed regulatory action of the wood preservative
uses of creosote, coal tar, and coal tar neutral oils, as
well as the inorganic arsenical compounds, and pentachlorophenol.
This document addresses tne risks and benefits of the
non-wood uses of creosote, coal tar, and coal tar neutral cils.
Hie non-wood use* of creosote, coal tar, and coal tar
neutral oils car be diviJed into these general categories:
herbicidal uses, fungicidal uses, insecticidal uses, and
disinfectant uses. Approximately 2% of the amount of creosote
produced annually is used for non-wood purposes. As a herbicide,
creosote is blended with petroleum distillates and applied
as a foliar spray on rights-of-way, industrial areas, fencerows,
and on ornamental gardens and lawns to control nutgrass.
Creosote and coal tar are registered for use to protect
cordage and canvas from fungal attack or deterioration.
The insecticidal uses of creosote, coal tar, and coal
tar neutral oils include use as a miticide, larvicide, ovicide,
and repellent. Specifically, the uses include: control of
animal parasites in animal quarters; traatment of gypsy moth
egg massesj control-of mosquito larvaet control of screwworms
in horses and mules; treatment of seed to prevent ingestion
by birds; animal dip to control parasites; and to control
flies in drain lines and garbage trucks and containers.
The disinfectant uses of creosote, coal tar, and coal
tar neutral oil include: to control fungi and bacteria in
seed potato storage areas and equipment, poultry and livestock
premises, and on tree wound dressings. Additionally, these
products are registered for home and institutional use.
In reaching a proposed regulatory decision regarding the
non-wood uses of creosote, coal tar, and coal tar neutral
oils, the Agency evaluated rebuttal comments submitted in
response to the PD-1 and public coments submitted in response
to the PD-2/3 published on the wood uses of these chemicals.
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The exposure data indicate that applicators of products
containing creosote, coal tar, and coal tar neutral oils used
for non-wood uses are subject to both dermal and inhalation
exposure during the application process.
These products are applied by brush, spray, wiped on or
the object/animal is dipped into the chemical. Two of the
currently registered uses, on seed potato storage premises
and equipment and on seed corn as a crow repellent, are
considered food uses requiring the establishment of tolerances
under Section 408 of the Federal Food, Drug, and Cosmetic
Act. There exists a potential for dietary exposure as a
result of these two uses. The livestock and poultry premise
treatment uses are considered to be non-food uses.
The Agency has determined that the use of products
containing creosote, coal tar, and coal tar neutral oils for
non-wood uses poses a risk of oncogenicity and mutagenicity
to the applicators. There is also potential risk as a result
of dietary exposure to these chemicals through the two uses
considered to be food uses as described above.
An analysis of the benefits associated with each registered
use concludes that for the majority of uses viable, effective
alternatives are available and in use. Several of the creosote,
coal tar, and coal tar neutral oil products registered for
non-wood uses are no longer marketed. Actual usage data for
the creosote, coal tar, and coal tar neutral oil products are
not available for most uses.
The following regulatory options were considered by the
Agency in reaching the proposed regulatory decisions:
(1). Continuation of registration without changes.
(2). Continuation of registration with modification
to terms and conditions of registration.
(3). Cancellation of registration.
Specific risk reduction modifications selected for turther
consideration under Option 2 are:
(1). Require protective clothing: impermeable gloves,
respirators, coveralls; require proper disposal
of protective clothing.
(2). Prohibit eating, drinking, and smoking during
application.
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(3). Restrict the sale and use of creosote, coal tar,
and coal tar neutral oils to certified applicators
or by persons under their direct supervision
and only for those uses covered by the certified
applicator's certification.
(4). Prohibit interior application.
Having evaluated the cancer and mutagenic risk associated
with the non-wood uses of creosote, coal tar and coal tar neutral
oil products, the Agency has determined that the continued,
unrestricted registrations of these use3 (Option 1) is
unjustifiable and that the risks outweigh the benefits for
both Options 1 and 2. Therefore, the Agency proposes to
cancel the use of these products for all uses listed below:
Herbicidal uses
- Ornamental flowering plants and ornamental lawns
- Product storage yards
- Agricultural premises and highway rights-of-way
Fungicidal uses - rope and canvas
Disinfectant uses
Livestock premises
- Poultry premises
- Home and institutional uses
- Transportation vehicles
- Tree wound dressings
- Metalworking fluids
- Seed potato storage premises and equipmment
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Use as larvicide, insecticide, repellent
Mosquito larvicide
Insect repellent
Animal repellent
Screwworm control
Bird repellent
Insect control
Animal dip
Gypsy moth egg mass control
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ACKNOWLEDGEMENTS
Lois Possi, Review Manager, Registration Division
Aaron Beloian, Microbiologist, Benefits and Use Division
Thaddeus Czerkowicz, Microbiologist, Benefits and Use Division
Harry Day, Chemist, Hazard Evalaution Division
Cara Jablon, Attorney Advisor, Office of General Counsel
John Kliewer, Entomologist, Benefits and Use Division
Robert O'Brien, Economist, Benefits and Use Division
Amy Risp\n, Chief, Science Integration Staff.
Hazard Evaluation Division
Alice Wegman, Attorney Advisor, Office of General Counsel
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PART I. INTRODUCTION
A. General Background and Organisation
The Federal Insecticide, Fungici.e, and Rodenticide Act
as amended (FIFRA) and its regulations require the Environmental
Protection Agency (EPA) to review the risks and benefits o£
uses of pesticides. On October 18, 1978 EPA issued Notices
of Rebuttable Presumption Against Registration and Continued
Registraticnp(RPAR) of pesticide products containing coal
tar, creosote, and coal tar neutral oils, inorganic arsenical
compounds, and pentachlorophenol. The presumption against
coal tar, creosote, and coal tar neutral oils was based on
validated studies showing that these compounds are oncogenic
and mutagenic. Position Document 1 (PD-1) issued with
the Notice of Rebuttable Presumption describes these studies
in detail.
In January, 1981 a Position Document 2/3 (PD-2/3) was
Issued that addressed the risks and benefits of the wood
preservative uses of creosote, coal t?r, and coal tar neutral
oils, the inorganic arsenical ccrnpounis, and pon.tachlorophenol.
This Position Document 2/3 addresses the risks and
benefits of the non-wood preservative uses of creosote, coal
tar, and coal tar neutral oils. The non-wood preservative
uses of the inorganic arsenical compounds and pentachlorophenol
will be considered in future position documents.
This document contains five parts. Part I is this
introductory section. Part II evaluates the potential risks
associated with the non-wood preservative uses of creosote,
coal tar, and coal tar neutral oils. Part II also includes
descriptions and evaluations of the risk evidence, exposure
data, rebuttal submissions, and the Agency's risk assessment.
Part III estimates and summarizes the economic benefits or
the nonwood uses of these chemicals for each use category
and describes the assumptions and limits of these estimates.
Part IV describes the range of possible regulatory options
and modifications to reduce the risks so that they are
exceeded by the benefits of these pesticides, and explains
the Agency's selection of some of these options for further
consideration. Part V evaluates the specific impact on the
risks, benefits, and other effects which would occur if each
applicable option and modification for each use category
were adopted and presents the options and modifications
selected for further consideration by the Agency.
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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 53(c)(5).
The term "unreasonable adverse effects on the environment"
i3 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 S 2(bb).
To register a pesticide, the administrator roust 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 the 162.11. (The RPAR process has been newly named
the Special Peview Process"). Among other things, this
section provides that a rebuttable presumption against registra-
tion shall arise if a pesticide rueets 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 humans 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.
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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 modification
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.
C. Chemical Background
1. Chemical and Physical Characteristics
Creosote and coal tar are extremely complex mixtures
containing hundreds of identifiable constituents. These
mixtures are produced by the high temperature carbonization of
coal, a process referred to as coking.
Coal tar is a black, viscous liquid or semi-solid with a
naphthalene-like odor and a sharp burning taste. It is
combustible and has a specific gravity of 1.18-1.23 (60/60°F).
Coal tar is soluble in benzene, carbon disulfide, chloroform,
and is partially soluble in alcohol, acetone, and methanol.
Coal tar is only sightly soluble in water (EPA, 1978).
Creosote and neutral oil are products derived from
coal tar. Both creosote and neutral oil may be distilled
from sources other than coal, but the terms "creosote" and
"neutral oil" in this document will refer to distillates of
coal tar. Creosote is a yellowish to dark brown oily liquid
with a naphthalenic odor and frequently contains substantial
amounts of naphthalene and anthracene. The distilling range
of creosote is between 200-400°C. Creosote is soluble in
alcohol, benzene, and toluene and immiscible with water.
Coal tar neutral oils are generally defined as a mixture
of naphthalene, fluorene, anthracene, and other neutral
hydrocarbons. Neutral hydrocarbons are those coal tar
hydrocarbons other than coal tar acids (such as phenols,
cresols, and cresylic acids), and coal tar bases (such as
pyridines, quinolines, and acridines).
The actual constituents of coal tar, creosote, and the
neutral oils are highly variable. They depend on the source
of the coal used to produce tar, the design and attendant
operating conditions^ (temperature, coking time, gas collection),
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systems of the coke ovens, and in the case of the coal tar
distillates the design and operating parameters of the still
(EPA, 1978).
Over three hundred compounds have been positively
identified in coal tar. it is estimated that as many as ten
thousand compounds may exist, though many are present only in
trace amountj (EPA, 1978). Because the composition of coal
tar and coal tar products is known to vary, they are usually
assayed and specified by their physical characteristics.
2. Use and Production
The non-wood preservative uses of creosote can be divided
into the following general categories: herbicidal uses,
fungicidal uses, insecticidal uses, and disinfectant uses.
Approximately 2* of the amount of creosote produced is used
for non-wood preservative uses. Therefore, the uses described
below are minor compared with the major uses of creosote as
a wood preservative.
As a herbicide, creosote is bxended with petroleum
distillates and applied as a foliar spray on rights-of-way,
industrial areas, fencernws, roofs and or. ornamental lawns to
control nutgrass.
Creosote ind coal tar are registered for use to protect
cordage and canvas from fungal attack or deterioration.
The insectidical uses of creosote, coal tar, and coal
tar neutral oil include use as a miticide, larvicide, ovicide,
and repellent. Specifically, the uses include: control of
animal parasites in animal quarters; treatment of gypsy moth
egg masses; control of mosquito and fly larvae and screwworms
in horses and mules; treatment of seed to prevent ingestion
by birds; animal dip to control parasites; and to control
drain flies and flies on garbage containers and garbage
trucks.
The disinfectant uses of creosote, coal tar, and coal
tar neutral oil include: control fungi and bacteria in seed
potato storage areas and equipment, poultry and livestock
premises, tree wound dressings, and metalworking fluids.
Additionally, these products are registered for home and
institutional use.
3. Tolerances
The Agency has established no tolerances or exemptions
from tolerances, and the U.S. Food and Drug Administration
(FDA) has established no action levels for creosote in or on
raw agricultural commodities. Under the provisions of 21
CFR, the FDA has not established an indirect food additive
regulation for holding, transporting, or packaging raw agri-
cultural products (EPA, 1981).
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II. RISK ANALYSIS AND ASSESSMENTS
This part o£ the Position Document is divided into
five sections. The first two sections discuss the rebuttal
comments received in response to PD-1 and the public comments
received in response to Position Document No. 2/3: Wood
Preservatives (PD-2/3) . The bases of the Agency's presumption
against registration of creosote* coal tar, and coal tar
neutral oils and the Agency's response to the rebuttals and
public comments are included in these sections. For creosote,
coal tar, and coal tar neutral oils, the rebuttable presumption
against registration was issued on the basis of oncogenicity
and mutagenicity.
The third and four^n sections address human exposure to
these chemicals for the various non-wood preservative uses.
The final section presents the risk assessment for oncogenicity
and mutagenicity.
In assessing the risks associated with a chemical, two
factors are considered: the toxic effect(s) of the pesticide
and the amount of exposure to the pesticide. The toxic
effects of concern for creosote were described in PD-1 as
the basis for the rebuttable presumption.
A. Basis of Presumption and Analysis of Rebuttal
and Public Comments Concerning Mutagencity
1. Basis of Presumption
In the studies summarized in PD-1 on creosote, coal
tar, and coal tar neutral oils as well as studies that have
been reviewed since the issuance of the PD-1, mutagenic
effects of creosote and coal tar/creosote were studied in
Salmonella typhimurium strains and in L51785f mouse lymphoma
cells. In both cases, these chemicals, upon metabolic activa-
tion, produced dose-related increases in mutagenic activity.
The results of these studies performed in submammalian
and mammalian test systems are summarized below.
Submammalian Test Systems
Dose-related mutagenic responses were found in
experiments for both creosote and creosote-coal tar
using the standard Ames Salmonella plate test (Simmon and
Poole, 1978; Simmon and Shepherd, 1978; and Bos et aK, 1983).
In experiments conducted at SRI, dose-related mutagenic
responses in three separate experiments were found for both
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creosote and creosote-coal tar using the standard Ames Salmonella
plate test. Responses were roughly linear in the concentration
range of approximately 5 to 100 ug of test material per
plate, assuming a density of 1 g/ml. The maximum increase
in numbers of revertants per plate was approximately tenfold
over background numbers. At concentrations of about 100
ug/plate, the responses level off, and then at higher concen-
trations the revertant counts decrease to zero as toxicity
of the test material becomes an important factor of the test
(Simmon and Poole, 1978? Simmon and Shepherd, 1978).
SRI observed positive responses for the frameshift-
sensitive test strains TA1538, TA98, TA1537, and TA100, but
not the base-pair substitution sensitive strain TA1535.
Mutagenicity was detected only in the presence of an exogenous
source of mammalian metabolic activation (S9 mix prepared
from livers of Aroclor 1254-induced rats). The production of
fraraeshift mutations and the requirement for metabolic
activation are consistent with Salmonella studies of indivi-
dual polycyclic organic compounds identified in creosote and
creosote-coal tar. (Simmon and Poole, 1978; Simmon and
Shepherd, 197b).
Bos et aJU (1983) evaluated small increases in concentration
(2,5,20, and 50 ug/plate) and found that creosote (type P—1)
caused a dose-related mutagenic response in Salmonella tester
strains TA1538, TA98, TA1537, and TA100, but not in TA1535 using
the standard plate test. The mutagenic responses were detected
in the presence of Aroclor 1254-induced rat liver S9 but not
in its absence. The maximum increase in numbers of revertants
per plate above the background number was approximately
tenfold (background number of revertants was within acceptable
range), in addition, these investigators added an epoxide
hydratase inhibitor (1,1,l-trichloropropane-2,3-oxide) to
their test and enhanced the mutagenic effects of creosote
twofold. Because this inhibitor enhances the mutagenicity
of benzo[a]pyrene by accumulation of an epoxide intermediate,
it is speculated by these investigators that polycyclic
aromatic hydrocarbons (PAHs) contribute to the mutagenicity
of creosote.
Litton Bionetics, Inc. (LBI) originally reported creosote
(type P-l) and creosote-coal tar (type P-l, Class C) to be
negative in the Ames Salmonella plate test but obtained
positive results upon retesting. In the initial experiments,
large increments in concentration (1, 10, 100, 1000, 5000
ug/plate) were tested. Mutagenic responses may have been
missed because of toxicity or because the test materials are
viscous materials that are relatively insoluble and technically
difficult to test (Nesnow, 1979). Dr. David Brusick of
Litton Bionetics, Inc. suggested that the negative responses
initially reported may been due to "the quality of S9 mix
preparations " (LBI, 1978 a,b).
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It should be noted that the positive controls requiring
metabolic activation were clearly mutagenic. In the retesting
experiments using creosote (type P-l), mutagenic responses
in TA1537 and TA98, several times over background levels,
were observed at 100 ug/plate in the presence of Aroclor-1254
rat liver S9 mix.
Mammalian Test Systems
Only one gene mutation study using mouse cells in cul-
ture was available for review. (Mitchell and Tajiri, 1978).
This study was an jLn vitro mammalian mutagenesis assay.
Mouse lymphoma cells (L5178Y), heterozygous at the thymidine
kinase locus (TK+/-), were used both with and without by
Aroclor 1254-induced rat liver homogenate (S-9 fraction) for
activation. The purpose of these tests was to determine the
mutagenic activity of creosote and coal tar/creosote on the
forward mutation frequency of the TK locus from heterozygous
(TK+/—) to homozygous (TK-/-). Ethyl methane sulfonate was
used as a positive control in the creosote experiments! and
dimethyinitrosamine was the positive control in the coal
tar/creosote experiments. For each concentration of test
chemical, the mutation frequency results were calculated as
the ratio of the number of mutant cells to the total number
of surviving cells. The induced mutation frequencies for the
tested compound are obtained by subtracting the negative
control's average mutation frequency from the treated sample's
mutation frequency.
Creosote and coal tar/creosote had similar effects on
the forward mutation frequency at the TK locus of the L5178Y
mouse cells, both with and without metabolic activation.
Dose-related increases in mutation frequencies were reported
for both test chemicals following metabolic activation.
However, without metabolic activation, the mutation frequency
in the creosote tests was reported to be weakly positive at
the highest concentration, whereas the experiments with coal
tar/creosote resulted in increases in the frequency of mutations
at the two highest concentrations (Mitchell and Tajiri, 1978).
2. Analysis of Specific Rebuttal and Public Comments
Concerning Mutagenicity
The comments and respective Agency responses that follow
are rebuttals submitted in response to the PD-1 on creosote,
coal tar, and coal tar neutral oils. These rebuttals were previously
published in the PD-2/3 (EPA, 1981) on the wood preservative use
of creosote, coal tar, and coal tar neutral oils and are included
in this document for completeness. The number in parentheses after
the title of each comment is an internal number assigned to each
comment received. A list of the comments is in Appendix A of
this document.
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Rebuttal Comment 1: Reliability o£ the Results of Simmon and
Poole, 1978 (2)
The American Wood Preservers Institute *AWPI) submitted
two unpublished microbial studies performed by Litton Bionetics,
Inc. (LBI, 1977, 1978) to invalidate the gene mutation results
of Simmon and Poole (1978). LBI, using the same assay (Ames
Salmonella test) as Simmon and Poole, twice investigated the
mutagenic potential of creosote and coal tar/creosote.
The rebutter considered the first Litton study (1977) to
be negative; tfce second Litton study (1978) was positive.
The rebutter's explanation for the positive results in 1978
was that the creosote may have aged and/or the rat liver
preparation was different from that used in 1977. The rebutter
states that the results of LBI's experiments show that those of
Sinunon and Poole cannot be relied upon as establishing the
potential for human mutagenicity of creosote mixtures.
Agency Responsei The Agency has reviewed the two studies
submitted by the rebutter and concludes that, although LBI's
1977 mutagenicity assays performed with microbial systems
were generally negative, the S^, typhimurium strain TA 100
demonstrated a positive response. This strain, when tested
in 1977 with metabolic activation by rat liver preparations,
was positive for mutagenicity in one experiment and negative
in another experiment. These conflicting results were not
explained by the authors; however, it is unclear whether the
same sample of creosote was analyzed and if the same rat
liver preparation was used.
The Agency agrees that it is possible that there may have
been differences in the rat liver preparations used in the
studies. These differences could have been caused by different
dose levels of Aroclor given to the rats, resulting in
different activation_characteristics of the rat liver
preparations. (The doses were not reported by LBI.) As for
the possibility of mutagenic products being formed upon aging
of the creosote, this aging process will also undoubtedly
occur in coal tar/creosote treating solutions.
Consequently, the Agency cannot accept the argument that
because LBI's tests showed some degree of indeterminance the
experiments performed by Simmon and Poole (1978) are invalid.
The Agency concludes that the LBI 1977 study indeed showed a
positive result for typhimurium TA 100, and the 1978 LBI
study also showed positive results for typhimurium TA 1537
and TA 98. Thus, the Agency does not consider LBI's results
to be negative, as does the rebutter, nor that these results
conflict with those reported by Simmon and Poole (1978).
Thus, the Agency concludes that the data of Simmon and Poole
are valid and supportive of the presumption of mutagenicity.
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Rebuttal Comment 2: Reliability of the Results of Mitchell
.. Tajiri, 1978 (2)
The AWPI claims that the study of Mitchell and Tajiri
(1978) is unreliable for the purpose of demonstrating poten-
tial human mutagenicity of creosote mixtures. This is due
primarily to the difficulty of interpreting the results of
these experiments where only weak mutagenic activity is
observed at the higher doses of creosote that cauied pro-
nounced cytotoxicity. The rebutter believes that observed
mutagenic effects are only valid when a 10% or greater survi-
val rate occurs in the detector cells treated with three
increasing doses. Because the Mitchell and Tajiri study did
not meet these criteria, the rebutter believes the results
of this study are difficult to interpret.
In support of this position, the rebutter submitted an
unpublished study. In these experimenter diploid human
embryonic lung tissue was used to study the unscheduled DNA
synthesis (UDS) caused by coal tar/creosote. These results
showed evidence of weak mutagenicity at high (cytotoxic)
levels of cceosote.
Agency Response: The Agency agrees that the occurrence of
cytotoxicity complicates the interpretation of the mutagenic
responses observed by Mitchell and Tajiri (1978). However,
even though the cytotoxicity is higher than desirable and
masking of the mutagenic response (e.g., due to the selective
killing of mutants or simply due to a low survival rate of
all test cells) may have occurred, the Agency concludes that
the Mitchell and Tajiri study demonstrated the mutagenicity
of creosote mixtures in the test system.
The Agency has reviewed the study submitted by the
rebutter and concludes that the LBI's results are consistent
with those of Mitchell and Tajiri, showing that creosote
induces unequivocal, albeit weak, unscheduled DNA synthesis
in human diploid WI-3H cells in the presence of rat liver
preparations.
Rebuttal Comment 3: Insufficient Data to Meet EPA's
Guidelines for Multitest Evidence (2)
The AWPI submitted the results of LBI experiments in which
creosote mixtures were tested in five microbial systems. In
all cases the results were negative for mutagenicity. The
rebutter believes these results show creosote does not meet
the RPAR risk criteria.
II-5
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Agency Response; To meet the RPAR risk criteria Cor potential
mutagenicity [40 CFR, Section 162.11(a)(3)(ii)(A)], a chemical
must be shown to cause qene mutations in at least two of the
thirteen test systems listed in the Proposed Guidelines [40
CFR, Section 163.84(b)(2)(i-iii)]. As it is stated in the
Agency's proposed guidelines [40 CFR Part 163 (III)(G)], "A
compound would be considered a mutagen if it produced positive
results in: two different kinds of tests for demonstrating
gene mutations; a mouse specific locus test? or anv kind of
test for demonstrating chromosome aberrations." The positive
results of Simmon and Poole (1978) and Mitchell and Tajiri
(1978) provide more than sufficient evidence for meeting the
mutagenicity criteria of the Guidelines. In addition, the
positive results from the Salmonella assays and the human cell
study (both submitted by this rebutter; see rebuttal comments
1 and 2) further support the presumption of mutagenicity.
Since two different kinds of tests (Simmon and Poole,
1976; Mitchell and Tajiri, 1978) showed positive results for
mutagenicity of coal tar/creosote solutions, the five additional
LBI studies showing negative results, although adding to the
Agency's data base, do not rebut the presumption of mutagenicity
in PD-1 .
It should be noted that these negative studies, which
were tests in submammalian systems, are inadequate studies and
not considered supportive of the non-mutagenicity of creosote.
Moreover, the effectiveness of these submammalian assays for
evaluating complex mixtures has not been determined, unlike the
Salmonella assay.
Rebuttal Comment 4: Bacterial Cell Membrane Uptake of
Creosote (2)
The AWPI asserts that the Salmonella strains used by
Simmon and Poole (1978) are inappropriate for mutagenicity
testing. This is because the cell membranes of these strains
have a specific "defect" allowing greater uptake of polycyclic
aromatic hydrocarbons (PAH's) than other cell membranes.
Agency Response: The Agency agrees with the rebutter that
Salmonella strains used in the Ames assay have an increased
permeability toward the large heterocyclic molecules. These
strains are used intentionally to mimic the permeability of
mammalian cells as much as possible. This is also true for
the Bacillus subtilis strain (used by LBI), which may have a
permeability to heterocyclic compounds greater than that of
the S^ typhimurJ urn strain used by Simmon and Poole. The
Agency concludes that the Salmonella strains used by Simmon
and Poole are appropriate for mutagenicity testing.
II-6
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Rebuttal Comment 5: Appropriateness of Rodent Liver
Homogenates for Activating Creosote
Mixtures (2)
The AWPI states that rodent liver enzymes are inappropriate
for activating creosote mixtures prior to the Ames Salmonella
test. The metabolic activity in rodent liver is much greater
than that in either human t»kin tissue or human liver. The
rebutter also points out that qualitative, as well as
quantitative, differences exist between rodents and humans
with regard to the metabolic pattern of polycyclic aromatic
hydrocarbons (PAH's). Consequently, as specific metabolites
of PAH's may be the actual mutagens, a PAH may produce
mutagenicity in one species (e.g., rodents) and not in another
(e.g.. humans).
Agency Response: The Agency agrees that there are some
qualitative and quantitative differences in enzymatic activity
between rodent liver preparations used in the tvphimurium
mutagenicity assays and preparations from human lTver or
skin tissue. However, the bacterial mutagenicity assay is
commonly used by scientists as a primary screening test for
chemicals which have mutagenic potential. A positive result
in these bacterial mutagenicity assays, although not intended
to be the sole basis from which an extrapolation is made to a
more complex biological endpoint (e.g., human mutagenicity),
does indicate, however, that the presumption of mutagenicity
for creosote and coal tar/creosote is not rebutted.
Rebuttal Comment 6: Extrapolation from In Vitro Experiments
to Human Mutagenicity (2)
The AWPI points out that complex factors limit extrapolation
from iri vitro mutagenicity experiments to in vivo human
mutagenicity.
Agency Response: The Agency agrees that it is difficult to
extrapolate from ijn vitro mutagenicity to i_n vivo human
mutagenicity. However, as discussed above (rebuttal comment 5),
in vitro experiments like those of Simmon and Poole (1978)
are intended to provide a rapid screening device for substances
that have a potential human mutagenic effect. The cesults of
the typhimurium assay are used in this document merely for
qualitative purposes.
II-7
II
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Rebuttal Comment 7: Potential for Nonsoraatic Cell Mutations (2)
The AWPI states that although bacterial mutagenicity
assays may be relevant to skin tumors, the potential for
nonsomatic (germ) "vll mutations is slight, since these
cells are distant from the site of contact with creosote and
the creosote is not likely to be systemically distributed
throughout the body.
Agency Response: The Agency rejects the assumption that
creosote is not likely to be systemically distributed through-
out the body. Studies performed by Ames et al^. (1973) showed
that when certain compounds are applied to the scalp of
humans, they are ultimately found in the urine. Therefore,
some compounds entering by dermal and/or inhalation routes
may not necessarily stay at the site of contact but may be
carried by the blood to other parts of the body. Whether
this fails to occur with creosote can only be determined by
experiments.
The following comments were submitted to the Agency in
response to the* Position Document No. 2/3 on the wood preserving
uses of creosote, inorganic arsenicals, and pentachlorophenol..
Comment Issue 1: Microbiological assays as evidence of creosote
mutagenicity
The AWPI 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. (LBI) (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,
II-8
la
-------
soot from city air, fly ash, and other combustion products.
One major problem in evaluating the potential mutagenicity of
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
Poole (1978) and Simmon and Shepherd (1978) studies were
roughly linear from approximately 5 to 100 ug/plate. Nesnow
(EPA,1979) also indicated that this heterogenous mixture is
toxic to Salmonella and is technically difficult to study
(Vaughn-Dellarco, 1983).
Thus, the contradictory (negative) results reported by
LBI (1978a, 1978b, 1978c) may reflect the difficulties in
testing creosote/coal tar. LBI only evaluated log intervals
that covered a large concentration range, and thus could
have missed a positive response in their initial 1978 experi-
ments because of toxicity. Also, after a Salmonella retest
of the material, Bresick (1978) concluded that creosote/coal
tar is mutagenic and that attempts to repeat the negative
results originally "sported by LBI 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 Jjn 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 mutation frequency (Vaughn-Dellarco, 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.
II-9
I 3
-------
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 a
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).
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 substance as a "human
mutagen." The purpose of in vitro tests, such as the Salmonella
assay, is to screen chemicals tor their potential mutagenicity
and/or carcinogenicity. 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 mutagen
(Vaughn-Dellarco, 1983).
It is recognized that creosote/coal tar was evaluated
*n ill vitro tests only. When evaluating the risk posed by
exposure to a mutagenic agent, several factors, including
absorption and metabolism, may alter mutagenic response in a
mammal compared to that in ^n vitro tests. Although jLri vivo
studies in mammals are necessary to better characterize the
risk of creosote/coal tar, this does not negate the results
from the jln vitro studies which do indicate the intrinsic
mutagenicity of creosote/coal tar (Vaughn-Dellarco, 1983).
11-10
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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). It
is their view to assume that the mutagenic components of a
complex mixture necessarily render the mixture itself mutagenic
is an invalid conclusion.
ency 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. ?*here 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 ma/ 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).
Comment Issue 5: Nonspecific toxicity as the paus.e af
unscheduled DNA synthesis
The AWPI (36A) pointed cut that nonspecific toxicity
may have caused the unscheduled DNA synthesis in the human
fibroblast diploid cell line Wl-38 (Litton Bionetics, 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 ^H-Tdr
incorporation. Unscheduled DNA synthesis is indicative of
damage to DNA, and therefore indicative of potential mutagenicity
(Vaughn-Dellarco, 1983).
3. Summary of Rebuttal and Public Comments
Concerning Mutagenic Effects
The comments do not invalidate the stxtdies of Simmon and
Poole (1978) and Mitchell and Tajiri (1978) as multitest
evidence for mutagenicity. The presumption of mutagenicity
for creosote and coal tar/creosote, as stated in PD-1, is not
rebutted.
11-11
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B• Basis of Presumption and Analysis of Rebuttal and
Public Comments Concerning Oncogenicity
1. Basis of Presumption
Dermal application of creosote has also been shown to
produce skin tumors in mice (see Table II-l). Roe et al.
(1958), for example, found that dermal application of creosote
to mice also produced lung tumors. Boutwell and Bosch (1958)
found that creosote had the ability to initiate tumor formation
when applied for a limited period prior to treatment with the
promoter croton oil. Sail and Shear (1940) showed that the
number of skin tumors following dermal treatment with creosote
and benzo(a)pyrene was greater than that produced by benzo(a)
pyrene or creosote alone.
It has also been reported that various kinds of workers
occupationally exposed to creosote developed skin tumors
(Henry, 1947; Lenson, 1956; O'Donovan, 1920; Cookson, 1924).
Many studies have shown coal tar to be oncogenic in
laboratory animals. For example, dermal application of coal
tar produced skin tumors in mice (Horton, 1961; Shabad et
al., 1971; Watson and Mellanby, 1930; Tsuitsui, 1918; Hueper
and Payne, 1960; Deelman, 1962; Bonser and Manch, 1932;
Gorski, 1959; Kennaway, 1925) and rabbits (Yamagiwa and
Ichikawa, 1915). Expos-re to coal tar via inhalation produced
lung tumors in mice (Horton, 1961; MacEwen et al.,' 1976;
Horton et al., 1963; Tye and Stemmer, 1967) and rats
(rta-:Ewen et a^L., 1976). Exposure of mice to coal tar aerosol
also produced skin tumors (McConnell and Specht, 1973; MacEwen
et al., 1976) .
Dose-response relationships for the oncogenicity of coal
tar have been found several times [e.g., skin tumors in mice
following dermal (Horton, 1961) or inhalation (McConnell and
Specht, 1973; MacEwen and Vernot, 1976) exposure]. Horton
(1961) and McConnell and Specht (1973) also found a dose-
response relationship tor the latency period (time until
diagnosis of tumors).
11-12
-------
Skin cancer has also been reported in fishermen and
others involved with the repairing and retarring of fishing
nets (Shambaugh, 1935), coal tar distillery workers (Mauro,
1951), and a coal tar barrel filler (Rosmanith, 1953).
As with creosote and coal tar, dermal application of coal
tar neutral oil has been shewn to produce skin tumors in mice
(Horton, 1961). Berenblum and Schoenthal (1947) found that
several chromatographic fractions of coal tar neutral oil
produced skin tumors when dermal]v applied to mice. Cabot
et al. (1940) found that mixtures of coal tar neutral oil
with benzo(a)pyrene produced fewer tumors than benzo(a)pyrene
alone, but suggested that this inhibiting effect was due to
skin damage.
2. Analysis of Specific Rebuttal and Public
Comments Concerning Oncogenicity
The comments and respective Agency responses that follow
are rebuttals submitted to the PD-1 on creosote, coal tar,
and coal tar neutral oils. These rebuttals were previously
published in the PD-4/3 on the wood preservative use of
creosote, coal tar, and coal tar neutral oils and are included"
in this document for completeness. The number in parentheses
after the title of each comment is an internal number assigned
to each comment received. A list of the comments is in
Appendix A of this document.
Rebuttal Comment 1; Reliability of Old Case Reports of Skin
Cancer (2)
The AWPI asserts that the case reports of skin cancer
from occupational exposure to creosote are not sufficient
evidence that creosote causes skin cancer in modern wood
treatment plant workers. This is because many of these
exposures occurred before World War II, before "current
hygienic practices and safety precautions" were in effect.
Furthermore, the rebutter states that the reports are anecdotal
in nature and do not contain enough details to rule out
other common causes of skin cancer.
Agency Response: As with case reports in general, it is
difficult to rule out entirely a role in these skin cancer
cases for factors other than creosote. The Agency believes,
however, that the early case reports suggest creosote has the
capability of causing skin cancers. Although not providing
direct evidence for a cause-effect relationship, these studies
do provide supporting evidence for the Agency's concern that
long-term exposure to creosote may pose a skin cancer hazard.
T'.ie studies also complement the numerous laboratory animal
studies showing creosote to be an oncogen (see Table IX-1).
11-13
I 1
-------
TABLE II-l
SUMMARY OF COAL TAR NEUTRAL OIL STUDIES
COAL TAR
Human Case Reports
Authors
Year
Substance
and Type
of Exposure
Occupation
of Exposed
Ind ividual
Type of Tumor
Response
Shambaugh 1935
Coal tar on
repair needle
held between
lips
Fishermen - Net
loft workers
Epidermal carcinomas
of the lower lip
Mauro
1951
Rosmanith 1953
Maugham
1980
Handling of
Coal Tar
Pitcn
Hot Coal
Tar Vapors
Crude coal
tar ointment
applied to
body below
head appro-
ximately 2-3
times a day
for 2-4 weeks
Tar distillery
workers
Tar barrel
filler
Persons
undergoing
the Goekerman
treatment for
psoriosis
during 1950-1954
Cancer of skin,
scrotum, cheek,
and lip
Spinocellular cancer
in scar of cured
erythematous lupus
infection
Non-melanoma
skin cancers
11-14
It
-------
TABLE Il-l (Continued)
COAL TAR
Animal Studies
Dermal Exposure
Authors Year
Substance
Tested
Animal 6
Strain
Type oE Tumor
Response
Yamagiwa 1915
ft Ichikawa
Tsuitsui 1918
Coal tar
Bituminous
coal tar
Rabbits (Strain
Undefined)
Mice - English
Papillomas of the
ear (site of
application)
Papillomas#
carcinomas and
spindle cell
sarcoma
Kennaway 1925
Watson fc 1930
Mellanby
Coal tar pro- Mice (Strain
ducts of Undefined)
450 C,
560 C, t
1,250 C
distilla-
tion temperature
Dermal Appli- Mice (Strain
cation of coal Undefined)
tar following
dermal appli-
cation of
fats, oils, or
tannic acid
Coal tar
dermal appli-
cation com-
bined with
addition of
butter to
diet
Mice (Strain
Undefined)
Skin tumors (higher
rate of carcino-
genesis at higher
temperatures)
Increased tumor
production
Higher incidence of
lung nodules
11-15
-------
TABLE II-l (Continued)
COAL TAR
Animal Studies
Dermal Exposure
Substance Animal & Type of Tumor
Authors Year Tested Strain Response
Bonser & 1932 Scottish
Manch blast
furnace tar;
English crude
tar
Mice (Strain
Undefined)
Papillomas and
squamous cell
carcinomas of
the skin
Gorski
Hueper 6
Payne
1959
1960
Coal tar
Coal tar
Nice
(Bn Strain)
Nice-Black
(C57 Strain)
Skin tumors (some
malignant)
Skin carcinomas
Horton
Deelman
Shabad
et al.
1961 Coal tars,
coal tar mix-
ture, benzo(a)
pyrene mixture
Coal tar dis-
tillates
1962 Coal
Tar
1971 Coal tar
Ointments
Nice
(C3M Strain)
Nice
(C3M Strain)
Nice (Strain
Undefined)
Nice (C57 CBA
Hybrid Strain)
Skin tumo*s in 75%
of each group of
animals
Skin tumors
Skin carcinomas
and papillomas
Skin tumors
11-16
•JP
-------
TABLE I1-1 (Continued)
COAL TAR
Animal Studies
Inhalation Exposure
Authors Year
Substance
Tested
Animal 6
Strain
Type of Tumor
Response
Horton
1961
Horton
et al.
1963
Tye &
Stemmer
1967
Kinkead;
McConnell
6 Specht;
MacEwen &
Vernot
1972-
1974
MacEwen &
Vernot ;
MacEwen
et al.
1976
Coal tar fumes
preceded by
inhalation o£
formaldehyde;
coal tar fumes
Coal tar
aerosol;
Coal tar
aerosol 6
gaseous
formaldehyde
Coal tar;
coal tar &
phenolic &
non-phenolic
fractions of
coal tar;
non-phenolic
fractions of
coal tar
Aerosolized
coal tar -
light oil 6
solid frac-
tion removed
Aerosolized
Coal tar
Mice (C3M
Strain)
Mice (C3H
Strain)
Mice (C3H/HeJ
Strain)
Mice (ICR-CP1)
Mice (JAX-CAF1)
Weanling rats
(Sprague-Dawley)
Yearling rats
(Sprague-Dawley)
Hamsters
(Syrian golden)
Rabbits (New
Zealand white)
Mice (ICR-CP1)
Mice (JAX-CAF1)
Rats (Sprague-
Dewley) Rabbits
(New Zealai.d
albino) Monkeys
(Macaca Mullata)
11-17
<3(
Both groups developed
Proliterative
alveolar neoplasia;
one mouse (group
unspecified) de-
veloped a squamous
cell carcinoma
Both groups
developed squamous
cell tumors of lung
and lung adenomas
Adenomas & carcinomas
of the lung
Mice developed skin
tumors due to
aerosolized
material deposited
on skin; Tumor
response was not
reported for
rabbits,
hamsters, or rats
Mice - Alveolargenic
carcinoma and skin
tumors; Rats -
Squamous cell car-
cinomas; No tumor
response was reported
for rabbits or monkeys.
-------
TABLE II-l (Continued)
CREOSOTE
Huroan Case Reports
Authors Year
Substance
Tested
Occupation o£
Exposed Individual
Type of Tumor
Response
Mackenzie 1896
O'Donovan 1920
Cookson 1924
Henry
1947
Lenson - 1956
Handling o£
Creosote
Handling o£
Creosote
Handling o£
Creosote
Handling o£
Creosote
Painting of
Creosote
Worker whd dipped
railway ties in
creosote
Workers who
creosoted timbers
Creosote factory
worker
3? men of various
occupations
Shipyard worker
Warty elevation
on arms; Papillmatous
swellings on scrotum
Skin cancer
Squamous epithelio-
mata on hand;
epitheliomatdus
deposits in liver*
lungs, kidneys and
heart walls
Cutaneous epithelio-
ma ta
Malignant cutaneous
tumors of the face
Il-it
-------
TABLE II-l (Continued)
CREOSOTE
Animal Studies
Dermal Exposure
Authors
Year
Substance
Tested
Animal &
Strain
Type of Tumor
Response
Sail &
Shear
1940
Creosote &
benzo(a)
pyrene
Mice (Strain A)
Accelerated tumor
formation
woodhouse 1950
Lijinsky
et al.
poel 6
Kammer
Boutwe11
6 Bosch
Roe
et al.
1957
1957
1958
1958
Creosote oil
#1 creosote
oil
Blended
creosote
oils;
Light
creosote
oil
Creosote
(Carbasota)
Creosote oil
(Carbasota)
Mice (Albino;
Undefined Strain)
Mice - Swiss
Mice (C57L
Strain)
Mice (C57L
Strain)
Mice (Albino-
random bred)
Mice (Strain
Undefined)
Papillomas &
carcinomas
Papillomas k
carcinomas
Papillomas &
carcinomas
metastatic growths
in lungs and lymph
nodes
Papillomas
Papillomas fc
carconomas
Skin & lung
tumors
11-1$
J 3
-------
TABLE II-l (Continued)
COAL TAR NEUTRAL OIL
TABLE Il-l (Continued)
CREOSOTE
Animal Studies
Dermal Exposure
Authors
Year
Substance
Tested
Animal ft
Strain
Type of Tumor
Response
Cabot 1940 Benzene
et al. Solution of
neutral oil
ft benzo(a)
pyrene
Mice - albino
"market* mice
Inhibitory effect of
tumor response as
compared to tumor
response with benzo
(a)pyrene (effect
credited to skin
damage)
Berenblum 1947
ft Schoental
Horton
1961
5 Coal tar
neutral oil
fractions
Coal tar
neutral oils
(maleic anhy-
dride extracts)
Mice (Strain
Undefined)
Rabbits (Strains
Undefined)
Mice (Strain
Undefined)
All fractions but
two were oncogenic
All fractions but
one were oncogenic
Produced tumors in
34.1 and 32.1 weeks
XI-20
AH
-------
The rebutters present neither firm evidence that the
current formulations of creosote are safer than the formuLations
used before World War II nor evidence as to the extent or
effectiveness of "current hygienic practices and safety
precautions."
Rebuttal Comment 2; Small Number of U.S. Case Reports (149)
Allied Chemical Corporation questioned the skin cancer
hazard from creosote manufactured and used in Che United
States. The rebutter points out that, of the mere eight
reports of skin cancer among exposed workers cited in PD-1,
only two were from the United States. One of these reports
concerns an individual who was a painter for 41 years prior
to a 3-year job working with creosote. The other report
deals with a fisherman working with tarred nets. The rebutter
states that exposures to paint solvents could have caused the
face cancer of the painter, and that exposure to tarred
fiuhing nets is not relevant to the use of creosote as a wood
preservative. The rebutter recognizes, however, that most
experts agree that long-term dermal exposures to high levels
of creosote poses a possible skin cancer hazard. The rebutter
presented a new survey of Allied plant workers documenting
skin lesions that these workers had incurred. The dermato-
logists questioned in the survey concluded that proper personal
hygiene and periodic medical surveillance would prevent
serious skin diseases.
Agency Response: Although the rebutter provides no evidence
showing that paint solvents may have contributed to the cause
of the painter's cancer, the Agency acknowledges the possibility
that such may have been the case. Similarly, although the
rebutter has submitted no data, the tar used for the fishing
nets may indeed be qualitatively different from that used
for wood preservation.
Still, the basis for the Agency's concern is not limited
to the eight human case reports cited in PD-1, but also
includes th<* 21 animal studies on coal tar and creosote (see
Table II-l). The Agency agrees with the rebutter that
creosote exposure, if continued for a long duration at high
levels, constitutes a skin cancer hazard.
Rebuttal Comment 3t Reliability of Henry, 1947 (143)
West European far industries criticizes t'-.e case report
study of Henry (1947) which reviewed 3,753 cases of cutaneous
epitheliomata. The rebutter points out that the National
Institute for Occupational Safety and Health (N10SH) discounted
this paper because Henry "did not describe the bases for his
conclusions."
11-21
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Agency Response: The Agency agrees with NIOSH and the
rebutters that the lack of certain information in Henry's
report, such as the number of workers exposed to creosote,
makes it difficult to quantify the relationship between
exposure and cutaneous cancer. However, Henry's paper does
provide strong evidence th-at the site of cutaneous cancer was
associated with the nature o£ a worker's occupation, thereby
supporting the occupational oasis o£ these cancers.
Rebuttal Comment 4: Health Records of Creosote-Exposed
Workers (151, 193)
The Association of American Railroads submitted a summary
of a 4-year study which reported 971 dermatitis or burn
cases caused by creosote in railroad workers. The rebutter
also summarized the health records of about 90 workers in
two railroad tie treating plants. These records cover a
period of about 30 years. The rebutter believes that, although
workers exposed to creosote may develop "initiative dermatitis*
or "transient eye involvement," the studies provide no evidence
of an increased incidence of creosote-related skin cancer.
In another rebuttal comment, Samuel Cabot, Inc. states tKat,
following a review o£ that company's employee files, no
"report o£ any critical or permanent illness linked to employee
exposure to creosote" was found.
Agency Responsex The summary reports submitted by the
rebutters do not indicate that the studies were specifically
designed to detect an increased incidence o£ skin cancer.
For example, they do not provide mortality, morbidity, or
exposure data.
Also, it appears that the studies consist of an examination
o£ voluntary reports of individuals medical complaints rather
than systematic surveillance o£ skin diseases possibly related
to creosote exposure. Therefore, the in£ormation provided by
the rebutters is not definitive evidence that creosote is not
associated with induction o£ skin cancer.
Rebuttal Comment 5i New epidemiology Studies (1)
(Coppers Company submitted three studies in support of their
conclusion that workers exposed to creosote are not subject
to an excess risk o£ cancer. Two of the studies are epidemio-
logical (proportional mortality)r and the third is a summary
of worker's health examinations.
Agency Response: The Agency does not believe these studies
either support or refute the rebutter's conclusion. The
11-22
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studies are deficient because in each one a biasing factor
exists due to the method of selection of deaths. For example,
it appears that individuals who spent a period of years
working for Koppers and then left for other employment prior
to retirement were not counted. The Agency assumes that the
data included only individuals who died while employed by
Koppers or after retirement from Koppers. Individuals who
left the company because of illness, and later died from such
illness, may not have been included in the data. The Agency
concludes that, as these studies did not have the proper
controls that should be present in good epidemiological
investigations, the studies are incomplete and inconclusive.
The third study is merely a summary of healthy workers'
health examinations. Much follow-up work is required before
this information can be of use in detecting serious diseases..
Rebuttal Comment 61 Metabolism of Creosote Components (149)
Allied Chemical Corporation states that the polycyclic
aromatic hydrocarbons (PAH's) contained in creosote are
metabolized and excreted in mammals. Implying that these
biological functions automatically reduce or eliminate the
oncogenicity of these compounds.
Agency Response: While it is true that mammals do metabolize
both oncogenic and nononcogenic PAH's, it is not true that
all the metabolites of these compounds are innocuous. Some
PAH's are metabolized to active oncogens regardless of the
route of administration or dose level (Dipple, 1976). Also,
it remains possible that some oncogenic PAH's exert their
biological influence before they can be metabolized completely.
Thus, PAH's may pose an oncogenic risk to exposed humans.
Rebuttal Comment 7t "Anticarcinogenic" Activity of Creosote
Components (2)
The AWPI states that creosote solutions contain
"anticarcinogenic" substances as well as suspected oncogens.
The rebutter suggests that the consequence of this may be
that the potential for any oncogenicity, due to the presence •
of "well-established carcinogens," is cancelled out.
Agency Responset The Agency is not aware of any evidence
that the presence of "anticarcinogenic" substances in creosote
solutions counteracts the oncogenic components. Although
creosote mty contain some inhibitory compounds, it also
clearly contains both carcinogenic initiators and promoters,
as well as complete carcinogens* Also, numerous laboratory animal
studies cited in PD-1 adequately demonstrate that whole
creosote is oncogenic (see Table II-l).
11-23
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Rebuttal Comment 8: Dermal Application of Coal Tar
Medicinals (191)
The Joint Industry Coal Tar Committee cited the testimony
of P.E. Weary and E.M. Farber before the Food and Drug
Administration's Antimicrobial Panel II (DHCW, 1977) as
evidence that even coal tar medicinals, which are applied
directly to the skin, do not cause skin cancer. Dr. Weary
concluded (page 11 of the DHSW document) that in his 21 years
of dermatologic practice, he had found nQ solid evidence that
coal tar products cause skin cancer. Dr. Farber sent
questionnaires to 91 physicians who had been using these
products for at least 30 years. Again, there was no indication
that these products caused any skin cancers (page 300 of the
DHEW document).
Agency Response: Although testimony of this type is informative,
these comments do not rebut the oncogenicity presumption for
creosote. In the same symposium transcript (pp. 181-4) it
was concluded that coal tar medicinals contain at least four
agents that cause tumors in laboratory animals: benzo(a)pyrene,
beta-naphthalamino, o-toluMino, and quinoline. Also, Dr.
Hoffman points out (page 184) that a review of the literature
in 1966 (Greither et al., 1966) revealed that "thirteen cases
of skin cancer were reported in patients who used ccal tar
preparations. Of these cases two were also treated with
ar- inicals."
In conclusion, the Agency is unaware of any adequate long-
term studies to characterize the oncogenic effects tof the use
of coal tar medicinals in the induction of skin cancer.
Rebuttal Comment 9: Reliability of House Skin-Painting
Studies (193)
Samuel Cabot, Inc. attacks the utility of mouse skin-
painting studies as a reliable basis of establishing the
oncogenicity of creosote. In the opinion of this rebutter,
the studies lack adequate controls, detailed information on
dose levels, route of administration, sex, strain and species
of test animals, and experimental design. Weisburger (1975)
is cited in support of invalidation of these earlier studies.
Agency Response: The Agency agre«s that two of the six
studies had no controls. Nevertheless, the consistent positive
response in tl.ese studies cannot be ignored. Older studies
cannot automatically be invalidated due to lack of conformity
to present-day protocols. Also, Or. weisburger*s article
11-24
<3?
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merely listed several variables which affect the carcinogenic
response in animal experiments. The mere listing of these
variables does not invalidate these specific studies.
Rebuttal Comment 10: Reliability of Horton et ,al., 1963 (149)
Allied Chemical Corporation suggests that the positive
oncogenic response found by Horton et al. (1963) with coal
tar aerosols may have been due to aggravation by the formaldehyde
carrier.
Agency Response: The positive oncogenic response in the
mouse study: with coal tar aerosols is not explained by the
effect of formaldehyde because the group treated with coal
tar alone gave a greater response than the group treated with
coal tar plus formaldehyde.
Rebuttal Comment lit Xnappropriateness of Rodents as Models
for Oncogenicity (2)
The AWPI questioned the reliability of rodent species
as models for oncogenicity in man. The rebutter states that
these species are inappropriate due to major differences in
the metabolic, pharmacokinetic, and biochemical characteristics
of rodents and man.
Agency Responset The Agency finds no merit in the rebutter's
comment, it is accepted Agency policy to rely on the results
of animal studies to demonstrate the oncogenic potential of a
chemical agent. This policy, as stated in the Interim Cancer
Guidelines (PR 41*21402-21405, May 25, 1976), is that "a
substance will be considered a presumptive cancer risk when
it causes a statistically significant excess incidence of
benign or malignant tumors in humans or animals."
The scientific rationale for using animal studies fpr this
purpose is multifaceted. First, very few industrial chemicals
and processes have been subjected to adequate epidemiological
studies to determine whether or not they cause carcinogenic
effects in workers. Second, epidemiological studies are
insensitive and little weight can be placed on surveys which
do not show positive results. Third, many industrial chemicals
have not been in production long enough for any effects to
be observable, bearing in mind the long latent periods for
chemically-induced cancers. Fourth, it would be unethical
to wait for evidence of harm in exposed workers when risks
can be established relatively quickly by animal experimenta-
tion.
11-25
if
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A risk assessment which relies solely on animal data would
be less reliable £or humans in a situation where definite
metabolic pathway differences can be shown between animals
and humans. Since the rebutter presented no clear-cut evidence
of such differences for the metabolism of creosote, there is
no basis for qualifying the risk assessment on metabolic grounds.
Rebutttal Comment 12: Lack of Oncogenic Response to
Benzo(a)pyrene (193)
Samuel Cabot, Inc. cites Dr. Weisburger (1975), pointing
out that after 8 to 10 years of skin applications to primates
of some known oncogens, including benzo(a)pyrene, no tumors
were observed. The rebutter submits this as evidence that
creosote is not oncogenic.
Agency Responset The major purpose of this section of Dr.
Weisburger's article was to show the inter-species variation
in response to oncogens, and not to demonstrate that
benzola)pyrene is nononcogenic. Moreover, on page 279 (Table
8.4) of her article. Dr. Weisburger lists both coal tar and
creosote as human oncogens.
11-26
3o
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The following comments were submitted to the Agency in
response to the Position Document 2/3 on the wood preserving
uses of creosote, inorganic arsenicals, and pentachlorophenol.
Comment Issue It 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 AVf?I (3SA) cites Spitzer et al. (1975}
as evidei.ee 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 *1.
study (1975), and concludes that the absence of-definitive
exposure data precludes the use of the Spitzer study
to refute the Shambaugh (1935) study. For example, it is
unclear as to whether the fishermen in the Spitzer study
placed needles moist with coal tar and/or coal tar-soaked
nets in their mouths. Also, the type of "tar" used in Spitzer's
study is not defined. It seems likely that pine tar or some
less toxic tar would have replaced coal tar used as a preser-
vative in Shambaugh's (1935) study by the time of Spitzer's
study (CAG, 1982).
Comment Issue 2t Coal tar distillates and cancer
The AWPI (36A) cites "Of Nice and Men and Coal-Tar Dis-
tillates: 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 Responset 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 lungs studies by Re|& and Buck (1956) as
evidence that there was no increased mortality to coking
plant employees from lung cancer; and studies by Doll et al.
(1956, 1972) which concluded that men exposed to coal carbon-
ization by-products did not experience excess mortality risk
from cancer of the lung, bladder# skin, scrotum or other
sites.
The Agency has carefully reviewed the studies cited
above and finds that there are deficiencies in each study
11-27
3l
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which preclude the Agency's concurrence with the author's
conclusions. The mortality studies conducted by Lloyd (1971),
Redmond (1976), and Redmond £t al. (1979) may not demonstrate
excess risk o£ skin cancer from coal tar distillates because
of the low case-fatality rate of skin cancer. With regard
to lung cancer mortality, almost a twofold increase in
deaths would be required to detect a statistically significant
difference between the observed and the expected, given the
expected number of lung cancer deaths among by-product workers.
In neither the Lloyd (1971) nor the Redmond et al. (1979)
studies was there a control for smoking, the most important
confounder for lung cancer in any occupational study
(CAG, 1982).
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 fout.d through a special 1952 census. If the
cohort consisted of workers currently employed in 1952, and
because there was little or no follow up of any of these mem*
bers, it appears that this study is basically a cross-sectional
Btudy of mortality in a conglomerate of several different coke
plants. The observed deaths appear to have occurred to meuibers
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 (19711 that men were removed from the
bcoks 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 used to cal-
culate expected deaths were derived or defined; therefore, it
is not clear if they are compatible with the definition the
authors used to derive the study population (CM* 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 tied
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 13c 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
11-28
3a
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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.
Agency Respon--et The Agency has based its qualitative conclu-
sion that creosote is an oncogen on both animal studies and
human case studies. The EPA rejects AWPI'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 Joekerman treatment (2-4 weeks) is
not comparable to an occupational exposure to creosote/coal tar,
(e.g. wood treaters).
The Maughman 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 patient's
ranged in age from one year to late adulthood, therefore, the
recall of information would not be expected to produce very
reliable data (CAG, 1982).
The incidence rates used to calculate the expected number
of skin cancer cases were derived from medical record abstrac-
tions 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 methods through ques-
tionaires may be a problem due to potential underreporting by
those surveyed. In analyzing the data, Maughman et al. (1980)
compared the number of non-melanoma 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 geographically, there would seem to
be no significant increase from the reported incidence figures."
However, the Agency cannot concur with the author's conclu-
sions because there was no adjustment for geographic areas
and because the observed number of cases exceeded the expected
rates derived from three of the four geographic areas (CAG,
1982).
11-29
33
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Comment Issue 4: 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 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 indus-
tries 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 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 distri-
bution 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 tac products.
11-30
3H
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Comment Issue #5: 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. Plickinger 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 nay 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.
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 compari-
son 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) (CAG, 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 sta-
tistics to the observed skin cancer rate in the study popula-
tion would be a biased comparison that would underestimate a
¦kin cancer risk if it was present (CAG, 1982).
Although a cross-sectionally-designed study will assess
current problems at the treatment plants, workers who have skin
cancer may have left the plants. The study population did indi-
cate 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 cloth-
ing 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 though their
clothing (CAG, 1982).
11-31
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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 the workers
that were examined by Tabershaw Occupational Medicine Associates
had not been at the treatment plants long enough, if skin or
other types of cancer were to develop from creosote exposure
(CAG, 1982).
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 population 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 6: Creosote and lung cancer among roofers
The AWPI (36A) states that the excess lung cancer mor-
tality 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 be-
cause only five skin cancer deaths were recorded,among the
5,939 roofing workers, the incidence of skin cancer among
the roofers and the general population is no different.
Agency Responset The Agency finds merit in AWPl's (36A)
comment on the lung cancer incidence rate but does not
concur with the comments regarding skin cancer. The Agency
concludes that some of the excess lung cancer deaths among
the roofers in the Hammond et al. (1976) study may have been
attributable to smoking. And, this excess may be enough to
make the association found by Hammond of occupational exposure
of roofers with lung cancer mortality, statistically not signi-
ficant. However, because the sample size of roofers is rela-
tively small, the results of the Hammond et al. study with
regard to lung cancer mortality must be considered inconclusive
(CAG, 1982).
However, the Hammond study of roofers was a mortality
study, not an incidence study. Incidence is the number of
new cases of a disease in a given population over a specified
time period, usually one year. Skin cancer mortality may be
a poor reflection of incidence because the case-fatlity rate
for skin cancer is so low (CAG, 1982).
11-32
3b
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Also, the number of skin cancer deaths among 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 (CAG, 1982).
Comment Issue 7: Creosote animal oncogen studies
The AWPI (36A) states that the EPA persists in maintain-
ing 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, EPA, 1981,). 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
modem epidemiological evidence.
Agency Response; As stated in the PD-1, the animal studies
presented show tumor production following dermal and inhala-
tion exposure to coal tar (Fed. Register, 43 FR 48154, Oct.
1978). The Agency has also presented in the PD-2/3 (EPA,
1981) 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)athracene, quinoline, and many others
are known carcinogens (EPA, 1981). These data provide an
overwhelming qualitative assessment of inherent hazard associ-
ated with creosote exposures.
For an analysis of the creosote epidemiological studies
see Comment Issues #T~through #6.
11-3 S
3*7
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3i Summary of Rebuttal and Public Comments
Concerning Oncogenic Effects
The comments submitted have presented no substantial
information which shows that creosote does not pose and
oncogenic risk to humans.
Data from animal experiments show that creosote induces
squamous-cell carcinomas and papillomas of the skin and
adenomas and carcinomas of the lung. These positive results
in laboratory animals are supported by the numerous case
reports of skin cancer in people heavily exposed to creosote.
Thus, the original conclusions presented in PD-1 are still
valid,:and the presumption of oncogenicity for creosote, coal
tar, coal tar neutral oils is not rebutted.
11-34
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C. Analysis of Rebuttal Comments Concerning Human Exposure
Comments on the exposure assessment presented in the PD-1
on creosote, coal tar, and coal tar neutral oils all pertained
to the use of these chemicals as wood preservatives. No
comments concerning exposure as a result of the non-wood
preservative uses of these chemicals were submitted to the Agency.
D. Human Exposure Analysis
1. Chemistry
Coal tar and neutral oils is an extremely complex mixture
produced by coking, the high temperature carbonization of
coal. Creosote is a lower boiling distillate of coal tar.
Both mixtures vary in composition depending on the temperature
of coking and the source of coal use (PD-2/3). Each chemical
entity has its own chemical characteristics such as solubility,
vapor pressure, viscosity, etc. Furthermore, each creosote
batch is often produced from different source material?
leading to a different chemical composition.
In distilling coal tar to form creosote, the lower
molecular weight compounds are concentrated. The balance of
polynuclear aromatic hydrocarbons (PAH's) in creosote contain
one to four rings, although larger PAH's such as benzo[a]pyrene,
benzo[j]fluorantaane, and benzanthracene have been positively
identified (PD-2/3). Lorenz and Gjovik (1972) have identified
the major constituents in creosote. Eighteen compounds,
accounting for about 75-85% of the total volatile creosote
material, were identified and are listed in Table 11-2. Table I1-3
presents a listing of all of the compounds found in creosote.
There is variation in the relative percentage of individual
components in different creosote samples. Creosote also
contains smaller amounts of phenolic constituents as well as
nitrogen-, oxygen-, and sulfr-containing heterocyclic ring
systems and aromatic amines.
Therefore, because of the variable nature of creosote,
coal tar, and coal tar neutral oil to which humans are exposed,
it is not possible to compute quantitative exposure estimat.es*
The exposure assessment will rate exposure potential to the
various non-wood uses qualitatively with respect to the degree
of exposure. The rating of exposure potential is based on
available information regarding the application methods.
11-35
31
-------
TABLE II-2
Major Components o£ Creosote a
Component Approximate Boiling Point
Percentage (°C)
Naphthalene
3.0
218
2-Methylnaphthalene
CM
•
241.05
1-Methylnaphthalene
0.9
244.64
Biphenyl
0.8
255.9
Dimethylnaphthalenes
2.0
268
Acenaphthene
9.0
279
Dibenzofuran
5.0
287
•
Flvorene
10.0
293-295
Methylfluorenes
3.0
318
Phenanthrene
21.0
340
Anthracene
2.0
340
Carbazole
2.0
355
Methylphenanthrenes
3.0
354-355
Hethylanthracenes
4.0
360
Pluoranthene
10.0
382
Pyrene
8.5
393
Benxofluorenes
2.0
413
Chrysene
3.0
448
Adapted from Lorenz and Gjovik (1972).
11-36
HO
-------
TABLE II-3
Compounds Present in Creosote
C.oumarone
1,2,3-Trimethylbenzene
Hydrindene
Phenol
Indane
Aniline
3,4-Dimethylethylbenzene
Ammonium thiocyanate
6-Methylcoumarone
O-Cresol
Benzonitrile
3 or 5-Methylcoumarone
n-Ondecane
Durene (1,2,4,5-t*tramethylben2ene)
4-Methylcoumarone
Isodurene (1,2,3,5-tetramethylbenzene)
p-Toluidine
0-Toluidine
p-Cresol
Acetophenone
m-Cresol
m-Toluidine
4-Methylindene
Tetrahydronaphthalene
2.4-Xylenol
2,6-Xylenol
2.5-Xylenol
2.4-Xylidine
m-Ethylphenol
2.5-Xylidine
p-Ethylphenol
Naphthaline
2,3-Xylenol
3.5-Xylenol
3»5-Xylidine
3.6-Dimethylcoumarone
4.5-Dimethylcoumarone
4.6-Dimethylcoumarone
Thionaphthene
2.3-Xylidine
3.4-Xylenol
Dimethylindane
Pseudocumenol (2,4,5-trimethylphenol)
3-Ethyl-5-methylphenol
2,3,4,5-Tetramethylpyridine
Iaopseudocumenol (2,3,5-trimethylphenol)
Quinoline (leucoline)
7-Hydroxycoumarone
Methylthionaphthalene
Isoquinoline
4-Hydroxyhydrindone
1-Methylnaphthalene
11-37
if
2-Methylquinoline
2,8-Dimethylquinoline
7-Methylquinoline
6-Methylquinoline
3-Methylquinoline
2.6-Dimethylnaphthalene
2.7-Dimethylnaphthalene
1.7-Dimethylnaphthalene
1,3-Dimethylisoquinolene
1,6-Dimethylnaphthalene
5-Kethylquinoline
4-Methylquinoline
5- or 7- Methylisoquinoline
3-Methylindole (skatole)
1,5-Dimethylnaphthalene
6-Methylisoquinoline (probable)
7-Methylindole
2,3-Dimethylnaphthalene
1,2-Diraethylnaphthalene
4-Methyl indole
5-Methylindole
3-Methyldiphenyl
5.8-Dimethylquinoline
4-MethyIdiphenyl
2-Methy1indole
0-Phenylphenol
1,3,7-Trimethylnaphthalene
a-Naphthol
Acenaphthene
a-Naphthofurane
B-Naphthofurane
2.3.5-Trixnethylnaphthalene
2.3.6-Trimethylnaphthalene
B-Naphthol
Diphenylene oxide
2,4,6-Trimethylquinoline
3,4'-Dimethyldiphenyl
4,4'-Dimethyldipheny1
g-Diphenyleneraethane
4,5-Benzindan
1-Naphthonitrile
(1-cyanonaphthalene)
1-Methyldiphenylene oxide
Pluorene
Rydroacridine
1-Naphthylamine
2-Methyldiphenylene oxide
2-Naphthonitrile
(2-cyanonaphthalene
Paraffin (octadecane)
Heneicosane
-------
TABLE II-3 (Continued)
2-Methylfluorene
3-Methylfluorene
p-Phenylphenol
Tricosane
Tetracosane
Pentacosane
Acenaphthalene
Dibenzofuran
9,10-dihydroanthracene
2-Phenylnaphthalene
9,10-Benzophenanthrene
Docosane
Nonadecane
Hexacosane
Heptacosane
Octacosane
Diphenylene sulfide
Phenanthrene
Tetramethylbiphenol
Anthracene
Acridine
2-Hydroxybiphenylene oxide
Phenanthridine
3-Methylphenanthrene
Carbazole
2-Hydroxyfluorene
4,5-Phenanthrylenemethane
9-Methylphenanthrene
1-Methylphenanthrene
2-Phenylnaphthalene
'lydroxyanthracene
Naphthacene
2-Methylanthracene
2,7-Dimethylanthracene
2-Methylcarbazole
1,2,3,4-Tetrahydrofluoranthene
Truxene
3-Methylcarbazole
Fluoranthene
2,3,5,6-Dibenzocouraarone
Pyrene
1,9-Benzoxanthene
2-Hydroxyphenanthrene
(2-phenanthrol)
Retene (8-methyl-2-isopropylphenanthrene)
1.2-Benzofluorene (naphthofluorene)
2.3-Benzofluorene (isonaphthofluorero)
Naphtho-2',3',2-anthracene
1,2-Benzonaphthacene
Phenanti>r idone
Dibenzothionaphthalene
Sulfur
Chrysene
Triphenylene
11-38
-------
The chemicals comprising creosote have been characterized
by McNeil (1952) into eight classes. These classes are
presented in the risk assessment section because they are of
interest toxicologically (Table II-6). Chemicals derived from
coal mined from different sources can vary in the relative
proportions of chemicals present. However, McNeil emphasizes
that all creosotes contain essentially the same classes of
chemical compounds, even while the proportion and distribution
of classes varies.
Coal tar and coal tar neutral oils are often blended
with creosote for the uses under consideration in this document.
Coal tar comprises the entire spectrum of non-aqeuous coke
oven volatiles. Because the condensate extends to boiling regions
higher than those of the creosote fractions* coal tar contains
* large number of 5- and 6-ring polynuclear aromatic hydrocarbons.
The Agency has prepared estimates of dermal and respiratory
exposure for the non-wood preservative uses o? creosote, coal
tar, and coal tar neutral oil. Table Ji-4 presents information
regarding the application practices use-by-use. Table II-5 is
a summary of the Agency's qualitative exposure analysis of creosote,
coal tar, and coal tar neutral oil.
11-39
H3
-------
TABLE II-4
Sunoary of Application Practices By Use for
Non-Hbod Uses of Creosote, Coal Tar, and Coal Tar Neutral Oils
USE
PESTICIDAL ACTION
MODE OF APPICAXIGN
-C
-C.
HERBICIDftL
1. Ornamental flowering
plant? ornamental
lawns
2. Product Storage Yarns
3. Agricultural Premises
(fencerows) and Highway
Rights-of-Way
FUNGICIDAL
Rope and Canvas
BIOCIEAI
1. Seed Potato Storage
Premises an6 Equipment
2. Livestock Premises
3. Poultry Premises
4. Home/Institutional Use
(toilets; washrooms;
water closets; garbage
cans; sinks)
Nutgrass oontrol
Heed and grass control
General weed oontrol
Prevent algae and fungi
Bacterial control - ringrot
Bacterial control - ringrot
Bacterial control
Bacterial control
Spot treatment
No information
Broadcast spray or spot
treatment
Brushed; sprayed;
Manually dipped, (ropes only)
Sprayed; dip tub.
Sprayed; wipe; mop.
Sprayed; wipe; mop.
Sprayed; wipe; map.
11-40
-------
TABLE I1-4
Sunroacy of Application Practices By Use for
Non-Wood Uses of Creosote, Coal Tar, and Goal Tar Neutral Oils
USE
PESTICIDAL ACTION
MODE OF APPICATION
5. Livestock
Transport
Vehicles
6* Tree Nbund
Dressings
7« Metalworking
Fluids
(Cutting Oils)
INSECTICIDE, MITICIEB,
LAKVIC1DE, REPELLENT
It Mosquitoes
Bacteria/virus control
Bacterial/fungal control
Bacterial/fungal control
Larvicide
Presumed to be
sprayed or mopped
Brushed
Metering puip or manually
Sprayed onto water surface to
control mosquito and fly larva
by covering water with a surface
film; not used for many years
2. Repellent
3. Horses/Mules
Animal
Bird
Insect
Screwwocm control
Brushed/sprayed on stalls
to prevent cribbing by horses
Applied to seed corn
Hand application
Not in use
XX-41 '
-------
TABLE II-4
Suwnary of Application Practic "Zy Use for
Non-Wood Uses o£ Creosote* Coal Tar, and Coal Tar Neutral Oils
USB PESTICIDAL ACTICN MODE OF APPZCATION
-C
4. Insect control
- Drain flies
- Garbage Trucks
5. Qypsy Moth Control
6. Animal Dip
(Non-food Animals)
Aids in control of flies;
(Orthodichlorobenzene is the
active ingredient in these products
that is the insecticidal agent)
Controls gypsy moth egg
masses
Mites
Rxired into drains
Sprayed
Brush
Dip, wash, or swab
11-42
-------
TABLE II-5
Sutnary of Exposure Analysis -
Won Wood Uses of Creosote, Coal Tar, and Cool Tar Neutral Oils
ASSUMPTIONS USED IN ANALYSIS
EXPOSURE POTENTIAL
Dermal Inhalation
HEHBICIQM.
1. Ornamental flowering
plants and ornanental
lawns
2. Product Storage Yards
3. Aricultural Premises
(fencerows) and Highway
Rights-of-Way
FUNGICIDAL
Rope and Canvas
a. 10% A.I. concentration used
b. Spot treatment - sprayed
c. Applied as needed
d. Product concentration is low
and minimal exposure is expected
a. 75% A.I. concentration
b. Sprayed
c. Estimated application frequency*
twice/year
a* 75% A.I. concentration
b. Sprayed
c. Estimated application frequency:
twice/year
a. 97% A.I. concentration
b. For ropes and canvas, product is brushed
and sprayed; ropes are sometimes dipped
into product.
c. Application to 1 product is considered
for estimating exposure; many products
are treated per day; 8 hour/day exposure
is assumed.
lew
low
mediun
mediun
mediun
medium
medium( brush)
high(spray)
high(dip)
medium (brush)
high(spray)
high(dip)
11-43
-------
TABLE II-5
Sunnary of Exposure Analysis -
Non-Wbod Uses of Creosote, Coal Tar, and Coal Tar Neutral Oils
USE ASSUMPTIONS USED IN ANALYSIS EXPOSURE POTENTIAL
Dermal Inhalation
BIOCIDAL
1-2% A.I. concentration low medium
Sprayed
Each worker applies product for
one day or less
Estimated application frequency}
1-5 tiroes/year
Because the use concentration is less
than 2%. exposure of these uses is
considered low; however, inhalation
exposure can be critical because
application is generally in enclosed
areas.
Potential dietary exposure
2. Livestock premises a. 1-2* A.I. concentration low medium
b. Sprayed, wipe, mop
c. Estimated application frequency:
12-16 days/year
d. Because the use concentration is less
than 2%, exposure of these uses is
considered low; however, inhalation
exposure can be critical because
application is generally in enclosed
areas.
1. Seed Potato Storage a.
Premises and b.
Equipment c.
d.
e.
f.
11-44
-------
TABLE II-5
Sumvary of Exposure Analysis -
Non-Wbod Uses of Creosote, Coal Tar, and Coal Tar Neutral Oils
USE
ASSUMPTIONS USED IN ANALYSIS
EXPOSURE POTENTIAL
Dermal Inhalation
3. Poultry Praises
4.
-£*
Hone/Institutional Use
(toilets; washrooms;
water closets; garbage
cans; sinks)
5.
Livestock
Transport
Vehicles
a. 1-2% A.I. concentration lew
b. Sprayed, wipe, mop
c. Estimated application frequency:
12-16 days/year
d. Because the use concentration is less
tjhan 2%, exposure of these uses is
considered low; however, inhalation
exposure can be critical because
application is generally in enclosed
areas.
a. 1-2% A.I. concentration low
b. Sprayed, wipe, mop
c. Estimated application frequency
cannot be determined
d. Because the use concentration is less
than 2%, exposure of these uses is
considered low; however, inhalation
exposure can be critical because
application is generally in enclosed
areas.
a* 1-2% A.I* concentration low
b. Estimated application frequency cannot
be determined
c. Not currently used
d. Because the use concentration is less
than 2%, exposure of these uses is
considered low; however, inhalation
exposure can be critical because appli-
cation is generally in closed areas.
medium
medium
mediun
11-45
-------
TABLE I1-5
Sunnacy of Exposure Analysis -
Non-wood Uses of Creosote, Coal. Tar, and Coal Tar Neutral Oils
USE
ASSUMPTIONS USED IN ANALYSIS
EXPOSURE POTENTIAL
Dermal Inhalation
6. Tree Ntxn)
Dressings
7. Metalworking
Fluids
(Cutting Oils)
v>\
INSECTICIDE, Mmcice,
LAHVICICE, REPELLENT
1. Mosquitoes Larvicide
2. Mosquito
Repellent
a. 971 A.I. concentration lot#
b. Brushed
c. Estimated application frequency:
20-30 tiroes/year
a. 41.2% A.I. concentration low
b. Applied by metering pump or manually
c. Estimated application frequency:
variable, frequency unknown
d. The application of this creosote product
is low; however, workers exposed to
cutting oils in the course of their work
will have frequent dermal contact.
The concentration in the oil is-much less
than tha 41.2% product.
a. Product not used for many years. More effective
products available.
low
low
a. Hand application
b. Estimated application frequency!
as needed
c. N,N-Diethyl toluamide is mud) more
effective.
high
low
11-46
-------
TABLE 11-5
Sunaacy of Exposure Analysis -
Non-WOod Uses of Creosote, Coal Tar, and Goal Tar Neutral Oils
USB
ASSUMPTIONS USED IN ANALYSIS
EXPOSURE POTENTIAL
Dermal Inhalation
3. Bird Repellent
4. Animal Repellent
a. 94% A.I. concentration
b. Mixed with seed corn before
planting
c. Potential dietary exposure
a. 99% A.I. concentration
b. Applied by brush or spray to
wood stalls* mangers* gates,
fence rails* poles, trees,
and horse trailers.
c. Spray is in enclosed area
leading to potentially high
inhalation exposure
low
low
low
high
5. Insect control
Drain flies ft a. Product in question contains
Garbage Trucks orthodichlorbenzene as the insecticidal
agent and creosote only aids in control.
6. Gypsy Moth Control a. Applied by brush lew low
b. Application frequency! onoe/year
7. Animal Dip a. A.I. ranges front less than 1% low lew
to 62%
b. Application method fay dip, swab or
wash 1-2 times per year
11-47
-------
E. Risk Assessment for Mutagenicity and Oncogenicity
1. Risk Assessment Cor Mutagenicity
The objective of this risk assessment is to determine
whether or not the complex mixtures creosote, coal tar, and
coal tar neutral oils have the potential to cause mutations
in humans. This assessment is based on two kinds of available
information: (1) data concerning the mutagenic potential of
the complex mixtures themselves, fcnd (2) data concerning the
mutagenicity of the individual compounds that have been
identified in these complex mixtures.
Creosote and creosote-coal tar have been shown to be
mutagenic in bacteria (Salmonella typhimurium) and mammalian
cells in vitro (L5178Y mouse lymphoma cells). In both test,
systemsr the complex mixtures caused point/gene mutations in
a dose-dependent manner, and the incorporation of an exogenous
hepatic metabolic activation syittem was needed to detect
these responses. In the bacterial tests, positive responses
were found primarily in frameshift-sensitive tester strains;
it should be emphasized that there are several known mutagens
identified in creosote and creosote-coal tar (e.g., certain
polycyclic aromatic hydrocarbons* aza-heterocyclic compounds,*
and aromatic amines) that are also primarily detected in
Salmonella as frameshift mutagens that require metabolic activation.
Creosote and creosote-coal tar were not detected as causing
genetic damage in yeast tests for mitotic recombination, in
Escherichia coli WP2 reverse mutation assays, and in differential
growth inhibition tests using repair-proficient and repair-
deficient strains of Bacillus subtillus and E. coli. However,
because of the limitations of these submammalian tests and
because of inadequecies in the studies conducted, the reported
negative results are not judged as evidence for the
nonmutagenicity of creosote and creosote-coal tar. This is
reinforced by the positive results obtained in Salmonella and
LS178Y mouse lymphoma cells and by the fact that these are
complex mixtures of compounds some of which are clearly
mutagenic. Also, there is suggestive evidence that creosote
caused unscheduled DNA synthesis in cultured human lung
fibroblast (Wl-38) cells.
Creosote is a complex mixture of organic chemicals. Of
particular toxicological concern are the polynuclear aromatic
hydrocarbons (PAH's), aromatic amines, and phenolic constituents.
Different creosote samples can be expected to contain varying
proportions of these three as well as other broad classes of
chemicals. Table II-6 presents the classification of chemicals
in creosote and information on the effect associated with
each class.
11-48
531
-------
TABLE I1-6
Classification of Chemicals in Creosote
Compound Effect Reference8/
1. Unsubstituted 6-membered aromatic ring systems (fused, unfused,
or mixed)
chrysene
mutagenic initiatory
carcinogenic
a,b,c,d,e,8,f, r
pyrene
co-carcinogen
(with fluoranthene,
benzo[a]pyrene),
mutagenic
f.r.b
benzo[a]pyrene
mutagenic
carcinogenic,
fototoxic,
teratogenic
a,b,c,d,n,o,g,r
benzole]pyrene
carcinogenic,
mutagenic
'r
benzo[a]anthracene
mutagenic*
carcinogenic
a,b,c,s,g,h
benzo[c)phenanthrene
initiator, mutagenic
r
naphthalene
inhibitor
1
phenanthrene
initiator, mutagenic
r
anthracene
mutagenic
dibenzanthracene
mutagenic
8
acenaphthene
mutagenic
triphenylene
mutagenic
r
a/ The key to the references it on p. 11-52
11-49
ST3
-------
TABLE I1-6 (continued)
Unsubstituted aromatic ring systems containing 5-numbered
rings
snoj
flouranthene
benzIj Jfluoranthene
fluorene
co-carcinogenic,
initiator,
mutagenic
carcinogenic,
mutagenic
mutagenic
f#r,s
9
r
Heterocyclic Nitrogen Bases
quinoline
indole
benzocarbazoles
isoquinoline
1-methyl isoquinoline
3-methyl isoquinoline
5-methyl quinoline
4-methyl quinoline
6-methyl quinoline
5-methyl isoquinoline
7-methyl isoquinoline
6-methyl isoquinoline
1,3-dimethyl
isoquinoline
acridine
carbazole
carcinogenic d
mutagenic s
carcinogenic h
mutagenic s
possibly carcinogenic d
possibly carcinogenic d
possibly carcinogenic d
possibly carcinogenic,
mutagenic d,s
possibly carcinogenic d
possibly carcinogenic d
possibly carcinogenic d
possibly carcinogenic d
possibly carcinogenic d
mutagenic s
mutagenic •
tI-50
51
-------
TABLE II-6 (continued)
Heterocyclic Oxygen and Sulfur Compounds
coumarone
thionaphthene
Alkyl substituted compounds
No effects found
in the literature
for this structural
class.
So
1-methyl naphthacene
2-methyl anthracene
methyl fluoranthene
1-raethyl naphthalene
2-methyl naphthalene
ethyl naphthalene
2,6-dimethyl
naphthalene
1,5-dimethyl
naphthalene
2r3->dimethyl
naphthalene
2.3.5-trimethyl
naphthalene
2.3.6-trimethyl
naphthalene
methyl chrysene
1,4-diraethyl
phenanthrene
1-methylphenanthrene
mutagenic a
mutagenic s
possibly carcinogenic d
inhibitor
inhibitor
inhibitor
inhibitor
inhibitor
accelerator
inhibitor
accelerator
initiator p,q
initiator, mutagenic
mutagenic
Hydroxy compounds
ar
phenol
p-cresol
o-cresol
m-Cresol
promoter
promoter
promoter
promoter
f ,m
m
11-51
SS"
-------
TABLE I1-6 (continued)
7. Aromatic amines
NH2
2-naphthylamine
carcinogenic
carcinogenic
carcinogenic
carcinogenic
carcinogenic
1
p-toluidine
o-toluidine
2.4-xylidine
2.5-xylidine
m
m
m
m
8. Paraffins and naphthenes
(n is large, e.g., greater than 15)
No effects found in the literature for this structural class.
* classes taken from McNeil (1952).
a. McCann et al. (1975)
b. Thilly and Liber (1979)
c. Nagao and Sugimura (1978)
d. Hollstein et aju (1979)
e. Sivak (1979)
f. Van Duuren (1976)
g. .IARC (1973)
h. CAG (1978b)
1. Schmeltz et al. (1978)
j. Epler et al. (1979)
k. Boutwe11 and Bosch (1959)
1. IARC (1974)
m. Weisburger et al. (1978)
n. Hyrobek and Bruce (1975)
o. Epstein et al. (1972)
p. Van Duuren (1966)
q. Van Duuren and Goldschmidt (1976)
r. IARC, 1983, Vol. 32.
8. Vaughn-Dellarco, (1983)
11-52
Sfe?
-------
The overall evaluation of the data regarding the
mutagenic activity of croosote, coal tar* and coal tar neutral
oils and the data regarding th-; mutagenic activity of the
individual compounds identified in creosote and creosote-coal
tar suggests that creosote and creosote-coal tar hove the
potential of mutagenicity in intcct mammals including humans.
It should be emphasized, that creosote and creosote-coal tar
were evaluated only in in vitro tests and that testing in
intact mammals has not Eeen performed. When determining the
risk posed by exposure to a mutagenic agent, several factors
(e.g., absorption, metabolism) may alter the mutagenic response
in the whole mammal compared to the mutagenic potential
determined jji vitro. Although creosote and creosote-coal tar
are judged as potential mammalian mutagens that may cause
somatic nutations (and somatic mutations may be involved in
the etiology of cancer), the data concerning genetic risk
with respect to germ cells are. too limited for any conclusions
at present.
11-53
S"7
-------
2. Risk Assesss-nt for Oncogenicity
Creosote and coal tar and many of their component
chemicals have been well characterized as carcinogens in
laboratory animals (PD-1, Coal tar. Creosote, and Coal Tar
Neutral Oils; PD-2/3 Wood Preservatives; IARC/ 1973* 1983).
These studies, along «ith the several reports in the literature
of skin cancer in people exposed to creosote and coal tars,
suggest that these chemicals are human carcinogens, even though
no valid epidemiology studies have been petformed of workers
using creosote or creosote/coal tar blends (CAG, 1977, 1982).
Two hundred ye»rs ago, scrotal cancer was observed in
English chimney sweeps (Pott, 1775). Since that time, several
reports have confirmed cases of cancer in humans resulting
from industrial exposure to coal tars (NIOSH, 1977). As
noted in the oncogenicity rebuttal section, Shambaugh (1935)
reported that fishermen who held tar-soaked needles in their
mouths while mending tarred nets, developed lip cancer as a
result. In an analysis oc the study of wood treatment plant
workers, the Agency notes that there were significant increases
in benign growths and pseudofolliculitis io the study
population (Tabershaw, 1979). These emotions occurred where
clothing rubbed against the skin rat her than in areas exposed*
to the sun, suggesting that these effects were caused by
exposure to the creosote preservative through the clothing.
Substantial epidemiological evidence is available to show
that exposure to coke oven emissions gives rise in workers to
an excess risk of death from lung cancer and cancers of the
bladder, prostate, pancreas, and large intestine (CAG, 1978a).
The airborne chemicals comprising coke oven emissions are
condensed to form coal tars.
Creosote, coal tar, and many of the individual chemicals
comprising these mixtures have been subjected to animal
carcinogenesis assays and short term mutagenesis assays in
the laboratory.
A CAG report (1977) summarizes several mouse skin painting
studies (Woodhouse, 1950; Poel and Kramer, 1957}
Lijinsky et al., 1957; Boutwell and Bosch, 1958) in which
creosote was~Tound to cause Lkin papillomas and carcinomas.
Ir. one study (Roe et al., 1958), lung adenomas were observed
as well as skin tumors in mice receiving dermal applications
of creosote oil.
The CAG report also summarizes numerous skin painting
studies in which coal tars produced skin cancer in mice and
rabbits. In addition, tumors of the lung were reported in
mice inhaling coal tar aerosols (Horton et al., 1963).
11-54
*5%
-------
Coal tar neutral oils have been shown to be oncogenic in
laboratory animals. For example, Berenblum and Schoental (1947)
tested several coal tar neutral oil fractions in mice and
rabbits. Most fractions were found to be oncogenic. In
1961, Horton showed that extracts (in maleic anhydride) of
coal tar neutral oils produced tumors in mice in about 33
weeks. Earlier, however, Cabot et aK (1940) applied benzene
solutions of benzo[a]pyrene with and without coal tar neutral
oil to the skin of albino mice. The coal tar neutral oil was
found to inhibit the tumorigenic response of benzo(a)pyrene.
A series of aromatic amines, among them some monocyclic
amines occurring in creoste (Nestler, 1974), were tested for
long-term toxicity by dietary administration to Charles River
rats and HaM/XCR mice (Weisburger et al., 1978). Of these
amines, ortho- and para-toluidine, 2,T^xylidine, and 2,5-
xylidine led to tumors in various tissues. Meta-toluidine
had questionable activity. The boiling points of these
compounds range from 200°C to 215°C. Chrysene, one of the
major components of creosote, is a 4-ring polynuclear
aromatic hydrocarbon (PAH) which boils at 448°C. As reviewed
by the IARC (1973, 1983), chrysene causes skin tumors in
mice. In addition, it acts as an initiator of skin cancer
in mice. (The oncogenicity of chrysene is presently under
review by EPA's Carcinogen Assessment Group.)
Because cosl tar contains an additional, higher boiling
spectrum of coke oven volatiles than creosote, it contains a
large number of 5- and 6-ring (PAH's). The carcinogenicity
of many of these larger PAH's has been studied and reviewed
extensively (CAG, 1978b; IARC, 1973, 1933). Known PAH
carcinogens in coal tar are benz[a]anthracene, benz[a)carbazole,
benzolb]fluoranthene, benzo(i)fluoranthene, benz(c]acridine,
benzola]pyrene, benzole)pyrene, chrysene, dibenzo(a,i]anthracene,
dibenzla,hi anthracene, dibenzola,h]pyrene, dibenzo[a,i)pyrene,
and indeno[l,2,3-cd]pyrene.
A number of chemicals in creosote and coal tar act as
co-carcinogens, initiators, accelerating agents, and inhibitors.
These chemicals were reviewed in PD 2/3, Wood preservatives
and IARC, 1983. (See Table II-6# 11-49). Thtse chemical
agents will affect the carcinogenic potential of creosote and
cresote/coal tar blends. Because of synergism among these
components, the carcinogenic potency of creosote or its coal
tar blends cannot be predicted by assaying samples of the
mixture for single carcinogenic components. Early attempts
to correlate carcinogenic potency with quantitative analytical
determinations of individual carcinogens in creosote
(Lijinsky et al., 1957) and petrochemical fractions
(Bingham et cTT, 1980) have been unsuccessful. Recently,
some researchers have interpolated potencies for complex
mixtures of hydrocarbons by comparing short tests with
11-55
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epidemiology data for marker chemicals or results of chronic
bioassays in laboratory animals. These methods are still
being evaluated by the scientific community. Their application
to creosote or its coal tar blends for risk assessment purposes
would require sophisticated sampling of the materials to
which users are exposed*
In addition to the fact that creosote and coal tar a*e
well characterized as animal carinogens, the several individual
case studies provide strong evidence of its potential as a
human carcinogen. Along with the case for oncogenicity of
whole creosote and coal tar, many of the individual component
chemicals have been shown to be carcinogens. The variable
nature of creosote and creosote/coal tar blends, the complex
nature of the material and the toxicological synergism of its
constituents preclude the use of a single component chemical
as an index of exposure for use in a quantitative risk assessment.
3. Conclusion
The exposure data indicate that applicators of products
containing creosote, coal tar, and coal tar neutral oils used
for non-wood purposes are subject to both dermal and inhalation
exposure during the application process. These products are
applied by brush, by spray, wiped on or the object/animal
is dipped into the chemical*
Two of the currently registered uses, on seed potato
storage premises and equipment and on seed corn as a crow
repellent, are considered food uses requiring the establishment
of tolerances under Section 408 of the Federal Pood, Drug,
and Cosmetic Act. There exists a potential for dietary
exposure as a result of these two uses. The livestock and
poultry premise treatment uses are considered to be non-food
uses.
•The Agency has determined that the use of products
containing creosote* coal tar, and coal tar neutral oils for
all non-wood purposes, poses a risk of oncogenicity and
mutagenic.effects to the applicators. There is also potential
risk as a result of dietary exposure to these chemicals
through the two uses considered to be food uses as described
above.
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Jk 4> * e £91^1%UL X A AllflilAUAU
A. Introduction
Part III contains the benefit analysis for the non-wood
uses of crosote, coal tar, and coal tar neutral oils. This
analysis is based on material presented in the report "The
Biologic ant Economic Assessment of Pentachlorophenol Inorganic
Arsenicals, and Creosote, Volume II: Non-Wood Preservatives"
prepared by the United States Department of Agriculture
(USDA), state agencies, and EPA* Additional information was
taken from the report entitled "Use and Exposure Assessment
of Coal Tar, Creosote, and Caal Tar Neutral Oil for Nonvood-
Preserving Pesticidal Application" prepared by The Mitre
Corporation, 1981 under EPA Contract No. 6801-5944.
There are several non-wood uses of creosote, coal tar,
and coal tar neutral oils. For each specific use the following
information is presented: usage, alternative chemicals
registered with the Agency for the same use, and the economic
inpact if the registration of creosote, coal tar, and coal
tar neutral oils were cancelled for the specific use.
For each use, alternative chemicals registered for the
use are discussed. In general, risk posed by the continued
use of the creosote, coal tar, and coal tar neutral oils
products is greater that that posed by alternative chemicals.
All of the alternatives are scheduled for review in the
Registration Standards (RS) program. It will be noted by
each alternative chemical only whether the chemical is currently
u..3ergoing RS review, has completed RS review, or if the
chemical is or has been in RPAR/Special Review.
B. Ornamental Flowering Plants and Ornamental Lawns
1. Usage
Creosote is currently registered as a herbicide for use
on ornamental flowering and ornamental lawns to control nut-
grass. For this use creosote is blended with petroleum dis-
tillates and applied directly as a foliar spray. There is
no information available on the amount of these products used
for this purpose. USDA personnel as well as turfgrass experts
and weed scientists are not aware of creosote products used
for this purpose.
2. Alternatives
Several currently registered alternatives to creosote
for use on ornamental flower gardens are: dichlobenilj
alachlor (RS in progress); simasine (RS in progreiss)*
metolachlor (RS completedproduct reregistered)j metolachlor
plus tank mix with Princep* 80W, 4L, or simasine. Registered
alternatives for use on lawns ai\d turf include: bentatonj
methanearsonic acid; ANA with 2,4-D; DSHA; and MSMA
(RS completed - product reregistered).
XIX-1
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3. Economic Impact
There are a number of federally registered effective
alternatives to creosote for use on ornamental flower gardens
and ornamental lawns to control nutgrass. Use of creosote
for this purpose is unknown and cannot be verified. Cancellation
of this use would have no economic impact.
C. Product Storage Yards
1. Usage
Creosote and coal-tar solutions have also been used by
the wood-preserving industry for the control of weeds and
grass on product storage yards. This use was one of convenience
rather than necessity because of the availability of tha
products to the wood-preserving industry. However* this
use has been substantially curtailed because of pollution
control regulations.
2. Alternatives
Information with regard to the usage of several available
alternatives is not available. However, it is generally
agreed upon by turfgrass experts, weed scientists, and USDA
personnel that the coal-tar products are poor substitutes
for several alternative herbicides currently available.
3. Economic Impact
There are a number of federally registered alternatives
to creosote and coal-tar solutions to control weeds and
grass. Cancellation of this use would have no economic
impact.
D. Agricultural Premises and Highway Rights-of-Way
1. Usage
Coal-tar creosote is registered for use on agricultural
premises along fencerows and along highway rights-of-way for
general weed control. Thsre is no information on the annual
poundage of these products used for this purpose.
2. Alternatives
The 1983 Weed Control Manual lists many possible
alternative chemicals registered for this use. Some of the
many alternatives that are registered and can be used are:
atrazine, 2,4-D, dicamba, amitrole (RS completed), ammonium
sulfamate (RS completed - product reregistered), MSMA, asulam,
bromacil, dalopon, MCPA (RS completed - product reregistered),
and hexazinone (RS completed - product reregistered).
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3. Economic Impact
There are a number of federally registered alternatives
to coal-tar creosote solutions for general weed control.
Cancellation of this use would have no economic impact.
G. Rope and Canvas Tarpaulins
1. Usage
One product, M&S Creosote Oil*, is registered for use
as a fungicide on rope and canvas. Data collected from rope
manufacturers indicated that this use is an old practice to
protect ropes from decay before the widespread use of synthetic-
fiber rope. Synthetic-fiber rope does not require a preservative
M&S Creosote Oil* is the only coal-tar base product
registered for use on canvas products to make them resistent
to the growth of algae and fungi. Additionally, this product
provides some resistance to water penetration. Specifically,
this product was used to rotproof sand bags. In 1980,
representatives of the Canvas Product Association and canvas
product finishers were not aware of any use of this product
on canvas products.
Approximately 4,000 gallons of this product are produced*
annually and is marketed through hardware stores. However,
estimates on the quantities of the product used on rope and
canvas are unknown.
2. Alternatives
The major alternative to the use of coal tar-based
products on rope is the substitution of natural fibers by
synthetic fibers. Alternatives to the creosote product for
use on canvas products arej mercury-containing fungicides
including phenylmercury triethanolamine lactate, phenylmercury
triethanolamine proprionate, and commercial mercury; and
copper-containing fungicides such as copper carbonate-ammonium
zirconyl carbonate and copper 8-quinolinoiate. None of these
alternatives imparts the secondary effect of water repellency.
3. Economic Impact
The cancellation of the coal-tar products for use on
rope and canvas products would have a minor economic impact.
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F. Seed Potato Storage Premises and Equipment
1. Usage
The purpose of the seed potato industry is to provide
seed for commercial potato production for the next year's
growing season* Disinfectants are used to control a highly
infectious tuber disease called ring-rot. Bacterial ring-rot
is spread through the use of diseased seed pieces, contaminated
equipment and contaminated shoes or premises. The presence of
ringrot in even one potato will disqualify the entire crop
from certification by USDA. The disinfectant is used on:
seed potato storage bins; the interior of the building; all
equipment entering the building potentially coming in contact
with the seed potato including crates, barrels, baskets, the
potato harvester, and trucks transporting the potatoes from
the field to the storage facility.
The only registered coal tar product used by the seed
potato industry is Kotarol*. This product is distributed to
seed potato growers throughout the Northeast United States.
In considering the five major potato producing areas,
significant amounts of coal tar are used only in Maine.
According to 1980 usage data, approximately 2600 gallons of
coal tar disinfectant are used by seed potato growers in
Maine each year.
The use of creosote, coal tar, and coal tar neutral oils
on seed potato premises and equipment is considered to be a
food use requiring the establishment of tolerances under
Section 408 of the Federal Food, Drug, and Cosmetic Act.
2. Alternatives
Alternative disinfectants for this use include:
quaternary ammonium compounds, formaldehyde (scheduled for
review under the Toxic Substances Control Act), and chlorine
compounds. Efficacy studies have shown that formaldehyde
products are equally effective as the coal tar product against
ring-rot bacteria.
3. Economic Impact
Efficacy data cannot be used to conclude that the seed
potato industry represents a critical use for coal tar disin-
fectants. Additionally, the seed potato use is considered a
food use and, therefore, in the absence of appropriate
tolerances the use should be cancelled. The cancellation of
the coal tar products for this use would not have a significant
economic impact on the industry but a complete cost/benefit
anilysis based on current usage data must be done before
a final regulatory decision is issued.
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G. Livestock Premises
1. Usage
Creosote, coal tar, and coal tar neutral oils are
acknowledged to be widely used as general livestock disinfectants
by the producers and distributors of these products. However,
specific end-use information is not obtainable due to the
fact that these products are purchased over-the-counter by
individual livestock farmers. The use of these products in
livestock premises is not considered a food use provided
proper restrictions are on product labels.
Use patterns of these disinfectants vary regionally
depending on the type of livestock in a specific area. Data
from producers and distributors of these coal tar products
indicate that the majority of these products currently used
by livestock farmers is to disinfect livestock buildings and
equipment. These products are not the primary disinfectant
used by large-scale commercial producers.
2. Alternatives
Alternatives for the coal tar disinfectants include:
synthetic phenol, cresylic acid, iodophers, hypochlorites
(RS completed - product reregistered), and quaternary ammonium1'
chlorides.
3. Economic Impact
The cancellation of this use is not expected to have a
significant economic impact.
H. Poultry Premises
1. Usage
Disinfectants containing creosote, coal tar, and coal
tar neutral oils were widely used in the poultry industry at
one time. However, the use of these products on poultry
premises has diminished. In 1971, EPA cancelled the
registrations of coal tar neutral oil/coal tar acid combination
products used in poultry houses. The use of these products
in poultry premises is not considered a food use provided
proper restrictions are on product labels*
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2. Alternatives
Alternative chemicals being used as disinfectants in
poultry houses include: quaternary ammonium chlorides and
synthetic phenolic compounds; cresylic acid; and formaldehyde
(scheduled for review under Toxic Substance Control Act).
A non-chemical method of controlling primarily bacteria and
viruses involves the reuse of litter. Litter is allowed to
build up for a period of 1 to 2 years. The build-up of litter
involves an anaerobic decay process involving heat which serves
as a disinfectant and kills bacteria, viruses, and parasitic
ova.
3. Economic impact
The cancellation of this use is expected to have no
economic impact.
1. Home and Institutional Use
1. Usage
Several products containing creosote, coal tar, and
coal tar neutral oil are registered for home and institutional
use. Registered use sites include* floors, walls, cellars,*
toilet rooms, sinks, washrooms, toilets, garbage cans and
garbage handling equipment, water closets, and urinals.
However, current use unrelated to farm use is unlikely. The
major reason for the lack of this use at most sites is the
strong, unpleasant odor associated with the products.
2. Alternatives
Alternatives to the coal tar containing products for
this use include: pine oils, phenolics, chlorine, and iodophors.
3. Economic Impact
The cancellation of this use is not expected to have a
significant economic impact*
J. Transportation Vehicles
1. Usage
Products containing creosote, coal tar and coal tar
neutral oil are used in transportation vehicles (airlines,
buses, trains, trucks) to disinfect tables, seats, walls,
toilets, and sinks. There is no currently reported use of
these products at these sites.
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2. Alternatives
Alternatives to the coal tar-containing products for
this use include: quaternary ammonium chlorides, substi-
tuted phenols, and iodophors.
3. Economic Impact
The cancellation of this use is expected to have no
significant economic impact.
K. Tree Wound Dressings
1. Usage
Creosote is currently registered for use as a tree
wound dressing to prevent decay in damaged trees. One product -
registered for this use Is M&S Creosote Oil*. An estimated
4,000 gallons of this product is produced annually but usage
for this site is unknown* A second product. Staffel's Tree
Dressing*, is no longer produced.
Toxicity tests show that fibrated asphalt paint plus
creosote applied to tree wounds caused some consistent injury
to cambrium tissue at the margin of the wound and reacts
unfavorably on the tree's natural healing process.
2. Alternatives
Tree sevice companies indicate that asphalt-based
compounds were the most commonly used products for tree wound
dressing. Scientific data indicate that tree wound dressing
is of questionable value and may only serve a cosmetic function.
3* Economic Impact
The cancellation of this use is expected to have no
economic impact.
L. Metalworking Fluids
1. Usage
One product, Wescol*, containing coal tar acids, coal
tar phenols, cresylic acids, creosote, plus two substituted
sodium phenates, is registered for use as a bactericide*
fungicide in metalworking fluids (also called cutting oils).
As of January, 1980 there was no production or sales of this
product.
111*7
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2. Alternatives
At least 65 products are registered as alternatives to
the single product containing coal tar/creosote. These
products are divided into two main types of formulations*
formaldehyde-releasing chemicals and non-formaldehyde-releasing
chemicals. In general, formaldehyde-releasing products do
not have a wide antimicrobial spectrum of efficacy as do the non-
formaldehyde-releasing products in that activity against fungi
is limited. Industry sources have stated that these two
general classes of metalworking additives are used alternatively
or in combinations to inhibit the growth of bacteria and fungi.
3. Economic Impact
The cancellation of this product will have no economic
impact.
M. Mosquito Larvicide
1. Usage
The neutral oil coal-tar acids are registered for use
in the control of mosquito larvae. These products are sprayed
onto the surface of stagnant waters forming a film which ob-
structs the breathing of the immatured aquatic forms. Current
usage of these products in the U.S. mosquito control programs
is very limited if at all.
2. Alternatives
Mosquito larvae can be effectively controlled by covering
the surface of the water in which which they occur with a
petroleum distillate of low volatility.
3. Economic Impact
Since the use. of neutral oil coal-tar acids
cant cancellation of the registratioons would not
to current mosquito control activities nor result
economic impact.
N. Animal Repellents
1. Usage
Creosote, coal tar and neutral oil products are used as
animal repellents. Information on the quantity of use of
these products as animal repellents is not available and it
cannot be verified that these products are used for all
repellent uses for which they are registered.
is insignifi-
be detrimental
in a significant
111-8
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One registered use is on lawns and flower beds to
discourage the use of these areas by dogs.
Creosote oil is registered for use on wood stalls,
mangers, gates, fence rails, posts, trees, trailer sides,
and similar wooden structures to prevent horses from cribbing,
biting, gnawing, or licking on the wood of these various struc-
tures. Data indicate that there are approximately 8.5 million
horses in the United States and 3.2 million horse owners.
While it is difficult to determine the extent of creosote
oil used for horse cribbing, probable usage is under 100,000
gallons annually.
2. Alternatives
No alternatives to the use of the coal t*r products on
stalls and wooden fences to prevent cribbing by horses are
available except for another coal tar distillate product,
anthracene oil.
3. Economic Impact
Price comparisons per quart for creosote and anthracene
oil indicate that anthracene oil products are less expensive
than the creosote oil products. Equal amounts of both of
these pesticides cover the same square footage of wood, and
manufacturers of these pesticides indicate that both products
remain effective for several years. Cancellation of this creosote
would not result in a significant economic impact.
O. Bird Repellent
1. Usage
Coal tar products are used in treating seed to prevent
or discourage the ingestion of seed by birds. One currently
registered product, containing a blend of creosote and neutral
oil, is used as a crow repellent on seed corn. This product
has been on the market for over 50 years and is used primarily
in an area extending from the northeastern United States
through Texas and along the eastern seaboard. The product has
limited use in the midwestern and western U.S. due to the
absence of a crow problem.
Another coal-tar distillate product registered for use
as a bird repellent has been out of production since 1978.
This use of creosote, ceal tar, and coal tar neutral oils is
considered to be a food use requiring the establishment of
tolerances under Section 408 of the Federal Food# Drug, and
Cosmetic Act.
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2. Alternatives
There are several products that can be used as alternatives
to the coal tar product for bird repellents. Copper oxalate
is used for this purpose, the cost is comparable to the
coal-tar product, and the application is simpler.
Mesurol*, 4-(methylthio)-3,5-xglyl methylcarbamate, is
also reported to be widely used as a repellent on corn and
other seed. This product is preferred by some planters over
the coal tar product since it acts as an insecticide as well
as a bird repellent. Mesurol* is 3-4 times more expensive
than either copper oxalate or the coal tar products.
Tetramethylthiuram disulfide (thiram - in RS process)
is widely used as a bird, rodent, and deer repellent but is
also effective as a fungicide. It is used to treat a variety
of seed types and as a foliar spray to discourage browsing -
by deer and rabbits.
Anthraquinone has been used as a bird repellent on pine
seed in direct seeding of open lands in the southern part of
the U.S. This chemical is widely used in the paper industry
and as a dye stuff.
\
Nonchemical alternatives available for crow repellents
include: exploders, traps, nets, and broadcasting amplified
alarm or distress calls.
3. Economic Impact
Data indicate that Mesurol* and thiram are more expensive
per bushel of seed corn than the coal-tar product but copper
oxalate is the same price as the coal-tar product.
A cancellation of the coal tar product should not create
any cost impact.
P* Insect Repellent
1. Usage
Coal tar is currently registered for use as an insect
repellent in preparations intended for use on human skin,
excrot for the forehead. This product is supposed to repell
gnats, mosquitoes, and deer flies. There is no evidence to
indicate that this coal tar product is still produced and
marketed for use as an insect repellent.
111-10
10
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2. Alternatives
There are approximately 110 registrations for products
that are potential alternatives for coal tar as an insect
repellent. N,N-diethyl-meta-toluamide (RS review completed -
product reregistered) whether alone or in combination with
other chemicals is the active ingredient in about 103 of the
registered products and is considered to be highly effective.
3. Economic Impact
Because this product is not being produced or marketed,
cancellation of this use would have no economic impact.
0. Screwworm Control
1. Usage
There is one creosote product currently registered for
treatment of screwworms in horses and mules. Data confirming
actual use and quantities used are not available.
2. Alternatives
Alternatives for control of screwworms in farm animals
include: coumaphos, ronnel, lindane in pine oil, and
diphenylamine in benzene. While no coal-tar distillate product
is included in the list of recommended control chemicals and
formulation there is indirect evidence to indicate that the
products are used for screwworm control.
3. Economic Impact
Cancellation of the creosote product would have little,
if any, economic impact. Although actual use cannot be
confirmed it is considered to be negligible.
R. Insect Control
1. Usage
Coal tar products are registered as larvicides and
disinfectants for use to control maggots and flies in garbage
trucks and neutral-oil products are also used to control
drain flies and their maggots ir drain lines.
There is one product registered for use on drain lines.
The label of this product claims "Kills drain flies". However,
one of active ingredients in this product is orthodichlorobenzene
which is clearly the insecticidal agent.
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2. Alternatives
Alternatives to the coal-tar products for this use
include: ronnel, methoxychlor, and orthodichlorobanzene.
3. Economic Impact
Cancellation of these coal tar products for this use
would not result in a significant economic impact.
S. Gypsy Motn Control
1. Usage
Neutral-oil containing products and creosote are used
in the regulatory treatment in the control of the gypsy moth
egg masses by the USDA Plant Protection and Quarantine Program.
Control efforcs are focused on finding and either treating
or destroying the egg masses of the gypsy moth that are
found durinq inspection of product** being shipped out of
quarantine areas. A standard practice is to search mobile
homes, or materials to be moved for egg mass deposits.
Visible egg masses are scraped from the surface of the object.
In areas where egg masses are hidden or difficult to reach,
creosote is applied by brush to kill the eggs. If egg masses
are found on forest products, vehicles, or other products,
they are coated with the coal-tar distillate in undiluted
form.
Under 100 gallot.-s/year of neutral-oil product is utilised
in this control program. The use of this product is considered
essential by USDA for preventing economic destruction by the
gypsy moth in presently non-infested areas as well as preventing
the future use of large amounts of insecticide to control the
problem.
2. Alternatives
Presently there are no registered alternatives to the
coal-tar distillates for regulatory treatments of gypsy moth
eg? masses. The USDA has conducted some research with common
household disinfectants such as Pine Sol*, detergents, etc.,
and finds them to be as effective as the creosote products.
3. Economic Impact
Cancellation of these neutral-oil containing products
and creosote are not expected to result in a significant
economic impact.
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T. Animal Dip
1. Usage
Coal tar distillates, including coal tar, have been
used as disinfectants for at least a century to control
parasites, such as ticks and mites, on animals. The present
uae of these products is restricted to use on horses, males,
dogs, and other non-food animals. While large animals are
wet down with a water emulsion formulation, small animals may
be immersed, sprayed, or bathed in the material.
Por dogs, there are two products registered by the EPA
for control of fleas, lice and sarcoptic mange; one product
for fleas and lice; one for lice alone; and one for sarcoptic
mange alone. Por horses, there are two products registered
by the EPA for control of both lice and psoroptic mange mites.
2. Alternatives
Over 80 alternatives are registered for use on dcgs for
lice and over 100 substitute chemicals are available for flea
control. The chemicals most frequently recommended by state
agencies for flea control are: carbaryl, coumaphos, DDVP,
malathion, methoxychlor, and rotenone. Chemicals recommended
by state agencies for lice control are carbaryl and malathion.
The 0S0A does not recommend coal-tar/creosote/coal-tar neutral
oils for use to control fleas or lice on dogs.
There are approximately 40 chemical alternatives
registered for use on horses to control lice and over 10
alternatives for equine psoroptic mange mite control. The
chemicals most frequently recommended by state agencies for
lice control on horses aret coumaphos, dioxathion, malathion*
and toxaphene. The USDA recommends coumaphos, crotoxyphos,
dioxathion and malathion for lice control on horses*
3. Economic Impact
Alternatives to the coal-tar distillates used as
insecticides to control parasites on non-food animals are
numerous. The cancellation of this use would not result in a
significant economic impact.
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PART IV: DEVELOPMENT OF REGULATORY OPTIONS
A. Introduction
In Parts II and III, the Aqency identified the risks and
benefits of the non-wood uses of creosote, cjal tar, and
coal tar neutral oil. As explained in Part I, PIFRA requires
the Agency to determine if the use of a pesticide meets the
statutory standard for registration by balancing the risks
and benefits of use. To carry out this mandate, the Agency
has developed a range of regulatory measures which are intended
to reduce the risks of use for the pesticides under review.
Part IV discusses the factors which have been taken into
account in developing the regulatory options for the non-wood
preservative uses of creosote, coal tar, and coal tar neutral
oil and describes in detail those measures selected for
futher consideration in Part V.
B. Basis and Rationale for Developing Options and
Modifications
There are three basic options for regulating all
pesticides:
Option 1 - Continuation of Registration without changes
Option 2 - Continuation of Registration with Modifications
to Terms and Conditions of Registration
Option 3 - Cancellation of Registration
The two extreme options. Option 1, Continuation of
Registration without change and Option 3, Cancellation of
Registration, are at opposite ends of the risk/benefit spectrum.
Adoption of Option 1 would be appropriate when the Agency has
concluded that the level of risk is acceptable in light of
the pesticide's benefits and that further risk reduction
measures are not necessary to assure that the use of the
pesticide meets the statutory standard for continued registration.
Adoption of Option 3, Cancellation, would be appropriate
when the Agency has concluded that the risks front a use
outweigh the benefits of that user and that theset risks
cannot be mitigated to an acceptable level, in light of the
benefits, by any other measures short of cancellation.
Cancellation prohibits the sale or the distribution of a
pesticide for a particular use or uses. The effect of
cancellation is to entirely eliminate the risks of a pesticide's
use or uses as well as the benefits. Cancellation may affect
all uses of a compound, or it may affect only specific usesv
specific formulations, or specific application methods.
IV-l
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Option 2 is appropriate when the risks of a pesticide
use can be reduced to an acceptable level, while preserving
the benefits of the use. This risk reduction is accomplished
by modifying the firms and conditions of the pesticide's
registration. These modifications, which are expressed
through the pesticide's labeling are, for the most part,
changes in the way the pesticide is used. These changes are
designed to reduce exposure to the pesticide, and thereby
reduce or even eliminate the risk from the pesticide.
C. Discussion of Option 2, Modifications to the Terms
and Conditions of Registration
The specific risk reducing modifications which the Agency
has selected for further consideration are presented in this
section.
1. Require Protective Clothing: Impermeable Gloves
Risks associated with exposure to all of the oncogenic or
mutagenic components of creosote could not be quantified.
Although there are many human case reports of human skin
cancer among creosote applicators (EPA,1981) there are no
studies available which can be used for a quantitative risk
extrapolation of low levels o£ exposure. To reduce the risk
caused by dermal exposure for uses of creosote, the Agency
will consider that all applicators using creosote must wear
gloves impervious to these pesticides in all situations when
dermal contact with then is possible.
This modification would require applicators to wear
gloves made of material impervious to the creosote, coal tar,
and coal tar neutral oil-containing products. Gloves would
be required when mixing the product, during actual application,
and when cleaning application equipment, such as brushes.
This protective clothing modification would apply to all
of the non-wood use categories of creosote, coal tar, and
coal tar neutral oil products and all applicators. When
applying these products by brush, by wiping or mopping, or
when objects/animals are dipped into the chemicals, the
primary site of dermal exposure is on the hands. Although
adequate experimental data are not available on the
permeability of gloves to these products, the Agency estimates
that appropriate gloves will reduce dermal exposure through
the hands by 90% in most use situations (EPA, 1984, PD-4).
This reduction assumes no pesticide penetration through the
gloves, and a small possibility of some exposure around the
cuff (EPA, 1984, PD-4).
IV- 2
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2. Require Protective Clothing: Respirators
This modification would require that applicators involved
in spraying creosote, coal tar, and coal tar neutral oil-
containing products wear respirators. Use sites where these
products can be applied by spray are: seed potato storage
premises and equipment; livestock premises; poultry premises;
home/institutional use; livestock transport vehicles; animal
repellent (on seed corn). Proper use o'f respirators would be
expected to reduce high inhalation exposure during the
application. The use of a half-mask canister or cartridge
respirator capable of trapping pesticide particulates and
vapors would reduce potential inhalation by about 90% (EPA,
1984, PD-4).
3. Require Protective Clothing: Coveralls
This modification would require persons applying creosote,
coal tar, and coal tar neutral oils to wear protective
clothing, such as disposable coveralls, to reduce risks to a
greater degree than the risk reduction from gloves alone. This
modification would apply to all non-wood uses of these chemicals.
4. Disposal of Protective Clothing
This modification would require applicators of creosote,
coal tar, and coal tar neutral oils to: change protective
clothing showing obvious signs of contamination; launder non-
disposable clothing separately from other household clothing;
clothing and workshoes or boots must be disposed of in any
general landfill, in the trash, or in any other manner approved
for pesticide disposal.
5. Prohibit Bating, Drinking and Smoking During
Application
This modification would prohibit home and commercial
applicators from eating, drinking, and smoking when applying
any of the creosote, coal tar, and coal tar neutral oil
products. This modification would apply to all non-wood
use categories of these chemicals. If adopted, this
modification would reduce the applicator*s oral exposure
to these products and would greatly reduce the opportunity
for accidental ingestion of these pesticides by homeowners.
6. Restricted Use
The Agency is concerned about the possibility of high
exposure to applicators who have not been properly trained in
the safe handling procedures for formulations of creosote
products which could be obtained "over-the-counter." Of
concern to the Agency is the potential for high exposure to
products requiring spraying and to products requiring mixing
IV-3
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and/or diluting where there could be some splashing of the
formulation resulting in dermal and inhalation exposure.
To protect the applicator from these potentially high
exposures to creosote products, the Agency proposes that the
sale and use of creosote products be restricted to certified
applicators or by persons under their direct supervision and
only for those uses covered by the certified applicator's
certification.
7. Interior Application Prohibited
This modification prohibits the use of creosote, coal
tar, and coal tar neutral oils from being applied indoors.
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PART V: PROPOSED REGULATORY DECISION
As stated in Part IV, the Agency has developed three basic
regulatory options to be considered with respect to pesticide
products containing creosote, coal tar, and coal tar neutral
oils that are used for non-wood purposes:
1. Continuation of registration without changes.
2. Continuation of registration with modification to
terms and conditions of registration
3. Cancellation of registration.
A. Risk/Benefit Analysis of Regulatory Options, Use-by-Use
1. Ornamental flowering plants and ornamental lawns
If registrations of creosote products were continued
without restriction both commercial applicators as well as
homeowners would continue to be exposed via spray treatments
and at risk to cancer. The benefits associated with this
use are inconsequential because of the numerous alternatives
available. The necessity use of these products for this
purpose is unknown and cannot be verified.
If registrations of creosote products were continued
with amended terms and conditions, the following provision
would apply: all applicators would be required to be certified
and to wear respirators and impermeable gloves. Exposure
and subsequent health risks would be reduced but the risks
would still outweigh the benefits for this use.
If registrations'of creosote products for this use were
cancelled, all risks to the applicators and homeowners from
these products would be eliminated. Cancellation of this
use would have no economic impact.
Having evaluated the cancer and mutagenic risk associated
with this use of creosote products, the Agency has determined
that the risks outweigh the benefits for Options 1 and 2.
Therefore, the Agency proposes to cancel the use of the creosote
products for use on ornamental flowering plants and
ornamental lawns.
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2. Product Storage Yards
If the registrations of creosote and coal tar products
tot use on product storage yards for general weed control
were continued without restriction, applicators would continue
to be exposed via spray treatments. These products have
been used by the wood preserving industry as a matter of
convenience rather than necessity. Use has been curtailed due to
pollution control regulations applicable to the wood-preserving
industry. Numerous alternatives are available. For these
reasons, there are no benefits associated with this use.
If registrations of these products were continued with
amended terms and conditions, the following provision would
apply: all applicators would be required to be certified and
wear respirators and impermeable gloves. Exposure and subsequent
health risks would be reduced but the risks would still
outweigh the benefits.
If registrations of these tar products were cancelled
for this use, all risks to applicators would be eliminated.
Cancellation of this use would have no economic impact.
Having evaluated the cancer and mutagenic risk associated
with this use of creosote and coal tar products, the Agency .
has determined that the risks outweigh the benefits for
Options 1 and 2. Therefore, the Agency proposes to cancel
the use of the creosote and coal tar tar products for use in
product storage yards.
3. Agricultural Premises and Highway Rights-of-Way .
If registrations of coal-tar/creosote products were
continued without restriction, applicators would continue to
be exposed via spray treatments to these chemicals* The
benefits associated with this use are insignificant because
there are numerous-alternative chemicals registered for this
use. There is no information on the annual poundage of these
products used for this purpose.
If registrations of these products were continued with
amended terms and conditions, the following provision would
applyt all applicators would be required to be certified
and wear respirators and impermeable gloves. Exposure and
subsequent health risks would be reduced but the risks would
still outweigh the benefits.
If registrations of these products were cancelled for
this use, all risks to applicators would be eliminated.
Cancellation of this use would have no economic impact.
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Having! evaluated the cancer and mutagenic risk associated
with creosote and coal tar products for use on highway
rights-of-way. with this use of coal-tar/creosote products,
the Agency has determined that the risks outweigh the benefits
for Options 1 and 2. Therefore, the Agency proposes to
cancel the use of the creosote and coal tar products for use
on agricultural premises and highway rights-of-way.
4. Rope and Canvas Tarpaulins
If the registration of a coal tar base product was
continued without restriction for use on rope and canvas
tarpaulins, applicators would continue to be exposed during
the process of dipping ropes and canvas products into these
chemicals. The benefits associated with continued use of this
product are insignificant and actual usage cannot be verified.
Various chemical alternatives exist but the major alternative
is thei substitution of natural fibers with synthetic fiber
in manufacturing rope.
If the registration of this product was continued with
amended terms and conditions, the following provision would
apply: all applicators would be required to be certified and
wear impermeable gloves. Exposure and subsequent health
risks would be reduced but the risks would still outweigh
the benefits.
If the registration of this coal tar base product were
cancelled for this use, all risks to applicators would be
eliminated. Cancellation of this use would have only a minor
economic impact.
Having evaluated the cancer and mutagenic risk associated
with this use of this coal-tar base product, the Agency has
determined that the risks outweigh the benefits for Options 1
and 2. Therefore, the Agency proposes to cancel the use of
the coal tar products for use on rope and canvas tarpaulins.
5. Seed Potato Storage Premises and Equipment
If the registration of the coal tar product used as a
disinfectant to control ring-rot bacteria in seed potato
storage premises and equipment was continued without restriction,
applicator* would continue to be exposed to this chemical
during the spray treatment. This use is considered a food
use and c:uld result in potential dietary exposure. Therefore,
it the absence of appropriate tolerances cancellation of the
use is proposed.
If the registration of this coal tar product was continued
with amended terms and conditions, the following provision
would apply: all applicators would be required to wear
V-3
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respirators and impermeable gloves and be certified. Dermal
and inhalation exposure and subsequent health risks would be
reduced. However, tolerances would still need to be established.
The provisions o£ Option 2 are expected to have minimal
impact on the economic benefits.
If the registration of this coal tar product was cancelled
for this use, all i:sks to applicators would be eliminated as
well as any potential dietary exposure. Cancellation of
this use would not have a significant economic impact*
Havir.g evaluated the cancer and mutagenic risk associated
with this use of coal-tar products, the Agency has determined
that the risks outweigh the benefits for Options 1 and 2*
Therefore, the Agency proposes to cancel the use of the coal-
tar products for use as disinfectants in seed potato storage
premises and on equipment.
6. Livestock Premises
If the registrations of coal-tar containing products for
use as disinfectants in livestock premises were continued
without restriction, applicators would continue to be exposed
to these chemicals. These products are applied by spray, or
are wiped Or mopped onto surfaces. Usage data are not
available due to the fact that these products are purchased
over-the-counter by individual livestock farmers and use
patterns vary regionally depending on the type of livestock
in a specific area. There are several alternatives to the
coal tar products available. The benefits associated with
this use are not significant.
If registrations of coal-tar containing products were
continued with amended terms and conditions, the following
provision would apply: all applicators would be required to
be certified and wear respirators and impermeable gloves.
Exposure and subsequent health risks would be reduced but
the risks would still outweigh the benefits for this use.
If registrations of coal tar-containing products for
this use were cancelled, all risks to the applicators
from these products would be eliminated. Cancellation
of this use would not a significant economic impact.
Having evaluated the cancer and mutagenic risk associated
with this use of coal-tar products, the Agency has determined
that the risks outweigh the benefits for Options 1 and 2.
Therefore, the Agency proposes to cancel the use of the coal-
tar products for use as disinfectants in livestock premises.
V-4
V
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7. Poultry Premises
Disinfectants containing creosote, coal tar and coal tar
neutral oils are registered Cor use on poultry premises. The
use of these products has consistently diminished since 1971
when EPA cancelled the registrations of coal tar neutral
oil/coal tar acid combination products used in poultry houses.
If registrations of these products were'.continued without
restriction, applicators would continue to be exposed to
these chemicals. Since several alternative chemicals are
available, the benefits associated with this use are not
significant.
If registrations of coal tar-containing products were
continued with amended terms and conditions, the following
provision would apply* all applicators i.'ould be required to
be certified and wear respirators and impermeable gloves.
Exposure and subsequent health risks would be reduced but
the risks would still outweigh the benefits for this use.
If registrations of coal tar-containing products for
this use were cancelled, all risks to the applicators and
homeowners from these products would be eliminated. Cancellation
of this use would have no economic impact.
Having evaluated the cancer and mutagenic risk associated
with this use of the coal tar products, the Agency has determined
that the risks outweigh the benefits for Options 1 and 2,
Therefore, the Agency proposes to cancel the use of the coal
tar products for use as disinfectants in poultry premises.
8. Home and Institutional Use
Several products containing creosote, coal tar, and coal
tar neutral oil are registered as disinfectants for home and
institutional use- If the registrations of these products
were continued without restriction, both commercial applicators
and homeowners would continue to be exposed to these chemicals.
Usage data are not available but the benefits associated with
the continued use are insignificant. Several alternative
chemicals are available.
If registrations of coal tar-containing products were
continued with amended terms and conditions, the following
provision would applyt all applicators would be required to
be certified and wear respirators and impermeable gloves.
Exposure and subsequent health risks would be reduced but
the risks would still outweigh the benefits for this use.
If registrations of coal tar-containing products for
this use were cancelled, all risks to the applicators and
homeowners from these products would be eliminated. Cancellation
of this use would not have a significant economic impact.
V-5
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Having evaluated the cancer and mutagenic risk associated
with this use of the coal tar products, the Agency has determined
that the risks outweigh »:he benefits for Option 1 and 2.
Therefore, the Agency proposes to cancel the use of the coal-
tar products for use as disinfectants in home and institutional
settings.
9. Transportation Vehicles
Products containing creosote, coal tar, and coal tar
neutral oils are used in transportation vehicles to disinfect
tables, seats, walls, toilets, and sinks. There is no
currently reported use of these products at these sites. If
the registrations o£ these products were continued without
restriction, applicators would continue to be exposed dermally
to these chemicals. There are alternative chemicals available.
If the registration of this use were allowed to remain
with amended terms and conditions, the following provisions
would apply: all applicators would be required to be certified
and to wear respirators and impermeable gloves. Exposure and
subsequent health risks would be reduced but the risks would
still outweigh the benefits.
If the registration of this use were cancelled, all
possible risks to the applicator from this product would be
eliminated. Cancellation of this use would have no economic
impact.
Having evaluated the cancer and mutagenic risk associated
with this use of creosote, coal tar, and coal tar neutral oil,
the Agency has determined that the risks outweigh the benefits
for Options 1 and 2. Therefore, the Agency proposes to cancel
the use of these products for use as disinfectants in
transportation vehicles.
10. Tree Wound Dressings
A creosote product is currently registered for use as a
tree wound dressing to prevent decay in damaged trees. If
the registration of this product were continued without
restriction, applicators would continue to be exposed dermally
to this chemical. There are alternative chemicals available
and the value of tree dressing is questionnable. There are
no benefits associated with this use.
If the registration of this creosote product were continued
with amended terms and conditions, the following provision
would app}yt all applicators would be required to be certified
and wear impermeable gloves. Exposure and subsequent health
risks would be reduced but the risks would still outweigh
the benefits for tnis use.
V-6
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If the registration of this creosote product for this use
were cancelled, all risks to the applicators from this product
would be eliminated. Cancellation of this use would have no
economic impact.
Having evaluated the cancer and mutagenic risk associated
with this use of creosote products, the Agency has determined
that the risks outweigh the benefits for Options 1 and 2.
Therefore, the Agency proposes to cancel this use of creosote
for use on tree wounds.
11. Metalworking Fluids
One product containing coal tar acids, coal tar phenols,
cresylic acids, and creosote is registered for use a bacterixide-
fungicide in metalworking fluids. As of 1980, there has be
no production or sale of this product. However, since the
product is still registered, regulatory options must be considered.
If usage of this product resumed, applicators would be exposed
to creosote/coal tar and at risk to cancer and mutagenic effects.
Alternative chemicals are available for this use. There are
no known benefits associated with the continued registration
of this product.
If registration of this use were allowed to remain with
amended terms and conditions, the following provisions would
apply: all applicators would be required to be certified and
wear impermeable gloves. Exposure and subsequent health
risks would be reduced but the risks would still outweigh
the benefits.
If the registration o£ this creosote/coal tar product
were cancelled, all possible risks to the applicator from this
product would be eliminated. Cancellation of this use is not
thought to have any economic impact since the product is not
currently used or marketed.
Having evaluated the cancer and mutagenic risk associated
with the use of this creosote/coal-tar product, the Agency has
determined that the risks outweigh the benefits for Options 1
and 2. Therefore, the Agency proposes to cancel the use of
this creosote/coal tar product for use as a bactericide-fungicide
in metalworking fluids.
12. Mosquito Larvicide
If registrations of neutral oil coal-tar acids for use
in the control of mosquito and fly larvae were continued
without restriction, applicators would be exposed via spray
treatment or during the spraying of the chemical onto the
surface of stagnant waters. Thes.% products have not been
used for this purpose for many years since more effective
altenatives are available. Therefore, there are no benefits
associated with the continued use of this product.
V-7
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If registration of this use were allowed to remain with
amended terms and conditions, the following provisions would
apply: all applicators would be required to be certified and
to wear respirators and impermeable gloves. Exposure and
subsequent health risks would be reduced but the risks would
still outweigh the benefits.
If tho registrations of neutral oil coal-tar acid products
were cancelled, all possible risks to the applicator from this
product would be eliminated. Cancellation of this use would
have no economic impact.
Having evaluated the cancer and mutagenic risk associated
with this use of neutral oil coal-tar acid products, the
Agency has determined that the risks outweigh the benefits
for options 1 and 2. Therefore, the Agency proposes to cancel
the use of these products for use as larvicides to control
mosquito larvae.
13. Animal Repellents
Creosote, coal tar, and neutral oil products are registered
for use on lawns and flower beds to discourage the use of
these areas by dogs and on wooden structures to prevent horse,
cribbing. If registrations of these products were continued
without restriction for use as animal repellents, applicators
would continue to be exposed to these chemicals and be at
risk to cancer and mutagenic effects. There are no alternatives
to the use of these products on stalls and wooden fences to
prevent horse cribbing except for another coal tar distillate
product, anthracene oil.
If registrations o£ these products were continued with
amended terms and conditions, the following provisions would
apply: all applicators would be required to wear impermeable
gloves and have to be certified. Exposure and subsequent
health risks would be reduced. The provisions of Option 2
are expected to have minimal economic impact.
If registrations of these products were cancelled for
this use, all risks to applicators would be eliminated.
Cancellation of this use would not have a significant economic
impact.
Raving evaluated the cancer and mutagenic risk associated
with the use of coal tar-containing products to prevent dogs from
use of lawns and flower beds and horses from cribbing on wooden
structures, the Agency has determined that the risks outweigh
the benefits for Options 1 and 2. Therefore, the Agency
proposes to cancel this use of the creosote products.
V-fc
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14. Bird Repellent
Coal tar products are used in treating seed to prevent
or discourage the ingestion oC seed by birds, particularly
crows. If registration of the coai tar products for this use
were allowed to continue without restriction, applicators
would continue to be exposed and at risk to cancer and
mutagenic effects. Alternative chemicals are available.
If registrations of these products were continued with
amended terms and cor-d'tions, the following provisions would
apply: all applicators would be required to be certified and
wear impermeable glove* and a respirator. Exposure and
subsequent health risks would be reduced but potential dietary
exposure would remain a problem. The provisions of Option 2
are expected to have minimal impact on the economic benefits.
If registrations of these products were cancelled for
this use, all risks to applicators would be eliminated and
there would be no potential dietary exposure. Cancellation
of this use would not have a significant economic impact.
Having evaluated the cancer and mutagenic risk associated
with this use of coal tar-containing products, the Agency
has determined that the risks outweigh the benefits in
Options 1 and 2. Therefore, the Agency proposes to cancel
the use of the coal tar products for use as bird repellents.
15. Insect Repellent
Coal tar is currently registered as an insect repellent.
If registration of the coal tar products for this use
were allowed to continue without restriction, applicators
would continue to be exposed and at risk to cancer and
mutagenic effects. There are many highly effective alternative
products registered for this use. There is no evidence to
indicate that the coal tar product is still produced and
marketed for use as an insect repellent. There are no benefits
associated with the continued registration of this product.
Option 2 allows the registration of these products to
continue with amended terms and conditions that applicators be
certified and wear protective clothing. However, for tMs
use protective clothing would be impractical since the product
is actually applied to human skin. There are no other amended
terms and conditions to the registration for this use that
would reduce exposure.
If registrations of these products were cancelled for
this use, all risks to applicators woull be eliminated.
Cancellation of this use would have no economic impact.
V-9
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Having evaluated the cancer and mutagenic risk associated
with this use of coal tar-containing products, the Agency
has determined that the risks outweigh the benefits in
Options 1 and 2. Therefore, the Agency proposes to cancel
the use of the coal tar products for use as an insect repellent.
16. Screwworm Control
There is one creosote product currently registered for
treatment of screwworms in horses and mules. Actual use of.
this product cannot be verified. If registration of the
coal tar products for this use were allowed to continue
without restriction, applicators would continue to be exposed
and at risk to cancer and mutagenic effects. Several alternative
chemicals are available for this use. There are no benefits
associated with the continued registration of this product.
If the registration of this creosote product were
continued with amended terms and conditions, the following
provisions would apply: all applicators would be required to
be certified and wear impermeable gloves. Exposure and
subsequent health risks would be reduced but the risks would
still outweigh the benefits for this use.
If the registration of this creosote product were cancelled
for this use, all risks to the applicators from this product
would be eliminated. Cancellation of this use would have no
economic impact.
Having evaluated the cancer and mutagenic risk associated
with this use of creosote, the Agency has determined that
the risks outweigh the benefits for Options 1 and 2. Therefore,
the Agency proposes to cancel the use of creosote for use on
horses and mules for screwworm corcrol.
17. Insect Control
If registrations of coal tar products and neutral oil
products registered as larvicides and disinfectants for use
to control maggots and flies in garbage trucks and flies in
drain lines were continued without restriction, applicators
would continue to be exposed to the3e chemicals and at risk
to cancer and mutagenic effects. There are several alternatives
available for this use. The benefits associated with this
use are not significant.
If the registrations of coal tar and neutral oil 'products
were continued for this use with amended terms and conditions,
the following provision would apply: all applicators would
be required to be certified and wear respirators and impermeable
gloves. Exposure and subsequent health risks would be reduced
but the risks would still outweigh the benefits for this
use.
V-10
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IC the registrations of these coal tar and neutral oil
products were cancelled for this use, all risks to the applicators
from this product would be eliminated. Cancellation of this
use would have no economic impact.
Having evaluated the cancer and mutagenic risk associated
with this use of these products, the Agency has determined
that the risks outweigh the benefits for Option 1 and 2.
Thereforet the Agency proposes to cancel the use of these
products for use to control maggots and flies in garbage trucks
and drain lines.
18. Gypsy Moth Control
Neutral oil-containing products and creosote are used in
gypsy moth control, specifically on gypsy moth egg masses.
If registrations of these products were continued without
restriction, applicators would continue to be exposed to
these chemicals and at risk to cancer and mutagenic effects.
There are no registered alternatives to the neutral oil/
creosote-containing products. Usage of these products is
reported to be minimal.
If the registrations of neutral oil/creorote-containing
products were continued for this use with amended terms and
conditions, the following provision would apply: all applicators
would be required to be certified and wear impermeable gloves.
Exposure and subsequent health risks would be reduced. The
provisions of option 2 are expected to have minimal impact
on the economic benefits.
If the registrations of these coal tar and neutral oil
products were cancelled for this use, all risks to the applicators
from this product would be eliminated. Cancellation of this
use would have a minor economic impact.
Having evaluated the cancer and mutagenic risk associated
with this use of neutral oil/creosote-containing products,
the Agency has determined that the risks outweigh the benefits
for Options 1 and 2. Therefore, the Agency proposes to cancel
the use of these products for use on gypsy moth egg masses.
19. Animal Dip
Coal tar distillates, including coal tar are registered
for use as disinfectants '^o control parasites, such as ticks,
on non-food animals. If registrations of these products
were continued without restriction, applicators would continue
to be exposed to these chemicals and at risk to cancer and
mutagenic effects. There are numerous alternatives registered
V-ll
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of use to control lice, fleas, ticks, and mites on non-food
animals. The benefits associated with the continued use of
these products are insignificant.
If the registrations of products containing coal
distillates were continued for this use with amended terras
and conditions, the following provision would apply: all
applicators would be required to be certified and wear impermeable
gloves. Exposure and subsequent health risks would be reduced
but the risks would still outweigh the benefits for this
use.
If the registrations of the coal tar distillate
products were cancelled for this use, all risks to the applicators
from this product would be eliminated. Cancellation of this
use would no economic impact.
Having evaluated the cancer and mutagenic risk associated
with this use of coal distillate~containing products, the
Agency has determined that the risks outweigh the benefits
for Options 1 and 2. Therefore, the Agency proposes to cancel
the use of the coal distillates products for use as an animal dip.
V-12
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B. Summary of Proposed Regulatory Decision
1. Ornamental flowering plants and ornamental lawns
Option 3. Cancel registrations.
2. Product storage yards
Option 3. Cancel registrations.
3. Agricultural premises and highway rights-of-way
Option 3. Cancel registrations.
4. Rope and Canvas Tarpaulins
Option 3. Cancel registrations.
5. Seed Potato Storage Premises and Equipment
\
Option 3. Cancel registrations.
6. Livestock Premises
Option 3. Cancel registrations.
7. Poultry Premises
Option 3. Cancel registrations.
8. Home and Institutional Use
Option 3. Cancel registrations.
9. Transportation Vehicles
Option 3. Cancel registrations.
10. Tree Wound Dressings
Option 3. Cancel registrations.
V-13
9o
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11. Matalworking Fluids
Option 3. Cancel registrations.
12. Mosquito Larvicide
Option 3. Cancel registrations.
13. Animal Repellents
Option 3. Cancel registrations.
14. Bird Repellent
Option 3. Cancel registrations.
15. Insect Repellent
Option 3. Cancel registrations.
16. Screwworm Control
Option 3. Cancel registrations.
17. Insect Control
Option 3. Cancel registrations.
18. Gypsy Moth Control
Option 3. Cancel registrations.
19. Animal Dip
Option 3. Cancel registrations,
V-14
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PART VI! BIBLIOGRAPHY
American Wood Preservers Institute. Rebuttal submission 1356
to EPA Position Document #1 on coal tar, creosote, and coal
tar neutral oil. 1980.
Ames, B.N. The detection of ch.-mical mutagens with enteric
bacteria. Chemical Mutagens; Principles and Methods for
Their Detection, A. Hollaender led.). Vol. 1. New York:
Plenum Press, 267-282. 1971.
Beloian, A. Summary o£ exposure based on use of creosote.
EPA internal memo to L. Rossi. March 2, 1984.
Berenblum, I. and R. Schoental. Carcinogenic constituents of
coal-tar. Brit, of Can. 1: 157-165. 1947.
Bonser, G.M. and M.D. Manch. Tumors of the skin produced by
blast-furuance tar. Lancet I: 775-776. 1932.
Bos, R.P., C.T.J. Hulshof, J.L.G. Theuws, and P.T. Henderson.
Mutagenicity of creosote in the Salmonella microsome assay.
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V^8
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