IITOVIATIOI
Lindane Position Document 2/3
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Acknowledgements
PROJECT TEAM
Richard Bright, Project Manager, SPRD
William Bumam, Pharmacologist, HED
Carroll Collier, Chemist, HED
Christine Chaisson, Toxicologist, HED
David Dellarco, Student Assistant, SPRD
Julian Donoso, Chemist, HED
Mark Dow, Entomologist, BFSD
Donald Eckerman, Economist, BFSD
Karen Flagstad, Writer/Editor, SPRD
Cara Jablon, Attorney, OGC
Janice Jensen, Chemist, HED
John Leitzke, Biologist, HED
David Severn, Chemist, HED
Gregory A. Thies, Project Manager, SPRD
Richard Troast, Senior Project Manager, SPRD
EPA PESTICIDE CHEMICAL REVIEW COMMITTEE fPCRC)
Charles Gregg, OWWM
Richard N. Hill, OPTS
Allen L. Jennings, 0PM
Donna R. Xuroda, ORD
John J. Neylan, OE
Edward Tuark, OANR
Marcia Williams, Chairperson, SPRD, OPP
Michael Winer, OGC
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Table of Contents
I. BACKGROUND 1-1
A. Introduction . 1-1
1. Chemical and Physical Characteristics 1-1
2. Registered Uses and Production 1-1
3. Tolerances 1-2
B. Applicable Sections of FTFUA 1-2
C. The "RPAR" Process 1-3
D. Regulatory History 1-3
E. Bases for the Rebuttable Presumption 1-4
F. Legislative Background 1-4
II. ANALYSIS OF REBUTTALS AND ASSESSMENT OF RISK II-1
A. Rebuttal Analysis II-1
1. Attempts to Rebut the Presumption of Oncogenicity II-1
a. Attempted Rebuttal Pertaining to Dosages Used in
Testing II-3*
b. Attempted Rebuttal Pertaining to Liver Toxicity as a
Test Interference II-5
c. Additional Studies Submitted in Attempted Rebuttal II-5
d. Coinaents Submitted on the National Cancer Institute
(NCI) Carcinogenicity Bioassay II-6
2. Attempts to Rebut the Presumption of Reproductive and
Fetotoxic Effects II-6
^
a. Attempted Rebuttals Pertaining to Naishtsin and
Leibovich (1971) II-9
b. Attempted Rebuttal Pertaining to Petrescu at al.
(1974) II-9
c. Attempted Rebuttals Pertaining to Earl er al. (1973) II-9
d. Attempted Rebuttals Pertaining to Exposure:
Fetotoxicity 11-10
e. Additional Studies Submitted in Attempted Rebuttal 11-11
f. Additional Agency Findings Concerning the Presumption
of Reproductive and Fetotoxic Effects 11-11
3. Comments Submitted on the Presumption of Acute Toxicity to
Wildlife: Aquatic Organisms 11-16
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4. Comments Submitted and Agency Findings on Possible
Adverse Effects II 17
a. Comments Submitted on Possible Adverse Effects:
Mutagenicity II-18
b. Ccnments Submitted and Additional Agency Findings on
Possible Adverse Effects: Blood Dyscrasias 11-18
c- Comments Submitted and Agency Findings on Possible
Adverse Effects: Acute Hazards to Humans and Domestic
Animals 11-22
(1) Acute Hazards: Studies Submitted on Inhalation
Toxicity 11-23
(2) Acute Hazards: Studies Submitted on Dermal
Toxicity . 11-24
(3) Acute Hazards: Studies Submitted on Oral and
Intraperitoneal Toxicity 11-24
(4) Acute Hazards: Additional Agency Findings
Concerning Central Nervous System Stimulation 11-25
(5) Increased Susceptibility of Children to Lindane
Poisoning 11-25
d. Comments Submitted on Possible Adverse Effects:
Population Reduction in Nontarget Avian Species 11-31
e- Comments Submitted and Additional Agency Findings
on Isomerization 11-32
(1) Chemical Driving Forces 11-33
(2) Isomerization in the Environment 11-33
(3) Isomerization in Plants 11-36
(4) Isomerization in Pats 11-36
B. Exposure Analysis 11-38
1. Persistence and Exposure 11-33
2- Comments Submitted on Exposure 11-39
a- Comments Submitted on Dietary Exposure 11-39
b. Comments Submitted on Exposure via Drinking Water . 11-39
c. General Comments Submitted on Exposure via Air Intake 11-41
d- General Comments Submitted on Exposure via Accumulation
in Human Adipose Tissue 11-41
e. General Comments Submitted on Work-Place Exposure 11-59
3. Dietary Exposure: Agency Determinations 11-59
111
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4.
Applicator and Honeowner/Householder/Occupant Exposure:
Agency Determinations
11-59
a.
b.
c.
d.
h.
i.
J-
k.
1.
m.
n.
Applicator Exposure:
Applicator Exposure:
Applicator Exposure:
Applicator and Homeowner
Exposure:
Applicator Exposure:
Applicator Exposure:
Applicator Exposure:
Applicator Exposure:
Applicator Exposure:
Applicator and Occupant
Exposure:
Applicator Exposure:
Applicator and House-
holder Exposure:
(1) Pet Anti-Flea Collars
(2) Dog Wash (Veterinary Use)
(3 ) Dog Shampoo
(4) Dog Dust
Applicator Exposure:
Hardwood Logs and Lumber
Seed Treatment
Avocados
Ornamentals
Cucurbits
Christmas Trees
Pecan Orchards
Forestry
Livestock
Structures
Pineapples
Pets
Household Uses
(1) Shelf Paper
(2) Floor Wax
(3) General Purpose Household Spray
(4) Smoke-Fumigation Devices
Applicator Exposure:
Minor Uses
C.
(1) Moth Spray (Aerosol) - Industrial Use
(2) Insect Spray - Uninhabited Buildings
(3) Empty Storage Bin Fog Spray
5. Total Body Dose Calculations
Risk Assessment
1. Risk: Carcinogenicity
2. Risk: Fetotoxic Effects
3. Risk: Acute and Subacute Central Nervous System Effects
II-6
II-6
11-61
I
II-61
11-61
11-61
11-62
11-62
11-62
11-63
11-63
11-63
11-63
11-64
11-64
11-64
11-65
11-65
11-65
II -<•
II-
11-67
11-67
11-67
11-67
11-67
11-72
11-72
11-73
11-77
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III. BENEFIT ANALYSIS
A. Introduction III-1
B. Underlying Assumptions and Limitations III-1
C. Hardwood Logs and Lumber III-6
1. Usage III-6
2. Alternative Methods of Control III-6
3. Economic Impacts III-9
D. Seed Treatment (Small Grains and Corn) III-8
1. Usage III-8
2. Alternative Methods of Control 111-12
3. Economic Impacts III-14
E. Avocados III-16
1. Usage III-16
2. Alternative Methods of Control 111-16
3. Economic Impacts 111-17
F. Ornamentals 111-17
1. Usage 111-17
2. Alternative Methods of Control III-18
3. Economic Impacts III-18
G. Cucurbits III-18
1. Usage III-18
2. Alternative Methods of Control 111-18
3. Economic Impacts 111-21
H. Christmas Trees 111-24
1. Usage 111-24
2. Alternative Methods of Control 111-24
3. Economic Impacts 111-24
I'. Pecans 111-24
1. Usage . 111-24
2. Alternative Methods of Control III-25
3. Economic Impacts III-2S
J. Forestry 111-29
1. Usage 111-29
2. Alternative Methods of Control II1-29
3. Economic Impacts 111-30
a. Commercial Forests 111-30
b. Seed Orchards and Gun Naval Stores 111-30
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Livestock
111-31
1. Usage
2. Alternative Methods of Control
3. Economic Impacts
L. Existing Structures
1. The Nature of Powder Post Beetle Infestation
2. Usage
3. Alternative Methods of Control
4. Economic Impacts
M. Hawaiian Pineapples
1. Usage
2. Alternative Methods of Control
3. Economic Impacts
N. Pets
1. Usage
2. Alternative Methods of Control
3. Economic Impacts
0. Household Uses
1. Usage
2. Alternative Methods of Control
3. Economic Impacts
P. Minor Uses
IV. Risk/Benefit Analysis: Development of Regulatory Options
A.
3.
Introduction
Salient Risk/Benefit Considerations
1. Salient Risk Factors
2. Salient Benefit Considerations
C. Development of Regulatory Options
1. General (Non-Use-Specific) Measures
a. Require Label Warnings for All Uses of Lindane
b. Classify Lindane for Restricted Use and Require
Applicator Certification
111-31.
III-3I
111-32
111-32
111-34
111-34
111-34
111-35
111-35
111-35
111-36
111-36
111-36
111-36
111-36
111-37
111-37
III-3
III-3
111-37
111-38
IV-1
IV-1
IV-1
IV-1
IV-4
IV-5
IV-12
IV-12
IV-12
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2. Use-Specific Measures IV-13
a. Hardwood Logs and Lumber IV-13
b. Seed Treatment IV-19
c. Avocados IV-19
d. Ornamentals • IV-20
e. Cucurbits IV-21
f. Christmas Trees and Forestry IV-21
g. Livestock IV-22
h. Structures IV-22
i. Pineapples IV-23
j. Pet Uses IV-23
k. Household Uses IV-24
1. Minor Uses IV-24
V. PROPOSED REGULATORY DECISION V-1
A. Risk/Benefit Analysis of Regulatory Options, Use by Use V-1
1. Hardwood Logs and Lumber V-1
2. Seed Treatments V-3
3. Avocados V-5
4. Ornamentals V-6
5. Cucurbits V-8
6. Christmas Trees V-9
7. Pecans V-10
8. Forestry V-11
9. Livestock V-12
10. Structures V-13
11. Pineapples V-14
12. Pets V-16
a. Dog Washes V-16
b. Flea Collars, Dog Dusts, and Dog Shampoos V-17
13. Household Uses V-1S
a. Shelf Paper V-18
b. Floor Wax V-18
c. General Purpose Household Spray V-18
d. Smoke Fumigation Devices V-18
14. Minor Uses V-19
a. Minor Uses Specifically Under Review V-19
1) Industrial Use Moth Spray V-19
2) Uninhabited Building Insect Spray V-19
3) Empty Storage Bin Fog Spray V-19
b. Other Minor Uses V-20
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B. Summary of Proposed Regulatory Decision V-20
1. Hardwood Logs and Lumber V-20
2. Seed Treatment V-211
3. Avocados V-21
4. Ornamentals V-21
5. Cucurbits V-21
6. Christmas Trees V-21
7. Pecans V-21
8. Forestry V-21
9. Livestock V-21
10. Structures V-21
11. Pineapples V-22
12. Pets " V-22
a. Dog Washes V-22
b. Flea Collars, Dog Dusts/ and Dog Shampoos V-22
13. Household Uses V-22
14. Minor Uses V-22
VI11
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List of Tables
Table II-1.
Table II-2.
Table II-3.
Table II-4.
Table II-5.
Table II-6.
Table IIV7.
Table II-8.
Table II-9.
Table 11-10.
Table 11-11.
Table III-1.
Table III-2.
Table III-3.
Table III-4.
Table III-5.
Table III-6.
Table III-7.
Comparison of Oncogenicity Studies Cited in the Lindane RPAR
Notice and the NCI Study in Mice. II-2
Summary of Studies Cited as Bases for the Presumption of
Reproductive and Fetotoxic Effects. II-3
Studies Submitted in Attempt to Rebut the Presumptions of
Reproductive and Fetotoxic Effects. 11-12
Summary of Studies Submitted on Lindane as a Possible
Mutagen 11-19
Acute Effects: Summary of Human and Animal Studies on
Lindane as a Central Nervous System Stimulant 11-26
Average Lindane Residues in Food (by Composite Category) 11-40
Exposure Data: Summary of Application Practices, Use by Use 11-42
Exposure Data: Summary of Exposure Analysis, Use by Use 11-43
Estimated Applicator Exposure, Present Use Practices 11-68
Total Body Doses (Applicators), Present Use Practices 11-70
Summary Assessment of Applicator Risk, Present Use Practices 11-74
Summary of Benefit Analysis III-2
Use (in Pounds) of Fortified BHC and Gamma Iscmer to Treat
Green Hardwood Lumber - 1975 III-7
Expected Values ($) With and Without Chemical Pest Control
of Hardwood Lumber Per 1,000 Board Feet III-9
Estimated Lumber Treated by Region in U.S. - 1975. 111-10
Economic Dollar Impacts on the Sawmill Industry 111-11
Estimated Annual Use of Lindane as a Seed Treatment, by Crop
- 1976. 111-13
Summary of Annual Costs for States Requesting Use of Lindane
on Ornamentals (in 1,000 Units) 111-19
IX
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Table III-8. Total Lindane-Treated Cucurbit Acreage, in Pounds A.I. and
Cost, 1976 - 1977. 111-20
Table III-9. Treatment of Cost of Lindane and Alternatives for Control of
Squash Vine Borers and Pickleworm on Cucumbers and Squash in
Southeastern U.S. 111-22
Table 111-10. Estimated Total Change in Cost of Production and Revenue to
Growers in Florida, Georgia, and South Carolina - 1976 -
1977. 111-23
*
Table 111-11. Number of Pecan Trees, Lindane Treated Pecan Trees, and
Amount of Lindane Used, Selected States (Estimates for 1978) 111-26
i
Table 111-12. Treatment Costs of Various Insecticide for Control of Pecan
Phylloxera in the Southeastern U.S. (Estimated for 1978} 111-27
Table 111-13. Annual Treatment Cost with Lindane Compared to Alternative
Control Measures on Pecans, Selected States, for 1976. 111-28
Table 111-14. Quantity of Lindane Used by U.S. Farmers on Livestock in
1964, 1966, 1971, and 1976 (USDA) 111-32
Table III-15. Quantity of Lindane Versus Alternative Pesticides Used by
U.S. Farmers on Livestock in 1964, 1966, 1971, and 1976. 111-33
Table rv-1. List of Protective Measures Considered, Use by Use IV-6
Table IV-2. Impacts of Protective Measures on Total Body Doses to
Applicators IV-10
Table IV-3. Impacts of Protective Measures on Applicator Risk IV-14
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LINDANE: POSITION DOCUMENT 2/3
I. BACKGROUND
A. Introduction
1. Chemical and Physical Characteristics
Lindane is the gamma isomer of the insecticide 1,2,3,4,5,6-
benzene hexachloride (BHC). Technical lindane contains at least 99 percent
gamma-3HC, the remaining 1 percent consisting of other BHC isomers
(Meister, 1978). Its melting point is 112.8 C. Its density is 1.85.
Its vapor press-ore is 3 X 10 mm Hg at 20 C. Lindane is soluble in
various solvents, and its solubility in water varies with temperature (10
ppm at 20 C). Lindane is stable to light, heat, air, carbon dioxide, and
strong acids, but is unstable in the presence of alkali (Blaquiere et al.,
1972).
2. Registered Uses and Production
Environmental Protection Agency (EPA or "the Agency")
records show registrations for about 700 lindane products (270 registrants)
and about 85 federally recognized intrastate registrations of state-
registered products. During the BHC RPAR ("rebuttable presumption against
registration and reregistration") proceedings, registrants of BHC and BHC/
lindane products were allowed to change their registrations to lindane to
avoid cancellation. All BHC registrations were either voluntarily
cancelled or amended to become lindane registrations.
Current registrations of lindane products reflect a wide
range of uses. The major use categories are hardwood logs and lumber, seed
treatment of small grains and corn, and livestock, but lindane is also used
on Florida avocados, ornamental plants, cucurbits, Christmas trees, pecan
orchards, commercial forests, existing structures (mainly homes), Hawaiian
pineapples, pets and their premises, household pests, etc. .Lindane pro-
ducts are formulated as wettable powders, emulsifiable concentrates, oil-
base sprays, dusts, granules, and pressurized products, including "one
shot" vaporizers, aerosols, and smoke products (Meister, 1978).
Hooker Chemicals and Plastics Corporation of Niagara Falls,
New York, has been the sole domestic manufacturer of lindane. In May .T976,
however, Hooker halted production of lindane pending completion of 2PA's
review of the chemical, and is currently importing lindane to supply its
customers (EPA 1978f). For the years 1972 through 1976, Hooker manufac-
tured a total of 3,684,000 pounds of lindane and a total of 4,914,900
pounds of the related compound fortified BHC (FBHC), which contains 42-43
percent gamma isomer, for a combined total of 3,598,900 pounds of ganana-3HC
isomer. Hooker's records show a pattern of declining production during
those five years. In 1972, 308,000 pounds of lindane and 1,621,960 pounds
1-1
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of FBHC were manufactured, for a combined total of 2,429,960 pounds. In
1976, the comparable figures were 702,000 pounds of lindane and 196,080
pounds of BHC, for a combined total of 898,080 pounds.—
3. Tolerances
Tolerances for residues of lindane in or on raw agricultural
commodities are listed in 40 CFR 180.133 as follows: 7 parts per million
(ppm) in or on the fat of meat from cattle, goats, horses, and sheep; 4 ppm
in or on the fat of meat from hogs; 3 ppm in or on cucumbers, lettuce,
melons, mushrooms, pumpkins, squash, summer squash, and tomatoes; 1 ppm in
or on apples, apricots, asparagus, avocados, broccoli, brussals sprouts,
cabbage, cauliflower, celery, cherries, collards, eggplants, grapes,
guavas, kale, kohlrabi, mangoes, mustard greens, nectarines, okra, onions
(dry bulb only), peaches, pears, peppers, pineapples, plums (fresh prunes),
quinces, spinach, strawberries, and Swiss chard; and 0.01 ppm (negligible
residue) in or on pecans.
3. Applicable Sections of FIFRA
Section 12(a)(1)(A) of the Federal Insecticide, Fungicide, and
Rodenticide Act (7 U.S.C. 136 et seq.) prohibits the sale or distribution
of pesticide products which are not registered by the SPA Administrator,
and section 3 of the Act sets forth the registration procedures. Before a
pesticide may be registered, however, the Administrator must determine that
its use will not result in "unreasonable adverse effects on the environ-
ment," defined in Section 2(bb) of FIFRA as "any unreasonable risk to man
or the environment, taking into account the economic, social, and environ-
mental costs and benefits of the use of any pesticide."
In other words, any decision on pesticide registration must take
into account both the risks and the benefits associated with the
pesticide's use.
Under Section 6(b) of FIFKA the Administrator may issue a notice
of intent to cancel the registration of a pesticide or to change its
classification if it appears that the pesticide or its labeling "does not
comply with the provisions of [FIF11A] or, when used in accordance with
widespread and commonly recognized practice, generally causes unreasonable
adverse effects on the environment." Thus, the Administrator may cancel
J/ During those same years, Hooker exported declining amounts of lindane
(232,120 pounds in 1972; 32,300 pounds in 1976) and F3HC (1,456,320
pounds in 1972; 47,480 pounds in 1976). According to USDA, declining
amounts of lindane were imported to the U.S. during the years 1972-
1974 (132,939 pounds in 1972, 5,757 pounds in 1973, and 3,525 pounds
in 1974). No lindane was imported in 1975 or 1976. Mo ?3EC was
imcorted 1972-1975.
1-2
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the registration of a pesticide that no longer satisfies the statutory
standard for registration; this standard requires, among other things, that
the pesticide "perform its intended function without unreasonable adverse
effects on the environment" [FIFRA 3(c)(5)(C)]. The Administrator may also
change the classification of any use of a pesticide if he determines that
such a change "is necessary to prevent unreasonable adverse effects on the
environment" [FIFRA 3(d)(2)].
C. The ."RPAR" Process
To implement its authorized functions, the Agency has designed
the Rebuttable Presumption Against Registration (RPAR) process, which
involves gathering data on the risks and benefits associated with the uses
of suspect pesticides. By allowing all interested parties to participate
by submitting information, the process enables SPA to make balanced
decisions concerning problem pesticides.
The RPAR process is set forth in 40 CFR 162.11, which describes
various risk criteria and provides that an RPAR shall arise if the Agency
determines that any of these criteria has been met.
Once a rebuttable presumption has arisen, registrants, appli-
cants , and interested persons may submit evidence in rebuttal, or in sup-
port, of the presumption. These parties may also submit evidence on the
economic, social, and environmental benefits of any use of the pesticide.
If the presumptions of risk are not rebutted, the evidence pertaining to
benefits must be evaluated and considered together with the evidence
pertaining to risk. Various risk-reduction measures and their costs are
analyzed. The Agency then determines whether the pesticide may be regu-
lated so that a balance is achieved between risks and benefits. If the
statutory balance cannot be reached for any given use, the registrations
for that use must be cancelled.
0. Regulatory History
Pesticides containing lindane have been federally registered
since the early 1950*s. A summary of regulatory actions on lindane through
1975 is given in Lindane; Position Document 1 (EPA 1977a).
On February 17, 1977, the Agency published a notice of rebuttable
presumption against registration (RPAR) and continued registration of
pesticide products containing lindane in the Federal Register (EPA 1977b).
Position Document 1 contains background and supporting data for the
presumptions of risk cited in the RPAR notice.
On April 28, 1977, Continental Chemiste Corporation petitioned
the U.S. Court of Appeals for the Seventh Circuit to issue a writ of
mandamus requiring EPA to withdraw the RPAR notice against that company's.
lindane smoke insecticide products. The company argued that the notice
violated the mandate of a previous decision by the Court to sec aside the
1-3
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Agency order cancelling Continental Chemiste lindane products [461 ?.2d 331
(7th Cir. Docket No. 71-1828, 1972)]. This petition was denied on
June 7, 19-77.
Certain pesticide products which have been subject to SPA regula-
tion under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA),
as amended, also fall within the statutory definition of "new drug" in the
Federal Food, Drug, and Cosmetic Act (FFDCA) and have been subject concur-
rently to regulation by the Food and Drug Administration (FDA). EPA and
FDA published procedures for joint review and approval of products that
fall within the statutory definitions of both "pesticide" and "drug" in the
Federal Register of December 22, 1971 (36 FR 242334), and September 5, 1973
(38 FR 24233). On November 9, 1979, however, an SPA regulation was pub-
lished [Federal Register 44( 2 15) :63749] which exempts from FIFRA regis-
tration requirements all pesticides which are designated solely for use on
human persons and as such are considered new drugs as defined by Section
201(p) of the FFDCA. All lindane products designated solely for use on
human persons will therefore be subject henceforth to regulation by the FDA.
E. Bases for the Rebuttable Presumption
The lindane RPAR notice cited three risk criteria which lindane
had met or exceeded: (1) acute toxicity to aquatic organisms [40 CFR
162.11(a) (3) (i)(3) (3)] , (2) oncogenic effects in test animals [40 CFR
162. 1 1 (a) (3) (ii) (A)] , and (3) chronic and/or delayed toxicity causing
reproductive or fetotoxic effects in test animals [40 CFR
In addition to these criteria, the RPAR notice listed four other
possible adverse effects of lindane for which insufficient evidence existed
to initiate a rebuttable presumption. The Agency requested registrants and
other interested parties to submit data on the following effects: (1) muta-
genicity, (2) blood dyscrasias, (3) acute hazards to humans and domestic
animals, and (4) population reduction in nontarget avian species. Informa-
tion was solicited also on the additional issue of the possible isomeriza-
tion of lindane (gamma-BHC) to the alpha and beta isomers of 3HC, which
have been shown to be oncogenic in rodents.
F. Legislative Background
FIFRA and its regulations require SPA to review both the risks
and the benefits of the uses of pesticides. Since issuing the RPAR notice
for lindane (SPA 1977b) , the Agency has received rebuttal comments and has
conducted in-depth risk and benefit analyses . This position document
(PD 2/3) responds to the rebuttal comments, summarizes the risks and
benefits associated with lindane, and recommends a regulatory option for
each use .
1-4
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This PD 2/3 also satisfies the substantive requirements of an
environmental impact statement. It fully discusses the scope of the
problem to be regulated, the process for selecting the alternative cours-es
of action, and the reasons for the Agency's proposed final decision. It
contains five parts. Part I is this introductory section. Part II pre-
sents an evaluation of potential risks of lindane. It includes descrip-
tions of the relevant laboratory data on risks, exposure data, and the
Agency's present risk assessment. Part III is a summary analysis of the
economic benefits of lindane. Part IV presents the process by which, on a
use-by-use basis, the Agency developed a range of the regulatory options
and selected specific options for in-depth evaluation. Finally, Part V
proceeds with a risk/benefit analysis of the regulatory options, use by
use, and summarizes the regulatory actions which the Agency proposes to
take concerning the registration and continued registration of pesticide
products containing lindane.
1-5
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H. ANALYSIS OF REBUTTALS AND ASSESSMENT OF RISK
As stipulated in 40 CFR 162.11(a)(4) respondents can rebut any presump-
tion against a pesticide by showing 1) that the Agency's initial determina-
tion of risk was in error or 2) that given current use patterns, exposure
to the pesticide is not likely to result in any significant chronic or
acute adverse effects. The rebuttable presumption against registration and
continued registration of pesticide products containing lindane drew
responses concerning the three presumptions of oncogenicity, reproductive
and fetotoxic effects, and acute toxicity to wildlife, aquatic organisms.
Consnents were also received concerning the possible adverse effects of
mutagenicity, blood dyscrasias, acute hazards to humans and domestic
animals, and population reduction in nontarget avian species, as well as
the additional issue of isomerization. Submissions pertaining to the
rebuttable presumptions and to other possible adverse effects, together
with the Agency's responses and additional findings, are reviewed in
Subsection II.A below. Rebuttal comments pertaining to exposure are
addressed in Subsection II.B, "Exposure Analysis." The Agency's
determinations on risk are given in Subsection II.C, "Risk Assessment."
A. Rebuttal Analysis
1. Attempts to Rebut the Presumption of Oncogenicity
In Position Document 1, the Agency announced a presumption
of oncogenic effects on the basis of three laboratory studies which ob-
served oncogenic responses when lindane was tested on mice. (See Table
II-1.) Goto et al. (1972) fed 5-week-old male mice 300 or 600 parts per
million (ppm) lindane for 26 weeks. Liver tumors were seen in 50 percent
of the 10 animals which ingested 600 ppm lindane, and a 2-fold increase in
the ratio of liver weight to body weight was observed at the same dose.
Five treated animals (25 percent) died early in the study. No oncogenic or
other liver effects were observed in the animals ingesting 300 ppm lindane.
Hanada et al. (1973) treated 6-week-old male and female mice
with 100, 300, or 600 ppm lindane for 32 weeks. The animals were there-
after maintained on a basal diet for 6 weeks and sacrificed 38 weeks after
feeding started. Tumors were found in 1 of 3 females and in 3 of 4 males
ingesting 600 ppm lindane for a combined rate of 64 percent (7 of 11). No
tumors were observed in the 29 control animals, in the 18 animals ingesting
100 ppm, or in the 16 animals ingesting 300 ppm Lindane. Doses of 300 ppm,
however, produced atypical proliferation of liver cells.
Thorpe and Walker (1973) fed 4-week-old mala and female mice
400 ppm lindane for 52 to 110 weeks. A statistically significant increase
in the incidence of hepatic liver tumors was reported, as well as meta-
stases to the lung in the lindane-fed animals relative to controls. Ninety-
six percent of the males had tumors, including 11 percent metastases.
Ninety-five percent of the females had liver tumors with no metastases.
II-l
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Table II-1.
Comparison of Oncogenicity Studies Cited in the Lindane RPAR
Notice and the NCI Study in Mice
Thorpe and Goto et al.
Walker (1973) (1972)
Hanada et al. NCI Study
(1973) (1977)*
Strain
Age
Sex
1
4 weeks
Both
Number/Group 29-45
Dose (ppm) in 400
diet
Duration
2 years
ICR-JCL
5 weeks
Male
20
300
600
26 weeks
dd
6 weeks
Both
10-14
100
300
600
37-38 weeks
Liver tumors
in males and
females, 96%
males and 95%
of females
treated com-
pared to 23-
24% of controls
(p <.0001).
Results Liver tumors Liver tumors Liver tumors
in males
and females
(3 of 4
surviving
males, 1 of
3 females at
600 ppm; no
tumors re-
ported in
controls).
Significant
in males
( p <.013 at
600 ppm.)
*The final results of the National Cancer Institute (NCI) carcinogenicity
bioassay are included here for purposes of comparison. (Only the prelimi-
nary results were available at the time PD1 was issued.) For discussion,
see Subsection II.A.I.d of text.
Liver tumors
in males
(50% of
treated
males at
600 ppm).
(P=.004
no tumors
in unre-
ported
controls.)
B.C.?,
o 3 1
5 weeks
Both
50
SO
160
80 weeks and
30 weeks of
observation
Hepatocellu-
lar carcinoma
in male mice
at low dose-
level of 80
ppm (?=0.001.)
High-dose group
showed less
significant
results (9/46
vs. 5/49;
p=0.10).
II-2
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Liver tumors were found in 24 percent of the control animals, but no
metastases were observed. Toxic effects leading to death occurred during
the first 3 months of lindane feeding for approximately 15 percent of the
animals. Moreover, for the entire 110-week experimental period, there was
a 90-percent total fatality record for lindane-fed animals as compared to
68 percent for controls.—
In response to our request for rebuttals and additional
information concerning oncogenicity as a presumed risk of lindane, the
Agency received nine responses from three registrants: Paper Products,
Inc. (30000/10 :*41), Hooker Chemicals (30000/10:#42), and Reed and Camrick
Pharmaceuticals (30000/10:&6C). The Agency has reviewed the material
submitted and has concluded that it does not invalidate the three studies
cited in the lindane KPAR notice and in P01 as bases for the presumption of
oncogenicity, nor is the presumption otherwise rebutted (2?A 1978a;5PA
197Sb).-
a. Attempted Rebuttal Pertaining to Dosages Used
in Testing
Paper Products, Inc. (30000/10:141) challenged the
Agency's presumption of oncogenicity by contesting the dosage levels used
in the three studies on which the presumption was based.
Concerning the Goto and Hanada experiments, the regis-
trant argued that the lindane dosages used were so high that only acute
toxic effects could be assessed. Specifically, the grounds for contention
were 1) that so many animals died from toxic effects that chronic oncogenic
potential could not be assessed from the few remaining animals, and 2) that
the acute oral LD=Q dose for these species was exceeded. Concerning the
Thorpe and Walker experiment, the registrant argued that the study consti-
tutes weak evidence of human carcinogenicity for four reasons. (1) The
dose used (400 pom) was too high to allow meaningful conclusions about
carcinogenicity.— (2) The strain used (CFI) is prone to hepatomas of
unknown causes. (3) Thorpe and Walker themselves questioned the biological
— Also mentioned in PD1 were the following lindane studies which
reported no oncogenic effects: Nagasaki at al. (1973) and Herbst
et al. (1975), mouse studies; Fitzhugh et al. (1950), Truhaut
(1954), Ito et al. (1975), and Ortega et al. (1957), rat studies.
— The related issue of whether lindane isomerizes in the
environment to alpha-3HC or in rats to alpha-and beta-BHC, both
of which have been shown to induce oncogenic effects in rodents,
is addressed in Subsection II.A.4.e.
— In this connection, the registrant argued the following points:
1) 15 percent of the animals died in the first 3 months,
2) 400 ppm is 70 percent of the I*D5-, ^ the species, and
3) only 3 percent of the females and 17 percent of the
males survived the entire axiseriment.
II-3
-------
significance of the tumors, chiefly because many co-factors ars known
to influence the development of liver tumors. (4) The spontaneous
incidence of extrahepatic tumors is very high (82 percent), and the lindane
treatment does not increase tumor incidence, but merely shifts the tumor
sites to the liver.
The Agency rejects the above arguments. With regard to
the Goto and Hanada experiments, Paper Products, Inc. did not state the
LD_ dose for either strain of mice used in testing. Nor did the regis-
trant cite the source for the contention that the LD_ for the animals
was exceeded. The argument based on LDj-n values is thus incomplete, and
the mortality and body weight gain in tne studies themselves must be used
to evaluate the toxicity. The Agency grants that the mortality in the
Hanada study is high,— and this, together with the relatively short
duration of the experiment and the small number of test animals, makes the
study in itself only a weak indicator of carcinogenicity. However, the
incidence of tumors in males was unmistakably high over a short period of
time (3 out of 4 lindane-treated males had tumors as compared with 0 out of
14 controls; p = 0.013), and this suggests that lindane may be carcinogenic
in dd strain mice. Because Goto did not state the percent survival through-
out the experiment, it is not possible to evaluate whether non-tumor mortal-
ity appreciably influenced tumor incidence. Body-weight gain was normal,
but considerable liver enlargement indicated that lindane was in some way
toxic to the liver. The omission of control group pathology data in this
study permits only a qualitative conclusion that lindane apparently induced
early stages of hepatocellular carcinoma.
In both the Hanada and Goto experiments, the liver
lesions consisted of tumors of the liver. In both experiments, the
findings are consistent with either carcinomas or the early stages of
hepatocellular carcinoma.
With regard to the Thorpe and Walker experiment, the
Agency acknowledges that mortality among the treated group (especially
females) was higher than among the controls. Nonetheless, the cumulative
tumor incidence among treated animals at three different stages (17, 21,
and 25 months) of the experiment was significantly higher than among con-
trols. Early mortality from the toxic effects of lindane was thus not
great enough to mask the carcinogenic effects. Regardless of other possi-
ble factors, the lindane-treated animals definitely developed a higher inci-
dence of liver tumors than did controls. This is sufficient cause for con-
cern that lindane could have a carcinogenic effect in humans. Concerning
the registrant's contention that lindane treatment merely transferred
tumors to the liver, the Agency points our 1) that it is extremely diffi-
cult to interpret changes in the incidence of tumors at several sites ccm-
4/
— Out of the initial group of approximately 10 animals, only 3
females and 4 malas survived to 36 weeks at 600 ppm.
II-4
-------
bined, as was done with extrahepatic tumors; and 2) that the decrease in
the incidence of extrahepatic tumors was not statistically significant.
For these reasons the reduction in extrahepatic tumors does not decrease
the significance of the tumors induced by lindane.
b. Attempted Rebuttal Pertaining to Liver Toxicity as a
Test Interference
Paper Products, Inc. (30000/10:141) argued also that
not only lindane but any compound given in doses large enough to produce
extensive liver toxicity will produce liver tumors. The further implica-
tion was that/ at doses low enough to be non-toxic to the liver, no carcino-
genic response would occur, and the compound would be safe.
The Agency rejects this argument. The registrant's
contention is based on a hypothesis which has not been established. It is
unfortunate that liver toxicity is not ordinarily examined in carcino-
genesis tests, and information on this point is seldom available. Until
such a correlation is shown, the Agency's position is that the coincidence
of liver toxicity with a carcinogenic response is not sufficient reason for
disregarding the carcinogenic potency of a compound.
c. Additional Studies Submitted in Attempted Rebuttal
In attempt to counter the three studies on which the
.presumption of oncogenicity was based, Hooker Chemicals (30000/10:342)
cited an 80-week study by Weisse and Herbst (1976). Weisse and Herbst
studied the carcinogenic potential of lindane at 12.5, 25, and 50 pom dose
levels in the food of NMRI male and female mice, 250 of each sex total.
The reported results showed no evidence of increased tumorigenicity.
The Agency rejects this rebuttal attempt. Weisse and
Herbst used a different strain of mice and lower dose levels than did the
three oncogenicity studies cited in the RPAR notice. Uncertainties about
the maximum .tolerated dose in this strain make it difficult to assess
whether the dose was high enough to cause a statistically observable
response. The three independent studies cited as bases for the original
presumption of oncogenicity showed a definite excess tumor induction in
treated groups. The presence of a fourth study with negative results at
uncertain dose level does not diminish the Agency's concern that lindane is
potentially oncogenic in humans.
Likewise in attempt to rebut the Agency"s presumption
of oncogenicity, both Hooker Chemicals (30000/10:?42) and Reed and Carnrick
Pharmaceuticals (30000/10:#6C) submitted various studies which on the whole
indicated no connection between lindane and mutagenic effects.
The Agency rejects these rebuttal attempts for two
reasons: 1) mechanisms other than mutation may cause cancer; 2) although
for some classes of chemicals there is a high correlation between carcino-
genicity in mammalian test systems and mutagenicity in certain microbial
II-5
-------
systems/ this correlation is not absolute, and false positive and false
negative indications do occur (EPA 1978a, 1978b). Moreover, three of the
tautagenic tests submitted by Hooker Chemicals in fact showed positive
results. These positive mutagenic results lend further support to the
Agency's original presumption of lindane's oncogenicity (SPA 1978b).
d. Comments Submitted on the National Cancer Institute
(NCI) Carcinoqenicity Bioassay
Although the NCI preliminary bioassay study on the
oncogenic effects of lindane was not a basis for the lindane KPAR, it was
mentioned in the RPAR notice, and comments on its significance were soli-
cited. In response, the registrants submitted the NCI final bioassay
report, which concluded that the study did not in itself demonstrate that
lindane is carcinogenic. (Refer to Table II-1, which compares the results
of the NCI study with the results of the three oncogenicity studies cited
in the RPAR Notice.)
The Agency rejects this rebuttal effort. While the
authors of the NCI bioassay concluded that because of the insufficiency of
their data, the bioassay does not constitute sufficient evidence of the
carcinogenicity of lindane, it does add to the body of evidence of similar
results found in the other three studies in that:
(1) The liver was the target organ. In the NCI study
lindane at 80 ppra triggered a highly significant response (hepatocellular
carcinoma) in male mice vs. pooled controls (19/49 vs. 5/49; p = 0.001).
While the high-dose group (160 ppra) did not show a significant increase (9/
46 vs. 5/49; p = 0.10), there was nevertheless an increase.
(2) Males were more susceptible than females.
In addition to the above similarities, the NCI study
provides evidence involving the same target organ in a different strain.
The Agency therefore judges that, considered together with the Thorpe and
Walker (1973), Goto et al. (1972), and Hanada et al. (1973) studies, the
NCI study provides additional evidence of the carcinogenicity of lindane.!/
2. Attempts to Rebut the Presumption of Reproductive and
Fetotoxic Effects
In Position Document 1 the Agency announced a presumption of
reproductive and fetotoxic effects on the basis of three lindane feeding
studies: Naishtein and Leibovich (1971), Petrescu et al. (1974), and Earl
— The NCI study was terminated after only 90 weeks because of the
poor condition of the animals. Since liver tumors are often lat;
appearing, the latent period may not have beer. Long enough to
result in the detection of ail potential liver tumors from the
lindane axrosura.
Il-fi
-------
et al. (1973), all of which reported adverse reproductive/fetotoxic re-
sponses. The results of each of these RPAR studies are summarized in
Table II-2. In response to our request for rebuttal comments and
additional information concerning the reproductive and fetotoxic effects
of lindane, the Agency received 15 responses from 3 registrants: Hooker
Chemicals (30000/10:1*42), Franklin Laboratories (30000/10:*37), and Paper
Products, Inc. (30000/10:*41).
The Agency has reviewed all rebuttal material submitted by
the registrants (EPA 1978c) and concludes regarding the original RPAR
studies 1) that the Russian studies Naishtein and Leibovich (1971) and
Petrescu et al. (1974) have a number of flaws which render them inadequate
to completely assess the reproductive effects of lindane and 2) that Sari
et al. (1973), which showed that lindane feeding significantly increased
the proportion of stillbirths to beagle dogs, stands unrebutted as valid
evidence of the fetotoxic effects of the pesticide.
While Earl et al. remains unrebutted as an original RPAR
study, several studies which have come to our attention during the rebuttal
period reinforce the Agency's concern about the reproductive and fetotoxic
effects of lindane. Seven studies submitted in attempted rebuttal by
Hooker Chemicals in fact indicate that lindane affects the reproductive
performance of.the animals tested as well as the condition and/or survival
of the fetus.— Two additional studies, Khera et al. (1979.) and
Trivonva et al. (1970), which the Agency has recently reviewed, provide
further indications of lindane-related fetal and reproductive effects.
The Agency's risk assessment of the reproductive and feto-
toxic effects of lindane has necessarily focused on fetotoxic effects. (See
Subsection II.C, "Risk Assessment.") The quantitative analysis is based on
data provided by Khera et al. (1979), Palmer and Lovell (1971), Palmer and
Neuff (1971), and Bauer and Frohberg (1972), the latter three studies
having been submitted during the rebuttal period by Hooker Chemicals (Table
II-3). The Agency was unable to perform a quantitative risk assessment of
the general reproductive effects of lindane based on available data.
6/
— These studies (addressed in Subsection II.A.2.e below and
summarized in Table II-3) stand as evidence that lindane causes
no teratogenic effects in rats, mice, or rabbits. However, the
Agency's presumption was based not on teratogenicity, but on
general reproductive and fetotoxic effects. An eighth rebuttal
study (Table II-3) submitted by Hooker, which indicated only that
lindane decreased the growth rate of female pigs prior to mating,
did not address the presumption.
II-7
-------
Tabla II-2. Summary of Studies Cited as 3ases for the Presumption of
Reoroductive and Fetotoxic Effects
Species
Protocol
Results
Reference
Mongrel
rats
0.05 and 0.5 nig/kg
in diet for 4 months
prior to mating &
pregnancy
I Increase in duration
I of estrous cycle and
I increased duration of
Iestrous at high dose;
I no effect of low dose.
Naishtein &
Leibovich
(1971)
Rats
5, 10, or 15 mg/kg
in diet in P, F ,
F , & F group
I Lengthened avg. dura-
ttion of pregnancy;
[decreased fertility
I index in 15 aig/kg
I group? retarded sexual
I maturation & depressed
I sexual function; pro-
lgressive increase in
I proportion of still-
|births in successive
I generations.
Petrescu et
al. (1974)
Beagle
dogs
7.5 or 15 mg/kg per
day in diet from day
1 or 5 of gestation
I Increased frequency of
I stillbirths in treated
I animals from 2% in
I controls to levels of
|c.18%, 23%, and 30%
I in dogs ingesting lin-
Idane at 7.5 mg/kg/day
I(beginning on either
I day 1 or day 5) or
115 mg/kg/day (begin-
|ning on day 5) during
|pregnancy. (No signi-
|ficant teratogenic
I effects.)
Earl et al.
(1973)
H-8
-------
The Agency's analysis of the rebuttals submitted regarding
the presumption of reproductive and fetotoxic effects is presented in the
succeeding Subsections II.A.4.a through e. Additional Agency findings are
addressed in Subsection II.A.4.f.
a. Attempted Rebuttals Pertaining to Naishtein
and Leibovich (1971)
Two registrants objected to this study. (Refer to Table
II-2.) Hooker Chemicals (30000/10:*42) argued that data essential for peer
evaluation were not provided. Franklin Laboratories (30000/10:#37) argued
that the study was based on an unknown number of test animals.
The Agency acknowledges that the data in the Nashstein and
Leibovich study is not presented in sufficient detail and doesn't meet
Agency standards in sustaining a presumption. However, even with these
deficiencies, the study does provide supportive information on fetotoxicity
which strengthens the conclusions reported in the Earl et al. study and
other studies (see Section II.2.e.).
b. Attempted Rebuttal Pertaining to Petrescu et al. (1974)
Hooker Chemicals (30000/10:342) argued that Petrescu et al.
(Table II-2) did not meet currently acceptable scientific standards: 1)
there was no discussion of toxic effects in dams; 2) there were too few
test animals per group; 3) the study was unusual in design (pregnancies
were repeated over the animals' lifetime for the F generation); 4) there
was no information on anticipated normal pathology in experimental or con-
trol groups; and 5) the fertility index appeared to be unusually low for
all groups, including control groups.
This rebuttal is accepted (EPA 197Sc). The Agency acknow-
ledges that Petrescu et al. shows deficiencies in design and fails to pro-
vide sufficient data so that the reported findings can be adequately
judged.
The Petresca study did show effects on fetotoxicity at doses
below those established for causing acute and subacute effects ( 5 mg/kg).
The presence of a second study (Palmer et al., 1972) (see Table II-3)
reporting no effects does not detract from Petrescu's reported results.
However, the Palmer study does reduce the strength of the Petrsscu study
and accordingly the Agency will not attempt to use Petrsscu as the sole
support of the fetotoxicity presumption, although the Agency will use
Petrescu1s results as supportive information in evaluating the risk of
fetotoxicity.
c. Attempted Rebuttals Pertaining to 5arl et al. (1973)
Two registrants objected to this study. (Refer to Table
II-2.) Hooker Chemicals (30000/10:242) argued that the study was invalid
in that 1) it lacked sufficient information for evaluation and 2) it used
II-9
-------
non-concurrent controls. In addition, Hooker cited a 32-week study in non-
pregnant beagles (Noel, 1970) which indicated that lindane (200 ppm dietary
intake) caused toxic effects at doses as low as 5 erg/kg-per day. Franklin
Laboratories (30000/ 10:$37) argued that the apparent increase in the inci-
dence of stillborn animals from lindane feeding was inconclusive because a
7.5 mg/kg dose produced 30.5 percent stillborn, while double that dose pro-
duced only 17.9 percent stillborn (a reduction of nearly half).
The Agency rejects these rebuttal attempts (Memo 1978a;
1978b). The Earl et al. study was published in 1973, and data from the con-
current controls were generated from January 1970 through October 1972.
Sari et al. provided data from several control groups, at least one of
which is clearly "concurrent" with the test groups. For this control
group, the percentage of stillborn pups was 5.7 percent, as compared to
30.5 percent stillborn in the 7.5 mg/kg group. The beagle study (Noel,
1970) cited by Hooker is not inconsistent with the observation of fetotoxic
effects in beagles at higher doses by Earl et al. (1973). The apparent
lack of a dose-response relationship does not invalidate the observed
increases of stillborn animals in treated groups as compared to controls.
d. Attempted Rebuttals Pertaining to Exposure; Fetotoxicity
For chronic effects risk criteria such as fetotoxicity,
Agency regulations require the Administrator to determine whether the
effect occurs at a dose level "substantially higher than that to which
humans can reasonably be anticipated to be exposed, taking into account
ample margins of safety" [40 CFR 162.11(a)(3)(ii)(B)1. As Position Docu-
ment 1 stated, "In the absence of an established level at which there was
no demonstrated effect and with a subsequent lack of basis for choice of an
'ample margin of safety,' it may be presumed that current exposure is suffi-
cient to produce reproductive and fetotoxic effects in humans" (EPA 1977a).
Only one respondent specifically addressed the issue of
ample margins of safety. Paper Products, Inc. (30000/10:341) construed the
applicable passage of 40 CFR (cited above) to mean that the Administrator
must make a specific determination of an ample margin of safety and argued
that, "unable to meet the evidentiary standards of its own regulations, the
EPA has simply dispensed with them." The registrant noted in this context
that its product (shelf paper) contains 15 ng of lindane per square foot
and argued that, using the smallest doses cited in Position Document 1 (0.5
mg/kg), a pregnant woman would have to ingest 2 square feet of the product
per day for four months to obtain a dosage comparable to that used in
Naishtein and Leibovich.
The Agency rejects the registrant's interpretation of Agency
regulations. The "evidentiary standards" of Agency regulations are ad-
dressed in the Subsection II.C.2 of this document, which establishes a no
observable effect level and discusses margins of safety for fetotoxic
effects from lindane exposure. The Agency points out also that the prin-
cipal route of exposure to this product is inhalation of lindane vapor
H-10
-------
released from shelf paper. [See Subsection II.B.2.m.(1}.] In its risk
assessment of lindane shelf-paper products, the Agency does not consider
ingestion to be an anticipated route of exposure.
e. Additional Studies Submitted in Attempted Rebuttal
In attempt to rebut the presumption of reproductive and
fetotoxic effects, Hooker Chemicals (30000/10:S42) submitted the following
seven studies which indicated no connection between lindane and teratogenic
effects in mice, rats, or rabbits: two mouse studies by Bauer and Frohberg
[1972 (confidential; unpublished)], one in which lindane was administered
via stomach tube and one in which lindane was injected subcutaneously; a
'rat study by Palmer and Lovell [1971 (confidential; unpublished}] in which
lindane was administered by intubation; a rabbit study by Palmer and Neuff
[1971 (confidential; unpublished)] in which lindane was administered via
intragastric intubation; a 3-generation rat study by Palmer et al. [1972
(confidential; unpublished)] in which lindane was administered in the daily
diet; a rat study by Reno [1976 (confidential; unpublished)] in which
lindane was injected subcutaneously; and a rabbit study by Reno [1976
(confidential; unpublished)] in which lindane was injected subcutaneously.
Hooker also submitted an eighth study, a French study by Duee et al.
(1975), in which'female pigs were administered lindane in the daily diet.
Lindane apparently had no effect on the weight gains of the sows during the
first month of gestation or on their rate of ovulation, and the number of
embryos and their weight were likewise reported unaffected. Table II-3
summarizes these eight studies. . •
The Agency rejects these rebuttal efforts (SPA 1973c; memo
197Sa, 1978b). Regarding the rat, mouse, and rabbit studies, the Agency
grants that no teratogenic effects (birth defects) were observed. However,
it must be emphasized that teratogenic effects are not at issue. The
Agency's original presumption was based not on teratogenicity but on general
reproductive or fetotoxic effects. Fetotoxic effects were in fact observed
in the submitted studies at or near (both below and above) doses that
caused maternal toxic effects.
The Agency has reviewed Duee et al. (1975) in translation
and finds that although no overt fetotoxic effects were observed, a lack of
data in the paper undermines the usefulness of the study. However, while
the Duee study cannot be used for establishing and providing sole support
of a presumption, the study does provide information on lindane's adverse
effects and adds to that body of knowledge.
f. Additional Agency Findings Concerning the Presumption of
Reproductive and Fetotoxic Effects
In addition to the eight studies submitted during the rebut-
tal period by Hooker Chemicals, Agency research has discovered two further
studies, Xhera at al. (1979) and Trivonva et al. (1970 [reviewed in
abstract]) of the renroductive and fetotoxic effects of lindane on rats.
11-11
-------
Table II-3.
Summary of Studies Submitted in Attempt to Rebut the Presumption
of Reproductive and Fetotoxic Effects
Species
NMRI
mice
NMRI
mice
Exposure 1 Duration of
Route | Exposure
1
Subcuta- | Days 6-15 &
neous | 11-13 of
| gestation
I
I
I
I
I
I
I
I
I
I
I
I
I
I .
I
Stomach | Days 6-15 &
tube | 11-13 of
I gestation
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
!
I
I
I
I
I
Dose | Results
I
6 mg/kg | Percent abortions ,
daily (early & late
[resorptions , mean
| fetal length, S
I sex ratio in test
I groups comparable
| to controls.
I Statistically sig-
Inificant increase
I in $ of congenital
Irunts in day 6-15
(group; 6 of 7
Irunts were from
I same liter.
|No teratogenic or
I maternal toxic
(effects observed.
1
12, 30 , | In day 6-15 group
60 (at 60. rag/kg, # of
mg/kg (abortions signifi-
daily (cantly increased,
(mean 1 of fetuses
| lower than in con-
(trol groups; mean
(fetal- weight sig-
Inificantly reduced
(as compared to
(controls receiving
I carrier/vehicle;
(this increase was
| significant com-
(pared to entire
(control group.
(The increase
| in abortions at
1 1 2 mg/kg/ day ( days
| 11-13) may not be
| lindane-related
| since the effect
(was not seen in
| the group fed 12
|mg/kg on days 6-15
(nor in the groups
| fed 30 mg/kg and
| 60 ag/kg on days
1 11-13. Maternal
| toxic ef f ecrts
(observed at 50
jag/kg; none at 30
(or 12 ag/kg.
. I
Reference
Bauer and
Prohberg [1972
(Confidential;
unpublished) ]
Bauer and
Frohberg [1972
( Confidential ;
unpublished) ]
11-12'
-------
Table II-3.
Summary of Studies Submitted in Attempt to Rebut the Presumption
of Recroductive and Fetotoxic Effects (Cont.)
I Species
I
(Female
(Specific
I Pathogen
(Free Rats
Exposure
Route
Duration of
Exposure
Dose
Results
Reference
Intuba-
tion
Days 6-15 &
gestation
I
0, 5, 10|Food consumption
20 mg/kgland maternal
daily (weight gain were (
(decreased at the 21
(higher doses.
I Statistically sig-
(nificant increase
|in skeletal varia-
jtion (extra ribs)
(at high dose.
(Possible increase
(in extra ribs at
(middle dose. NOEL
|for fetal and
(maternal affects 5
(mg/kg/day.
I
Palmer and
Lovell [1971
(Confidential;
unpublished)]
New Z.
white
rabbits
Intra- | Days 6-18 of
gastric | gestation
intuba- |
tion |
I
0, 5, 10|All treated
20 mg/kg|animals showed
daily (increased respira-
(tion and drowsi-
Iness and decreased
[weight gain; * of
(animals which con-
(ceived slightly
(lower at 10 & 20
|mg/kg. Statisti-
(cally significant
(decrease in 13-
|ribbed pups at 5
|mg/kg and an in-
| crease at 20 mg/
|kg. Since in rab-
|bits the normal If
(of ribs is 12
(pairs, the effects
(at 5 me/kg are not
(adverse.
Palmer and
Neuff [1971
(Confidential;
unpublished)]
11-13
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Table II-3. Sunanary of Studies Submitted in Attempt to Rebut the Presumption
of•Beoroductive and Petotoxic Effects (Cont.}
Species
| Charles
River
Rats
Rats
Exposure | Duration of |
Route | Exposure 1 Dose Results
!
Diet Continuous |0, 25, No adverse effects
|for 3 genera- | 50 , or in parental gener-
Itions |100 ppm ation. No effects
| | daily on litter mortali-
| | jty, size, and
I | [weight or mean pup
| | weight from birth
I | |to 21 days post .
| I Ipartum. Mean ab-
| | | so lute liver
| | | weights in high
| | | dose males and fa-
| | | males of F-3b gen-
| | jeration signifi-
| | | cantly increased
| | |(p<0.01) compared
| | to controls. Mean
| | [relative organ
| | [weights signifi-
| | jcantly increased
| | | (p< 0.001) in high-
| | jdose males . Female
| | | liver/body weight
| | [significantly in-
| | [creased in females
| at all doses
| | (p<0.00 1 at high
I | [dose) . Enlarged
| [hepatocytes in-
| | [creased in 50 and
| | | 100 pcm groups.
| | [Gestation index in
| | |F-Ob litter was
| [98.9% in controls
| and 92.7^ in high-
| | [dose group ( due to
| | | 13 of 15 stillborn
| [litter).
i
Subcuta- Days 6-15 of | 0 , 5, 15 [All doses caused
aeous gestation [30 ag/kglan increase in
injection | daily fetuses having an
| extra rib when
| compared to con-
| trols. ^OEL for
| jaiatemal effects
| is 5 ag/kg; natar-
i | ( cent . )
I
Reference
Palmer, Cozens,
Lovell et al .
[1972 (Confi-
dential ; uncub-
lished)]
'
Reno [1976
( Confidential ;
unpublished) ]
I
i
11-14
-------
Table II-3. Summary of Studies Submitted in Attempt to Rebut the Presumption
of Reproductive and Fetotoxic Effects (Cont.)
I Exposure | Duration of
Species | Route | Exposure
1 1
Rats | |
(Cont.) | |
1 1
1 1
1 1
1 1
1 1
Rabbits | Subcuta- | Days 6-18 of
| neous | gestation
| injection |
I I
I I
I I
I I
I I
I I
I I
I I
I I
I • I
I I
I I
I I
I I
I I
I I
I I
I Female I Diet 1 30 days prior
I pigs | | to mating and
| | 30 days of
I (gestation
I I
I I
I I
I I
I I
I I
I I
I I
I
Dose | Results
I
|nal toxicity ob-
| served in two high
| dose groups . No
| teratogenic
(effects observed
| in fetuses.
I
0 , 5 , 1 5 | No embryotic or
mg/kg; | teratogenic
high- (effects in 5 & 15
dose | mg/kg fetuses.
group: (Maternal toxicity
45 (observed in 15 and
mgAg/ (45-30 mg/kg
days, 6- | groups. High-dose
9, S 30 [fetuses not ex-
mg/kg, (amined for terato-
days | genie effects due
10-18 (to high incidence
| of maternal toxi-
(city. Statist-
ically significant
(incidence of re-
j sorptions observed
| at 45-30 mg/kg.
I
I
0.50 and | Both doses appar-
500 ppm (ently decreased
daily | growth rate prior
| to mating . No
| effects on weight
(gain during first
| month of gestation
|nor on
-------
Khera et al. (1979) administered orally a 50 percent lindane
formulation, Senesan, to pregnant rats from day 5 through 15 of gestation.2/
The doses used were 6.25, 12.5, or 25 mg/kg/day of the formulation, corres-
ponding to approximately 3.15, 6.25, or 12.5 mg/kg/day technical lindane.
Although maternal body weight data were not given, the authors reported
that the average maternal body weight for the high-dose group decreased on
day 15 and at necropsy, though this decrease was not considered statistic-
ally significant. There was no compound-related effect on incidence of
live fetuses, dead plus resorbed fetuses, or mean fetal weight, and the
incidences of anomalous litters and individual anomalies were similar to
controls. There was, however, an apparent increase in the number of
fetuses having wavy and extra ribs and delayed ossification of calvarium
in the mid-dose group. This increase was not tied to a significant
increase in the number of litters with anomalous fetuses per the number of
litters examined, but rather was the result of large numbers of affected
fetuses within fetus litters. Effects analogous to those observed at the
mid-dose level were not observed at the high-dose level (12.5 mg/kg/day)
though slight maternal toxic effects were evident at this dose.—
Trivonva et al. (1970) fed lindane to female rats for 90
days at 5 mg/kg/day and for 138 days at 10 mg/kg/day. No reproductive
effects were observed at the lower dose, whereas the higher dose caused a
reduction in litter size and fecundity.
3. Comments Submitted on the Presumption of Acute Toxieity to
Wildlife; Aquatic Organisms
In Position Document 1, the Agency cited studies showing that
application of greater than 0.000116 pounds/acre of Lindane to a 6-inch
layer of water would exceed one half the 96-hour t,C_, for pink shrimp, a
marine/estaurine species having the lowest I*C_. among representative spe-
cies. Also cited were studies showing that application of greater than
0.00273 pounds/acre of lindane in a 6-inch layer of water would exceed one
half the 96-hour LC for brown trout, a fresh-water species having the
lowest LC--: among representative species.
7/ Xhera et al. are employed by the Bureau of Chemical Safety, Canadian
Government. Benesan was obtained through Chipman Chemicals Ltd.,
Stoney Creek, Ontario.
8/ Because of the uncertain pattern of the results reported by Xhera et
al. (no dose-response was established, and the effects observed at 6.25
mg/kg/day were relatively slight), the Agency has for risk assessment
purposes considered the no observable effect level (ilCEL) of this par-
ticular study to be 12.5 mg/kg/day as the authors concluded. (See
Section II.C.2.)
11-16
-------
The Agency received no rebuttals to this presumption of risk.
However, the United States Department of Agriculture (30000/10:*13)
commented that in the USDA Forest Service's "operational use of lindane,
precautionary measures are taken to ensure that the spray does not
directly, or indirectly, get into streams." Likewise, Hooker Chemicals
(30000/10:142) suhmitted that "lindane should not be applied directly to
water."
The Agency points out that the original presumption of acute toxi-
city to aquatic organisms was issued even though no known lindane products
remain registered for aquatic uses 1) to insure that all lindane products
with label directions for aquatic use would be acted upon, and 2) to
address registered non-aquatic uses which — via means such as .drift or
runoff — might result in lindane-contaminated aquatic environments. Be-
cause no lindane products are currently registered for direct aquatic appli-
cation, the presumption is hereby withdrawn. The Agency remains concerned,
however, about the possibilities of drift or runoff should any non-aquatic
lindane product be misused.
4. Comments Submitted and Agency Findings on Possible Adverse Sffects
In addition to initiating presumptions on oncogenicity, reproduc-
tive and fetotoxic effects, and acute toxicity to aquatic organisms, the
Agency requested additional evidence in situations where it had reason to
believe risk concerns were present. The Agency sought information both in
situations where additional information could assist the Agency in
determining where its risk criteria were met and in situations, where the
potential of. unreasonable adverse effects, outside the triggers, were
presented.— The Agency has chosen to treat significant risk informa-
tion not anticipated by current risk triggers as giving rise to risk
concerns that are appropriately handled within the framework of the RPAR
process and is therefore including this type of risk information in this
Position Document.
The effects where the Agency sought additional information
include (1) mutagenicity, (2) blood dyscrasias (3) acute toxicity hazard to
humans and domestic animals, and (4) population reductions in non-target
avian species. The Agency also requested registrants and other interested
persons to submit information on the possible isomerization of gamma - 3KC
(lindane to alpha - or beta BHC, which have been shown to be oncogenic in
rodents. The succeeding subsections treat the potential adverse effects
listed above, and give the Agency's assessment of the information received
and its additional findings conerning these effects.
9/
— In situations where a pesticide's use presents unreasonable risks
not covered by the RPAR criteria, Section 162.11(a)(S) provides that
the Agency may commence cancellation proceedings. However, where the
Agency is issuing a proposed RPAR decision document, it is in the
public interest for the Agency co include all risk concerns bearing on
registrability in this document, including additional risk information
outside the SPAR triaaers.
11-17
-------
a. Studies Submitted on Possible Adverse Effects; Mutagenicity
In Position Document 1 the Agency cited several investiga-
tions of lindane's mutagenic capacity and concluded that existing data did
not establish that lindane is a mutagen, and that risk criteria warranting
a rebuttable presumption had not been met. Additional information on this
area of concern was solicited, however, and during the rebuttal period, two
registrants, Hooker Chemical Co. (30000/10:242) and Reed and Carnrick
Pharmaceuticals (30000/10 :=r6C) , submitted several studies (Table II-4) on
the mutagenic potential of lindane, all of which have been reviewed by the
Agency (EPA 1978C). Although lindane triggered positive mutagenic re-
sponses in two metabolic activation tests and one host-mediated assay with
S. typhimurium, negative mutagenic results were observed in one metabolic
activation test with S. typhimurium, two dominant lethal studies in rats,
and one cytogenetic analysis of Chinese hamster bone narrow.
The Agency has also reviewed a report by Ishidate and
Odashina (no date) of a cytogenetic assay in Chinese hamster £ibroblasts,
in which the authors observed gaps and breaks occurring at the high dose.
In evaluating this study, the Agency found that the occurrence of breaks
was not statistically significant. The reported observations of gaps and
breaks at a dose which appeared to produce cytotoxicity and in the absence
of a dose-effect relationship, do not support a presumption of mammalian
mutagenic potential.
«
The Agency has reviewed and evaluated all data which have
become available since PD 1 was issued (EPA 1978a; EPA 1978b; SPA 1978c).
In view of the test results outlined above and in Table II-4, the Agency
reaffirms its original position that on the basis of available evidence no
presumption of mutagenicity is justified at this time. However, because
indications of mutagenesis constitute indirect evidence of carcinogenicity,
the positive responses observed in several studies have bearing on the
Agency's presumption of oncogenicity (EPA, 1979). The presumption of
oncogenicity is thereby qualitatively reinforced.
b. Comments Submitted and Additional Agency Findings _on Possible
Adverse Effects; alood Dvscrasias
In Position Document 1 the Agency cited several case studies
which indicated that aplastic anemia, hypoplastic bone marrow, and other
blood dyscrasias in humans were associated with exposure both to lindane
alone and to lindane in combination with other chemicals. Additional infor-
mation was solicited. The Agency pointed out in ?D1 that the medical case
histories cited did not satisfy epidemiologic criteria for establishing a
cause-effect relationship between lindane exposure and blood disorders.
However, the Agency was, and is, concerned that differences in sensitivi-
ties may create a subgroup of the population which might be more than
ordinarily susceptible to possible lindane-related blood dyscrasias. In
this connection the Agency is especially concerned about cases of exposure
to children.
H-13
-------
Table II-4. Summary of Studies Submitted on Lindane as a Possible Mutagen
(Rebuttal *
I Reference
1
|Van Dijck
|& Van de
I Voorde
1(1976);
|*42 (Vol.
I IV, |
I Sec. 36)
I
(Reno
I (1976)
I #6 (pp.
| 104-118)
I
I
I
I
I
I
I
I Rohrborn
1(1975);
|*42, (Vol.
|V, Sec.
I 39)
I
I
I
I
I
I Rohrborn
1(1977);
|*42, (Vol.
|V, Sec.
I 40)
I
I
I
I
I
Study Type
Ames test (metabo-
lic activation with
mouse liver micro-
somes); Dose-
response test
with activation
Dominant lethal
Ames test (metabo-
lic activation with
mouse liver micro-
semes)
Ames test (metabo-
lic activation with
mouse liver micro-
somes)
Species & Strain
S. typhirmurium ,
TA 98, 100, 1535,
1537, 1538, 1950,
1978
Sprague-Dawley
rats
S. typhimurium,
TA 1535, & 1538
S. typhimurium,
TA 100, 98, 1535,
5 1538
Doses
1 & 1,000
ug/plate ; 1 ,
10, 100, &
1000 ug/
plate
0, 1, 3, & .
10 mg/kg
daily,
subcutane-
ous injec-
tion for 10
weeks
0.3125,
0.625, 1.25,
2.5, S 5 ug/
plate
93, 139, S
208 ug/plate
Results
No DNA killing
or reversion to
Iprototrophy ; No
Imutagenic
[potential
I
I Significant
increase in
I dead implants
at week 1
(appeared to be
I function of
statistics a
low control
lvalues ; no dose
I response
Probable base-
Ipair substitu-
tion (TS 153 S);
I highly signifi-
cant increased
I frequency of
[frame shift
[mutation ( 195X)
in TA 1538
I
Slight bac-
| teriostatic
[effect; 2.59X
I increase muta-
[tion in TA
1535; 2.72X in-
crease in TA
1539 at highest
[dose
•All rebuttal references cited carry the prefix 30000/10.
11-19
-------
Table II-4. Summary of Studies Submitted on Lindane as a Possible Mutagen (Cont.)
I Rebuttal
I Reference*
1
| Rohrborn
1(1976);
If 42, (Vol.
|V, Sec.
141)
I
I Rohrborn
1(1976);
|*42, (Vol.
|V, Sec.
|42)
I
I Rohrborn
1(1977);
1 342, (Vol.
|V, Sec.
|43)
I
ICerey
I et al . ,
|1975
I
Study Type
Host activation
(male NMRI mice)
Cytogenetic bone
marrow analysis
Dominant lethal**
Dominant lethal
Species & Strain
S. tychimurium,
TA 1535
Male & female
Chinese hamsters
Male rats
Male rats
Doses
0.5, 5, & 50
mg/kg
0.125, 1.25
& 12.5 mg/
kg for 5 •
days
1.5, 7.0 S
15 mg/kg per
day for 8
weeks
1.5, 7.0 SL
15 mg/kg per
day for 8
weeks
I
I Results
I
I8.73X increased
I mutation at
I highest dose
I
I
I
I No significant
I responses;
I doses were 10 ,
|100, S 1,OOOX
| AD I for humans
I
| None
I
I
I
I
I
I Reported as
I positive**
I
I
*All rebuttal references cited carry the prefix 30000/10.
**The Cerey et al. study was reported as positive, but no supporting data was
included in the publication. The Agency also could not obtain the necessary
information from the authors. Therefore, while the authors claim this study
to be positive, without the substantiating data, the Agency will not attach
any significant strength to this study.
11-20
-------
Concerning blood dyscrasias as a possible adverse effect
of lindane, the Agency received 16 responses frcm four registrants: Hooker
Chemicals, Franklin Laboratories, Paper Products, Inc., and Seed and
Carnrick Pharmaceuticals. Six of the submissions (30000/10: ir4A; 34B; =MC
$18A; #41; $42) were indeterminate as to whether there exists a cause-
effect relationship between lindane exposure and blood dyscrasias in
humans. Of those six submissions, three argued that exposure from specific
lindane products was so low that no risk is involved. Another four submis-
sions from Hooker Chemicals (30000/10:£42), which attempted to show that
lindane does not cause blood dyscrasias in humans, could not be evaluated
because supporting data were either absent or insufficient. In addition,
however, Hooker submitted six studies surveying various human populations
for a relationship between lindane and blood dyscrasias. These six surveys
lend support to the Agency's original determination that there is insuffi-
cient epidemiologic evidence to establish such a cause-effect relationship.
In addition to the material submitted by registrants,
further data on lindane and blood dyscrasias have come to the Agency's
attention since PD1 was issued. Specifically, the Agency is aware of two
in-progress epidemiological studies in Iowa and Illinois and in Hawaii,
respectively, the first of which was prompted by a clinical incident
linking lindane and a child's blood disorder. The case in question
involved a 32-month-old Illinois boy who was diagnosed as suffering from
aplastic anemia secondary to lindane exposure and led to an epidemiological
study of exposed households in Iowa and Illinois by the Iowa
Epidemiological Study Center.
10/
Lindane was present in the child's blood at 1.6 ppb.—
Analysis of the blood of other family members showed the following levels
of lindane: father, 4.9 ppb; mother, 3.1 ppb; and sister, 8.1 ppb. A
lindane vaporizer in the house had been operating continuously since 1970.
It was discovered that the distributor of this product sold lindane vapor-
izer crystals on a continuing basis, .servicing homes and businesses at
about 375 locations in Illinois and Iowa during 1973.
As a result of these findings, the Iowa Epidemiologic Study
Center has undertaken a special study of 473 people in private homes in
Iowa and Illinois who had been exposed to lindane in connection with hcme-
use vaporizers for varying lengths up to 26 years. Because lindane is
absorbed in many exposed surfaces during vaporizer use, then revolatized
from these surfaces into the air, exposure to lindane extends beyond the
time of actual operation of the vaporizer. The Agency has received some
preliminary, statistically unchecked results of this study. In the 235 •
households surveyed, 440 blood samples were taken and analysed for lindane
and chlorinated hydrocarbons. Approximately 70 percent of these samples
contained lindane ranging from 1 to 46 ppb. Air samples were taken in 10
percent of the homes, and lindane was found in the air in every home.
IP/ Another recent incident indicative of the particular sensitivity of
children to the potential effects of lindane is addressed in connection
with acute central nervous system effects [Subsection II.A.4C!4)(c)
below]. The case in question involved the death of a two and one half
month old infant who had been treated for scabies with a commercial
lindane orcduct.
11-21
-------
A total of 478 health questionnaires have also been compiled. Because the
study remains to be completed, the final results of the Iowa study will be
presented in Position Document 4.
The second epidemiological study, currently being conducted
in Hawaii, was prompted by the occurrence of five cases of aplastic anemia
in Maui County (population: approximately 50,000), a relatively high inci-
dence given that aplastic anemia is generally considered a rare disorder
(national mortality rate: 0.1/100,000). The Agency has reviewed protocol
and progress reports and has telephone interviewed the Hawaii Project Direc-
tor of this study (Memo 1980a). The 2-year study is designed to detect
blood dyscrasias associated with a wide range of organochlorine pesticides,
including lindane. Data are being gathered on patients with diagnoses of
aplastic anemia, agranulocytosis, and blood dyscrasias. The approach of
the study is as follows: 1) to obtain lists of patients with the above-
named diagnoses, 2) to solicit statewide cooperation from all family practi-
tioners, pathologists, and hematologists, 3) to administer questionnaires
to patients concerning pesticide usage - home and occupational usage, and
4) to review medical records, both hospital and out-patient, for demo-
graphic and pertinent clinical data. The results of this study will not be
available until the end of the 1980 calendar year, and the Agency is at
this time unable to judge whether or not the study will prove useful in
terms of establishing or disproving a causal relationship between lindane
and blood dyscrasias. The Agency has been advised, however, that "there is
no evidence which focuses attention on lindane at this time." The final
results of the Hawaii epidemiology study will be presented and evaluated
together with the results of the Iowa study in Position Document 4.
Taking into account all currently available data, the Agency
must reaffirm its original position that insufficient evidence exists to
firmly establish a cause-effect relationship between lindane exposure and
blood dyscrasias. The Agency points out, however, that the epidemiological
data submitted do not satisfactorily answer the very complex question of
whether the hematopoietic tissues of certain individuals, particularly chil-
dren, might be peculiarly sensitive to lindane.
c. Comments Submitted and Agency Findings on Possible Adverse
Effects; Acute Hazards to Humans and Domestic Animals
In Position Document 1, the Agency cited 99 health-related
incidents recorded by the SPA Pesticide Episode Reports System (P2KS) be-
tween 1966 and 15 June 1976 which implicated products containing lindane.
In that connection registrants were requested to submit any data they might
have on the acute toxicities, both dermal and inhalational, of their lin-
dane products, including products formulated with other active ingredients.—
11/ "Episodes" include all association with a given pesticide and do not
always imply ingestion. The PSRS data do not necessarily include all
incidents which have occurred during the given time span.
11-22
-------
Eighty-four of the incidents cited in PD1 involved humans, and the majority
of these occurred in the home. Fifteen involved domestic animals. Of the
84 human incidents, 49 involved lindane as a sole active ingredient, and
35 listed lindane in combination with another active ingredient. The major-
ity of the lindane-only cases involved children (in 24 cases the child
ingested the pesticide) and half of the lindane-only episodes led to clinic-
al symptoms. Hospitalization followed by death occurred in five of the epi-
sodes. The majority of the incidents attributed to lindane in combination
with another pesticide involved adults. Clinical symptoms were cited in
less than half of these episodes, and two cases resulted in death.
Fifteen livestock or domestic pet incidents were reported, nine involving
lindane as a sole active ingredient and six involving lindane in
combination with another active ingredient.
The submissions received during the rebuttal period are
addressed in Subsections (1) through (3) below. These comments did not
mitigate the Agency's concerns over lindane exposure. In addition to the
studies submitted by registrants and in addition to the evidence which was
cited in PD1, data have come to the Agency's attention which show that
exposure to lindane, both in test animals and in humans, can cause adverse
effects manifest in particular as symptoms of central nervous system (CNS)
stimulation. In this connection there is evidence also to suggest that
children are especially sensitive to the acute toxic effects of lindane.
Additional Agency findings concerning the acute effects of lindane as a CMS
stimulant are presented in Subsection (4) below. The Agency's assessment
of the acute and subacute toxic risk of lindane is given in Subsection
II.C.3.
(1) Acute Hazards; Studies Submitted on Inhalation
Toxicity
Two registrants, Chevron Chemical Co. and Reed and
Carnrick Pharmaceuticals, submitted -data intended to demonstrate that
lindane poses no acute inhalation toxicity. Chevron (30000/10:£38)
submitted a study in which groups of five male and five female Sprague-
Dawley rats were each exposed for one hour to about 50 ing/liter vapor and
75 mg/liter aerosol of a commercial lindane product. Although the animals
were ataxic after one hour of exposure to the vapor, they recovered within
24 hours. No toxicity or deaths resulted from exposure to the aerosol.
Test rats in both groups showed weight gains comparable to controls. At
autopsy, no gross pathological changes were attributable to lindane. This
study has been reviewed by the Agency (SPA 1973c). The exposure chamber
("tunnel chamber") was neither described nor referenced to existing litera-
ture. Mo data were given on uniformity of distribution of the test
material, chamber temperature, humidity, or handling conditions of the
animals. No raw data to substantiate the study's findings were provided.
In an effort to show that lindane presents no respira-
tory hazard, Reed and Carnrick (30000/10: =?6C) submitted an acute inhalation
toxicity study in rats. Five male and five female adult rats were exposed
for one hour in a 40-liter glass chamber to a concentration of 12.3 ng
lindane/liter [sic, Agency calculation = 14.4 mg/liter]. No toxicity
11-23
-------
or positive pathological findings were observed after the 14-day observa-
tion period. The Agency has reviewed this study and considers it invalid
(SPA 1978c) for the following reasons. The chamber, the generating system,
and the exposure conditions were not adequately described. Nor did the
authors state whether the (undescribed) atomizer, used to introduce the
test material into the chamber, produced respirable particles. Data given
in the study do not provide information on the LC_fl dose-response.
(2) Acute Hazards: Studies Submitted on Dermal Toxicity
Two registrants, Reed and Camrick Pharmaceuticals and
Chevron Chemical Co., submitted a total of five studies on the dermal toxi-
city of lindane. Reed and Carnrick (30000/10 :#6C) submitted four studies
on lindane as a scabies treatment. Three of the studies, Woolridge (1948),
Halpern et al. (1950), and Xorneblee and Combes (no date), involved human
patients, none of whom experienced side effects when treated with lotion
formulations containing from 0.15 percent to 1 percent lindane. The fourth
study, Mohrmann (1976), involved rats which were treated with a commercial
lindane-formulated lotion sold for human use. At autopsy, none of the rats
showed gross pathological effects. The Agency has evaluated these studies
(EPA, 1978c). Two of the studies performed on human patients, Halpern et
al. (1950) and Woolridge (1948) were found valid. The third epidemic-
logical study, Xorneblee and Combes (undated), provided insufficient data
for Agency validation. The fourth study, Mohrmann (1976) on rats, was
likewise found valid (SPA, 197Sc).
Chevron Chemical Co. .(30000/10:138) submitted a study
on the dermal toxicity of a commercial lindane spray product to adult male
rabbits showing an H>50 of 922 mg. a.i./kg. The Agency has reviewed this
study and considers it valid (SPA 1978c).
In addition to the five studies outlined above, the
Agency received from Hooker Chemicals (30000/10:*42C) a tabulation of data
for acute toxicity in rats, primary skin irritation in rabbits, and primary
irritation of rabbit eye mucosa. Because experimental procedures were not
included, the Agency was unable to determine the validity of these data.
However, the EPA scientists who reviewed the material noted that it was "in
general agreement with other similar studies" (SPA 1978c).
(3) Acute Hazards; Studies Submitted on Oral and
Intraperitoneal Toxicity
Hooker Chemicals (30000/10:*42C) submitted a study on
acute toxicity in rats following oral and intraperitoneal administration of
lindane. Sats were incubated with aqueous suspensions of lindane at doses
ranging from 64 to 400 mg/kg, and intraperitoneally injected with aqueous
suspensions of lindane at doses ranging from 32 to 125 ag/kg. The Agency
has reviewed this study and considers it valid (SPA 1973c). The U-0 for
both exposure routes was determined for days 1, 7, and 14 after applica-
tion. The I"3-n for intraperitioneal injections was 69 mg/kg for all
three days; for incubation, the I
-------
(4) Acute Hazards: Additional Agency Findings Concerning
Central Nervous System Stimulation
Since the publication of the lindane RPAR notice and
PD1, additional data have come to the Agency's attention which show that
exposure to lindane, in humans and in laboratory animals, can cause symp-
toms of acute poisoning which are typical of central nervous system (CMS)
stimulation. See Table II-5.
Peripheral nervous system involvement is described in
studies by Dallemagne et al. (1950), White and Larrabee (1973), and Schwarz
and Xaschowitz (1968). These studies describe degeneration of neurons,
acting as a sympathetic ganglionic blocking agent, and lowered excitability
of the retina from exposure to lindane (Memo Undated b). Studies by St.
Ctoer (1971) and Desi (1974) also showed CSS involvement leading to
seizures, convulsions, and learning impairment.—
Symptoms in the animals appear in the following order:
1) increased respiratory rate, 2) restlessness, 3) intermittent muscle
spasma, 4) salivation, 5) disequilibrium, 6) convulsions, 7) collapse, and
8) death.
Symptoms of acute human poisoning are similar to those
displayed by laboratory animals and appear in this order: 1) dizziness, 2)
headache, 3) nausea and vomiting, 4) diarrhea, 5) tremors, 6) weakness, 7)
convulsions, 8) dyspnea, 9) cyanosis, and 10) circulatory collapse. When
tested in humans, the following results were obtained with the 100 percent
gamma isoner (Hayes, 1963): 40 mg/day (.66 mg/kg/day) x 14 days - no
effect; 4.5 me three times daily x 3 days (2.3 mg/kg/day) - no effect; 180
mg/day repeated (3 mg/kg/day) - dizziness and diarrhea after several days.
(5) Heightened Susceptibility of Children to Lindane
Poisoning
The Agency is concerned in particular about the
f» to rsror?ii^f> ar-iira af-Fpff <5 in f-hi 1 r'-'-pn .— fl<5
potential for lindane to produce acute effects in children,— as
12/
— While not directly demonstrating effects to the CNS, Xoransky and
Ullberg (1964) demonstrated that lindane was distributed in the CMS 24
hours'after administration. The radioactive lindane used in this study
was found almost exclusively in brain structures containing white •
marker (Memo Undated b).
In a second study, Litterst and Miller (1975), after 50 minutes i.v.
infusion of lindane in dogs, found lindane in the white matter and, to
a lesser degree, in grey brain natter. These studies add significant
weight to the reported CNS effects.
13/
— Even though it may not meet the acute toxicity trigger, this
risk factor is being treated by the Agency as part of the regulatory
ecuaticn.
11-25
-------
Tnltlu 11-5. Acute Eltevtat Summary of Human, ami Aninal Sfcutllaa on I.tlitlune an • Control Itorvoua fiyaten Otlamlant
Aii 1 ma la Ihnana
Rofotencua Bpccloa
IHiul (I9M) NlaLar n
Dooatje Roaulta References Doauye
2.S ng/kg/day After 22 daya, docreascd llayoa. (1963) (1O-30%)
lleaulta
Approximate equivalent of
rata, mile x 4O daya
ami fuiaala
5 *>9/kg/day
• 40 daya
I
ro
en
1O MU/kg/day
• 40 day<*
SO Itg/kg/day
• 40 tlaya
|>er (omidiica on • Sklnnoc
IXJK focJIixj teat was
noted (due to tncroaaeil
Irrltalilllty). Ik) other
changes wore noteJ.
Decreased |>ar[omaiioa
In Bkliinur box touta
aixl ware tunning teat*.
Ellqlit Inoreaaa In
kldnoy weight and Dome
brain honorrlimjo noted
at autopsy.
Aa at S
Ikiuieaoed body weight
gain tote, eplecn
eiilargtiitcnt, and .
Increaned liver
wolghtu notoil at
autoiiay - greatly
decreased |>erCornanca
In Eklnner tax and
• ace tuniiliKj teat a.
4O ing/day x 10 daya
(oral)
(60-05*)
40 ing/day * 14 days
(oral)
110 ing/day
repeated (oral)
(loot)
40 ing/day * 14 daya
(oral)
45 mg 3 tlmea
dally x 3 daya
(oral)
10O mg/day repeated
(oral)
O.7 Mj/kg/day yielded dlarrluia
after Otli day
Approximate equivalent of
O.7 »g/kg/day yielded no
observed effeot
A|>proBli»attt equivalent of
1.9 mg/kg/day yielded diarrhea
attar Cth day
Approiiliaata eijulvalent of
0.7 «K|/kg/day yielded no
observed effect
Approximate equivalent 9 I
2 mg/kg/day ylolJuJ no
obaurvod effeot
te equivalent of
3 pig/hg/day yielded
dlexlneaa and diarrhea
after aeveral daya
-------
Tablo 11-5. taute effuctai fiumnary of Human aikl Aiilnal Btuillea on Llndane as a Central Narvou» By a tea Btinulant (Cont.)
IU:furcncca
Ail I ma la
Bpeclea
lltunana
Donoija
Rasulta
References
Douogo
Results
6t:hwurz and 2 epeulea of 3 mij/anlnal
Kuucliowltz (19CO) crcHja
M
M
I
White un.l Mult, female In vitro
l^rralx:u (1973) Chnrlea River Tncubutlon
rats of ganglia
HeauureiuoiitB of flicker
fusion freqiiunclea 111
ait electloretliioyrom
nhoweJ tl>nt lliiJana
decreaacJ tho efflcluncy
of the vlaual process
at different llylit
Inteitaltlea uixl colors.
CHS excitability waa
confirmed by accun|>aiiy-
lucj Increaaua In arapll-
tudco of reo|H>naea In
tliuue teata. (Eenol-
tlvlty of the nurveo
Inureaoed but efficiency
or apeetl decrvaaed) .
Action potential In
|>out
-------
Table 11-5. Acute Effectsi Summary of Hunan and Animal Studlea on Llndano aa a Central Hervouu By8tea Stimulant (Coiit.)
Koferuncva
lldiilped
Iliuaana
Reaulta Rnforenceo Dooaqu Rcoulta
2 of 4 anlntalu allowed
Increaaed excitability.
There were no death* or
convulalona.
M
M
I
to
CX)
- aliaved
Hcanllng nala 60
Now Zealand - eliavcd,
strl|>[>cd
- ahavcd,
d«|i Hated
Ha oliuervcd effecta
Excitement In all| 4 of
6 died.
Excitement In all
anliualai OO» death.
EKCltunvnt and ccuivul-
sI on In 2 of 6t no
duatha.
uitd
female rata l.p.
Icijoutlon of 20O
with 14C-UHC allowed
clear localization In
brain whltu matter
(after 24 huurn), and
In Hoctloiis rich In
nyelln fllxira.
-------
Table 11-5. Auiita CffeutBi nummary of Human and Animal Utudlea on l.lndana aii • Central llervouo By at on Utlmulant (Cont.)
I
K)
VD
deferences
I.I It ei at ami
Mlllor (19/5)
Aiilnata
Epeclea Douacjo
Hale beagle (l.v.)
docjB 2.4 My/kg
wllli of
without |iru-
treatment
with |i|ioiio-
barbltal
ItiuaaiiB
Peotilta ' ItoCerencea Dooaga Itouulto
Ilia vtudy ahowetl
l'i«f eroiitlal aautum-
latloit In liralu
ntcuuturuu - white
natter. PcetreaUneiit
(6O day>) with
15 my/kij/doy |>liuno-
barbltal duciuaaoj
luvolu of llndano In
lira In (no cliaixjo in
blood lovulat and
dtiureased event* of
eulxure.
St. (Ha
(19/01
Female rate (i.v.)
anntholcKjy
otudy revealed ohangea
lit liver, nuucle,
kidney and narve
tleaue. Harkod narve
degeneration waa noted
and ayna|iuee were nout
vulnerable.
-------
there is a significant possibility that children are more sensitive to the
toxic effects of lindane than adults. Although limited data are available
at the present time to establish that children display an increased
sensitivity to lindane, it is believed that pubescent children are likely
to have a heightened susceptibility to harm from pesticide exposure in
general. Some of the factors likely to make pubescent children more
susceptible than adults to the toxic effects of pesticides include the
"greater uptake of (pesticides) in the developing tissue and organ systems
of younger aged children", "increased susceptibility to asthma", "increased
susceptibility to agents that interfere with calcium metabolism", "increa-
sed susceptibility to agents that interfere with protein utilization", and
"increased sensitivity to hormonal imbalances." (Memorandum from Peter F.
Infante, Director, Office of Carcinogen Identification and Classification,
OSHA, to Grover Wran, Director, Health Standards Program, OSHA (June 16,
1978), cited in National Association of Farmworkers Organizations, et al. v.
Ray Marshall, U.S. Court of Appeals, D.C. Civil Action No. 79-1044). On
the basis of similar developmental factors, prepubescent children would
also be expected to display a greater sensitivity to pesticides. Moreover,
the potentially higher exposure per unit of body weight for young children
and the possibility of underdeveloped detoxification systems in very young
children would also appear to pose significant concerns.
Furthermore, the Agency's concern about the suscepti-
bility of children is supported by both animal data on the effects of
lindane and clinical cases of lindane poisoning in children.
An experiment with rabbits showed that immature animals
display a very pronounced sensitivity to lindane compared to adult animals.
Hanig et al. (1976) treated rabbits with a single topical application of 1
percent lindane at 60 mg/kg. Young adult (2 to 3 kg) and just-weaned
(6-week-old) male New Zealand rabbits were either shaved; shaved and
depilated; or shaved, depilated, and "stripped" with adhesive tape. The
animals were observed for three weeks. Fifty percent of the young adults
that had been shaved, depilated, and stripped showed only mild excitement
after treatment. Treated weanling groups, however, showed severe CNS
symptoms of excitement, convulsions (all groups), and death (50 to 70
percent of the animals) if the skin was depilated and stripped. The Agency
has reviewed this study and has concluded that the data presented
support its concern that children may be more sensitive than adults to the
acute toxic effects of lindane.—
14/
— The weanling controls which were shaved, depilated and stripped
did not exhibit excitement or convulsions but did suffer a high
mortality rate. The authors concluded that the stripping process was
too severe for the weanling rabbits and that the high mortality rate
of the controls did not negate the high incidence of excitement and
convulsions in the treated orouo.
11-30
-------
A number of clinical cases of lindane poisoning in
children also heighten the Agency's concern about the special sensitivity
of children to the acute effects of lindane. One case which illustrates
the significance of lindane's potential to produce acute effects of the
central nervous system involved the recent death of a two and one half
month old infant who had been treated for scabies with a commercial lindane
product. Lindane was found in the child's heart blood at 33 ppb, in the
urine at 2 ppb, and in the brain tissue at 100 ppb. Doctors who reviewed
the case at the University of Miami Epi-Studies Pesticides Laboratory
agreed that the concentration of lindane in the brain at a level three
times higher than in the blood was.the most probable cause of death
(University of Miami Memo, 1979). —
In view of the potential of heightened sensitivity of
children to pesticide exposure, a cautious approach is warranted toward
setting margins of safety levels for children exposed to lindane. Current
scientific information is, in the Agency's judgment, insufficient to set
separate margins of safety levels for children. The most that can be said
is that the margin of safety figures for adults are probably too high to
assure the safety of children.
a. Comments Submitted on Possible Adverse Effects:
Population Reduction in Nontarget Avian Species
The Agency cited studies in the lindane RPAR
notice which showed that exposure to DDT and its metabolite, DDE, caused
eggshell thinning in wild birds. The Agency was concerned that lindane (an
organochlorine pesticide like DDT) might adversely affect populations of
nontarget avian species. In addition, a study on lindane's effects on
chicken eggs was cited which showed that lindane reduced hatchability and
reproductive efficiency. However, the Agency considered these data
insufficient to initiate a rebuttable presumption.
No comments were submitted in rebuttal to this
concern. The Environmental Defense Fund (30000/10 : #43) suggested that
exposure of lindane to avian species should be considered. The Agency has
reviewed this concern (Memo, 1977) and has concluded that there is no new
evidence showing adverse effects on avian species and that there is little
evidential basis for concern. Because chickens are not representative of
wild avians, no determination that lindane adversely affects nontarget
avian species can be made on the basis of the chicken study cited in the
notice.
— Because it involves a child, the example of this infant death
attributable to the CMS effects of lindane warrants comparison with the
recent case of a 32-month-old Illinois boy who was diagnosed as suffering
from aplastic^nemia secondary to lindane exposure from a vaporizer used in
his home. Refer to Subsection IV. A. 4.b above regarding blcod dyscrasias
as a cossible adverse effect of exposure to lindane.
11-31
-------
b. Comments Submitted and Additional Agency Findings
• on Isomerization
In Position Document 1 the Agency citad studies
which suggested that lindane (gamma-BHC) may isomerize in the environment
to alpha-BHC, and in rats to alpha- and beta-3HC. The question of isomeri-
zation was raised as a potential concern based on data establishing that
the alpha and beta isomers of SHC induce statistically significant onco-
genic changes in seven different rat and mouse strains. Three registrants,
Hooker Chemical Co. (30000/10:#42), Franklin Laboratories (30000/10:237),
and Paper Products, Inc. (30000/10:341) commented on the issue of
isomerization.
The most extensive comments were submitted by
Hooker Chemical Co. and these may be summarized as follows:
1) Chemical-driving forces favor degradation of
lindane, not isomerization.
2) Isomerization of gamma-BHC to alpha-BHC
apparently takes place in sediments, but to such a low extent that it is
not of significance for the environment.
3) The fact that many research articles have
reported degradation but not isomerization, and that the one article which
did report isomerization of grass (Steinwandter, 1975a) used conditions in
which substantial microbial populations were present, render it unlikely
that isomerization takes place in plants to any considerable extent. The
results of the Steinwandter study may also not be reproducible.
4) The Kamada (1971) rat study, cited in ?D1, is
deficient in several respects (enumerated below), and isomerization in rats
is very doubtful.
a) The analysis of the rat tissues was
carried out by gas chrcmatography using only one column.
b) There were only two animals in the
control group.
c) In the livers of the control animals
beta-3KC was found in rather high concentrations.
d) A comparison of the data from the rats
treated with beta-3HC with the data from the control animals could be
interpreted to indicate that beta-3HC is also isomerized to alpha-3HC.
e) No detailed information is given about
the gas chroiaatographic determination of the purity of the isomers used.
Although it is stated that in each acrive ingredient only one isomer was
detectable, it is Itncwn that traces of other isomers are generally also
present.
11-32
-------
f) No details about the contamination of
the feed and oil used are given. Oils in particular very often contain
different amounts of organochlorine substances such as BHC isomers.
g) The appearance of the various isomers
which were not administered in comparison to the values from the controls
cannot be regarded as significant, and the appearance of these isomers as a
result of isomerization is very doubtful.
Franklin Laboratories (30000/10:$37) and
Paper Products, Inc. (30000/10:*41) pointed out additionally 1) that the
formation of alpha-3HC from an intermediate benzene tatrachloride is
difficult to visualize since two chlorines would have to be added back to
the molecule in the process, and 2) that because of apparent contamination
of the food fed to the rats, it is difficult to interpret Kamada's work.
The Agency's response to these collective
comments is presented in Subsections 1) through 4) below. The discussion
also includes other information received by the Agency since the
publication of PD1.
1) Chemical Driving Forces
Although, as noted in PD1, the relative
thermodynamic stabilities of the four major BHC isomers are in the order
gamma
-------
The studies by the Matsumura group also
reported the formation of small amounts of alpha-3KC from the microbial
degradation of lindane. In these studies Pseudomonas putida was cultured
in the presence of C-labeled lindane, together with various cofactors.
When nicotine adenine dinucleotide (NAD) was present in the culture, 3
percent of alpha-BKC was reported as a metabolite after 20 days incubation.
In this case 73,5 percent of the original radioactivity was recovered as
lindane. Without NAD, or in the presence of many other cofactors, no alpha-
BHC was reported. Very little degradation proceeded under these conditions.
Hooker's comment on these studies did
not dispute the formation of the alpha-iscmer, but instead concluded, based
on the low yields of this isomer and much higher yields of other
degradation products, that "the isomerization of gamma-3HC in the
environment is not of significance for the environment."
A number of additional studies on the
microbial degradation of lindane have been published since PD 1. A brief
survey of the more important studies follows. Kohli et al. (1976) de-
scribed several radio labeling studies of lindane degradation in hydroponic
lettuce cultures. After four weeks under aerobic conditions, 78 percent of
the total radioactivity was lost through evaporation, 17.3 percent was
recovered as unchanged lindane, and the rest consisted of chlorobenzene
metabolites, including hexachlorobenzene, and chlorinated phenols. These
metabolites were identified by gas chromatographic and mass spectral com-
parison with authentic materials. No alpha-3HC was reported.
Tu (1976) reported the presence of a
large number of lindane metabolites fron several bacterial and fungal
cultures. Chlorocyclchexenes and chlorobenzenes predominated, but
quantitative results were not reported.
Heritage and MacRae (1977) reported the
degradation of both lindane and alpha-3HC by Clostridium sphenoides under
anaerobic conditions. In cell suspensions of this soil bacterium, the
ganana- and alpha isomers typically disappeared after two and four hours,
respectively. Tetrachlorccyclohexenes were identified as intermediates by
gas chromatography and mass spectrography. Alpha-3HC formation from the
lindane-inoculated culture was not reported.
Mathur and Sana (1977) studied the
degradation of radiolabeled lindane by soil bacteria under both aerobic and
anaerobic conditions. After eight weeks incubation, 70-86 percent of the
C-radioactivity was recovered as lindane from the anaerobic cultures.
The principal metabolites were di- and tri-chlorobenzenes and tezra- and
pentachlorocyclohexer.es, and no alpha-3HC was reported.
11-34
-------
Kohnen et al.-j£1975) measured the
release of chloride ion and carbon dioxide from Cl- or '"*C-labeled
lindane in submerged (anaerobic) and moist (aerobic) soil cultures. Under
anaerobic conditions, 86.5 percent of total chlorine was liberated as
chloride ion in 52 days, while only 6 percent of total carbon was liberated
as CO in 77 days. The amount of isomerization to alpha-3HC was
stated to be 1.1 percent, but no experimental details were given. 3y
comparison, under aerobic conditions only 9 percent of total chlorine and 3
percent of total carbon were liberated in 105 days.
In a later study by the same authors
(Jagnow et al., 1977), a survey of bacterial cultures showed that 7-93
percent of total chlorine was released as chloride ion from lindane under
anaerobic conditions. No data on the isomerization of lindane were pre-
sented. However, the following statement was made: "It cannot yet be
decided, whether these HCH-isomers were formed by isomerization of gamcia-
HCH during incubation, or if they were already present in the gamma-HCH
preparation and became relatively enriched during the degradation of the
gamma-HCH."
Engst et al. (1979) studied the anaero-
bic degradation of lindane by a mixed culture of bacteria and reported the
transitory appearance of alpha-3HC during 39 days of incubation. The
highest ratio of alpha-BHC to lindane was 2.3 percent after about six days.
Much lower levels of alpha-BHC, as well as even lower levels (not speci-
fied) of the delta- and beta-isomers, were indicated during later stages of
the incubation. Pentachlorocyclo'nexene, tetrachlorobenzene, and unknown
polar metabolites were also reported, but no yield data were given.
It seems reasonable to generalize from
all of these studies on the microbial degradation of lindane that the major
pathway of degradation involves dechlorination rather than iscmerization.
Metabolites of lindane containing fewer chlorine atoms are consistently
reported. Moreover, the disappearance of lindane by volatilization,
together with the appearance of chloride ion, strongly suggests that
extensive degradation of lindane to lower molecular weight substances,
including carbon dioxide, occurs in most cases. Several research groups
have identified alpha-3HC and hexachlorobenzene as minor metabolites, but
the extent of production of these metabolites appears to be no more than a
few percent at best, and under most conditions they apparently are not
detectable. Because the isomerization of lindane appears to require
anaerobic conditions, which are generally sequestered from efficient
exchange with the aerobic environment, and because alpha-3HC also appears
to be degraded under anaerobic conditions, the comment by Hooker Chemical
Co. that the microbial isomerization is not significant is accepted by the
Agency.
11-35
-------
3) Isomerization in Plants
A study by Steinwandter (1976a), in
which isomerization of lindane to alpha-BHC in plants was reported, was
cited by Hooksr Chemical Co. during the rebuttal period though it was not
mentioned by the Agency in ?D1. In this study, lindane was converted to
alpha-BHC after application to hay for six months. At the end of the
experiment, the hay had decayed and was densely colonized by microbial
growth. In comparison to the control sample, which had 0.018 ppm of alpha-
BHC, the created sample had 0.043 pom of the alpha-isomer. Since the hay
had been treated with 2.5 ppm of lindane, the formal yield of alpha-BHC was
about 1 percent. In a communication to Hooker Chemical Co., Steinwandter
(1976b) stated that he was unsure whether he could reproduce these results.
Since the publication of PD1,
Steinwandter has published additional studies, in which the formation of
beta-BHC from alpha-BHC at an apparent yield of about 2 percent was claimed
(Steinwandter, 1978a), and which presented some crude rate data on the iso-
merization process (Steinwandter, 1978b). These reports have similar dif-
ficulties with contamination of experimental material and present only
minimal additional evidence. The data (Stsinwandter, 1978b) appear to show
that: alpha-BHC is formed rapidly but also is degraded rapidly. No data are
presented concerning the fate of the approximately 98 percent of the
lindane that did not isomerize to alpha-BHC. The resolution of peaks in
the chromatograms presented is not adequate to allow unequivocal
identification and quantification of alpha-BHC.
The validity of the conclusion that
lindane is isomerized to alpha-BHC in plants is questionable because of the
contamination of experimental materials by the HKC isomers, because of the
presence of the dense microbial growth in the materials, and because of the
lack of adequate analytical detail. Since the yields of alpha-BHC, beta-
BHC, and HC3 are at best low (1-2 percent), the Agency must conclude that
isomerization of lindane to its isomers does not take place to any
appreciable extent.
4} Isomerization in Rats
The Agency cited in PD1 a study by
Xamada (1971) in which each of the four 3HC isomers were fed for one week
to separate groups of four rats each. Blood, urine, liver, and kidneys
were then analyzed for each of the isomers. A fifth group of four rats was
included as a control. Kamada reported levels of beta-3HC in the livers in
excess of control levels when the rats were fed either alpha-BHC or gaimna-
3HC. He concluded that these isomers may be isomerized to beta-3HC by the
rat.
11-36
-------
A number of deficiencies in this study
(listed earlier) have been pointed out by Hooker Chemical Co. These points
are generally correct. In fact the rats in the control group had high
levels of alpha-3HC (0.05 ppm), beta-3HC (.02 ppm), and gamma -3HC (0.15-
0.16 ppm) in the liver, as well as extremely high levels of alpha-SHC and
especially gamma-3HC (4.3 ppm) in the kidneys. Chadwick (1976) also
pointed out some of the same deficiencies and argued that it is difficult
to interpret the results of the study.
The Agency contacted Dr. Xamada in 1973
and obtained the following additional information (Kamada, 1978):
1) The 3HC isomers used in the study
had the following purity: alpha-BHC, 99 percent; beta-3HC, 99.7 percent;
gamma-BHC, 99 percent; and delta-3HC, 99 percent. Peaks of other isomers
were not observed on gas chromatograms.
2) The commercially sold feed fed to
rats was contaminated with gamma- and alpha-3HC, as well as with much lower
levels of beta-BHC. Exact records of this data are no longer available.
3) No attempt was made to measure
other lindane metabolites in the rat tissues.
In an attempt to reproduce the results
of Xamada, Sichler and Heupt (1977) fed lindane of 99.95 percent purity to
29 rats for eight weeks. They found 767 ppm of lindane in the kidneys but
only 0.047 ppm of alpha-BHC, which is less than the amount of the alpha-
isomer expected on the basis of the measured impurity. No alpha-3HC was
found in the liver at a detection limit of 0.002 ppm. A research group at
CIEL in Germany is presently carrying out additional studies on the
possibility of lindane isomerization in rats. No data are as yet available
to the Agency.
Copeland and Chadwick (1979) treated
groups of weanling rats with several different levels of lindane over
periods of time extending to 24 weeks, followed by a single large oral dose
24 hours before sacrifice. They reported that the levels of alpha-3KC in
the livers did not exceed levels which would be expected on the basis of
the alpha-SHC consumed as an impurity, and concluded that bi-oisomerization
does not play a significant role in the metabolism of lindane by the rat.
3ased on the totality of information
available on the metabolism of lindane by rats (e.g. Zngst et al., 1976),
on the failure cf other research groups to reproduce the results of the
original Kamada study, and on the problems of contamination in that study,
the Agency concludes that isomerization of lindane to its isomers in rats
has not been established.
11-37
-------
3. Exposure Analysis
1. Persistence and Exposure
A persistent pesticide provides a greater opportunity for
exposure than a non-persistent pesticide. Since pesticidal risk is a func-
tion of exposure and toxicity, it follows, all else being equal, that a
persistent pesticide presents a higher risk potential than a non-persistent
pesticide. Lindane, as we show below, is a persistent pesticide.
As discussed in Position Document 1, lindane is a member of
a class of organochlorine pesticides, which, as a rule, are more persistent
in the environment than-other classes of pesticide compounds. This
persistence is due largely to the chemical stability of the organochlorine
compounds and their slow degradation by plant and animal enzymatic systems.
Lindane is quite mobile in the environment. Residues of lindane have been
detected in all types of environmental media, including water, air and soil
samples, homes, and plant and animal tissues. The presence of lindane
residues at sites far removed from its application attests in particular to
the long term persistence of the pesticide. Lindane residues have been
found, for example, in rainwater samples from several countries (Ref. 3 s
9,?D ;M),-in birds, penguins, skuas and cormorants, fish, Mototheria sp.
and planktonic krill in Antarctica (Tatton and Ruzicka, 1967), and in seals
and an arctic fox In Greenland (Clauscen, et al., 1974). Lindane residues
have been found at low levels in drinking water from various sources in the
United States (SPA, 1975) and in ambient air samples from selected states.
For example, during the years 1970 to 1972, lindane residues were found in
58% of 2,479 ambient air samples from 14 to 16 selected states; in 1976,
lindane air levels of 2.2 ng/m were detected in Miami, Florida; 0.3 ng/
ma in Tort Collins, Colorado; 0.5 ng/m in Lafayette, Indiana; 16.2 ng/
m in Jackson, Mississippi; and 0.4 ng/m in Harrisburg, Pennsylvania
(EPA, 1976b).
The persistence of lindane in the soil is dependent on a
number of factors, including soil type, soil organic matter, water content,
soil temperature, and lindane concentration. Although lindane is
eliminated from the soil at a faster rate than most other chlorinated
hydrocarbon insecticides, it is still persistent when compared with other
classes of pesticides. In long-term tests of the persistence of lindane,
for example, the remaining residues in soil after a 15-year period ranged
from 0.2% to 3-3% of the amount of lindane applied (Lichtenstein et al. ,
1971 and Voerman and Besemer, 1970). Lindane residues in soil appear to be
fairly low; for example, in 1970, 0.4% of 1506 cropland sitas sampled had
detectable lindane residues which varied between 0.01 and 0.15 ppm. The
primary factor responsible for the low residue levels of lindane in the
soil is the high vapor pressure of lindane which results in a rapid
volatilization of the compound from the soil. This volatility lessens the
availability of the compound for degradation by soil microbes, but
ultimatelv contributes to the oersistence of lindane in non-soil media.
II-33
-------
Lindane has been found in the body, organs and tissues of
mammalian, avian and aquatic species with greatest shortage in the body
fat. Monitoring data show, for example, that lindane residues occurred in
human adipose tissue in 0.77%, 1.56% and 0.56% of the samples collected
during 1970, 1973 and 1974. The mean level of lindane residues in human
adipose tissue for the years 1970 to 1974 was less than 0.1 ppm on a lipid
basis (Xutz et al., 1976).
2. Comments Submitted on Exposure
a. Comments Submitted on Dietary Exposure
Hooker Chemicals (30000/10:342) and Burroughs Wellcome
Co. (30000/10:34A) submitted a total of seven comments on dietary exposure
of humans to lindane, which the Agency has evaluated (EPA 1973d).
Hooker Chemicals argued in general terms that residues
of lindane in food are low. In addition, Hooker cited FDA data which
showed that the daily intake of lindane has dropped from 0.007 mg/kg per
day in 1967 to 0.0000084 mg/kg per day in 1974. Hooker also noted that,
although no analytical method can distinguish between gamma isomer
resulting from BHC or lindane use, the decline in lindane intake follows
the decline in the amount of BHC produced and used in the U.S. over the
years. Burroughs cited the saae FDA data for 1973-1974 showing a range of
lindane residues in beef from 0.0004 to 0.012 ppm.
The Agency agrees that lindane levels in food have
decreased. The Agency believes, however, that if the FDA market survey
errs, it is more likely to underestimate than overestimate residues
actually ingested, because of FDA's method of compositing samples before
chemical analysis. The FDA market basket survey remains the most reliable
source of residue data available. Since BHC is no longer in general use,
the Agency considers that source of gamma-BHC to be no longer pertinent. .
Hooker submitted data as evidence that lindane residues
on vegetables and fruit are generally lower than 0.5 ppm. The Agency
agrees that residues of lindane on fruit and vegetables are generally less
than 0.5 ppm.
Hooker Chemicals (30000/10:"42) cited a study showing
that the application of lindane as a seed treatment did not result in
detectable lindane levels in wheac, oats, and barley. The Agency notes
that a review of FDA's monitoring data of whole grain for human consumption
showed 2.5 percent samples positive for lindane at a mean residue level of
<0.03 ppm (1973d).
b. Comments Submitted on Exposure Via Drinking Water
Hooker Chemicals (3000/10:^42) commented that lindane
residues in drinking water are generally well below the limit of 0.004 ug
lindane/litsr sec by EPA's Water Supply Division.
11-39
-------
Table II-6. Average Lindane Fesidues in Food (by Composite Category)
Composite
Food Category
Dairy
Products
Meat, Fish,
& Poul try
Grain and
Cereals
Potatoes
Leafy
Vegetables
Legume
Vegetables
Root
Vegetables
Garden Fruits
Fruits
Oils, Fats i
Shortening
Sugars and
Adjuncts
Beverages
Total
FDA Food
Factor
25.7%
9.0%
14.2%
6.2%
1.3%
2.3%
1, 1%
3.1%
7.4%
2.4%
2.3%
24.0%
Avg of All
Samples (ppm)
0.0027
0.0017
0,0001
Trace
0.0
0.0
Trace
0.0015
0.0
Trace
0.0029
0.0
Daily Intake In
mg/1 .9 kg diet
(70-kg adult)
0.00135
0.00030
0.00003
0.00043
0.0
0.0
0.00009
0.00009
0.0
0.00013
0.00015
0.0
0.00266
11-40
-------
Most of the data cited by Hooker on this issue derived
from Position Document 1. An additional study by Bevenue (1971) found only
4 percent of 45 samples taken in Hawaii positive for lindane in drinking
water. (The average was 0.000.2 ug/liter.) Another study, Achari (1975),
found residues of 1.19 ppt in ground water (mostly wells) in South
Carolina. Considering the information just cited and the low residues of
lindane reported in surface waters, which are more likely to be contami-
nated with pesticides than is drinking water, the Agency finds it reason-
able to agree with the registrant that lindane residues in drinking water
are generally below 0.004 ug/liter (EPA 1978d).
c. General Comments Submitted on Exposure Via Air Intake
Based on data in Position Document 1 (SPA 1977a),
Hooker Chemicals (30000/10:242) argued that normal air intake will expose
the general population to between 0.00017 and 0.0017 ug lindane/kg per day,
or 1/1,000,000 to 1/10,000 of the World Health Organization/Food and
Agricultural Association's (WHO/FAO) acceptable daily intake (ADI) of
0.0125 mg/kg per day. Hooker also argued that even the highest lindane
levels in air are far from hazardous to humans, and that relatively high
levels of alpha-3HC in ambient air samples could not be due to isomeri-
zation of lindane to alpha-3HC in sediments followed by volatilization.
The Agency has evaluated this comment (EPA 1978d).
Whereas Hooker used a respiratory volume of 6 liters/min, the Agency
believes a more reasonable breathing rate for light work is 23.6 liters/
min. Based on exposure to a 60-kg adult, the Agency has established a
daily exposure of 0.011 ug/kg per day, or about 1/1,000 of the ADI. The
Agency also points out that the importance of lindane residues in air is
their contribution to the total body burden of lindane. The general issue
of isomerization is addressed in Subsection II.A.4e, wherein the Agency
concludes that isomerization in the environment is not of major signifi-
cance but does add to the overall risk presented by lindane.
d. General Comments Submitted en Exposure Via
Accumulation in Human Adipose Tissue
Based on data in Position Document 1 (EPA 1977a) ,
Hooker Chemicals (30000/10 :=r42) argued that lindane does not accumulate in
human adipose tissue to hazardous levels. The registrant also argued that
the only apparent reasons for beta-3HC in human adipose tissue are that
large amounts of 3HC have been used in the U.S. in the past 25 years, that
residues of beta-3HC are still common in food, and that beta-3HC has a
greater tendency to store in human adipose tissue and has a greater half-
life in adipose tissue than other 3HC isomers.
The Agency has reviewed these comments (EPA 1978d).
According to data from EPA's Human Monitoring Programs for 1970 to 1974,
1.1 percent of samples analyzed showed lindane residues in human adipose
tissue averaging 0.1 ppm. The Agency points out that the importance of
these residues is their contribution to the total bodv burden of lindane.
11-41
-------
oi
roraulAtlon
(2?X ?-*pr»y«cj
*ir iprayari
iooa (raw crap; ijriyec
Low pr«»jur« li
p*ct! ipray&t
nyLlox*ra
a.OB* w/w in w«ear Vnan naadad Hand TUA praasvut
t Li/icra XirSiiat tprayar
Apply
Lew voiua* »or»y (iaclc
^tcx) «?pL^4C ts r-in
oii poi.ic
l ;»1. O.i» p«r '.0
-------
Table II-8. Exposure Data: Summary of Exposure Analysis — Use-by-Use
Use
Hardwood Lorj£
and Lumber
M
I
Assumptions Used in Analysis
Dermal
a) Seven ml of aqueous solution wet 2
averaye hands up to the wrist.
b) Total surface area of two hands = 0.082m*
c) Total skin area exposed (head, neck, and
hands) during operation = 0.294m2.
d) Operator is exposed to cumulative dose
equivalent to single wetting of all exposed
skin.
e) Lindane concentration in final
diluted mixture is 0.5'i (from labels).
Exposure Analysis
Estimation of Unit, Time & Exposure
Dermal
iiKj/hr
16
Respiratory
mg/hr
0.09
Exposure
Duration
hr/year
2000
Annual
Exposure
mg/year
D: 32,000*
Cohort
at
Risk
persons
2,400
R:
Respiratory
a) All surface areas surrounding dipping
vat are saturated with lindane.
b) Saturation vapor concentration of lindane
20°C - O.Sug/1.
c) Due to open air conditions, saturation
equilibrium is not reached.
d) lot lindane saturation represents best
estimate of air concentration.
e) Adult maJe breathing rate = 1.8 m /hr.
Calculations;
Dermal: 7 ml or 7 g mixture x 0.5%
x 0.294/0.082 = 0.125 g/day
or 16 mg/hr.
Respiratory: 0.5 ug/1 or 0.5 iug/m3 x 0.1
x 1.8 m3/hr = 0.09 mg/hr.
* I) = Dermal
* K - Respiratory
-------
Table TI-8. Exposure Data: Summary of Exposure Analysis — Use-by-Use (Cont.)
UtiC
i-t
M
I
Used in Analysis
Exposure Analysis
Estimation of Unit, Time & Exposure
Dermal Respiratory Exposure Annual
Cohort
at
Duration Exposure Risk
mg/hr
mg/hr
lir/year
ing/year persons
Seed treatment Dermal
Based on Hayes (1975):
a) One yram of lindane 25% dust formulation
can completely cover the hands (0.082m ).
b) Operator skin area exposed (head, neck,
and hands) - O.294m2.
c) Durincj iui.xi.mj operation only 20% of
1 i.ndane formulation reaches exposed skin.
Respiratory
Based on US-HEW (1974):
a) Average lindane formulation air
concentrations surrounding drill-box
rig = 10 mg/w .
b) Adult male breathing rate = 1.0 m^/hr.
c) Operator spends approximately 60
minutes per day mixing seed.
180
4.5
1.7
D: 306*
R: 7.7*
130,000
Calculations;
Dermal: 1 g x 25% x 0.294/0.002
x 20% = 100 rng/hr
Respiratory: 10 mg/m3 x 25% x 1.0 m3/hr = 4.5 mg/hr
Avucudou
Hased on Wolfe ot al. (1967):
a) Spraying operations for avocados
are identical to those for other fruit
orchards.
b) Reasonable values for calculating
dermal and respiratory exposures are 50 and
0.1 mg/hr, respectively (Wolfe et al., 1967).
c:) A single pest control operator treats
one average avocado farm in one day, twice a
year.
50
0.1
16
D: 000*
R: 1.6*
* D =- Dei mo I
A R - Kesp i fatory
-------
Table I.l-G. Exposure Data; Summary of Exposure Analysis -- Use-by-Use (Corit.)
Use
Assumptions Used in Analysis
Exposure Analysis
Ornamentals
Cummer cia.'L
App L icators
Homeowners
M
M
Based on Wolfe et al. (1974):
a) Mean dermal and respiratory exposure
levels are 3.6 and 0.021 mg/hr, respectively,
as determined for ferithion spray solutions
containing 0.06% a.i. and assumes 1 hr workday.
b) A 0.5% w/w lindane solution is used.
c) A commercial applicator works 3-8 hours
a day for 1-15 days per year.
d) A homeowner sprays only one hour per year.
Estimation of Unit,
Dermal Respiratory
mg/hr mq/hr
30 0.2
r
Calculations :
Dermal: 3.6 mg/hr x
Respiratory: 0.021 n
Time & Exposure
Exposure
Duration
hr/year
3-120
1
0.5
0.06 = Jl
0
nq/hr x
y 0
Cohort
Annual at
Exposure Risk
mq/year
D: 90-
3600*
R: 0.5-
22*
D: 30*
R: 0.18*
.5
.06
persons
30-1200
75,000
mg/hr
Ciicurbi ts
Based on Staiff et al. (1975):
a) Mean dermal and respiratory exposure
levels are 0.4 and 0.001 mg/hr, respectively,
as determined for paraquat solutions contain-
ing 0.025 w/w a.i. applied at 100 gal/acre.
b) Spray-diluted lindane mixture contains •
453 g of lindane in 200 gal. water per acre
(0.06% w/w).
1.9
0.005
Calculations:
2.45
Dermal: 0.4 mg/hr x
Respiratory: 0.001 mg/hr x
D: 4.7
R: 0.01
950
0.06 200
x = 1-9 mg/hr
0.025 100
0.06
0.025 100
200
x = 0.005 mg/hr
* D = Dermal
* It =-
piratory
-------
Table It-0. Exposure Data: Sumiuairy of Exposure Analysis — Use-by-Use (Cont.)
Use
Assumptions Used in Analysis
Exposure Analysis
Christmas Trees
(Stump--:} I ash
and trunk)
i-1
I
.F-
based on Wolfe et al. (1974) :
a) Spray particle size distribution is
similar to that involved in fenthion
treatment using direct spray for mosquito
control.
b) Mean dermal and respiratory exposure
levels are 3.6 and 0.021 imj/hr, respectively,
as determined for fenthion spray solutions
containing 0.06% a.i.
c) There is a seasonal correction factor
of 0.32 clue to reduction of body surface
area exposed during stump-slash treatment
in early spring.
d) Use dilution is 0.5% w/w for stump/slash
and 0.05 for trunk.
Estimation of Unit,
Dermal
mg/hr
9.6
(iitump-
slash)
3.0
(trunk)
Respiratory
mg/hr
0.2
(stump-slash)
0.02
(trunk)
Time & Exposure Cohort
Exposure
Duration
hr/year
9 D:
R:
D:
R:
Annual at .
Exposure Risk
my/year persons
07 10,000**
(stump) *
1.8 (stump)*
27 (trunk)*
0.2 (trunk)*
Calculations;
Dermal: 3.6 mg/hr x
3.6 mg/hr x
Respiratory:
0.5
0.06
0.05
0.06
0.021 mg/hr x
x 0.32 = 9.6 mg/hr (stump-
slash)
- = 3.0 mg/hr (trunk)
0.5
0.06
= 0.2
(Foliar)
based on Hatchelor and Walker (1954) :
a) Spray particle size distribution is
similar to that involved in hand-gun
pressure spraying of fruit orchards with
parathion.
b) Mean dermal and respiratory levels are
56 and 0.2 mg/hr, respectively, as deter-
mined for parathion spray solutions contain-
ing O.OVt, a.i.
c) Use dilution of the lindane spray is
O.OIU a.i.
90
0.3
Calculations ;
Dermal: 56 mg/hr x
0.08
„ QC
D: 010*
R: 2.7*
= 90 mg/hr
Respiratory: 0.2 mg/hr x ' =0.3 mg/hr
* I) - Dermal
* l( - Ku:;pi ratory
**Tol.cil estimated applicators, all application modes.
-------
Use
Pecan Orchards
n
1-4
I
-i i
Table II-O. Exposure Data: Summary of Exposure Analysis — Use-by-Use (Cont.)
Assumptions Used in Analysis
Based on Wolfe et al. (1967):
a) Spraying operations for pecan trees
are identical to those for other fruit
orchards.
b) Reasonable values for calculating
dermal and respiratory exposures are 50 and
0.1 mg/hr, respectively.
c) A single pest control, operator treats
one average pecan farm in one day, once a
year.
Exposure Analysis
Estimation of Unit, Time & Exposure Cohort
Dermal Respiratory Exposure Annual at
Duration Exposure Risk
ing/hr
50
mg/hr
0.1
hr/year
mg/year persons
7.9
D: 395*
R: 0.8*
1200
* I) ^ Dermal
* l< - Respiratory
-------
Table II-O. Exposure Data: Summary of Exposure Analysis — Use-by-Use (Cont.)
M
I
*-
CO
use
forestry
.ivestock
Assumptions Used in Analysis
Based on Wolfe et al. (1974):
a) Mean dermal and respiratory exposure
level of 3.6 and 0.021 mg/hr, respectively,
as determined for fenthion spray solutions
containing 0.06% a.i.
b) Use dilution for lindane is 0.5% a.i.
c) Applicators treat 32 trees per day,
5 minutes each tree, 30 days a year.
Based on Wolfe et al. (1974):
a) Operator exposure in dipping operations
is negligible compared with spray operations.
b) Mean dermal and respiratory exposure
levels are 3.6 and 0.021 mg/hr, respectively,
as determined for fenthion spray solutions
containing 0.06% a.i.
c) Use dilution is 0.045% a.i. for lindane.
Exposure Analysis
Estimation of Unit, Time & Exposure Cohort
Dermal Respiratory Exposure Annual at
Duration Exposure Risk
mg/hr
mg/lir
hr/year
mq/year persons
30
0.2
80.1 0: 2400* 1000
R: 16*
Calculations:
Dermal: 3.6 mg/hr x
0.5
0.06
= 30 mg/hr
Respiratory: 0.021 x °'5 =02 mq/hr
0.06 y
2.7
0.02 Beef 2.09 D: 5.6*
R: 0.04*
Pigs 2.39 D: 6.5*
R: 0.04*
Calculations;
Dermal: 3.6 mg/hr x
Respiratory: 0.021 x
.045 _
.06
0.04 5
0.06
2.7 mg/hr
= 0.016 mg/hr
30,000
210,000
* D = Dermal
* 1< - Respiratory
-------
Table 11-8. Exposure Data: Suimnary of Exposure Analysis — Use-by-Use (Cont.)
Use
Structures
Applicators
M
I
Residents
Assumptions Used in Analysis
Based on Batchelor and Walker (1954):
a) Dermal and respiratory exposures are
56 and 0.2 mg/hr, respectively, as determined
tor parathion spray solutions containing
0.05'i a. i.
b) Spraying time is one hour per home.
c) A dilution of 0.5% lindane w/w is used.
d) It is estimated that between 500-1,000
applicators treat 10,000 homes, that it
takes one hour to treat one home, and that
this is done 10-20 days per year.
Baaed on USPHS Communicable Disease Center
(1952):
a) Dermal exposure is negligible.
b) An 05-day weighted average concentration
of l.indane in the air of a treated room is
estimated to be 0.05 ug/1.
c) A dilution factor of 0.5 for diffusion
into untreated second story living space.
d) A 1.2 mVlir breathing rate.
e) Occupants are exposed 24 hours per day
for 04 days per year.
* D - Del-mill
* l< - Kuspiratory
Exposure Analysis
Estimation of Unit, Time S Exposure Cohort
Dermal Respiratory Exposure Annual at
Duration Exposure Risk
mg/hr
mg/hr
hr/year
mg/year persons
560
Calculations:
10-20 D: 5600-
11,200*
R: 20-40*
0.5
Dermal: 56 mg/hr x Q '„,- = 560 mg/hr
0.5
U . -*
Respiratory: 0,2 mg/hr x Q Q^ = 2 mg/hr
0.03
2016
R: 60*
Calculations;
Respiratory: 0.05 ug/1 x 0.5 x 1.2 m3/hr
x 1000 1/m3 =0.03 mg/hr
500-1000
10,000
(houses)
-------
Table 11-0. Exposure Data: Summary of Exposure Analysis — Use-by-Use (Cout.)
Assumptions Used in Analysis
Exposure Analysis
I'i i
M
I
ui
o
Based on Severn (1970):
a) There is no dermal exposure.
b) Low concentrations of pesticide vapors
above soil surface are directly proportional
to their vapor pressures.
c) Inhalation exposure of pineapple workers
to DiiCP was estimated to be 13 ucj/hr.
d) l.indane vapor pressure = 3 X 10~5mm llg at
20°C; that of DUCP = 0.8 mm llg at 21°C.
e) A 11-hour work day, once a year, is assumed.
Estimation of Unit, Time G Exposure
Dermal
mg/hr
Respiratory Exposure
Duration
mg/hr hr/year
4.9 X 10~7 14
Calculations :
Respiratory: 13 ug/hr x 3.0 x
4.9 x 10~7 mg/hr
Annual
Exposure
mg/year
6.9 X 10~6
10~5/.0 =
Cohort
at
Risk
persons
1600
-------
Table II-O. Exposure Data: Summary of Exposure Analysis — Use-by-Use (ConU.)
Use
Assumptions Used in Analysis
Exposure Analysis
Estimation of Unit, Time & Exposure
Dermal
mcj/hr
Respiratory
mg/hr
Exposure
Duration
hr/year
Annual
Exposure
my/year
Cohort
at
Risk
persons
L'ets
Pet Collars
a) I.indanc is released at a constant rate
for 6-Q weeks.
b) Lindane is incorporated into collar, not
on surface; total dermal contact by human
handling is negligible and unquantifiable.
c) Data for 5% a.i. DDVP (Shell Chemical
Company 1976) incorporated into cat collars
can be extrapolated for lindane. The
concentration of DDVP in the air of a room
housing one animal wearing one 5% collar is
0.35 ug/m3.
d) There is no difference in the volatility
of lindane and DDVP.
e) There is a dilution factor of 1.0 to
account for the difference between the study
area (40 in ) and a standard living area (480 m )
t) Use formulation is O.Glt a.i. lindane.
g) Sedentary breathing rate = 1.2 nr/hr.
h) A person would be exposed 24 hours per day,.
365 days per year.
5.1 X 10
-6
0760
R: 0.045* ND**
Calculations;
Respiratory:
0.35 ug/ni x 0.61%/5.0% x .1 x
1.2 in3/hr = 0.0051 ug/hr =
5.1 X 10~6 mg/hr
U - Respiratory
*"* ND - Not Detennined
-------
Table II-8. Exposure Data: Summary of Exposure Analysis — Use-by-Use (Cont.)
Use
Assumptions Used in Analysis
Exposure Analysis
Estimation of Unit, Time t, Exposure
Dermal
mg/hr
Respiratory
mg/hr
Exposure
Duration
hr/year
Annual
Exposure
mcj/year
Cohort
at
Risk
persons
M
I
Ul
Dog Welsh
Veterinarians
a) A veterinarian exposes both hands to
dilute product 5 in in. day, 26 times a year.
b) Final formula density = 0.85 g/ml at
10'i w/w liudane, cone. = O.OQ5 g lindane/ml,
o) 1 ml of solution can "just wet" hands.
d) Mo respiratory exposure occurs.
0.14 - 2.17 D: 0.3* 130,000
Calculations;
Dermal: 8 oz x 29.57 ml/oz x 0.005 cj/ml x
1/22.5 gal. x 1 gal./37Q5 ml x 7 ml x
1000 mg/g x 5 min./60 min. =0.14 mg/hr.
Owners a) No dermal exposure for owners occurs.
(I'o:.;!-- b) Animal has access to area with volume of
treatment 12,OOO ft3.
exposure) c) Hue of. lindane is 0.236 my/ml of final
solution for post wasli exposure.
d) After towel drying, 79 ml of wash
solution is retained by small dog; 237 ml
by large dog.
e) When a dog is washed, there is exposure
for 72 hours, once a year.
f) Assumed dilution factor of 10 for air
exchange.
g) Assumed breathing rate = 1.2 in /hr.
8.9 x 10 5 72
(small dog)**
2.7 x 10"*
(large dog)**
D: 8.9 x 10 5-
Calculations;
Respiratory
(Post Wash):
2.7 x 10
-4*
79 ml x 0.236 mg/ml x 1/12,000
X 0.034316 ft3/! x 1.2 m3/hr x
0.1 = 1.3 x 10
-4
mg/hr.
15,000,000
A 11 - Dernidl
AA I'<>:;l.--Wiish respiratory exposure
-------
Table II-Q. Exposure Data: Summary of Exposure Analysis — Use-by-Use (Cont.)
Use
Assumptions Used in Analysis
Exposure Analysis
Estimation of Unit, Time & Exposure Cohort
Dermal Respiratory Exposure Annual at
Duration Exposure Risk
mg/hr
mg/hr
hr/year
mcj/year persons
Dog ShampOG
Appli cators
t-t
I
Ul
Kes i dents
(I'ost-
exposure)
a) Concentrate comes in direct contact with
shampooer' s hands.
b) Per washing, total volume of 15 ml soap
comes in contact with hands.
c) Contact time of concentrate with hand is
3 seconds, then 0.5% solution is diluted
with water used to wet dog's hair (assumed
to be 1/2 pint) and contact time with
"diluted" soap is 5 min./dog wash.
d) 7 ml "just wet" hands.
e) There is no respiratory exposure during
shampooing procedure.
f) Iiindane transfers to oily layer of dog's
pelt.
a) 15 ml (375 ug) of a 0.5% lindane
formulation is retained by small dog;
45 ml (1115 ug) by large dog.
b) Animal has access to area with volume
ot 12,000 ft3.
c) Assumed breathing rate = 1.2 m /hr.
d) 7 ml "just wet" hands.
e) Lindane volatizes for 72 hours after
treatment; 26 treatments per year.
23.0 - 2.2 D: 51.4* ND**
Calculations;
Dermal: 0.5 g/100 ml x 15 ml x 10 mg/g x
1/265 ml x 7 ml x 60 min/5 min = 23.8 mg/hr
1.0 x 10~5
(small dog)
5.3 x 10~5
(large dog)
1072
R: 0.034-0.1*
Calculations:
375 ucj/12,000 ft3 x 0.034316 ft3/! x
Respiratory . ..
(small dog): 1.2 m3/hr x 1000 1/m3 x 1/72 x
1 mg/1000 ug = 1.8 x 10~5 mg/hr
* U - Dermal
* i< - Respiratory
**ND - Nut Determined
-------
Table II-O. Exposure Data: Sununary of Exposure Analysis — Use-by-lJse (Coat.)
Use
Assumptions Used in Analysis
Exposure Analysis
Estimation of Unit, Time & Exposure Cohort
Dermal Respiratory Exposure Annual at
Duration Exposure Risk
HRj/hr
mg/hr
hr/year
iiui/ycar persons
Duat
Appl i caters
M
i
Ul
Kes idents
(I'ost-
treatmeiit
exposure)
a) Total lindane (1% dust) formulation
contacting skin represents 20% of maximum
amount that would cover exposed skin area
intentionally dipped in lindane dust
(1 y fine powder needed to completely
cover 1 pair of hands, or 0.00 m^) .
b) Maximum dust inhaled over 2 minute
treatment period is 10 nuj/m-5.
c) All "dust" is respirable size
(10 u or less).
d) 0.294 m^ is the area of exposed
skin from neck, head, hands and fore-
arms. Area of hands is 0.00 i«2 _
e) A treatment takes 2 minutes and is
repeated every two weeks for the entire
year, i.e. 26 treatments.
f) V.inclaiie will volatilize at a steady
rate tor 3 days, at which time all lindane
will, have vaporised.
a) The assumptions used for docj wash,
resident respiratory exposure, apply
to exposure to dcxj dust.
b) A typical, pet requires 2 oz (56 g)
of iv powder per treatment.
c) There is no dermal exposure.
d) A resident would be exposed 12 hours
per day, for 3 days per treatment,
26 t iiueu a year.
220.5
0.12
0.87
D: 191*
R: 0.1*
ND* *
Calculations;
Dermal: 1 g/0.08 m2 x 0.294 m2 x 0.01 x 1000 mg/g x
0.2 x 60 min/2 min = 220.5 mg/hr
Respiratory: 10 mg/m3 x 1.2 m3/hr x 0.01 = 0.12 mcj/hr
0.0027
Calculations:
U: 2.53*
ND**
Respiratory:
56 g x 0.01 x 103 mg/g x 1/72 x
1/12,000 ft3 x 0.034316 ft3/! x
1.2 m3/hr x 1000 1/m3 x 0.1 =
0.0027 niy/hr
* I) - Dei.mil I
* i< -; Respiratory
**HD -- Nol Di.:term.inet.i
-------
Table II-B. Exposure Data: Sununary of Exposure Analysis — Use-by-Use (Cont.)
Household Uses
Shelf I'aper
t-i
M
I
ui
ui
Assumptions Used in Analysis
Exposure Analysis
Estimation of Unit, Time & Exposure Cohort
Dermal Respiratory Exposure Annual. at
Duration Exposure Risk
nuj/hr
nig/hr
hr/year
ing/year persons
a) Inhalation is primary route of exposure.
b) After 105 days, 40% of the lindane will
have vaporised.
c) A 12-foot roll of shelf paper containing
15 mg lindane per ft2 of paper is used to
treat three 4X4X0 meter rooms.
d) Assume a 1.2 m3/hr breathing rate.
e) Assume no dermal exposure.
0.002
2520
R: 5*
11,000,000
Calculations:
Respiratory:
15 mg/ft2 x 0.4 x 12 ft2 x l/3a4m3
1/105 x 1.2 m3/hr = 0.002 mg/hr
Floor W<:ix a) One pound of wax treats 800 ft 17 times
per year.
b) Lindane will dissipate from waxed surfaces
totally over a 3 week period.
c) The air exchange is assumed to be 0.33 per
hour due to outside ai.r infiltration in a
12,000 ft3 house.
d) I'er treatment, 2770 mg lindane is applied,
which is equal to 4.5 mg/hr evaporation
rate.
t;) Assume no dermal exposure.
f) Assume a 1.2 m /hr breathing rate.
0.01
0760 R: 08*
100,000,000
Calculations:
Respiratory:
4.5 mg/12,000 ftj x 0.66 x
0.034316 ft3/! x 1.2 m3/hr x
1000 1/m3 = 0.01 mg/hr
K - Kuspi ral.ory
-------
Household
n
I-H
I
(It
O\
I'umi gali on
Devices
Table II-U. Exposure Data: Summary of Exposure Analysis — Use-by-Use (Cont.)
Assumptions Used in Analysis
a) A coarse spray (0.11 w/w lindane) has
O.Ol'-t particles between 40 and 60 microns,
and 0.1% between 40 and 100 microns, with
95% of spray being deposited on surfaces.
b) A 12,000 ft3 house will have 12 02
applied over 5 minutes, once a year.
c) Assume no dermal exposure.
d) Assume a breathing rate of 1.2 m3/hr.
(based on WAUf Institute Inc., 1970:
Average air concentration is 0.014 ug/1 on
a year round basis (26 applications per year)
Exposure Analysis
Estimation of Unit, Time & Exposure Cohort
Dermal
mg/hr
Respiratory
mg/hr
0.0001
Exposure
Duration
hr/year
0 . 08 R :
Annual at
Exposure Risk
mg/year persons
1.0 x 10~5* ND**
Calculations:
Respiratory:
12 fl oz x 0.001 x 29.6 ml/fl 02
x 0.001 x 1000 mcj/ml x 1/12,000 ft3
x 0.034316 ft3/! x 1.2 m3/hr x
1000 1/m3 x 5 min/60 min = 0.0001 mg/hr
0.017
Calculations:
8760 R: 149*
NU**
Respiratory: 0.014 ug/1 x 1.2 m3/hour x 1000 I/in3 x
1 nig/1000 ug = 0.017 mg/hr
* I; - Kciipi iratory
**MD =- Hot Determined
-------
Tahiti :iJ-B. Exposure Data; Summary of Exposure Analysis — Use-by-Use (Cont.)
Assumptions Used in Analysis
Exposure Analysis
Estimation of Unit, Time & Exposure Cohort
Dermal Respiratory Exposure Annual at
Duration Exposure Ri.sk
mcj/hr
mg/hr
hr/year
mg/ycar persons
Minor
Moth Spray -
Industrial Use
a) Applicators
M
I
Ul
Baaed on Gay et al. (1975):
a) Aerosol of 0.1% lindane produces 50%
of particles 10 microns or less and 50%
between 10 and 40 microns.
b) Ninety percent of spray impinges
on clothing and therefore is not
subject to inhalation.
c) Clothes are treated in well-ventilated
areas tor a 2 minute period at a time.
d) l.iudane concentrations in vicinity
of spray and at time of spray are similar
to those ot a 30'i Freon 12 formulation,
which was 44.25 ppm in the breathing zone.
e) All other components of the Freon 12
formulation behave in a similar manner,
but their air concentrations are directly
related to the concentration stated in
the Freon 12 formulation.
f) Spray repeated 26 times per year.
0.21 0.87 R: 0.18* NO**
Calculations;
Respiratory: 44.25 x 0.1/30 x 0.00119 mg/1 x
1.2 m3/hr x 1000 l/m3 x 0.1 = 0.21 mg/hr
b) Occupants
(l-out-
Trea tment
exposure to
Impregnated
M.i t e r i a 1 s)
a) Twenty-eight grams of 0.1% spray are
used every 2 weeks on a year-round basis.
b) vaporization rate is continuous over
2-week period, at which time all lindane
vapor i iced.
c) Effective volume of work space is
6000 ft3 infiltration from outside is
.33 times per hour.
d) Exposure is J.O hrs per day, 365 days
pur year.
3.8 x 10
-4
3650 R: 1.4*
Calculations:
Respiratory:
28g x 0.001 x 10 mg/g x 1/336 hr x
1/6000 ft2 x 0.034316 ft3/! x 1.2 m3/hr
x 1000 1/m3 x .66 = 3.8 x
1.0 4 mg/hr
*
**
rutory
Determined
-------
Use
Minor Uses (Cont.)
Insect Spray -
lln i nhabi ted
Iln i.ldi ngs
Table I.T-0. Exposure Data: Summary of. Exposure Analysis — Use-by-Use (Cont.)
Assumptions Used in Analysis
Exposure Analysis
Estimation of Unit, Time & Exposure
Dermal Respiratory
Exposure
Duration
Annual
Exposure
Cohort
at
Risk
mg/hr
mg/hr
hr/year
nig/year persons
a) A concentrate of 20% lindane is diluted
1/9 (2.2H.) and applied as an aerosol.
b) Treatment time is 2 minutes with no
secondary exposure 12 times a year.
c) Air concentration assumed to be
comparable as in Gay et al.,
1975: 44.25 ppm after a 2 minute spraying
with a 30% freon formulation.
d) The breathing rate is assumed to be
1.2 m:j/hr.
e) 1 ppm of lindane in air •- 0.0119 mg/1.
46.7
Calculations:
Respiratory:
.40
R = 18.7*
ND**
2.2/3O x 44.25 ppm x 0.0119 mg/l/ppm x
1.2 u.3/hr x 1000 1/m3 =46.7 mg/hr
CO
Empty Storage
Ui ii fog Spray
a) All applications made with fogging
machine.
b) Droplets all 40u or less.
c) Applicator exposed to residual airborn.
parti.cl.es, not to main fog cloud.
d) Applicator does not wear respirator
for overage exposure of 5 min./appl.
e) l-'ormulation density = 0.0 g/ml. =
6.7 Ibs/gal.
i) Application 1 per mo., year round.
g) A 0.5'i w/w lindane solution is used.
h) A dosage rate of a gallon per 10,000 ft .
i) Particle size distribution of "fog" is
in same order of magnitude as an aerially
applied fine pesticide aerosol.
62.6
R = 62.6'
ND**
Calculations;
Respiratory:
1 gal/10,000 ft3 x 0.034316 ft3/! x
6.7 Ib/gal x 454 g/lb x 0.5g/100g x
103 mg/ x 1.2 rn3/hr x 1000 1/m3 =
62.6 mg/hr
* l< -• Respiratory
** ND - Not; Determined
-------
e. General Comments Submitted on Work-Place Exposure
Paper Products, Inc. (30000/10: =M1A) submitted an
epidemiological study on 64 employees whose work involved the use of
lindane. Employees were divided into three groups according to years of
exposure, and into another three groups according to blood levels of total
BHC, including lindane. Sleven biochemical and eight hematological
examinations were carried out. The study reported no differences between
these groups of employees. The registrant argued that the study indicated
no adverse effects from lindane on liver functions and hematopoietic
systems of these workers.
The Agency does not disagree with the conclusions that
no effects were noted. However, the limited population observed and extent
of parameters measured dictate that the probability of noting an adverse
effect would be negligible. Therefore, this study is decidedly not ade-
quate to demonstrate that workers exposed to lindane experience no adverse
effects to the liver or the hematopoietic system.
3. Dietary Sxposure; Agency Determinations
For purposes of determining exposure to lindane from
residues on food, the Agency has used data showing lindane residues
calculated for 12 composite food categories from the FDA market basket
(total diet) survey during the period 1971 to 1976 (SPA 1973e) . Table II-6
shows the average lindane residue in each composite category, and the daily
intake of lindane from this average in mg/1.94 kg diet. The total of the
average daily exposure for all 12 food categories was then converted to
mg/kg body weight per day for an average adult consuming 1.94 kg focd/day.
The calculations shown in Table II-6 derive from actual
residues and according to the Agency's best determination represent a
reasonable estimate of dietary exposure. It should be pointed out, how-
ever, that average daily dietary exposure is likely to be somewhat higher
for children than for adults. This would be due to 1) the relatively high
residues of lindane in dairy products as compared to other food categories
(Table II-6), and 2) the relatively high proportion of dairy products in
the diets of young children.
4. Applicator and Homeowner/Householder/Occupant Sxposure;
Agency Determinations
The Agency has prepared estimates of dermal and respiratory
exposure for those uses of lindane which are under review. Following the
Agency's policy of making cautious and prudent assumptions in the face of
-------
the uncertainties which, given current methodologies, 'underlie exposure and
risk calculations, these estimates are based on worst-case assumptions
about actual use practices. Wherever possible, actual exposures are in-
cluded in the calculations. Table II-7 shows representative formulations
together with uicd.es and recommended rates of applications. Agency calcu-
lations are based on representative formulations- Table 11-3 is a summary
of the Agency's exposure analysis of lindane, use by use; assumptions and
calculations (60-kg adult weight assumption) are included. Assumptions are
Agency-generated unless specifically designated otherwise. The following
Subsections (a) through (n) briefly outline information pertinent to the
assumptions proceeded upon for each use.
a. Applicator Exposure: Hardwood Logs and Lumber
The U.S. Department of Agriculture (30000/10:£49)
submitted a description of three commonly used methods of BHC application
in sawmills. Since lindane has replaced BHC in sawmills, the three methods
now apply to lindane use: 1) Green chain dip vat, wherein freshly sawed
boards are completely immersed prior to stacking; 2) green chain spray,
wherein the lumber is conveyed through a spray booth equipped with a low-
pressure spray system; and 3) lumber package dip vat, wherein stacked
lumber is immersed into a dip vat, then allowed to drain. These procedures
take place in a covered but open plant, with workers assisting in guiding,
pulling, and stacking the lumber. The USDA states that workers who handle
treated lumber are provided with rubber gloves, aprons or.rain suits, and
boots. If these items were used exactly as prescribed, little dermal
exposure would result (EPA 1978d). However, subsequent inspection of some
sites by SPA revealed that not all workers wore this protective gear, and
not all gloves were impermeable to lindane. The Agency has calculated
exposure for head, neck, and hands. It is assumed that the general surface
areas surrounding the vats are saturated with lindane, and inhalation
exposure results from vaporization peaking at a 10-percent lindane air
concentration. Yearly exposure is assumed to be 3 hours per day, 250 days
per year.
b. Applicator Exposure: Seed Treatment
This analysis is based on a typical formulation con-
taining 25 percent lindane. The Agency has assumed that dermal and inhala-
tion exposures from barrel treatment and seed drill-box rigs will be about
equal. Exposure in these situations would be from air-borne dust generated
during pouring of lindane powder and stirring of seed-powder mixtures,
whether by hand or mechanically. The Agency has assumed also that seed
treaters do not wear respirators or protective clothing,and that r.o more
than 1.7 hours oer dav is soent at this oceration.
11-60
-------
c. Applicator Exposure: Avocados
A lindane concentrate is diluted to a 0.04 percent
weight-to-warer (w/w) solution and applied as a spray to control infesta-
tion of avocado trees in Florida. Two applications are made at a 6-week
interval. The Agency assumes that a single applicator treats one grove in
a day, twice per year. Both dermal and respiratory exposures are antici-
pated.
d. Applicator and Homeowner Exposure; Ornamentals
Lindane sprays are used by homeowners and commercial
nursery workers, usually as a dilution (0.5 percent w/w lindane in solvent)
of a 20-percent lindane formulation. Hand-held hydraulic or compressed-air
sprayersare used. Use patterns vary greatly and the range of possible expo-
sures varies with duration of spraying time and with the number of applica-
tions per season. It is assumed that the applicator wears no protective
clothing, gloves, or respirator (worst-case scenario).
Concerning homeowners, it was assumed that a homeowner
expends one hour applying one pound of the formulation per year.
For commercial application it is assumed that 3600
acres are treated by a manpower force ranging from 30 to 1200 persons per
year. Exposure time ranges from 3 to 120 hours per year per person. The
extremes of this range are thought to be unlikely, but an average exposure
time is not known.
e. Applicator Exposure; Cucurbits
For this analysis, the Agency has selected a typical
formulation which contains 25 percent lindane diluted to a 0.06 w/w
(lindane to water) spray, applied by a row crop boom sprayer. Three to
four applications are cade per season, and an applicator is thought to be
exposed for 0.7 hours per application.
f. Applicator Exposure: Christmas Trees
Back-pack sprayers or handgun pressure sprayers are
used to apply lindane solutions (0.05 percent to 0.5 percent w/w lindane in
water) to Christmas trees and freshly cut stumps during winter, early
spring, or summer for several pest control measures. Several application
methods are used, with foliar treatments resulting in higher exposure than
stump or trunk treatments. No exact numbers cf applicators or applications
for each use can be calculated because the pests and usage situations vary
greatly. There are approximately 10,000 private Christmas tree growers
throughout the United States, and the exposures per grower will be con-
sidered averages of total lindane usage. Since use practices and ambient
temperature during treatment will vary greatly, the Agency has calculated
an exposure range derived from a combination of the three main modes of
11-61
-------
use. The exposure and risk are expressed as a range between the extremes
predicted for these uses. This should include most patterns of use and
variations.
g. Applicator Exposure: Pecan Orchards
Lindane is used in a single-spray application to
foliage with a groiind airblast sprayer. A typical formulation of 12.5
percent lindane is diluted to a 0.05 percent w/w lindane in water spray. A
single pest-control worker can treat one average farm in one day (approxi-
mately 8 hours), once per year. There are approximately 1200 pecan farmers
in the United States, and we assume all use this procedure and each does
his own spray operation. It is assumed that no protective clothing,
gloves, or respirator are used.
h. Applicator Exposure; Forestry
Lindane is used in emergency conditions to spot-treat
insect infestation sites. Large areas are not ordinarily covered by any
single application, and the total use of lindane for controlling forest
insect pests is about 4,000 pounds a.i. per year. A 0.5 percent (w/w of
emulsified lindane in water) solution, diluted frcm a 20 percent formula-
tion, is applied to the back of infested trees as a low-volume spray (back
pack) to the point of run-off. The exposure analysis and risk calculations
assume that no protective clothing, gloves,or respirator are used. However
the Agency is aware that the U.S. Forest Service enforces its requirements
for protective garb and safe-handling procedures. Use practices by applica-
tors not employed by the Forest Service are less predictable. It is esti-
mated that one operator could work at this operation for 30 days per year.
i. Applicator Exposure: Livestock
As an emulsion, lindane is applied as a pressurized
spray or dip .to farm animals. Treatment periods vary with labels, but
treatments can be repeated as frequently as every two weeks. Considering
geography and climate, range of pest to be controlled, etc., it is reason-
able to conclude that no more than nine such applications would be done per
annum. The emulsions are 2 percent and 25 percent concentrates diluted
in water for the dip or spray. For purposes of this analysis, the Agency
has selected a formulation which yields a final spray solution of 0.045
percent w/wlindane in water (EPA 1978e]. It is assumed that the operator
wears no protective clothing, gloves, or respirator. Exposure estimates
herein were calculated for spray application to swine, where exposure rates
are highest. Exposure to dip vat operators is considered to be less than
this due co the different operation procedure. In aany cases, a lindane-
toxaphene mixture is used for these applications, in which case the lindane
excosure would be one half to one third that calculated here.
11-62
-------
The assumptions in this use profile represent a. worst-
case estimate for body surface exposed, concentrations used, and exposures
per annum. An applicator is assumed to be exposed for about 2 hours per
year in the actual spraying procedure.
j. Applicator and Occupant Exposure: Structures
A lindane emulsifiable concentrate (0.5 percent w/w
lindane in water) diluted from a 20-percent lindane formulation is applied
with a paint brush along small areas or applied with a coarse spray for
large areas. An estimated 10,000 houses are treated per year.
For the applicator, both dermal and inhalation exposure
are assumed to be relevant during the 1-hour application time. It is
assumed that an average pest control operator treats between 10 and 20
homes per year.For home occupants, only inhalation exposure is anticipated.
Terminix International (30000/10 : s26) argued that
exposure to humans and non-target organisms is almost non-existent since
lindane is retained in the wood under-structure where it is applied. The
registrant also stated, "Because lindane is water based this also reduces
its vaporization and dispersal into non-target areas," The Agency believes
that lindane is more volatile than the registrant suggests. Lindane's
vapor pressure at 30 C is 1«3.x 10 mmHg, compared to DDT at 7.3 x
10" and dieldrin at 9.9 x 10 (EPA 1978d). Data supplied by the CDC
report are considered more definitive than the assumptions suggested by
this registrant.
k. Applicator Exposure: Pineapples
Registration for use of lindane on pineapples is
presently restricted to the state of Hawaii (ZPA 1978e). In this use,
lindane is injected into the soil with a fumigant before planting. Based
on an exposure analysis for a similar use of DBCP, the Agency assumes that
the primary route of exposure is by inhalation, and that at the low concen-
trations of pesticide applied, vapor concentration levels in air above soil
will be a direct function of the vapor pressure, regardless of the relative
mole fraction of the pesticide applied to the soil. After the lindane is
injected, the field is covered with a plastic mulch. Potential for
exposure depends on duties performed (equipment operator, mulch operator,
or supervisor) during an assumed 14-hour working day. However, the
anticipated hourly exposure associated with any of these functions is very
saall (approximately 5 X 10 mg/hr).
1. Applicator and Householder Sxposura: Pets
(1) Pet Anti-Flea Collars
For this analysis, the Agency has selected a
typical formulation containing 0.61 percent lindane and assumed a dilution
factor of 10 (£PA 197Se). The Agency has extrapolated from Shell Chemical
11-53
-------
Company (1976) data on 5 percent DDVP incorporated into cat collars.
According to label directions, collars are effective for 6-3 weeks. A
constant release rate during this period is assumed in connection with
inhalation exposure. Because the lindane is incorporated into the collar
rather than on the surface, dermal exposure via handling the collar is
considered negligible.
(2) Dog Wash (Veterinary Use)
For this analysis, the Agency has selected a
typical formulation containing 10 percent lindane (final use concentration
is 0.085 gm lindane/ml) (EPA 1973e). The Agency assumes that a veterinary
technician would treat 10 dogs per day, exposing both hands (unprotected)
for 5 minutes during each dipping application. Inhalation exposure during
this treatment period was not considered to be significant.
The Agency also considered post-treatment inhala-
tion exposure to dog owners from lindane volatilized from the treated ani-
mals. The Agency assumed that the estimated residue would volatilize
completely within three days, during which time the dog would be in common
residence with the owner (SPA, 1978e). It is conceivable that some lindane
may contact human skin if the animal is handled. This would be a highly
variable and extremely small exposure. Absorption rates from brief contact
would also be extremely small. However, even minimal exposure to and
absorption by children must be viewed with extreme caution. The Agency has
no data by which to gauge acceptable margins of safety for children.
(3) Dog Shampoo
For this analysis, the Agency has selected a typic-
al formulation containing 0.5 percent w/w lindane in an oil soap base (EPA
1978e). The Agency assumes that the concentrated product will directly
contact the shampcoer's hands for 3 seconds, that a total of 15 ml soap
will contact the hands during each washing, that the 0.5 percent concen-
trate will be diluted with one-half pint water, and that hands are in this
diluted soap for 5 minutes during each washing. This procedure is repeated
25 times per year.
The Agency also examined post-treatment inhalation
exposure to dog owners from lindane volatilized from dogs washed with the
above formulation.
(4) Oog Dust
Animals are dusted with a one-percent lindane dust
by hand application. The Agency assumes that 26 applications are made per
year and residents are exposed to the animal 50 percent of the day post-
application. Dermal exposure estimates were made for the treatment pericds
and inhalation exposure estimates were mace for the immediate post-
application period when lindane would volatilize from the animal's pelt
(EPA I973e) .
11-04
-------
m. Applicator Exposure; Household Uses
(1) Shelf Paper
Lindane-impregnated shelf paper is registered for
use in non-food areas such as chests, drawers, closets, and storage areas.
It is estimated that four and one-half million rolls of shelf paper are
sold per year. The Agency assumes two rolls per year are used per house-
hold, and therefore that two and one-quarter million households per annum
contain the product.
The human contact time, during which the paper is
spread onto the desired area is very brief, and the Agency does not con-
sider this dermal exposure significant. The primary route of exposure is
inhalation of the vaporized lindane. The Agency assumes that 40 percent of
the lindane will be released over a 105-day period at a constant rate.
Three registrants, Millen Industries (30000/
10:#7A), Paper Products (30000/10:341), and Athena Corporation (30000/
10:?f18A), submitted a total of five comments on exposure from lindane-
treated shel paper (ZPA 1978d). The comments dealt in general with expo-
sure through food stored on treated shelf paper, and with lindane air con-
centrations from shelf paper in enclosed areas. None of these comments
were pertinent to the Agency exposure analysis, which determined that the
primary route of exposure from this product would be from_inhalation of
vapors in open areas (SPA 1978e.)
(2) Floor Wax
A solvent-based floor wax, laced with lindane (0.5
percent w/w) is used on various floor coverings at normal maintenance inter-
vals (2-3 weeks). Application methods vary considerably.
Dermal exposure from application is anticipated
but could not be estimated due to variation in application methods. Dermal
exposure after application is also possible, especially for children. How-
ever, this highly variable situation also disallows a reasonable estimate
of exposure.
The Agency assumes that the significant exposure
mode will be due to respiration of the lindane vapors for three weeks after
wax is applied to the floor.
(3) General Purpose Household'Spray
A 0.1-percent lindane spray, formulated in
petroleum distillate is registered for use in homes in surfaces of beds,
carpets, draperies, etc. The spray produces particles about 40 microns
size and 95 percent of the sorav volume deoosits on surfaces (2?A 1973e) •
11-65
-------
Contact with the sprayed surface could possibly
result in some dermal exposure, but because of the varied nature and
extremely varied surface areas (and types of surfaces) involved, calcula-
tion of dermal exposure is not possible. However, for most situations,
dermal contact is likely to be insignificant (e.g. curtains, carpets,
etc.). In some cases, the dermal contact may be relevant (crib mattresses,
rugs in homes of small children), but defensible estimates cannot be.made.
The Agency assumes that 12 ounces of spray will be applied in a home
(volume of 12,000ft ) and the airborne particles will be evenly distri-
buted throughout the home, and will have an effective longevity of 5
minutes.
(4) Smoke-fumigation Devices
These devices, variously termed fumigators, smoke
generators, "bug-tabs," "moth-clouds," etc. produce over a very short time
period either a smoke, fume, or fog of lindane with or without associated
non-volatile particulates such as carbon. The purpose of the device is to
produce a super-saturated suspension and/or vapor of lindane in an enclosed
space.
Typical formulations for this use contain 2.3
percent to 20 percent lindane, and maximum vapor concentration varies from
0.4 to 1.9 mg/ft (average of 0.3 mg/ft ) [EPA 1978e]. The Agency
assumes that treatments will be biweekly all year.
Grain -storage bins, greenhouse, household areas,
etc. are treated. Label directions instruct to clear the area of house-
hold pets and persons. Since it is assumed that persons are not in the
area during fumigation, dermal exposure should not occur. Estimates of
exposure due to contact of material"' after application cannot be made,
although such exposure may occur.
The Agency assumes that the major exposure mode
would be via respiration of residual vapor in the household er.vironment
during the 2-week post-application period. It is important to note that
lindane is absorbed onto the surface of many materials during vaporizer
use. Exposure is therefore continuous as lindane is revolatized from these
surfaces. A study by the U.S. Public Health Service demonstrated that 20%
of the lindane residues initially deposited on painted walls during
vaporizer use were present in these surfaces after 179 days (E?A, 197Se).
Continental Chemiste Corporation (30000/10:419)
submitted data by WAJIF (1970) to determine the amount of lir.dar.e deposited
on food left exposed during smoke-fumigation. (Leaving food and eating
utensils exposed during use is against label directions.) The Agency
points out that the principal route of exposure to lindane from this
product is through inhalation. Nevertheless, using the registrant's
figures, the Agency has determined that a 60-kg person who eats from a
10-inch dinner plate the day after treatment with the registrant's product
could be exposed to 0.1153 me lindane, or 15 percent cf the acceptable
daily intake (Memo 1978c)
TT-66
-------
ToUl t» I l-O. Lu t liRdttut AI»I>! icutoi" Cx|H»iiure. I'l outmL Hue Pracl. Ice a
Duli.ial lluui>liatoiy_
(onj/lir) |m,|/lli)
11.10
ll.ii ilw.i.i.l t.uiiitxir 16 0.09
Ui»:il •ITualmuilt Illll 4.5
ftvocu.tiiu 50 O.I
Oi uninciit a 1 u
llomc.iwiioiu 30 U.IB
Ci,.i...,ui ,;lal 10 O.IU
<:ii.:iul,ltu 1.9 0.005
i-l
|-| Cl.i lul III..L, li.:ou 3-90 0.02-0.)
1
°'t ' fu.:.lli Oi.:ll..r.lo 50 O.I
O>
fin out ly JO 0.2
I.I vi.nl ...jk 2.7 11.02
Hi i nut ur i:u
A|.|.l Ic-uluru 560 2
()t:.:.i|,»iil.ii - 0.01
IM..., /,,.,,!. ,u - 4.9 M Id
I'llt Illl.tU
f.lt C.lll.l.u - 5.1 M 10 '
IIOIJ Uliul>
f.,.,.1 l.:nliii a 0.14
1'i.ul - A|>|>! lnnl.l'iil - U.'J x 10
2.7 x 10 "*
III /.lay imj/oUy*
Ouriaat lluu|*l f 0toi'y
U 127.8 0.72
1.7 306 7.U
U 402 0.6
1 10 0.18
J-U 90-240 0.54-1.44
0.7 • 0.12 0.0036
II 24-1140 0. 111-30
7.9 VJ(i 0.6
2.67 7.8 0.6
2.1-2.4 5.4-6.6 0.06
1 55.8 I.U
24 - 0.72
14 - 6.6 x 10~6
24 - 1.2 x 10~2
O.OU'I 1.2 x 10
24 - 2.16 x 10" -
6.6 x 10*
tluy/yr
250
1
2
1
1-15
3.5
1.2
'
30
1
10-20
U4
1
365
26
3
ilKj/yr*
Dei'uidl ll«iU|>l t'atory
11,950 IUO
1U6 7.U
004 1.2
10 O.IH
90-1.600 0.54-21.6
0.42 0.0126
2U.8-I.OOU 0.216-36
196 0.6
214 IU
5.4-6.6 0.06
55U-I.1I6 IU-36
60. 4U
6.6 x 10~6
4.3U
O.OJI2
6.40 x 10.
1.911 K 10
nl h *lc i i»n\ tiii'l i'mi|il i a I ory
-------
Table 11-9. Estimated Applicator Txpoiiuru, Proliant Use Practices (Cont.)
Ol
Durinal Haupl ratqry
(m.j/lir) (aig/hr) •
UbU
l)oy bhuiupin)
Appl IcaLoru 23.8
I'oiit-Appllcatloii - 1.8 x 10 -
5.3 x 10
l)0(J Duut
Appllcatoru 220.5 0.12
l-oiiU-Appl loatlon - 0.0027
UOtlUiillOld tlllOll
iilmll: 1M>|.ur - 0.002
floor Wax - 0.01
llotiucliol'i ijpray - 0-0001
I'n:. ilij.it Ion Uovlcea - 0.017
Minor tluu^
H.Lli ripcay,
Inaiuitrlal Uuu
b|>i-ay - 0.21
lm|,L'.!.jiiaLed Materlala - 3.6 X 10~
llr/day
0.083
24
0.03
12
24
24
0.08
24
0.03
10
nig/day*
Durmal Respiratory
1.90
4.32 x Ifl" -
1.27 x 10"
6.6 3.6 x 10~3
3.24 x 10"
4.8 x 10"
0.24
7.8 X 10~6
0.408
0.066
3.6 x 10
day/yr
26
78
27
78
105
365
1
365
26
365
mq/yr*
Durutal Ruuplratory
51.40
3.37 x 10 j -
9.92 x 10~
170.2 9.72 x 10~S
2.53
5.04
87.6
5.0 x 10~6
148.92
1.716
1.314
liul 1 Jli
46.7
0.03
1.38
\
12
16.56
62.6
0.08
4.98
12
59.76
* Loth tluruial and respiratory
\
-------
Tal>le II-IU. Total Uoily flouuu (Apfil Icdtora) , Preutmt Hue 1'iactlccu
Ilin! ll.jlm.il II|.lnk
limuial piij/klratory nnj/kq/tlay*
0.012
0.130
0.01
0.003
O.dO'J-0.24
6 x I0~5
0.027-0.04
0.01
0.01
1 x I0~i|
1 x 10"
0.03
0.012
Total
mty/k<|/tiay
0.225
0. 181
0.68
0.053
0. 159-0.424
0.00226
0.067-1.24
0.6U
0.14
0.01
0.012
0.96
0.012
Annual Total
m,i/|( u/yr
56. 3
0. IUI
1.35
0.053
0. IS9-0.424
0.000
O.OU-1.5
0.60
4.2
0.01
0.012
9.6-19.2
1.000
>ij Wauli
A|>|>! I..-ill in o lilt
I'l>ul-A|i|il Ic.l-
tlon
2 K 10
-5
I.I x 10
-7
I.U M 10
-6
3.6 x 10
I. x 10
-5
-4
l.t x 10
-7
I.H X 10
-6
3.6 x 10
1.1 x 10
1.1 X 10
6.6 x 10
-7
5 x 10
2.8 x 10
0.4 x 10
-4
-3
-3
Illllt i'<:ii|»I i at.oi y uptake nautiinuil
-------
TnMo 11-10. Total Ibxly lioaun (A|>1>1 Icatoru) , finunut Duo Practlcun (Cunt.)
llunujl ll^l nkel
A,.,.I li.al u 10\
I'oul -A|t|kl l«:at Ion -
llaHjii ral.ofy in<|/k<|/l ll u\n ay,
1 " I II.1.1.ill l.ll lino
M.I 1 tt r 1 a 1 u
6.0 X 10
1.1 X 10
6 x 10~5
-4
6.0 x 10
-1
1.1 x 10
6 x 10~5
-4
2.5
2.7 x 10
-1
2.) x 10
— 2
ll.ll l.llll.JH
0.0 J7
0.017
0.4
Ki»|il y SI »M tt»)d
III it to'i :ii»i .1 y
O.I2U
0 . 1 211
1.5
'Illllt lu,,i|il i ..< .u y ii|.t ,>ko duuil
-------
absorption of lindane from liquid formulations is tsn percent, and one
percent frcm dry formulations (Gross, 1978). Total body dose calculations
for each use of lindane under review are summarized in Table 11-10. In
lieu of any information on oral, or inhalation absorption, the Agency will
assume 100 percent uptake of ingested or inhaled lindane (Gross, 1973).
C. Risk Assessment
Based on the exposure levels calculated for each use of lindane
under review (Subsection II.3), the Agency has evaluated the degree of risk
for carcinogenicity, fetotoxic effects, and acute and subacute central
nervous system effects (SPA 1978g).
Because the Agency did not perform a quantitative exposure analy-
sis for all the numerous minor uses of lindane, no quantitative risk assess-
ment could be performed for minor uses other than those which are specific-
ally under review. The Agency believes, however, thatsince there will be
some level of exposure, however small, from these various 'uses, there will
also be some corresponding risk to the users of these products. In addi-
tion, the Agency points out that, even though exposure to, and risk from,
these minor uses may be small, their importance is in their contribution to
the total body burden of lindane in the general population.
The succeeding subsections address the Agency's risk assessment
of lindane in terms of 1) carcinogenicity, 2) fetotoxic 'effects, and 3)
acute and subacute central nervous system effects.
1. Risk; Carcinocenicity
The Agency has extrapolated estimates of the carcinogenic
risk from lindane exposure using the one-hit or exponential model with no
assumed threshold.— This model is used by the Agency in various
forms for nearly all of its carcinogenic risk assessments. Admittedly,
these risk extrapolations involve many uncertainties. Among those
extrapolations which most subject the estimates to error are the high-dose'
animal to low-dose human conversions. Others are dose rate effect and the
actual human exposure.
The following statement, published by the Interagency
Regulatory Liaison Group (IRLG), is representative of the Agency's stance
in the face of the uncertainties involved in quantitative cancer risk •
assessments:
Despite the uncertainties, risk estimates can be and are being
made, not only by some regulatory agencies but by other scien-
tific bodies. Because of the uncertainties, however, and because
157
— Another estimate of r^sk was also developed, but tr.is one used
the log-probit ^odel. The estimates frcm this nodal are being
reviewed by the Agency's GAG and will be discussed in ?0 4.
-------
of the serious public health consequences if the estimated risk
were understated, it has become common practice to make cautious
and prudent assumptions wherever they are needed to conduct a
risk assessment. This approach has a precedent in other areas
because of gaps in knowledge. Thus current methodologies, which
permit only crude estimates of human risk, are designed to avoid
understatement of the risk. It must be recognized, however, that
in some circumstances this cannot be guaranteed because of other
factors that may enhance human response, such as synergistic
effects. Thus risk assessments should be used with caution in
the regulatory process.
With the present state of knowledge, the quantitative assessment
of cancer risks provides only a rough estimate of the magnitude
of the cancer risks; this estimate may be useful in setting
priorities for control of carcinogens and in obtaining a very
rough idea of the magnitude of the public health problem posed by
a given carcinogen.—
Multi-test evidence indicates that lincane causes oncogenic
effects in mice. (Refer to Subsection II. A.I.) For purposes of extrapo-
lating use-by-use estimates of the cancer risk posed by lindane to humans,
the Agency has chosen to use the results of Thorpe and Walker (1973). This
study was selected because the number of animals with tumors in both males
and females was significantly above the respective controls, because the
number of animals with tumors were comparable in each sex', and because the
experiment had an extremely low ? (pool) value (<10 ). The Agency has
little doubt that lindane is carcinogenic to mice at the doses used in this
experiment (SPA, 1979).
Estimated cancer risks for each use of lindane under review
are.given in Table 11-11. Dietary cancer risks are estimated at 1.7 :c
10 or roughly 17 tumors per million people. The dietary risk is
additive to other risks (e.g., applicator, residential) posed from exposure
to lindane from other sources.
2. Risk; Fetotoxic Effects
The Agency's risk assessment of the reproductive and feto-
toxic effects of lindane has necessarily focused on fetotoxic effects. The
Agency was unable to perform a quantitative risk assessment of the general
reproductive effects of the pesticide based on available data. Fetotoxic
risk to humans has been evaluated by comparing the no observable effect
level (NOEL) in animal studies with the highest estimated daily acute expo-
sure for each use. The resulting ratios are referred to as margins of
safety (MOS) and represent crude measures of risk to exposed populations.
— Quoted from IXLG, "Scientific 3ases for Identification of
Potential Carcinogens and Estimation of Risks," 44 ?3 39853, 39S71-72
(5 July 1979 ).
-------
l.li; 11-11. yumm.ny
of Applicator Itli.k, 1'ruseiit Hue I'
Cancer Probability
Kel'ol.ox Ic 1 ty (teneral Acute Toxlclty
II:..: Mar.jin of U.ifety Itil.jin of Safety
ll.ii dwood Lumber 22 11
;;.:<:. 1 Tl ,:..! U..:I.C 211 14
Avocado (iioveu / 4
1 . l|,.i,,..',»m.:i Use '34 47
I?. r,.i,m,<;i<:i dl Hie 31-12 16-6
C.iciu 1,11 u 2,500 1,250
clirisiiu.iu Treeti 75-4 37-2
l'.-«:.ui:i 7 4
M l-'..i .::.! . y 3C. 1U
1 I.I v.::.l •„ K (Spi.iy bip)
-' II.:. :t 500 250
4~* r.iik 4 If. 208
SI 1 in: tin e:~>
1 . li.l.ubll .,nl :, 4lb 3
.'.. Applicator:! 5 3
i-ine.ippl.suV 4.5 x I07 2.3xl07
I't-l :.
1. !'.:! .llHi-l|.:.i collars JxlO° 1.4x10^
'.'. . h,..| U.,:.li
.1) Appl ic.il ..i :; 2.5xlo'' 1.3xll'|5-
L) |M:.t-Ap|>l Icut lull 1 . .Ixlll^-'l. 5x 1O 0. 7x1 0^-2. 2x1 04
I'.at lluate
Lifetime Kluk'
2.CxlO"2
U.3xlO~S
6.2x10-4
2.4xlO"5
7.3x10-5 to 2.9xlO~J
4.1xlO'6
3.7xlo"5_5 .QxlO"4
3.1xlO-4
5.0xlO-&
4.GxlO"4
4.4xlO"3 to U.llxltt"
io-)2
2xl()~4
2.4xlO"7
7.0x10"°
1'eruonu
240O
130.OOO
275
75,000
30-1200
'J50
10,000 Creat variation
1200
1000 Anticipated to U;
male workers
250,000
10,000-12,000
40,000 luMiseu: all a.je
500-1000 yroiipu ex|.oaed
1601)
III)**
130,000
15,OUO,UOO
(:lvt:ii i lie exi i <:n>e I Y lil.jli iuui<|in^ i*f ui.it'ety tor thi: thre^liolil efftji:!.^ of fototox iol ty and acute toxicity,
i ho A,|i:nuy .;,:.ii;i t.l.ii-:, llie pi eiiumpt Ion cm plneuppleu i..l>iLl(,| for the:le two effects.
-------
Tnhlo 11-11. Siui|ii|4(y A.uuuuuinui>i of A|'(>1 Iculor Illak, I'cuuunt Uuo I'ultuiiio (Cent.)
Concur l'tol>ul>i Illy
Kuloloxlclly Cultural Acule Toxic Illy estimate
Margin i>f_Saf£l-y ^iii'ji"_i;£ .Salijty l.ttutliuu Hlak*
KalIwdloJ I
I'craoim
liuiiiaika
I.) ro:>t-A|>|>l loollon
4. IK,i) final
u) Ain'l l*:atoi:
lit |-oal.-A|.|>l Icutlou
llotiuultol*! IJunu
I . SI.elf I'.ll.uC
I6,b66
J.040
Ui.OOO
'J,260
6,l)OO
U.lll
41.666
4.6)0
l.OUO
3.6x10
2xUr6
1.5x10
J.'JxlO
lll>"
Mil"
III)4'
Illi'4
11,000.000 Ml a.ju ycouou
l. flooi 11. .M
625
6.1x10
IOO.OOO.OOO All &UUO
lloil^oliolil lj|iidy
).li«10
7
C.OulO
-4
ll|>*
All tliJU (JCUI103
Ul
•t. tiiuoku fliiul'JBtloi
ItoV I CUU
~HM
I'Jd
l.lxlO
Illi* * Ant lol |>4l feit
laof llnou
I. li..ltiul i I a I llau llol li ti|iioy
- A|i|>l Icnllou
4.5x1(1
-6
Z. Oiilnlu.l.ll c.l llul lillixjo
I . l-jnol y UloroiJO
III il l'*ol: UKjiOcmio Iky tltla IHO<|U.
Cui..:<)i Auouusiiiunt Hi oti|> (CM.) uul Inulu aiituiuluil 16 AiKjiiuL 1'JCJ.
Ilitlui fioiuo CM|M>UIII'U auo«uti|it I oitd may «1lttoi' oll'jlitly tuxu Llioqe ti
(lt(»:it en l<:ti I til. loua .
til
20
1.9xlo"
5.5MIO
"4
In tlio maojlil of oofcty
'«»*
I'CO only
'" iii> iini not
-------
It should be emphasized that, as with the cancer risk assess-
ment of lindane, considerable uncertainty surrounds the assessment of fate-
toxic risk. The anticipated adverse effects of a pesticide vary with the
extent of exposure associated with its various uses, and the Agency has
necessarily made cautious and prudent assumptions concerning exposure.
(Refer to Subsection II.3., "Exposure Analysis.") Because current methodo-
logies permit only rough estimates of human risk and because of the serious
public health consequences if the estimated risk were understated, it is
likewise Agency practice to use the most conservative results from the
animal data in making risk estimates for the human population.
Although fetotoxic effects are considered a chronic human
risk, it should be pointed out that fetotoxicity can result from a single
exposure. Hence the Agency is concerned about possible cases of both acute
or subchronic exposure to pregnant women.— The Agency's focus of
concern is on the potential injury to the fetus resulting from the mother1s
exposure to lindane, whether such injury occurs in either the presence or
in the absence of toxic signs in the mother. The data on lindane indicate
that the pesticide has the potential to cause fetotoxic effects both in the
absence and in the presence of maternal toxicity at dose levels close to
human exposure levels. (Refer to Subsection II.A.2.)
Although Earl et al. (1973), which showed that lindane feed-
ing at both 7.5 and 15.0 significantly increased the proportion of still-
births to beagle dogs, stands unrebutted as evidence of the fatotoxic
effects of the pesticide, the study did not determine a NOEL and therefore
cannot be used as a basis on which to calculate margins of safety for feto-
toxic effects. On the basis of the following studies, however, the Agency
has been able to determine a NOEL of 5 mg/kg/day. Oral studies rather than
available studies using the subcutaneous route were selected for risk
assessment purposes because the oral route (g.avage) is that route which has
been historically and consistently used for risk evaluation, and the route
specifically identified as.the route of choice in the SPA Proposed Test
Guidelines (Subpart ?) . Dermal toxicology, when done, often appears to
exert excessive stress on a pregnant animal and poorly indicates the actual
dose absorbed.
a. Palmer and Loveil [1971 (confidential;unpublished)], an
oral fetotoxicity study involving femals specific pathogen free rats: NOEL
5 mg/kg/day.
b. Palmer and Neuff [1971 (confidential; unpublished)], an
oral fetotoxicity study involving Mew Zealand white rabbits: NOEL at least
5 mg/kg/day.
13'
—' In connection with the various uses of lindane on pets, the
Agency is also concerned about potential fetctoxic effects in cases of
exposure to pregnant animals.
-------
c. Bauer and Frohberg [1972 (confidential; unpublished)],
an oral fetotoxicity study on MRI r.ice: NOEL 30 tag/kg/day.
d. Xhera et al. (1979), a rat oral fetotoxicity study
using 50 percent formulation expressed as active ingredient:
NOEL 12. 5~ mg/kg/day.—'
At doses greater than 5 mg/kg, the major fetal effect was an
increase in, skeletal variations (extra ribs) as compared to controls. This
determination was complicated by the following two factors: (1) often the
percentage of fetuses having an extra rib was within a so-called normal
range of 3-41 percent (20 percent average) for CD rats, and 25-75 percent
(47 percent average) for New Zealand white rabbits;— (2) except in
Xhera et al. (1979), the litter was not used as the unit for statistical
analysis. Because of the possibility that a disproportionate number of
affected fetuses might belong to a single dam, the litter, rather than the
entire number of fetuses per dose level/ is the preferred unit for
analyses. Approximate margins of safety for fetotoxicity as calculated by
the Agency are presented, use by use/ in Table 11-11.
Given a total dietary exposure, under current use patterns,
of 0.003 mg/kg/day, dietary risk of fetotoxic effects is estimated in terms
of an approximate margin of safety of 800,
3. Risk; Acute and Subacute Central Nervous System Sffects
Available studies in humans and in diverse species of ani-
mals (dogs, rats, rabbits, frogs, chickens) report notably parallel results
in connection with the acute and subacute toxic effects of lindane. [Refer
to Subsection II.A.4.c.(4) and Table II-5.] Lindane has been shown to have
an affinity for the fat-rich (white) nerve tissue, where it accumulates and
causes symptoms of acute and subacute poisoning which are typical of cen-
tral nervous system (CHS) stimulation. Actual symptoms correlate closely
with theoretical mechanisms as well as aecnanisms observed in vitro in
various nerve types. Laboratory and epidemiological evidence has been
reinforced by clinical findings (including tissue residue analyses) in
conjunction with the recent death of a two-and one-half month old infant
—/ Palmer -and Lcvall (1971), ?aliner and Neuff (1971), and Bauer
and Frohberg (1972) were submitted by Hooker Chemicals during the
rebuttal period. (Refer to Table II-3.) Xhera et al. (1979), an
additional study discovered and reviewed by the Agency during the
rebuttal period, is addressed in Subsection II.A.2.f above.
20/ -
— Palmer, A.X. Sporadic Mai formations in Laboratory Animals
and their Influence on Drug Testing Advances. E;
-------
who had been treated for scabies with a commercial lindane product. A 110
ppb concentration of lindane ^3 .the child's brain was established as the
most probable cause of death.—
Symptoms in animals appear in the following order: 1)
increased respiratory rats, 2) restlesness, 3) intermittent muscle spasma,
4) salivation, 5) disequilibrium, o) convulsions, 7) collapse, and 8)
death. Symptoms of acute poisoning in humans are similar to those dis-
played in laboratory animals and occur in this order: 1) dizziness, 2)
headache, 3) nausea and vcmiting, 4) diarrhea, 5) tremors, 5) weakness, 7)
convulsions, 3) dyspnea, 9) cyanosis, and 10) circulatory collapse.
3ased on Hayes (1963), the Agency has determined an approxi-
mate no observable effect level (NOEL) in adult humans of 2.5 tag/kg/day.
To recapitulate, Hayes observed the following results when 100 percent
gamma isomer (lindane) was tested in humans: 0.66 mg/kg/day x 14 days—no
effect: 2.3 mg/kg/day x 3 days—no effect: 3 mg/kg/day repeated—dizziness
and diarrhea after several days. These findings correlate closely with the
reported findings of Desi (1974), in which dosages of 2.5 mg/kg/day adminis-
tered to Wistar rats induced no pathological effects but triggered in-
creased irritability as measured in performance tests.
A NOEL of 2.5 mg/kg/day for adult humans is inevitably a
rough approximation, and the following points should be emphasized:
a. Effects at low dosage levels may be reversible.
b. Subtle, sub-symptomatic effects may occur below 2.5
mg/kg/day, and these changes could affect the functional efficiency of
nerve transmission.
c. Among adults there may be a high degree of variation
in sensitivity to the CMS effects of lindane.
d. Sensitivity in the young may be considerably greater
than that of adults (Hanig at al., 1976).
Thus a NOEL of 2.5 mg/kg/day may well be underrepresentative
for certain subgroups of the population, especially children, who might be
particularly sensitive to the toxic effects of lindane.— It should
be pointed out also that workers whose functions call for a high degree of
— Other lindane-related deaths have been reported, but only in
connection with this recent instance were the results of tissue
analyses available. [Refer to Subsection II.A.4 above and Hayes
(1963).]
22 /
— In connection with the various pet uses of lindane, the Agency
is also concerned about the potential acute effects of lindane to
young animals.
-------
nerve-motor coordination might experience decreased efficiency at unspeci-
fiable doses below 2.5 mg/kg/day.:i—
Acute and subacute CNS risk to humans has been evaluated by
comparing a 2.5 ng/kg/day NOEL with the highest estimated daily acute expo-
sure for each use of lindane. The resultant margins of safety (MOS) repre-
sent rough measures of risk to exposed adult populations. (See Table
11-11.) 3ased on available data, specific margins of safety for children
could not be calculated but are likely to be considerably lower than those
estimated for adults.
Given a total dietary exposure, under current use patterns,
of 0.003 mg/kg/day, dietary risks of CNS effects are estimated in terms of
an approximate margin of safety of 1600.
23/ ?or the pineapple use, the margin of safety for acute and fetotoxic
effects is sufficiently high (2.3 x 10 ) and (4.5 x 10*),
respectively, that the possibility of adverse effects and acute and
fetotoxic effects is extremely slight. Under Agency regulations, a
presumption for an acute effect may be rebutted when it is shown
that the pesticide "when considered with the formulations,
packaging, method of use, and proposed restrictions on and
directions for use and widespread and commonly recognized practices
of use, the anticipated exposure to an applicator or user and to
local, regional or national populations of nontarget organisms is
not likely to result in any significant acute adverse effects"
[subsection 162.11(a)(iii)(4)(i)]. A chronic effect presumption
such as fetotoxicity may be rebutted "when considered with the
proposed restrictions on use and widespread and commonly recognized
practices of use, the pesticide will r.ot concentrate, persist or
accrue to levels in man or the environment likely to result in any
significant chronic effects" [subsection 162.11(a)(4)(ii)]. In
view of the exceptionally high margin of safety for the acute and
fetotoxic effects for pineapples, the rebuttable presumption
against registration for these effects on the pineapple use has
been rebutted.
-------
III. BENEFIT ANALYSIS
A. Introduction
Material presented in this section is based primarily on an in-
depth Preliminary Benefit Analysis of Lindar.e (PSA) (EPA 1978f); it is not
based on an alternative version prepared by USDA in October, 1979. The
approach taken in this joint EPA/USDA effort was to evaluate the.economic
benefits of lindane in terns of the economic impacts which would result if
lindane uses yere cancelled, and users were forced to employ available
alternatives.— Economic impacts were calculated at the user level on
a use-by-use basis. Impacts at the commodity and consumer levels were then
projected, where appropriate. The analysis was based on the most recent
data available (1975-1977). Estimated impacts are expressed in 1977
dollars. However, data on the extent of pest problems and pest control
methods are exceedingly limited. This necessitated a number of assumptions
in connection with the potential total effects of cancelling lindane.
Therefore the estimates are rough approximations and subject to revision if
data become available.
As Table III-1 shovs , three uses account for 87 percent of an
approximate total of 901,000 to 937,000 pounds of lindane used each year in
the U.S.: seed treatment (48 percent), hardwood lumber (22 percent), and
livestock (17 percent). The major economic impact from the cancellation of
lindane would fall in the hardwood logs and lumber industry. A major
impact is possible in connection with lindane seed treatment, but data
limitations have precluded any assessment in quantified terms. Moderate
impacts are estimated for the ornamental, cucurbit, and Florida avocado
industries. In general, minor impacts are projected in the forestry and
Christmas tree industries, although individual growers could experience
major impacts. All other users, including livestock farmers, would
experience only minor economic impacts. Should all uses of lindane be
cancelled, total quantifiable yearly impacts are estimated at 5181,000,000.
The projected major and minor impacts derive primarily frcm a
lack of adequate alternatives to lindane. For some uses, there are no
known alternative control methods for the target pests. For some other
uses, the alternatives are reported to be ineffective or to affect product
quality.
3. Underlying Assumptions and Limitations
In addition to specific limitations noted in the individual
analyses presented in the subsections below, certain general limitations
wera common to all analyses of lindane uses. These are as follows:
1. Published data or experimental results identifying yield
changes were generally unavailable. Therefore, expert opinions of
knowledgeable persons familiar with lindane use served as the bases of
economic impacts.
2. Published data specifying alternate insect control
strategies for each use were unavailable. Expert opinion was used to
Generate imcacts of alternate control strateaies.
Alternatives were identifies
frcm lists cf EPA-racistered testicices
ill
T-l
-------
Table 1II-1. Summary of Benefit Analysis
Extent of Use Availability
A.I. pounds Treatment Units ot" Economic
list: Sil.e .mil (M* (II Units) Alternatives
Hardwood 200,000 3,365,705,000 None
l.umli.ji (22t) board ft
Seed -126,000 13,01)9,000 acres None for
'IY.JU Lmen t (-Ib'-t) small grains; small
(sm.iU. 3,000,000 acres grains;
gra.inu corn several for
and coi:i>) corn
Avo.--a.los 7,000 7,000 acres Hone for
(I1-*.) mi. rids;
1-1 several for
, webbing
IXJ worm
Orn.imentals 17,000 3,630 acres Mo alterna-
(cuiiiniiii.-c ia 1 (2'i) tives for
cind hous»i-- most pests
hold ns<::i)
Cni;nr:l)i t;s 11,000 11,600 acres Alternatives
( 1 t) exi st witli
varying
levels of
efficacy
Clir i st mas Unknown llnknovyfi Chemical
Trues alternative
l:or white
pine weevils
only; cul-
tural alter-
nfiti ves not
evaluated
Economic
Extent
Nature ($/year)
Yield S $147,020,000
quality
loss
Yield Not
loss for quantifiable
small except for
grains, corn
lentils, ($690,000)
and dry
peas
Yield B, 700, 000
and
quali ty
loss
Produc- 20,600,000
tion
cost in-
crease &
yield
loss
Produc- 176,000
tion cost
i ncrease
& yield
loss
Produc- Mot quanti-
t:ion fiable
cost In-
crease t
yield
loss
Impacts
Significance Social Community
Major
Possible major
impact for small
small grains,
lentils, and dry
peas; minor for
corn
Moderate Regional impact in
Florida
Moderate Regional impacts on
landscape configuration;
property losses to
homeowners
Minor
Major to Possible regional hired
some indi- labor impacts, parti-
vidual cularly in the Lake
growers; States
aggregate
impact not
estimated
Dm: to round.-d calculations, percentages add up to 99.6 percent total.
-------
Table III-l. Summary of Benefit Analysis (Cont.)
t-i
n
»-i
I
L.J
A
Use Si te
Pecans
Forestry
Livestock
Structures
P i iiucippl es
" "
Extent of Use
. I. pounds Treatment Units
and (%)* (II Units)
33,600 440,000 trees
(44,)
4 , 000 Unknown
(0.54)
140,000 - 20,122,000
1.76,000 head
(I'M)
1,000 10,000
(0.14) homes
19,000 9,650 acres
(24.)
Availability
of Economic
Alternatives
Alternatives
exist with
varying
efficacy
Alternatives
only partly
replace
lindane in
forest mcjmt
Alternatives
generally
available &
efficacious
Equally ef-
fective al-
ternatives
exist
None to
replace
i.ts role
in dual
treatments;
UDCP £, EDO.
offer some
anti-
symphylid
control.
Impacts
Economic
Extent
Nature ($/year) Significance Social Community
Produc- $1,374,000 Minor
tion
cost in-
crease &
yield
loss
Yield & Not quanti- Minor
quality fied
Produc— $1,003,000 Minor
tion
cost
increase
Possible Near zero Minor if Possible labor £
cost in- PCP is community impacts if
crease available there are multiple
adverse UPAK decisions
Yield $1,018,000 Minor Possible labor &
loss (4 years) community impacts if
there are multiple
adverse RPAR decisions
-------
Table III-l. Suimuary of Benefit Analysis (Cont.)
Impacts
Extent of Use
A.I. pounds Treatment Units
Us«j Site and Cl) * (II Units)
Pots 30,000 Unknown
(3'i)
I) Pel:
Col liiirs
2 ) 1 )o. j
Wash
3 ) 1 K >i |
•1)|KK)
Dust
Household 12,000 Unknoxvn
1 . Shell: (1'i)
P.I per
2. k'loor
Wax
Availability Economic
of Economic Extent
Alternatives Nature ($/year) Sicjnif icance Social Community
Several ef- Possible Near zero Minor
fective al- cost in-
ternatives crease
available
Several ef- Possible Near zero Minor
fective al- cost in-
ternatives crease
available
|-J 3. I Ion se-
ll Iml,I
I ..........
'1 . t'uiii i -
ij
-------
n
M
l-l
I
(Jl
U;jc SJ te
3 . Empty
Stor-
_ Table ITI-1. Summary of Uc:ne£it Analysis (Cont.)
Impacts
I2xtcnt of Ilao Availability
A.T. pounds 'I'rcatnujnt Uni.ts ot" Economic
and Ci)* (If Units) Alternatives Nature
Economic
Extent
($/year) Significance
Social Couununity
Bin
Fuij
SpTcl y
All
900,600
036,600
$180,868,000
-------
3. In cases of unknown insect activity levels, it was assumed
that infestations were more severe in climates known to be conducive to the
insect and less severe in inhospitable climates.
4. Because of the imprecise nature of the data used to
determine effects on yields and prices, the analysis fccused on direct
impacts to users. No attempt was made to quantify impacts beyond this
level.
C. Hardwood Logs and Lumber
1. Usace
Lindane, the gamma isomer of 3HC, is registered for control
of the following pests on logs and lumber: 1) bark beetles, including pine
bark beetles; 2) wood-boring insects, including wood-boring beetles,
flatheaded wood borers, round-headed wood borers, powderpost beetles,
lyctus beetles, and ambrosia beetles. The powder-post and lyctus beetles
are drywood pests only; the remainder attack logs and lumber only after the
moisture content falls below 48 percent.
SPA is at present allowing lindar.e to be substituted for
3HC, which has been cancelled, in products registered for use on logs and
lumber. Mill owners are currently phasing in lindane as a substitute for
BKC in their pest control programs. Due to the present changeover, actual
figures for lir.dane use are unavailable. It is assumed, however, that
lindane will entirely replace 3HC. Consequently, the figures given in
Table III-2 should be regarded as applicable to lindane per se, although
they are expressed in terns of both lindane and 3HC.
Data are unavailable on the extent to which lindane is
actually used to treat lumber in sawmills. The estimates given in Table
III-2 below have been developed by the Agency. The estimates presented do
not include usage on hardwood logs because no data are available.
Therefore, logs were not included in the benefit analysis. The remainder
of this section deals exclusively with lindane application to lumber .—
2. Alternative Methods of Control
No chemical controls other than lindane are registered for
acolication to green lumber to control ambrosia beetles or flatheaded and
roundheaded borers, which are the pests of main economic importance to the
hardwood sawmill industry. Copper naphthenate is registered to control
powderpost beetles on lumber. ?entachiorophenoi (?CP) is registered to
control3wood-bcring beetles on logs and pcwderpost and lyctus beetles on
lumber.—
2/ Hefer to ?3A (2?A 1973f), pp. 51-57.
2/ Pentachioroohenol is currentlv under RPA5. review.
III-o
-------
Table IIJ-2. Use (in Pounds) of Fortified UIIC and Gamma Isomer to Treat Green Hardwood Lumber - 1975
High Est imate Low Estimate Mean Estimate
Uegion of U.S. t'UIIC* Gamma Isoiner FBIIC Gamma Isomer FBIIC Gamma Isomer
North Central 201,700 04,700 02,200 34,500 142,000 59,600
t Northeast
South 373,900 157,000 284,900 119,600 329,400 130,300
Total
Eastern U.S. 575,700 241,700 367,000 154,200 471,400 190,000
^Fortified benzene hexachloride (FUI1C) contains approximately 42-43 percent gamma isomer.
a/ The range presented in Table TII-2 is based on the total
-"—
estimated volume of lumber treated.
b/ According to the Bureau of Census (1976), 97 percent of
hardwood produced i.n this country came from the Eastern U.S.
as comprised o£ two regions: 1) the northeast and north
central region (35 percent) and 2) the southern region (62
percent). As defined by the Bureau, the northeast and
north central region consists of Maine, New Hampshire,
Vermont, New York, New Jersey, Pennsylvania, Ohio, Indiana,
Illinois, Michigan, Wisconsin, Minnesota, Iowa, North
Dakota, Nebraska, and Kansas; the southern region consists
otr Delaware, Maryland, District of Columbia, Virginia, West
Virginia, North Carolina, South Carolina, Georgia, Florida,
Kentucky, Tennessee, Alabama, Mississippi, Arkansas,
Louisiana, Oklahoma, and Texas.
-------
For the most economically important hardwoods (oak,
gum, cottonwood, hickory, and elm), which constitute 65 percent of the
total hardwood production, there are no non-chemical control methods which
do not reduce the lumber quality to below marketable levels. For other
hardwoods, there are non-chemical methods including kiln-drying, and "snd-
racking" (rapid no-heat curing). End-racking produces warping and cracking
which severely reduces lumber quality. Kiln drying introduces a 10-15
percent deterioration to those species which can be kiln dried. Kiln
drying is most effective for northern hardwoods, principally maple, and is
generally less effective for southern hardwoods where the insect problem is
most severe. This coupled with the high cost of kilns makes this control
method impractical.
3. Economic. Impacts
According to the National Forest Products Association
(NFPA), the hardwood sawmill industry is characterized by snail family-
owned mills (NFPA, 1977). These mills are generally each capable of
producing 10,000,000 board feet of lumber annually.
Impacts from cancellation of lindane were estimated based on
production costs of $163 per 1,000 board feet, gross revenue of $193 per
1,000 board feet, and estimates of loss provided by the NFPA. These
impacts are shown in Table III-3.
Estimates of the total impact to the hardwood Industry
should lindane be cancelled are given in Table III-5. The impacts were
calculated from the average loss figures shown in Taile III-3 and the esti-
mates of total lumber treated with 3HC and lindane given in Table III-4.
The estimates are presented in terms of ranges as well as most likely
estimates.
Given the absence of chemical alternatives, and given the
infeasibility of the limited non-chemical alternatives, the eccnomic
Impacts experienced by the hardwood lumber industry are expected to be
substantial should lindane be cancelled.
D. Seea Treatment (Small Grains, Corn, Lentils, and Drv Peas)
1. Usace
Lindane is registered as a seed treatment for small grains
(wheat, barley, oats, and rye), corn, and ether crops such as sorghum and
a number of vegetables. Lindane is generally formulated in combination
with a fungicide and applied to the seed as a planter box treatment.—'
4/
- When plateless or air planters are used for corn, planter hex treat-
ments may become ineffective because of the loss of pesticide remaining
on the seed (3oce et ai., 1976). Air and piateless planters are ~ore
efficient than conventional plate planters. As the new air and piate-
less planters replace conventional planters, the acreage which could be
effectively slanted with olantar box seed treatments will diminish.
III-3
-------
Table Til- 3. Expected Values ($) V
I'er 1,000 Board Feet—
anc* Without Chemical Peat Control of Hardwood Lumber
H
M
H
1
Species— B1K
1U;<1 dak
Ucip Gum
Wi: i qhteii
Average
a/ Estimates
Expected Val
Lindaue or No Control
: Control Moderate Attack
194.00
153.00
190.00
were rounded
172.00
141.00
170.00
to the nearest
ue
No Control
Severe Attack
138.00
120.00
137.00
dollar.
Value
No Control
Moderate Attack
22.00
12.00
21.00
Loss
No Control
Severe Attack
55.00
33.00
54.00
b/ Species chosen were felt to be representative of all hardwood species.
-------
Table Tir-4. Estimated Lumber Treated by Region in U.S. - 1975.
M
l-t
M
1
l(c>j ion
Noi.'theast
ami North
Collt I'd 1
South
Lumber
Product ion
1000 bd. ft.
1,778,500
3,170,300
Estimated
% Lumber Treated
Min Max Mean
% % %
treated treated treated
33 81 57
64 84 74
Estimated Lumber
(1000 bd.
min max
586,900 1,440,600
2,034,100 2,669,800
Treated
ft.)
mean
1,01 3,700
2, 352,000
O
-------
Table Tl'I-5. Economic Dollar Impacts on the Sawmill Industry —'
a/
Per Average Mill Total Per Region Most Likely
Mini mum Maximum Minimum Maximum Total Impact
Northeast £, 119,027
North Central
South
Eastern U.S.
Total
154,526
306,001 21,168,900 54,244,000 21,168,900
395,966 49,113,900 125,851,100 125,851,100
70,282,700 180,095,200 147,020,000
a/ Hounded to the nearest $100.
-------
As a seed treatment, lindane is used to control wireworms, seedcom beetles,
and seedcom maggots, sporadic pests which cause non-germination of seeds
or weak seedlings. The treatments are made primarily as insurance against
potential damage and afford protection to the seed and ensure germination.
However, under high levels of soil pest infestation the seed treatment does
not protect newly emerged roots or shoots which are also subject to attack
by wireworms and additional pests.
As Table III-6 shows, approximately 426,000 pounds of
lindane are used annually for seed treatment. Of that total, about 31
percent is used to protect small grain seed from the wireworm complex, and
about 15 percent to protect corn seed from wireworms, seedcom maggots, and
seedcorn beetles. An additional 3 percent is applied to lentils and dry
peas. Because small grain (primarily wheat), corn, lentil, and dry pea
seed treatments comprise 99 percent of total lindane used for seed treat-
ment purposes, this analysis focuses on these applications. Approximately
13.1 million acres of small grains are planted with lindane treated seed
annually. Approximately 6.0 million acres representing 39 percent of North
Dakota small grain acreage and 1.3 million acres or 55 percent of the Idaho
small grain acreage are planted with lindane seed.
2. Alternative Methods of Control
Heptachlor is presently registered to control the same
spectrum of pests as lindane on small grains and corn.— , There are no
other viable registered alternatives to lindane for small grains. However,
viable alternatives are registered for seed treatment of corn. Diazir.on is
registered as a corn seed treatment to control seedcom maggots and seed-
corn beetles (and as a soil treatment to control wireworm). Chlorpyrifos
is registered as a seed treatment to control seedcorn maggots, but it is
not registered to control wireworms or seedcorn beetles. Other alternatives
to control the soil insect complex in com are available, but these are for
soil application (ore-plant) and not as seed treatments.
6/
3. Sfficacv of Lindane Seed Treatment and Alternatives—
The efficacy of lindane used a seed treatment has been demon-
strated in numerous studies and for a variety of crops including small
grains and com. Studies were conducted by: Dogger and Lilly (1949),
Hocking (1949), Cwen (1950), Slmore (1953), Kulash (1953), Frost, .Anderson
and Slmore (1954), Hastings and Cower. £1954), Ditman, Cox and Kantzss
(1955), Daniels (1955), Kulash and Monroe (1954 and 1955), Hoffmaster and
Mugent (1956), Lilly (1955), Xuiash (1956), Bowling (1957), Harvcod,
Mel sen and Talford (1957), Apple, Strong and Raffensparcer (1953), Long and
— The Tinal Order of the Administrator in the Chlordane/Heptachior
Cancellations (signed March 6, 1973) phases out this alternative, and
heptachlor use on barley, oats, wheat, rye, and corn will be cancelled
effective September 1, 1932.
6/ _ . .
— iccncmic data summarized in tr.is subsection r.avs ceen aeve_ocec
3UDolemental to the Preliminary Benefit .-.nalvsis of Lindane (?3A
-------
Table III-6. Estimated Annual Use of Lindane as a Seed Treatment,
by Crop - 1976.
Croo
Small Grains
Wheat
Barley, oats and rye
Corn
Lentils and dry peas
a/
Other crops-
Totals
Lindane A.I.
( Pounds )
344,400
(250,400)
(94,000)
64,300
11,000
5,900
425,600
Percent Used as a
Seed Treatment
81%
(59%)
(22%)
15%
3%
1%
100%
a/
— Includes dry beans, sorghum, sunflowers, sugar beets, and
vegetables .
-------
Lilly (1953 and 1959), and Bigger and Decker (1966). While the efficacy
data support the effectiveness of lindane seed treatments at low to
moderate levels of infestation, it has been shown that under heavy infesta-
tions of wireworms, wireworms not killed or repelled at planting time or
during germination, may ultimately reach sprouts or seedlings (Xulash,
1953).
One of the most recent studies was conducted in Washington
in 1977-1978. The study evaluated 20 different compounds as seed coatings
to dry land wheat for control of wireworas. Only three compounds provided
statistically significant increases in plant stand counts as compared to
the control. These were: lindane, chlordane, and heptachlor (Perkins and
Harwood, 1979) .
Agriculture Canada has submitted unpublished test data to
the Agency which evaluate the effectiveness of lindane seed treatments of
cereal grains and rape. The test data spanning 1952-1976 show the
effectiveness of lindane in reducing wireworm populations and improving
stand counts (3urrage, 1980).
4. Economic Impacts
Very little biological information is available which is
necessary to cuantitatively estimate the economic impacts of a lindane seed
treatment cancellation on small grains, lentils, and dry peas. Although
the efficacy of lindane in improving stand counts and reducing wireworm
damage has been quantitatively demonstrated, other critical information has
not been developed. Tor example, information relating stand counts to
yield losses is not available, nor is information relating yield losses
with varying intensity of wireworm infestations in relevant geographic
locations available. Data identifying the frequency of infestations
exceeding the economic thresholds for various crops in various locations ar=
not available, and data indicating the efficacy of lindane with varying
levels of pest infestation have not been developed.
The lack of biological data on small grains, lentils, and
dry peas has severely hampered economic impact analysis, since the expected
value of yield losses over time cannot be estimated and alternative
chemicals are not available to control the soil pests. Therefore, economic
impacts can only be qualitatively estimated for these crops. In the case
of com, chemical alternatives are available and expected yield losses can
be estimated; therefore quantitative economic estimates have been mace.
Corn '^
Lindane is applied to corn seed at a cost of approximately
SO.15 per acre— . Diazinon seed treatments can be substituted for
lindane seed treatments at a cost of approximately SO.20 per acre where
seedcorn beetles and seedcorn maggots are the pests requiring control. The
substitution of diazinon seed treatments for lindane seed treatments would
result in increased chemical costs of $190,000 annually on the 2.S million
acres of corn olantsd with lindane treated seed.
— iconcmic data siimmarized in this subsection nave been developed
sucolamentai to the Prelir.ir.arv Benefit .-.r.alvsis if Lindar.e (Z?A 1973 )
— All costs are in 1977 dollars.
-------
However, diazincn seed treatments do not effectively control
wireworm damage. It is estimated that approximately 1 million corn acres
or less are infested with wireworms annually. Most of this acreage is
currently treated with soil insecticides. It is estimated that
approximately 100,000 acres infested with wireworms would not be treated
with soil insecticides and would be infested with wireworms resulting in
yield losses. Yield losses are anticipated to average approximately 2
bushels per acre based on U.S. average corn yields of 93 bushels per acre
(1976-1978) and a 1966 study performed in Illinois where an average yield
increase of 2.2 percent was reported for the seed treated versus untreated
plots (Bigger and Decker, 1966).
Assuming corn prices of $2.50 per bushel, yield losses
combined with increased treatment costs would average approximately $5.05
per acre on the 100,000 wirewcrm infested acres. On the remaining 3.7
million acres increased costs of $0.05 per acre would be experienced.
Aggregated user costs for the cancellation of lindane on corn seed are
estimated at $690,000 per year. The level of production losses anticipated
(less than .003 percent) is not expected to result in economic impacts at
the market or consumer level.
Small grains
Growers are currently treating small grain seed with lindane
at costs ranging from approximately $.20 per acre for winter wheat to $.46
per acre for barley. Lindane is applied to protect the seed from wireworm
damage. There are no alternative chemicals available other than heptachlor
for wireworm control for small grains.
For the reasons described at the beginning of this Economic
Impacts section no quantitative analysis of impacts is possible. However,
the potential for impacts can be described qualitatively. Should lindane
be cancelled, economic impac-s would most likely fall into two patterns :
a. Fields planted without pesticides and damaged by pest
infestations might be replanted if timing and other environmental factors
were favorable. The estimated cost of replanting an acre of wheat is
about $12.00, including machine operation, labor, and seed. Replanted
fields may also experience yield losses because of insects and less
favorable germination and growing periods; the frequency and damage of
these losses cannot be determined.
b. Insecticidal treatments would not be made and sporadic
yield losses would result, but for any of a variety of reasons, the damaged
area would not be replanted (the frequency and magnitude cf these losses
cannot be determined).
111-15
-------
These two outcomes point to a potential for economic impacts
en small grains currently planted with lindane-treated seed. Of the
grains, spring-planted small grains could be seriously affected, and this
would be felt most severely in North Dakota, Idaho, and Minnesota, where
wireworm infestations are most severe and where 50 percent of spring-
planted grains are grown. An estimated 12-percent of U.S. small grain
acreage is planted with lindane-treated seed; however, as much as 30
percent of U.S. spring wheat acreage is planted with treated seed. In
North Dakota and Idaho 30 percent and 55 percent of the small grain acreages
are with lindane-treated seed, respectively. Should lindane be
cancelled, and should extensive wireworm damage result, major regional
impacts are possible for spring-planted small grains at the user level. If
significant production losses were to occur, cancellation could also result
in potentially major spring-planted small grain market level impacts. The
Agency has not found nor have data been submitted to estimate the likelihood
or magnitude of this occurrence.
Lentils and Dry Peas
Approximately 3 percent of lindane seed treatment formula-
tions are applied to lentils and dry peas, crops which are commercially
produced only in Idaho and Washington. About 35 percent of lentil acreage
and 100 percent of dry pea acreage were planted with lindane-treated seed
as insurance against wireworm damage.
No alternatives to lindane seed treatment are available for
these two crops. Data on possible yield losses from wireworm infestations
are not available. However, given the high percentage of lindane seed
treatment en lentils and cry peas — depending upon the extent of wireworm
damage which might otherwise occur — cancellation rr.ay result in economic
impacts at the user and market levels. The Agency has not found, nor have
data been submitted to estimate the likelihood or magnitude of this
occurrence.
E. Avocados
1. Usage
Lindane replaced 3HC on avocados after the cancellation of
3HC and is used extensively in Florida to control mirics and webbingwortrs •
Approximately 7,000 pounds of lindane are used on about 3C percent of the
crop in Florida to control these pests. Florida avocado production
currently represents roughly 22 percent cf U.S. avocado production.
Lindane is net used en avocados in California (the other domestic producer)
because mirics are not pests of economic significance ir. that state.
2. Alternative Methods cf Centre!
There are no registered chemicals for mirid control except
lindane. Parathicn is registered to control webbingwcrms. There are no
non-chemical control methods which produce a marketable crop for the fresh
avocado market.
-------
Preliminary results of a nearly completed study indicate
that acephate and permethrin are effective materials for mirid control.
Neither is currently registered for this use. Permethrin seems to have
residual effects ecual to those of lindane. The residual effectiveness of
9/
acephate is reportedly much shorter.—
3. Economic Impacts
A lack of hard data exists with which to quantitatively
evaluate fruit losses (downgrading or complete loss due to fruit drop)
resulting from mirid damage in the absence of lindane. According to state
experts, the economic impacts frcm cancellation are estimated as a
possible loss of 70 to 80 percent of the Florida avocado crop, though loss
of early varieties could approach 100 percent. Loss is a combination of
physical damage and/or cosmetic scarring which can lower grade. While a
percentage of damaged crops would be sold to avocado processors, this would
not offset the loss incurred by diminished sales to the fresh avocado
market. Currently, the processed fruit market absorbs only about 5 percent
of Florida's avocado production.
According to local experts, — losses would approximate
22,000 tons of avocados at a cost to users of $8.7 million assuming no
change in grading standards. — If these standards were relaxed the
proportion of the loss attributed to cosmetic damage frcm mirids would be
reduced.
The anticipated losses are strictly frcm lack of mirid
control. As an alternative and anti-webbingworm pesticide, parathion
causes no substantial economic impacts.
F. Ornamentals
1. Usage
Lir.dane is used on a variety of woody ornamentals and floral
and foliage plants to control primarily borers, thrips, and Isafminers.
Actual usage data are unavailable, and the estimates submitted by Hooker
Chemical (74,840 pounds), USDA (13,402 pounds), and the National Arborist
Association (3,580 pounds) vary greatly. Moreover, the USDA estimate is
based solely upon reported, use in only 6 states .
9/
— NOTE: These are preliminary results of a laboratory study and not
a small plot field trial.
10/
— A. Sarano'^s ki , Florida State Dept. of Entomology; H. Goicveoer.
— rnu.
The gradinc standard for avocados is at 22 FR 6205.
-------
2. Alternative Methods of Control
Lindane is the only pesticide presently registered to
control all borers on all wcody ornamentals. Chlorpyrifos and endosulfan
are registered for borer control only on selected species of ornamentals•
Alternate pesticides are generally available for the pests of floral and
foliage plants presently controlled by lindane.
3. Economic Impacts
Because data were unavailable, a precise quantitative
analysis could not be performed. Estimates of projected losses are shown
in Table III-7. These estimates are taken from reports of the states which
reported on the USDA information survey. Total impacts on the woody
ornamental industry may total 520.6 million dollars. As a whole, this is
expected to be of less than major significance to the industry. Impacts on
individual firms could be sizable. Impacts on the floral and foliage
industry are expected to be minor.
G. Cucurbits
1. Usage
Lindane is registered for control of various insect pests
(including aphics, cucumber beetles [striped and spotted], cutworms,
melonworms, pickleworms, squash bugs, squash vine borers, and white grubs)
on cucurbits such as canteloupe, cucumber, pumpkin, squash, and watermelon.
Lindane treatment is used on only 12 percent of America's fresh market
cucurbits .
Data concerning lindane usage on cucurbits are available
frcm only three states: Florida (total cucurbit acreage: 17,900 acres),
South Carolina (total cucurbit acreage: 14, 600 acres), and Georgia (total
cucurbit acreage: 10,500 acres)— (See Table III-S). Twenty-two
percent of the total cucurbit acreage of these states was treated with
cucumber and squash acreage in the U.S. As Table III-3 shows, the common
practice is to apply lindane to cucurbits frcm one to eight times during
the growing season. However, experts generally consider four applications
per season to be sufficient.
2. Alternative Methods of Control
Pickieworms and squash vine borers are the target insects of
main economic importance on cucumbers and squash. Seventeen pesticides
other than lindans are Z?A-registered for use against these pests en squash
and cucumbers. USDA recommends carbaryl, endosulfan, and lindane.
T . . . ... . , . .
— Lincane may aj.so ce usea in otner states to control squasn vine
borers and pickiewcrms, but no pertinent data are available.
111-13
-------
Til bit; II1-7. Summary of Annual Costs for States Requesting Use of Lindane on Ornamentals
(in 1,000 Units)
Lilac Itorer
State on Lilac
1'eiinyyl van ia
Ohio 0.065
Tennessee
1 owa
Ok Icihoma
Maryland 0.200
i ndianu 4.7
Missouri
Gooi
-------
Table III-3. Total Lindane-Treatad Cucurbit Acreage, in Pounds A.I. and
Cost ~ 1976-1977.
State
Item
Florida South Carolina
Georgia
Total
Total Cucurbit Acreage 27,900
Total Cucurbit Acreage 2,790
Treated with Lindane
Percent of Total Treated 10%
Acreage
Number of Applications 1-2
Pound of A.I. Used Per 0.25
Application Per Acre
Ppounds A.I. Used 1,046
Insecticide Cost $11,339
14,600
800
5.5%
7-3
0.25
1 ,500
316,260
10,500 53,000
3,000 11,590
75.2% 21.9%
4
0.25
3.6
0.25
3,000 10,546
336,720 3114,319
111-20
-------
According to state entomoicgis.ts, most growers in Florida
use carbaryl in combination with endosulfan and methorayl to control borers
and pickleworms, and the same combination is probably used in Georgia.
Methcmyl is used in South Carolina. However, no data are available on the
extant to which these alternatives to lindane are presently used, either on
a state or on an aggregate U.S. basis. All of these alternatives,
particularly carbaryl, are toxic to bees and could conceivably cause yield
losses due to a loss of pollination.—
3. Economic Impacts
There should be no overall change in the U.S. production of
cucurbits if lindane were cancelled. Only 12.2 percent of the fresh market
cucumber acreage is treated with lindane. Experts from Florida and South
Carolina, the two states with greatest cucurbit acreage, estimated that
the use of alternative chemicals would not affect yield.
As Table III-9 shows, replacing lindane with carbaryl would
result in slightly decreased annual production costs; replacing lindane
with endosulfan would increase production costs slightly; and replacing
lindane with methomyl would result in production costs that are approxi-
mately twice the costs of treating with lindane.
Florida and South Carolina entomologists report no antici-
pated yield loss if lindane were cancelled; Georgia entomologists In
contrast, report potential yield losses of up to 25 percent. Assuming no
yield loss in any states, estimated impact on cucurbit growers should
lindane be cancelled is minor, $176,000, a figure derived from the cost of
alternatives recommended by the states (see Table 111-10} . The estimate
of economic impact, assuming a 25 percent yield loss in Georgia and a shift
to state recommended alternatives is $2.4 million. The conflict in
estimates is surprising because the target pests in ail three states,
namely pickleworms and squash vine borers, are the same.
Furthermore, Georgia, the state reporting a potential
yield loss, is bounded on the north by South Carolina and on the south by
Florida, two states reporting no anticipated yield loss. Hence, 'in terms
of climate, soil conditions and other considerations, one would not expect
Georgia to present a yield impact situation that would be very different
frcm the other two states.
In the Agency's judgement, the projected yield loss for
Georgia has not been substantiated by supporting documentation that would
be sufficient to override the conclusion that the yield impact in Georgia
should be similar to the situation in Florida and Sourh Carolina. The
Agency feels it must conclude that the impact of lindane's cancellation in
Georgia would be very minor, until such time as the Agency is presented
with substantial information to the contrary.
— See ?3A, pp. 408-420.
III-2I
-------
1JI-9. Treatment of Cost of I.indane and Alternatives for Control of
Squash VJne Horer and Pickleworm on Cucun\bers and Squash in
Southeastern U.S.
t-i
t-i
n
I
IvJ
to
1 1
1,1
ct
Ki
Mi
lai.'d. i c i du
i ndu ue
u-bui y 1
ldOSU.1 £
;l homyl
p.: 1
-------
Table III-10. Estimated Total Change in Costs of Production and Revenue to
Squash and Cucumber Growers' in Florida, Georgia, and South
Carolina - 1976-1977
Site/Pest
and State
Estimated Total Change
in Costs Using Alternatives
Cucumbers
Florida
Georgia
South Carolina
Squash
Florida
Georgia
Total
(-)$96
$86,880
$32,580
$3,183
$54,060
$176,507
-------
H. Christinas Trees
1. Usage
Lindane is used to control five major p-ests which attack
Christmas trees (pine regeneration weevil, northern pine weevil, pales
weevil, pine root collar weevil, and white pine weevil). Little data are
available on the amount of lindane used in the Christmas tree industry, and
responses to the USDA survey did not provide enough estimates on which to
base assumptions of use. Therefore, this discussion addresses all issues
qualitatively.
2. Alternative Methods of Control
Oxydemeton-methyl is registered for control 'of white pine
weevil infestations of established stands of Christmas trees. No other
pesticides are registered for control of the other insects which infest
Christmas tree stands.
Non-chemical control methods are available for some insect
pests, although at present they are not generally used because they are
labor-intensive and costly. These include early pruning, cultural land
clearing, removal of old stumps, and alternate planting sites. However,
cultural practices, if carried out diligently, are expected to suppress the
pests to an acceptable level.
3. Economic Impacts
Without usage data, quantification of overall impacts is not
possible, but the following statements can be made. Generally, oxydemeton-
methyl is about 1.2-2 times the cost per acre of lindane (31.50 - 3.00 per
acre versus $1.30 per acre) and increase in grower costs is $.20 - $1.70
per acre. Cultural controls (non-chemical) are costly insofar as they are
labor-intensive, and the effectiveness of cultural control methods is based
upon the availability of labor. Xost growers are expected to employ
alternate control methods (chemical or non-chemical) where feasible, or
shift Christmas tree production to tree species (e.g. Douglas fir) which
are less susceptible to pest damage. The most severe impacts frcm
cancellation of lindane would be borne by a few individual growers who for
various reasons are unable (because of climatic or planting site
limitations) to adopt alternate controls or species of tree. Mo estimate
can be made of the number of farms to which this ccuid happen.
I. Pecans
1. Usace
In response to a recent CSDA survey, seven states (Alabama,
Arkansas, Georgia, Mississippi, Louisiana, Oklahoma and Texas) reported
usinc lindane on cecan craves. The orimarv use is to control shvllcxera.
111-24
-------
Although lindane is also registered to control shoot curculio on pecan
trees , shoot curculio is not an economic threat to pecans and therefore no
pesticides are used to control this pest. As shown in Table III- 11, 33,000
pounds of lindane are used on 447,300 pecan trees. Collectively, these
states represent 76 percent of the U.S. pecan production. No data were
supplied by the states producing the remaining 24 percent of the pecans .
2 . Alternative Methods of Control
Alternative feasible pesticides currently include malathion,
oils, and endosulfan. — However, no data are available to determine
the extent of use of any alternate chemical.
3. Economic Impacts
The comparable costs of treating pecans with lindane and the
alternative chemicals of choice, namely endosulfan, oil ( dormant) , or
malathion, are listed in Table III- 12 and 111-13. Growers who
substitute endosulfan for lindane would experience decreased seasonal
pesticide costs of 23 cents a tree. The use of oil (dormant) as an
alternative for lindane would result in an increased seasonal cost of 51.18
per tree^ malathion use would cost $7.00 more than lindane per tree each
season.—^ The owner of a hypothetical 20-acre pecan grcve with 12
trees per acre would save $55.20 if endosulfan were substituted for
lindane; by using oil, the same owner would occur an additional cost of
$283 over lindane. If malathion, the most expensive alternative, were used
and all other variables of production remained constant, 'this owner would
incur an additional cost of $1,685 per year.
Entomologists consider endosulfan to be as effective as
lindane, and no yield losses are anticipated if endosulfan entirely
replaces lindane. Endosulfan is registered for pecans under FIFRA 24(c) in
Mississippi or Louisiana and has Federal registrations for other crops . In
view of endosulfan1 s regulatory history, it is appropriate to consider
endosulfan a viable, registrable alternative for lindane on pecans. The
Agency expects that endosulfan would become, in most instances, the
14/
— iRcosulran is registered under FIFRA 24(c) in Mississippi and
Louisiana.
15/
— Frcm pecan crop budgets developed at the university of Georgia,
total fixed and variable costs per acre (excluding land and irriga-
tion) are 3538 per acre per year. Total costs to pecan growers would
increase as much as 15.1 percent per acre per year, if an average 2.5
applications of malathion are used instead of lindane. Costs would
increase 2.5 percent per acre using oil (dormant). And costs to
growers in Mississippi and Louisiana would increase 0.1 percent per
year usinc endcsulfan.
-------
111-11. Number of Pecan Trees, Lindane-Treated Pecan Trees, and Amount
of Lindane Used, Selected States (Estimates for 1976)
1-1
M
Georgia
Missi ssippi
Ok Icihoiua
Texas
Other*
Total
( Avg . Percent ]
Pecan Trees
Bearing ••
Nonbea r i ng
1 ,000
1,359
255
532
1,549
U36
4,531
Iteari ng**
1 ,000
1,212
202
421
1,171
567
3,573
Li ndane-T
reated
bearing +
Nonbearing Bearing
1 ,000
40 .8
4U.4
42.6
232.4
83.6
447.8
1,000
36.4
30.4
33.7
175.6
56.7
340.8
Trees
Bearing +
Honbear ing
Percent
3
19
8
15
10
(11)
Lindane Usage (a.i.)
on Bearing and Non-
bearing Trees
1,000 Pounds
3.1
3.6
3.2
17.4
6.3
33.6
Alabama, Arkansas, and Louisiana. J.indane usage data were not provided by
Lliese states. The Agency assumes that bindane usage in these three states
was equal to the weighted average of treated bearing and nonbearing trees as
reported for the states of Georgia, Mississippi, Oklahoma, and Texas.
' Pecan trees do not bear fruit until approximately 10 years of age.
-------
l-l
l-i
Table 111-12.
Treatment Costs of Various Insecticides for Control of Pecan
Phylloxera in the Southeastern U.S. (Estimated for 1976)
1 nueutii ci de
I.i ndiine
Hal.athion
Gi 1. ( dot want )
lindotail tan
Label
Kate
Per Tree
0.075 pounds
0.67 pounds
0.7 tja lions
0.15 pounds
Price
per Unit
a . i .
Cost Per Tree Per Application
Material
Labor (.
Equipment
Total
15.00
4.36
3.30
6.00
1.13 0.55
2.92
2.31
o.yo
0.55
0.55
0.55
1.68
3.47
2.86
1.45
Applications
Per Season
Number
1
2.5
1
1
Seasonal Cost
Per Tree
Dollars
1.68
8.68
2.86
1.45
-------
Table 111-13.
Annual Treatment Cost with Lindane Compared to
Alternative Control Measures on Pecans,
Selected States, for 1976
n
1-1
1-1
I
lx>
CD
Annual
Slat c-
(Jeonj j a
M i uu i ssi ppi
Ok Icihoma
Texas
Ot.lier States*
Total
Treatment
1. i lulu Me
(>U.5
01. 3
71.6
390.4
MO. 4
752.2
Cost of Using Alternatives on
Malathion Oil
354.1
130.9 30.3
531.7
112.B 129.0
605.0 691.0
Endosul
9
70.2
16.1
86.3
Affected Trees
fan Total
354.1
70.2
169.2
531.7
257.9
1,383.1
Increase in
Compared to
285.6
(-11.1
97.6
141.3
117.5
630.9
Cost
Lindane
)
'Alabama, Arkansas, and Louisiana. (See Table 111-13.)
-------
alternative of choice, considering that it is lower in cost than iindane and
equally effective. The impact of Iindane's cancellation would be negligi-
ble if endosulfan were federally registered or if other states granted
24(c) registrations. The Agency believes it to be highly likely that
endosulfan will be used as a substitute for Iindane in those areas where
Iindane is presently used on pecars .
The Agency also has developed a second scenario based on the
premise that endosulfan would not become more widely available. This
analysis was based on information provided by State entomologists working
from current registrations. These entomologists indicated that Iindane
would most likely be replaced with endosulfan in Mississippi, with
malathion in Georgia, with malathion and oil in Oklahoma, and with oil in
Texas. Under this scenario, total pest control costs would increase for
these major states (and three minor use states) by approximately $63,000 if
Iindane were unavailable. If malathion is substituted for Iindane in
Georgia and Oklahoma, average yield losses of 25 percent to growers would
be anticipated. The use of oil is estimated to produce yield losses of 33
percent in Okalahoma, and 2.5 percent in Texas.— Under this
scenario, the lost production to growers would be $742,000. Overall loss
to growers from increased costs and yield declines would be around $1.4
million.
J. Forestry
1. Usage
Lindane is used mainly on pines and conifers to control
several types of beetles (e.g. Southern pine beetle, turpentine beetle, and
mountain pine beetle). While Iindane is presently not widely used, it is
the only pesticide which is effective in controlling insects in trees
already infested, and as such it serves as an option should other methods
fail. Approximately 1,700 pounds of Iindane were used in the U.S. for
forestry uses (1975-1976 growing season). It is used primarily in the
South by the U.S. Forest Service and cooperating state agencies.
2. Alternate Methods of Control
Alternate chemicals presently registered include er.dcsuif an ,
ethylene dibrcraide,— dicrotophos, and chlcrpyrifos• Additionally,
caccdylic acid, a herbicide, is registered for killing trees, thereby
creating "trap" trees for the beetles.——
,u - .....
— These two production losses are not necessarily inconsistent in
that the Texas figures are an average based on treated trees (which is
greater than infested trees) while the Oklahoma estimate is based en
an average of infested tress. In any case the economic impacts remain
minor.
17/ _„
— itnyiene oicrcraice is uncer ."J?AJl review.
13/ , , . .
— rvr.en ceetj.es lay tneir eggs in cacccyiic acia-treatea trees,
larvae are "tracoed" because the dead trees do not provide sufficient
fcod for their survival.
111-29
-------
Non-chemical control methods are already used in forests
to guard against infestation. Methods used are basically good
silvicultural management (e.g. growing trees on favorable sites, thinning
stands, preventing tree damage, and removing weak or damaged trees)•
Additionally, practices designed to suppress infestations (e.g. salvaging
infested trees, cut and leave, and cut and burn procedures) are prevalent.
Chlorpyrifos has been shown effective against southern pine beetle and
other forest pests (USDA Forest Service, 1979). Non-chemical methods are
also effective suppression techniques in all but severe infestations.
3. Economic Impacts
a. Commercial Forests
If lindane were cancelled, impac-s would be felt
primarily in the Southern forests. No impacts are expected in cooler
climates since insects are not active there, and cultural, non-chemical
control of insect pests is practiced.
Among southern forests, small private land owners would
take the brunt of a cancellation, because this group relies heavily on
chemical control and cannot generally afford labor-intensive cultural
management practices prevalent on publicly owned or corporately owned land.
a. Seed Orchards and Gum Naval Stores
As a control method which can effectively impede the
spread of infestations, lindane is considered an important, control option
bv seed orchard owners and by producers of naval stores, primarily because
their individual trees are highly valuable and the possibility of bark
beetle infestation is considered a serious economic threat. It would
appear that chlcrpyrifos is at least as effective as lindane (U3DA Forest
Service, 1979). There are approximately 10,000 acres of seed orchard in
the Southeast, the major area involved. Orchard seed has been valued as
high as $1,000 per pound, whereas "wild" seed gathered frcm non-orchard
trees is valued at about $35 to $50 per pound. Gum naval stores producers
are also located in the Southeast. In 1976, producers in Georgia, Florida,
Mississippi, and Alabama produced crops valued at $5.5 million. Naval
stores production has declined as petroleum-based synthetics have been
developed. Demand may increase, however, if petroleum becomes unreasonably
axoensive.
-------
Seed orchards are generally very well cared for, and
outbreaks of beetle infestation are relatively rare. Lindane has not been
reported used in recent years on either seed orchard or naval stores-
producing trees. The value of lindane to both seed orchard owners and
naval stores producers is as insurance against unpredictable and
potentially devastating beetle attacks.
19/
X. Livestock (Spray)—
1. Usage
As a livestock spray, lindane is registered for controlling
numerous pests (e.g., fleas, flies, lice, mites, and ticks) on livestock
(i.e., beef cattle, hogs and pigs, sheep, goats, and horses) and in
livestock premises (e.g., barns, pens, sleeping quarters, and shelters).
Lindane use patterns have fluctuated frcm year to year, but there has been
a distinct.decline between 1971, (416,000 pounds) and 1976 (176,000
pounds).— This decline is shown in Table 111-14, which lists USDA
estimates of lindane usage on livestock for 1964, 1966, 1971, and 1976.
2. Alternative Methods of Control
A total of 18 alternative chemicals to lindane .are
registered for the major livestock class/pest combinations.— Not
ail alternatives apply to each livestock class/pest combination, but there
are more than ten alternatives for each combination, except for mites on
hoes and pigs . (Only three alternatives are registered for this applica-
tion, and one, methoxychlor, is registered for use only in combination with
toxaphene or malathion.) The control of mites in general—not only on hogs
and pigs, but also en other classes of livestock—is problematic because of
a lack of efficacious alternatives to lindane.
Table III-15 lists estimates of alternative pesticides
versus lindane used on livestock for 1964, 1966, 1971, and 1976.
19/
— Lindane is apparently very rarely used as a livestock dip,
though it is registered for dip as well as spray applications .
— This decline is frcm USDA estimates. However, Hooker Chemical
has reported usage for 1976 of 139,000 pounds, which supports the
USDA estimates.
— The 18 alternatives are Carbaryl (Sevin), Chlorpyrifcs
(Dursban), Couraaphos (Co-Ral), Crotoxyphcs (ciodrin), crufcmate
(Ruelene), Dioxathion (Delnav), Famphur (Warbex), Fenthion (tiguvon),
Imidan/prolate, malathicn, methoxychlcr (marlate) [registered only in
combination with malathion or tcxaphene for rnite control on hogs],
Phenothiazir.e, pyrethrins (synergized) , Rabon/Garcor.a, Rcr.r.ei
(Korlan), trichlorofon (Dylcx), Vapcna (DDV?) and toxaphene (currently
ur.der R?AR review) .
-------
Tct I lie: 111-14.
Quantity of Lindanu Used by U.S. farmers on Livestock in
1964, 1966, 1971, and 1976 (USOA)
i-i
i-i
I
I.i vc stock
Class
Hucf Cattlii
lloijs ciiui 1J J ys
liuii.y Cuttlfc
Sllt:e[>
I'ou.I tr y
Other
•rota 1
1964
186
143
1'J
10
2
N/A
360
Use in 1 ,000-pounds Units
1966 1971
130
124
24
6
5
4
293
226
164
14
4
5
3
416
1976
79
91
3
2
*
1
176
* - Less tlian 500 pounds .
tl/A — Data not available.
-------
Table 111-15. Quantity of Lindane Versus Alternative Pesticides Used by U.S.
fanners on Livestock in 1964, 1966, 1971, and 1976
Pestici de
I.i ndcine
Toxapliene
Muthoxyc-hlor
CotlMUlpllOt;
lu'xinel
Mai ii Lhj.cn
Dioxathion
1964
360
4,703
1,200
766
755
602
N/A
1,000
1966
293
3,670
1,509
434
391
735
43
Pound Units
1971
416
4,575
1,980
168
470
652
59
1976
176
2,376
2,360
517
403
1,104
100
1-1
I
-------
3. Economic Impacts
For beef cattls, the annual cost of lindane treatment ranges
from SO.33 to §0.45 per animal; annual cost of alternative treatments
ranges from 50.33 to $0.52 per animal. For hogs and pigs, the annual cost
of lindane treatment ranges from $0.16 to $0.35 per animal; annual cost of
alternative treatments ranges from $0.18 to $0.49 per animal. Should
lindane be cancelled for livestock applications, pest control costs can be
expected to increase slightly. Total' annual increase in the continental
U.S. is estimated at $1,033,400 ($233,500 for beef cattle, $349,800 for
hogs and pigs). Because efficacious alternatives are available (except for
mite control) and because the cost increase for alternatives is small (a
maximum of $0.03 per animal per year), no effect on production yield or
quality is expected, and no significant market impacts are anticipated,
unless mites become an endemic problem in a herd. A recent report by the
National Academy of Sciences recommends the use of lindane over any other
insecticide including the organophosphates because control can be obtained
with only one application. Other pesticides are not as effective and
require multiple applications, which can lead to development of genetically-
induced resistance (Langford, 1980).
L. Existing Structures (Powderpost Beetles)
1. The Nature of Powder Post Beetle Infestation
Powder post beetles live inside wood. Because of the slow
pace of their reproduction and spreading, significant powder post beetle
damage nay not occur until after 15-30 years or more of infestation
(Williams, 1979). Sometimes infestations of powder post beetles die
naturally, and not all infestations cause economic damage requiring
treatment.
2. Usage
Lindane is used to spot-treat existing structures, mainly
houses, against wood-boring powder-post beetles (ancbiids, lyctids, and
bostichids) and drywood termites. Though the amount of lindane currently
used to treat existing structures is uncertain, it is believed to be small
(less than 1,000 pounds on 10,000 or 12,000 houses). Chicrdane has been
the chemical of choice for this application. However, this use of
chlordane has been cancelled—though existing stocks can still be used
legally. As a substitute for chlordane, lindane has a potantiai annual
market of about 10,000 pounds for this purpose.
3. Alternative Methods of Control
As pointed out by several state extension services, infesta-
tion can be prevented, and presumably retarded, by the use of painted or
otherwise, finished vocd. In the event that wood is structurally damaged,
threat wood can be replaced with sound wood, which can be painted or
finished to zrevent future infestations.
-------
Several chemical alternatives to lindane are, moreover,
registered for use on existing structures/ including copper naphthanate,
methyl bromide, sulfuryl fluoride, creosote, creosote oil, and pentachloro-
phenol (PC?). PC? is the state recommended alternative to chlordane, which
was cancelled for this use.
4. Economic Impacts
The economic impact of cancelling the structural use of
lindane is likely to be extremely slight. Chemical treatment can generally
be avoided by painting or otherwise finishing wood surfaces. Should
chemical treatment be considered desirable, PC? is available as an
effective and economically competitive alternative to lindane. The cost of
the chemical used in a spot spray treatment for powder post beetles is,
moreover, a small parr of the treatment cost, and the total treatment cost
with either PC? or lindane is comparable (5200-250) per hcrae). For the
chemical cost, lindane is applied at a rate of one gallon of 0.5 percent
solution at a cost of 0.48 per 500 square feet, and PC? is applied at a
rate of one gallon of 5.0 per cent solution at a cost of $5.95 per 500
square feet). If PC? remains available, no significant cost impacts to
pest control operators are predicted in the event that the use of lincane
as a spot spray treatment against powder post beetles is cancelled.
Finally, lindane use is basically limited to spot treatment
application. In cases of very severe infestation, fumigation is the
treatment method used. Methyl bromide and sulfuryl fluoride are used as
fumigants and at the cost of 51,000-52,000 per home.
M. Hawaiian Pineapples
1. Usage
Lindane is registered for use in Hawaiian pineapple
production to help control symphylics, root-f eedir.g insects which attack
pineapple roots soon after planting. Lindane is generally used in
combination with soil fumigants to aid in control of symphylics.
The Hawaiian Pineapple Growers' Association estimates that
annual use of lindane on Hawaiian pineapples ranges from 18,000 to 48,000
pounds. Other sources report to SPA that 19,300 pounds is the estimate of
annual use of lindane on Hawaiian pineapple fields . Hawaiian pineapple
production is based on a 3- or 4-year production cycle, which generally
includes two harvests and a fallow period of 2 to 12 months. Approximately
13,400 acres are planted each year, and in 1977 total pineapple acreage was
43,000 acres (down from 58,000 acres in 1972). Lindane is applied, at the
beginning of the growing cycle, to approximately 9,550 acres each year,
which represents about 72 percent of annually planted acreage and about 22
percent of total pineapple acreage.
111-35
-------
2. Alternative Methods of Control
The following soil fumigants, which primarily control
nematodes, can give some assistance in controlling symphylids:
dibroracchloropropane (DBCP), ethyiene dibrcmide (EDS), Telone, and DD (a
mixture of 1^3 dichloropropene, 1,2 dichloropropane, and related C-
compounds).— • Ground preparation is important in assuring symphyiid
control since fumigants will vaporise off the soil in improperly prepared
or excessively, moist soil. Furaigants do not have residual action and offer
no protection against possible late infestations. Lindane is used
primarily as additional protection to compensate for adverse soil condi-
tions and late infestations. Insufficient data on the effectiveness of
lindane'and the probability of late syraphylan infestation, however, render
the true value of lindane difficult to confirm. At present, there is no
non-chemical method of controlling symphylids.
3. Economic Impacts
Hawaiian Pineapple Growers' Association officials have
estimated that if lindane were unavailable as an anti-symphyiid treatment,
and growers were thereby forced to rely on the various dual-purpose
fumigants, the result would be an annual crop loss of about 0.8 percent
(about 5150 tons of the annual crop), valued at $515,000 at the farm level.
During a 4-year production cycle, the Hawaiian pineapple industry would
have to absorb a loss, at present farm value, of $1,018,367.—
However, no .firm data are available to substantiate the estimate. This
constitutes a minor impact on the pineapple industry. No consumer impacts
are expected because foreign supplies are presently available, and price
impacts from an annual crop loss of 5,150 tons would be negligible.
N. Pets
Lindane is registered for control of ticks, fleas, lice, and
mites on dogs , cats, and their premises. Registered products include anti-
flea cat collars, dog wash, dog shampoo, and cog dust.
1. Usage
Current data indicate that lindane is not widely used on
pets and their premises. About 30,000 pounds are used annually to treat
pets for parasite problems, including scabies (mange)-causing mites. In
the concentrations necessary for parasite control, lindane is tox^c to
cats, but not to dogs. Only Ohio still recommends lindane for control of
fleas on cats .
— Chlorcpicrin is also registered as a dual-purpose soil fumigant
but it is not reported used.
— N'cne of this loss would be incurred the first year because the
first pineapple crop untreated with lindane would net be harvested fc:
20 .Tenths, and growers would in fact save the estimated $33,000 spent
each vear for lir.dane. This annual savir.c has been factored into the
estimated total 4-year loss of $1,013,267. Second-year Icsses vcuid
be 3250,970, third-year losses 34-42,162, and fcurth-year Icsses
34 12 , 225.
-------
2• Alternative Methods of Control
There are 15 registered pesticide alternatives to lindane
for control of insect pests on cats and dogs. The major alternates are
carbaryl, coumaphcs , pyrethrins, resmethrin and ronnel. However, none of
these are reportedly effective against scabies-causing mites.
Several preventive, non-chemical methods also help control
parasites which attack pets. Ticks on dogs can be discouraged if grass and
weeds are kept mowed along paths and around pet preraises . Owners of dogs
and cats can control fleas by thoroughly vacuum-cleaning infested rooms,
Including carpets, rugs, upholstered furniture, and other items which may
harbor eggs or larvae.
3. Zconomic Impacts
Lindane and its various alternatives are generally in the
same price range. Should lindane be unavailable for use on pets, any
economic impact would be too small to measure, and this holds for both
short-terra and long-terra perspectives.
0. Household Uses
Lindane is registered to control the following household pests:
ants , centipedes , clothes moths, house fleas, odorous house ants,
cockroaches, bedbugs, gnats, little black ants, scwbugs, carpet beetles,
mosquitoes, scorpions, spiders, waterbugs, and silverfish. Under the
general category of household uses there are four major applications of
lindane:
(1) Shelf Paper
(2) Floor Wax
(3) General Purpose Household Spray
(4) Smoke-Fumigation Devices
1. Usage
In its various applications as a household pest control,
lindane is used by both commercial pest control operators and individual
homeowners. Hooker Chemicals Company estimates that 31,971 pounds of
lindane are used annually for household purposes,(12,488 pounds for shelf
paper and 19,483 pounds for other applications).—
2. Alternative Methods of Control
There are a number of chemical alternatives to lindane as a
household pesticide. The most recommended alternatives include diazinon,
malathion, naphthalene, paradichlorcbenzene, methoxychicr, and dichlcrvos.
— USDA estimated 33,788 pounds cf lindane a.i. -used -annually for
household cur-cses. An SPA survev cf pesticide use in households
reported no use of lindane. S?A economists consider the Hooker
estimate to be the best estimate available.
-------
3. Economic Impacts
Because data on frequency of use and relative efficacy of
lindane and its alternatives are not available, comparative costs of
application could not be calculated. In general, however, effective,
ccmpetitively priced alternatives to lindane products are available.
Should use of lindane as a household pesticide be cancelled, no economic
impacts are expected.
P. Minor Uses
(1) Moth Spray (Aerosol) - Industrial Use
(2) Uninhabited Buildings - Insect Spray
(3) Empty Storage 3in Fog Spray
The Agency received no responses frcm registrants or user groups
to its request for information concerning the benefits of those minor uses
listed above or any of the other registered uses for lindane. The Agency's
review of the benefits of lir.dane uses also did not report any data on the
benefits of these particular applications or the other uses. In the
absence of such information, the Agency must proceed on the assumption that
the benefits Involved are negligible.
111-33
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IV. Development of Regulatory Options
A. Introduction
In the previous Sections II and III, the human and environmental
risks associated with the uses of lincane were examined, and the benefits
associated with each use were identified insofar as data were available.
As explained in Section 1, FIFRA mandates the Agency to achieve a balance
between the competing considerations of risks and benefits. To carry out
that mandate, the Agency has developed a range of regulatory options and
proceeding on a use-by-use basis, has evaluated each option for its impacts
on both sides of the risk/benefit equation.
This section of Position Document 2/3 briefly summarizes the
salient risks and benefits associated with the uses of lindane and de-
scribes the process by which the Agency developed potential courses of
action. Section V proceeds with a use-by-use analysis of the risk/benefit
impacts of the regulatory options and explains the course'of action which
the Agency proposes to adopt and implement.
3- Salient Risk/Benefit Considerations
In performing a risk/benefit analysis of the uses of lindane, the
Agency identified several salient factors, on both sides of the risk/bene-
fit equation, which became determining considerations in the development of
regulatory options. These considerations are reviewed below.
1. Salient Risk Factors
As detailed In Section II, two of the original risk criteria
cited in the RPAR notice as bases for the Agency's presumption against lin-
dane stand unrebutted and represent significant chronic human risks:
(1) oncogenicity, and (2) reproductive/fetotoxic effects.- The studies
which showed that lindane is oncogenic in mice constitute evidence that the
pesticide poses a cancer risk to man. Likewise the studies which indicated
that lindane causes fetotoxic effects in test: animals are cause for concern
that lindane is fetotoxic to humans. Because no lindane products are
currently registered for direct aquatic application, the third presumption -
- acute hazards to wildlife, aquatic species — has been withdrawn.
In addition to the risk criteria upon which the lindane R?AR
was based, the Agency identified as areas of concern the following possible
adverse effects of the pesticide and requested additional information: (1)
mutagenicity, (2) blood dyscrasias, (3) acute hazards to humans and domes-
tic animals, and (4) population reduction in nontarget avian species •"
\J Although fetotoxic effects are considered a chronic risk, it should
be pointed out that fetotoxicity can result from a single exposure.
2_/ The additional issue of chemical isomerication effects of lincane,
also mentioned in the "JAR notice, is not a determining consideration
for reasons civen in Subsection II.A.4.a of this zosition document.
IV-1
-------
Concerning mutacenicity per se, the Agency has en the basis
of available data determined that risk criteria warranting a rebuttable
presumption have not been met. However, since indications of mutagenesis
constitute indirect evidence of carcinogenicity, the positive resoor.ses
observed in several studies lend qualitative reinforcement to the Agency's
presumption of lindane's oncogenic effects.
Regarding lindane-rsiated blood dyscrasias, the Agency has
likewise determined that risk criteria warranting a rebuttable presumption
have not been met. Although insufficient evidence exists to firmly estab-
lish a cause-effect relationship between lindane exposure and blood
dyscrasias, the Agency remains concerned, however, that the hematopoietic
tissues of certain individuals, particularly children, might be especially
sensitive to lindane.
Regarding acute hazards as lindane-related adverse effects,
the Agency is, as a result of further SPA research, concerned in particular
aiout the acute effects of lindane on the central nervous system (CMS),
especially with regard to children.- Studies have ccme the Agency's
attention which indicate that lindane bioaccumulates in the CMS, triggering
symptoms of acute poisoning which are typical of CNS stimulation. The
results of a recent study (Hanig et al., 1975) indicate further that young
animals (weanling rabbits) are more sensitive to the OJS effects of lindane
than are adults, and these results take on added significance in light of
the recent fatal lindane poisoning of a child in Florida. Given this
evidence, the Agency concludes that as a CNS stimulant, lindane poses a
human risk and that this risk is particularly significant in cases of
exposure of children.
Concerning population reduction in nontarcet avian scecias
as a possible adverse effect of lindane, the Agency has determined that
risk criteria warranting a rebuttabls presumption 'nave not been met and
that there is little evidentiary basis for concern.
3/ Additional Agency findings concerning the acute effects of lir.dane on
the central nervous svstem are addressed in Subsection II.A.4.c.(4)•
IV-2
-------
The Agency's concern regarding the potential for lindane to
produce both acute and chronic effects in humans is heightened by the
persistence of lindane in the environment. As residues of lindane can
remain in the environment for a long time period, the potential duration of
lindane exposure following application of the chemical presents a
significant problem. The persistence of lindane poses a particular concern
for home uses, such as structures, household uses and pets, where residents
can experience substantial long-term exposure to lindane residues.
Moreover, in general, there is concern about the bioacc-umulation of lindane
in humans and the burden this places on the body's systems in view of the
widespread use of the compound and its mobility to sites far removed from
the treatment areas .
The avenues of exposure to lindane are (1) dietary (oral),
(2) dermal, and (3) inhalational. According to Agency calculations, a
likely dietary exposure to the general population via lindane residues on
food is 0.003 mg/kg per day.— This represents a lifetime oncogenic
risk of 1.7 x 10 or roughly 17 potential cancers per million people.
Given established use patterns, the subgroups subject to
dermal and inhalational exposure are pesticide applicators, both profes-
sional and non-professional, and persons who might be in the vicinity
during or immediately after application. Again, special concern is war-
ranted in connection with children, who may be more sensitive to the toxic
effects of lindane than are adults. Workplaces and residences are the use
sites of main concern.
Additionally, the Agency's concern about the environmental
fate of lindane is further heightened by the lack of information on
disposal methods for lumber dipping operations. The Agency believes that
unless disposal methods preclude release of lindane into the environment
there exists a potential for indiscriminate release of lindane whenever the
machinery and tanks are cleaned of debris which occurs normally during the
milling operations.
4/
— Agency calculations of dietary exposure to the general adult public
are civen in Subsection II.3.1.
IV-3
-------
2. Salient Benefit Considerations
The benefits of lindane were assessed in terms of economic
impacts which would result if its uses were cancelled and users thereby
forced to employ available alternatives. As derailed in Section III,
should lindane be cancelled, the major economic impact may be expected to
fall in the hardwood logs and.1 lumber industry. Major impacts may occur in
production of hardwood and ultimately consumer gocds lumber, if
cancellation occurs and if alternatives do not prove feasible.—
Possible major impacts would occur for small grains; however, at this time
the Agency does not have quantifiable data to support these impacts.
Moderate impacts are anticipated in connection with
avocados, ornamentals and cucurbits. These moderate impacts on the local
producer would have no expected significant impact on the nationwide
production of avocados and cucurbits or the maintenance and production of
ornamental trees and shrubs.
For all other uses of lindane minor to insignificant impacts
are projected to the growers and producers. The Agency does not expect any
measurable impact on nationwide production or prices of food, or any other
facet of the agricultural economy.
The Agency anticipates that regulatory action short of
cancellation will have no significant impact en the agricultural econcmy.
In the course of the Agency's benefit analysis, a general
lack of effective alternatives to lindane emerged as a notable issue of
concern. No alternatives to lindane are currently available for use on
hardwood logs and lumber or in small grain seed treatment. Certain target
pests of avocados, ornamentals, Christmas trees, forestry, and pineapples
can be controlled by substitute chemicals, but no alternatives are
registered which control all the pests of concern. For use on cue-orbits
and pecans, alternatives can be employed with varying levels of efficacy.
For scabies-causing mites en pets and mites on livestock no completely
effective alternatives are registered.
The Agency's analysis of benefits was hampered to a great
extent by inadequate quantifiable data. 3ata limitations wera especially
problematic in connection with seed treatment, the major use of lindar.e.
The Agency was unable to project potential yield losses (except for corn)
and no quantitative estimate of the economic impacts of a seed treatment
cancellation could be mads. Quantifiable benefit data were unavailable
also in connection with two lesser uses of lindane, forestry and Christmas
trees. Again for these two uses, assessment of benefits was limited
entirely to Qualitative terms.
wit.™ a seed treatment cancellation, cuar."
available.
IV-4
-------
C« Development of Regulatory Options
With regard, to pesticide products containing lindane, three basic
regulatory options have been developed for consideration:
1. Continue registration without restriction.
2. Continue registration but amend the terms and conditions of
registration.
3. Cancel registration.
Cancellation of registration (Option 3) represents an absolute
regulatory response, for it means that the sale or the distribution of the
pesticide for the use at issue is unqualifiedly prohibited. Unrestricted
registration (Option 1) likewise reflects an absolute regulatory response
for it means that sale and distribution are unconditionally continued.
Registration with amended terms and conditions (Option 2), however,
represents a range of possible courses of action in that the specific terms
and conditions of registration are formulated or modified by the Agency on
a use-by-use basis.
The process of developing a full range of regulatory options by
which a statutory risk/benefit determination with respect to pesticide
products containing lindane might be achieved focused on means to reduce
levels of human exposure to the pesticide. The Agency has assessed the
various exposure situations at issue and has developed for consideration a
number of specific measures by which exposure and risk might be reduced via
amendments to the terms and conditions of registration. The general and
use-specific measures discussed in the following subsections have been
selected and reviewed based on both potential effectiveness and economic
and practical feasibility.
Table IV-1 lists specific protective measures taken into consider-
ation. Table IV-2 shows the reduction in total body doses anticipated in
connection with these measures. Table rv-3 shows estimated reductions in
risk.
IV- 5
-------
Table IV- 1. List of Protective Measures Considered, Use by Use*
Use
1 lardwood 1 og
and lumber
Seed treatment
AvOCUdOS
Items
Impermeable
protective
cloth 1 ng
Protect ive
clothiiuj,
Paper masks
I
Oi
Protective
cloth Ing
and
Impermeable
ylovesj or
Roof-type
shelters
Description
-Elbow-length neoprene
ijloves, boots, and aprons
-tony-sleeved work shirts,
long pants
-Gloves to be vised during
mixing
-Disposable paper masks to
be used during mixing
-Long-sleeved work shirts,
long pants
-Wide-brimmed hats
-E Ibow- length
neoprene gloves
-Or roof-type shelters on
machinery employed
Affects on Exposure
-Dermal exposure to hands, arms,
feet, and body avoided
-Respiratory exposure not altered
-Dermal exposure to arms, legs,
and hands avoided
-Some reduction in dermal
exposure to face
-Inhalation of dust particulates
eliminated
-Reduction of dermal exposure
to arms, legs, and hands
-Some reduction of dermal exposure
to head, face, and neck area
-Respiratory exposure not altered
Ornamentcil a
1. Homeowners
2. CommercI a 1
App I ica tors
Cucurhi ts
Protective -Long-sleeved work shirts,
Clothing, long pants
Impermeable -El bow-length neoprene
gloves gloves
Protective -Long-sleeved work shirts,
clothing, long pants
Impermeable -Elbow-length neoprene
gloves, gloves
llespi rators -Respirators
Protective -Long-sleeved work shirts,
clothing long pants
-Reduction of dermal exposure
to arms, hands,and legs
-Respiratory exposure not altered
-Reduction of dermal exposure to
arms, hand, legs, and hands
-Reduction of dermal exposure to
face
-Elimination of respiratory
exposure
-Reduction of dermal exposure
to arms and legs
-------
I-I
I
Table IV-1. List of Protective Measures Considered,
Use I terns Description
f:l>r i stmas Trees Protective
cloth ing,
Impermeable
Pecans
Forestry
Livestock
-Long-sleeved work shirts,
long pants
-Elbow-length neoprene
ylovea, boots, gloves, boots, and aprons
aprons
Protective
clothiny,
Impermeable
gloves; or
Roof-type
shelters
Protective
cloth Ing,
Impermeable
gloves
-Long-sleeved work shirts,
long pants
-Elbow-length gloves
-Wide brimmed hats
-Or roof type shelters
on machinery employed
-Long-sleeved work shirts,
long pants
-Elbow-length neoprene
gloves
Protective -Long-sleeved work shirts,
clothing, long pants
Impermeable -Elbow-length neoprene
gloves, boots, gloves, aprons, and boots
aprons
Use by Use (Cont.)
Effects on Exposure
-Dermal exposure to hands, arms,
feet, and body avoided
-Respiratory exposure not
altered
-Reduction of dermal exposure to
arms, legs, and hands
-Some reduction of dermal
exposure to head, face, and neck area
-Respiratory exposure not
altered
-Reduction of dermal exposure
to face only
-Respiratory exposure not altered
-Dermal exposure to hands, arms,
feet, and body avoided
-Respiratory exposure not altered
Structures
1 . I nliub i iiants
(lone
-------
Table IV-1. f.ist of Protective Measures Considered, Use by Use (Cont.)
I
U)
P i
Items
None Applicable
Description
Hone Applicable
Pots
I . Dog Washes
App'l. i- Protective
Ccitors clothing,
gloves and apron
None Applicable
b. Post
App] icat ion
I1 lea Collara, Hone Applicable
l)o
-------
Table :iv-1. List of Protective Measures Considered, Use by Use (Cont.)
Uses 1 tenis Description Effects on Exposure
Mi mil' Uses None Considered None Considered None
1. Motli Spray,
1 iHlnstr i a I Use
2. Insect Spray,
lln i nhabj te<1 Uuildj ngs
Jl. tinpty Storage 11 in
l-'oij Spray
-------
T«il»l e IV- 2. Impact of I'jcotoct Ivo Htauutcq on Tot Hi liotly lk>tiuu Lo At*l*J lea tot* a
l):iti Dciuml Uptoko% Durmal my/kfj/Jay
ll.ii.»l 10% 0.0-iO
:;<:<:.!• T|-<;nlini!lit 1% O.O113
JWoiruilofi 1O% 0 . 66 /
(U iiiiuuM.t ula
Hoiiif'wiici-fj 10% O.O1
Coi.im. A|>|.l l<;ul "10 1O% 0.02-0.06
Cue, ill, till 10« O.O0014
<:lifliilm.in Lrucju 10% 0.009-0.269
I'ccim Oi cl^n. l,i 10% 0. IS
i-J Ki.runl.ry 10% O.O9
|'
,.„ l.lv/c-iil.ock 10» O.O02
O
SI", i iu:l lit 'Ml
A|i|. 1 1 cat OL'S 1(>% 1.35
(k:i:.i|..mrii
l'l.,.;.,,,,,l,:u
' l-olu
I'.:L 0,1 In, U
1 I-,') ll,».;l,
i A|.|.l !.:.,( ,,i 11 !()% O.OOO04
! I'ntM Ai'itl l<:>it li,il — —
llunplmloty imj/K
-------
. _, .
I- ::|,i.iy
lltl|>l Oipk.l I 4-ll
n;.l.:i liil:i
Tallin IV-2. lm|>:u:t ti of I'jiol i:i:t I vu llc'.iiiili i::i or Tot.il! lli_xly Don.in to A|>|>1 IcallOCEl (Coiil . )
l^tf-l Annual Total
ii'iin.il ll|,i.ik.:\
l\|.|>lli:.it:il A|>|vl I »:al I
«III:)(:|H ttil il:i«::t
all.-. If |.;iii.:i
floor n.ix
Ivim.il nnj/kij/il.iy Hcnjili ul ory iny/kij/.liiy *
2.J x 10"' 7.2 x I.!, .,1,1 I .-.I
llul l.lln<|:i - ' - O.OJ7 O.037 0.4
i:iii|>i.y .*:i «>i-.-it|u
n I ii Ki.i| :;|,i.ly - _ O.I 20 (1. 120 1.5
'HUH lli:!i|>l i .1(01 y n|>lnko iiM>iiuin'toi M) , 1-fusuiiL Hue I'tactlccii
-------
1. General (Non-Use~Specific) Measures
The following measures have been considered in connection
with the broad spectrum of lindane uses.
a. Require Label Warnings for All Uses of Lindane
Under FIFRA, the Agency may require that precautionary and
warning statements appear on pesticide labeling. Given the oncogenic,
acute toxic, and fetotoxic risks of lindane, and given the special
sensitivity of children to the toxic effects of the pesticide, the Agency
considers additional label warnings to be a reasonable precautionary
measure. Therefore, the following warnings are proposed as label
precautions for pesticide products containing lindane.
Label Warning
The United States Environmental Protection Agency has determined that
lindane causes cancer and fetotoxic effects in laboratory animals, and
central nervous system effects in both humans and laboratory animals.
Users: Because lindane is highly toxic, extreme care should be
exercised in handling this product. [Use of this product
is limited to certified applicators only. Users are
required to wear all recommended protective clothing.
Protective clothing should be laundered separately, and all
users should shower thoroughly after handling this product.
Do not use .lindane products on pregnant or young
animals.}—
Women: Women of child-bearing age should not be involved in the
mixing, loading, or application of this product. Exposure
to lindane during pregnancy must be avoided.
Parents: Children are very sensitive to the toxic effects of this
pesticide. Avoid use in areas where children might be
exposed.
b. Classify Lindane for Restricted Use and ?.ecuira
Applicator Certification. —'
Under ?!FR&, hazardous pesticides may be classified for
restricted use and limited to use only by certified applicators. This
measure would remove lindane from the open market and restrict its use to
certified applicators and persons under their direct supervision.
Classified for restricted use, lindane products would be available only to
those users who have in fact undergone a certification program. Such
programs are designed to encourage 'greater responsibility on the part of
applicators and thereby reduce exposure and adverse effects, and ara
administered primarily by the states .
6_/ Bracketed matariai would be included as appropriate for those uses of
lir.dane for which dedicator certification and protective clcthir.ci
requirements are imposed and/cr those uses which involve livestock cr
pet applications.
]_/ >
-------
All applicators would be required to obtain
certification. If implemented this measure would have a negligible effect
on benefits. All states currently have certification programs. Non-
certified applicators would have to make minimal investments in
certification courses.
2. Use-Specific Measures
a. Hardwood Logs and Lumber
Require that applicators wear impermeable (neoprene)
aprons, boots, and elbow—length gloves.
Three principal lindane treatment methods are used in
the hardwood logs and lumber industry: 1) green chain dip vat, whereby
freshly sawed boards ara completely immersed prior to stacking; 2) green
chain spray, wheraby the lumber is conveyed through a "spray booth"
equipped with a low-pressure spray system; and 3) lumber '"package dip vat,"
whereby packages of stacked lumber are immersed into a vat, then allowed to
drain. These procedures take place in a covered but open plant.
As workers assist in guiding, pulling, and stacking the
lumber, they are subject primarily to dermal but also to respiratory expo-
sure to lindane. Exposure is estimated at 31,950 mg/yr (dermal) and 130 mg/
yr (respiratory). At this level of exposure, cancer risks are estimated at
2.6 x 10 " and margins of safety at 11 (acute effects) and 22 (fato-
toxicity).
Measures short of cancellation by which exposure and
risk to workers in the hardwood logs and lumber industry might be reduced
were considered by the Agency based on their potential to reduce levels of
dermal exposure, the primary source of risks to lumber plant workers.
Because non-impermeable clothing could easily become saturated due to the
application methods' involved with this use, only impermeable clothing could
measurably reduce dermal exposure. The Agency has determined that
requiring workers to wear elbow-length impermeable (neoprsne) gloves,
impermeable aprons, and impermeable boots would reduce dermal exposure to
the hands, trunk, and legs, which are the crucial points of contact. The
estimated reduction in risks to be achieved via these risk-reduction
measures are given in Table IV-3. However, it should be pointed out in
this connection that according to the OSDA, workers who handle treated
lumber are already provided with rubber gloves, aprons or rain suits, and
boots . Subsequent inspection of some sites by 2?A revealed that not all
workers wore this protective crear.
-------
Table IV-3.- Impacts of. Protectiv tiasures on Applicator Risk
I
i —
.1-
MARGIN OF
Risk
Reduction Fetotox i.c.i ty
Measures Before After
SAFETY
General Acute
Toxic i.ty
Before After
CANCER PROBABILITY
ESTIMATED
LIFETIME RISK
Before After
ESTIMATED
PERSONS
EXPOSED
II.-
llci rdwood Tuipe nneable
I.oijs and Protect! ve
Lumber Clothiiiy
Seed
Treat-
ment
( tillla 11
ijra i nu
ami corn)
Avooados
I'1:0tecL i.ve
Cloth i IKJ ,
Paper Masks
Protective
Clothlny ,
y 1 o v e s ; or
Hoof- type
she 1. te i:u
22
28
03
4-10
31
42
220
15
2.6 x 10~2 6.9 x 10
Q.3 x 10
-5
5.0 x 10
-6
-4 -6
6.2 x 10 2 x 10
2400
130,000
275
Ornamentals
I. Home- Protective
owner Cloth i n
-------
Table IV-3. Impacts of Protective Measures on Applicator Hisk (Cont.)
MARGIN OF SAFETY
Risk General Acute
Reduction Fetotoxicity Toxicity
e Measures Before After Before After
cans Protective 7 31 4 15
Clothing,
Impermeable
gloves; or
Roof- type
shelters
CANCER PROBABILITY
ESTIMATED
LIFETIME RISK
Before After
3. 1 x 10~4 7.5 x 10~5
ESTIMATED
PERSONS
EXPOSED
1200
Forestry Protective
Clothing,
Impermeable
Gloves
Livestock Protective
Clothing,
Impermeable
Gloves, Boots,
Aprona
36
42
18
21
1.9 x 10
-3
5.5 x 10
-4
416
1,786
208
893
5.0 x 10
-6
1.3 x 10
Structures!
Hone
416
'I iihab L ta 111:a App 1 icable
Applicatora Protective
Clothing
Impermeable
Glovea,
Reapi rators
416
37
4.6 x 10
-4
18
4.4 x 10
U.8 x 10
-3
-3
4.6 x 10
1.2 x 10
2.5 x 10
-4
-3
I'i ne-
app I o:j
Mono .
Applicable 4.5 x 10 4.5 x 10 2.3 x 10 2.3 x 10
10
-12
10
-12
1000
250,000
10,000 - 12,000
houses
1600
-------
Table 1V-3. Impacts of Protective Measures on Applicator Risks (Cont.)
Use
MARGIN Ob1
RJtik
Reduction l-'etotoxi ci t:y
Measures Before After
SAFETY
General Acute
To x i cl^
Before After
CANCER PROBABILITY
ESTIMATED
LIFETIME RISK
Before After
ESTIMATED
PERSONS
EXPOSED
1 . Do ij
a. Appll- Protective 2.5 x 10 1.2 x 10 1.3 x 10 6.2 x 10
ccitoi's Clothing,
Impermeabl e
Gloves and
aprons
b. Pout None
1.4x10 1.4x10 0.7x10 0.7x10
cu Lion
2. Other
2.4 x 10 4.8 x 10~8
7.0 x 10~ 7.0 x 10~
130,000
115,000,000
c\ . !•' 1 ea None
Collars Applicable
3 X 10
3 X 10 1.4 X 10b 1.4 X 10 2 x 10 4 2 x 10~4
Not
Determined
b. Do
-------
Table 1V-3. Impacts of Protective Measures on Applicator Hicks (Cant.)
Use
lion
Use
1 .
2 .
3 .
4 .
CANCER PROBABILITY
ESTIMATED
MARGIN Of SAfETY LIFETIME RISK
Kisk General Acute
Reduction Fetotoxici_ty__^ ___2!Sii£iJtX__-_
Measures Before After Before After Before After
c . Doy Hone
Dusts Considered
-5 -5
1. Appli- 83,000 03,000 41,666 41,666 1.5 x 10 1.5 x 10
ca tors
-5 -5
2. Post- 9,260 9,260 4,630 4,630 1.9 x 10 1.9 x 10
application
sehol d
y
She if None _ _
-5 -5
Paper Considered 6,000 6,000 3,000 3,000 3.9 x 10 3.9 x 10
floor None
-4 -4
Wax Considered 1,250 1,250 625 625 6.7 x 10 6.7 x 10
General None _ _ _ _
7 7 7 7 -11 -11
Puipose Consi- 3.8 x 10 3.0 x 10 1.9 x 10 1.9 x 10 6.0 x 10 6.0 x10
Household dered
Spray
-3 -3
Smoke Hone 700 700 350 350 1.1 x 10 1.1 x 10
l-'umi licit ion Consi dered
ESTIMATED
PERSONS
EXPOSED
Hot
Determined
Hot
Determined
Hot
Determined
Not
Determined
Not
Determined
Duv j i:t;s
-------
Table '[V-3. Impacts of Protective Measures on Applicator Risks (Cont.)
CANCER PROBABILITY
ESTIMATED
MARGIN OF SAFETY LIFETIME RISK
Klsk General Acute
Reduction Fetotox i cl ty Toxic i ty
(l:;<; Measures Before After Before After Before After
Minor Uaea
1. I'ndiiu- None Applicable
ti ial
U;;e Moth
Spray
a. Appli- 0 x 10'1 0 x 104 4 x 1Q4 4 x 10 1.3 x 10~ 1.3 x 10~
eatery
*~ J — ^ _ c.
7* b. I'oyt- 000 800 400 400 1.1x10 1.1 x 10
'~ rtppli-
0) ' l
Of.it ion
2. (In in- Hone
habited Applicable 135 135 60 60 1 .9 x 10~b 1.9 x 10~
Bui Id i ii'ja
1 nuect
Spray
.1. Empty Hone
Sl.ora.je Applicable 39 39 20 20 5.5 x 10~~4 5.5 x 10~4
Bin
ESTIMATED
PERSONS
EXPOSED
Not
Determined
Not
Determined
Not
Determined
Hot
Determined
-------
b. Seed Treatment
Require that applicators wear long-_sleeved workshirts
and long pants, and cloves and disposable paper masks during mixing.
In applying lindane products to seeds, applicators are
exposed to airborne lindane dust particles generated during pouring and
mixing of seed powder mixtures, whether by hand or mechanically. Dermal
and respiratory exposure incurred by applicators are estimated at 306 mg/yr
and 7.8 ng/yr, respectively. At this level of exposure, cancer risks are
estimated at S.3 x 10 and margins of safety at 14 (acute toxicity) and
28 (fetotoxicity).
Measures short of cancellation by which exposure and
risk to acolicators night be reduced were selected for consideration based
on their potential to reduce levels of dermal and respiratory exposure.
Due to the method of preparing the lindane mixture for use, inhalation of
dust particulates could be eliminated by the use of either a respirator or
a paper mask. Because respirators are not only expensive but impractical
for seed treatment application practices, paper masks were selected for
consideration in the Agency's risk-reduction calculations. Crucial points
of dermal exposure are the arms, legs, and hands of the applicator.
Protective clothing requirements comprised of long-sleeved shirts, long
pants, and gloves would reduce dermal contact to these crucial areas. The
paper mask would also reduce dermal exposure to the face. • The estimated
reduction in risks to be achieved via these risk-reduction measures are
given in Table IV-3.
c. Avocados and Pecans
1 ) Require that applicators wear lor.c-sleeved work
shirts, lone pants, wide-brimmed hats, and impermeable (neocrene) albow-_
lencth gloves: or
2) Require a roof-type shelter on machinery being
employed.
Lindane is applied to pecan and avocado tress via
a one-man air-blast or an air-delivery sprayer, once per year in pecans or
twice per year in avocados. These procedures subject applicators to dermal
and respiratory exposure to lindane estimated at 304 mc/yr and 1.2 mg/yr
respectively for avocados and 3S6 mg/yr and 0.6 mg/yr for,pecans. At this
level of exposure cancer risks are estimated at 5.2 x 10 (avocados) and
— 4 ~
3.1 x 10 (pecans) and margins of safety at 4 (acute toxicity) and 7
(fetotoxicity).
Measures short of cancellation by which exposure
and risks to applicators might be reduced were considered by the Agency
based en their potential to reduce levels of dermal exposure, the primary
source of applicator hazard for these uses. Due to the spray application
TV — 1
-------
methods involved, crucial points of dermal exposure are the hands, arms,
and lacs of the applicator. The Agency has determined that requiring
applicators to wear long-sleeved work shirts, long pants, a wide-brimmed
hat, and impermeable gloves would reduce lindane contact with the crucial
points of exposure, and would also reduce dermal exposure to the face,
head, and neck areas. The estimated reduction in risks to be achieved via
these risk-reduction measures is given in Table IV-3.
d. Ornamentals
1) Homeowner Use: Require that homeowners wear
long-sleeved work shirts and long pants, and impermeable (neoprene) elbcw-
lengrh gloves.
2) Commercial Use: Require that applicators wear
long-sleeved work shirts, long pants, impermeable (necprsne) elbow-length
gloves, and respirators.
For ornamental use lindane is applied as a
dilution (0.5 percent w/w lindane in solvent) of a 20 percent lindane
formulation via hand-held hydraulic or compressed-air sprayers. Use
patterns for ornamentals vary greatly and the range of possible exposure
varies with duration of spraying and the number of applications per season.
These exposures range from 30 rag/yr( dermal exposure) and 0.13 mg/yr
(respiratory exposure) for homeowners applying the chemical to a few trees
once a year, to a range of 90 - 3,600 mg/yr (dermal exposure)' and 0.54 -
21.6 mg/yr (respiratory exposure) for commercial nursery workers applying
the chemical to a large number of trees over a 15-day period. This
exposure range results in an estimated cancer risk to applicators of
roughly 2.4 x 10 -2.9 x 10 and margins cf safety of roughly 94
(fetotoxicity) and 47 (acute toxicity) for homeowners and from 31 - 12
(fetotoxicity) and from 15-6 (acute toxicity) for commercial applicators.
Measures short of cancellation by which exposure
and risks to applicators might be reduced were selected for consideration
based on their potential to reduce levels of dermal and respiratory
exposure for this use. Due to the application method involved, crucial
points of dermal exposure are hands, arms, and legs. Lindane is applied to
ornamentals in the form of a spray, and protective clothing could
reduce dermal exposure to these areas. The Agency has determined that
requiring commercial and homeowner applicators to wear long-sleeved work
shirts, long pants, and elbow-length impermeable gloves would reduce
iindane contact with the crucial points of dermal exposure. Commercial
applicators would have the added requirement of wearing a respirator, which
would eliminate respiratory exposure and further reduce dermal exposure by
protecting the face. Homeowner applicators would be exempt frcm this
requirement due to the cost cf che article and the short duration cf their
exposure to lindane. Table IV-3 snows the es-imared reductions in risk
which would be achieved via these risk-reduction measures.
-------
e. Cucurbits
Require that ^applicators j*ear lone-sleeved work
shirts and long pants.
For use on cucurbits lindane is applied with a row
crop boon sprayer. This procedure subjects applicators to both dismal and
respiratory exposure estimated at 0.42 mg/yr and 0.0126 mg/yr, respective-
ly. At this level of exposure, cancsr risks are estimated at 4.1 x 10
and margins of safety at 1,250 (acute toxicity) and 2,500 (fatotoxicity)•
Measures short of cancellation by which exposure and
risk to applicators night be reduced were considered by the Agency based on
their potential to reduce levels of dermal exposure, the primary source of
exposure and risk in connection with this use. Due to the application
method involved, non-impermeable clothing could reduce dermal exposure.
The Agency has determined that requiring applicators to wear long-sleeved
•*ork shirts and long pants would reduce dermal exposure to the arms and
legs, which are crucial points of exposure. The estimated reduction in
risks to be achieved via these risk-reduction measures is given in
Table IV-3.
f. Christmas Trees and Forestry
1) Christmas Trees: Require that applicators wear
long-sleeved work shirts and long pants, and impermeable (neopranej
aprons, _boots , and elbow-lenqrh cloves.
2) Forestry•;_ Require that applicators wear long-
sleeved work shirts and long pants, and impermeable (neoprene) elbow-
length gloves.
For use on Christmas trees and in forestry lir.dane
is applied either by small back-pack sprayers or by small tractors pulling
mini sprayers. These procedures subject applicators to dermal exposure
estimated at 224 mg/yr (forestry)and 28.3 - 1,008 mg/yr (Christmas trees)
and respiratory exposure estimated at 18 mg/yr (forestry) and 0.216 - 36
mg/yr (Christmas trees]. At this level of exposure cancer risks are
estimated at 1.9 x 10 (forestry) and 3.7 x 10 ~" - 6.8 x 10
(Christmas trees). Margins of safety are estimated at 18 (forestry) and
from 37-2 (Christmas trees) for acute toxicity and 36 (forestry) and
75-4 (Christmas trees) for fetotoxicity.
-------
Measures short of cancellation by which exposure
and risk to applicators might be reduced were considered by the Agency
based on their potential to reduce levels of dermal exposure, the primary
source of risks for these users. Due to the applicator methods involved,
both r.cn-impermeable and impermeable clothing are necessary to rsduca
dermal exposure. For use in forestry, crucial points of exposure are the
hands, arms, and legs. To reduce dermal exposure to these areas the Agency
has determined that applicators would have to wear long-sleeved work
shirts, long pants, and elbow-length impermeable (neoprene) gloves.
Christinas tree use of lindane poses added applicator exposure to the torso
and feet. As a result the Agency has determined that applicators would be
required to wear impermeable aprons and boots in conjunction with the risk-
reduction measures stated above. The estimated reductions in risk to be
achieved via these risk-reduction measures for forestry and Christmas tree
use of lindane is given in Tabls IV-3 •
g. Livestock
Require that applicators wear long-sleeved work
shirts and lone pants,and impermeable (neoprene) aprons, boots, and
elbow-length gloves.
For use on livestock lindane is applied as an emulsion
via pressurised spray to farm animals. This procedure subjects
applicators to exposure estimated at 5.4 - 6.6 mg/yr (dermal exposure) and
0.06 mg/yr (respiratory exposure). At this level of exposure, cancer risks
to applicators are estimated at 5.0 x 10 , and margins of safety at 415
(fetotoxicity) and 208 (acute toxicity)•
Measures short of cancellation by which exposure and
risk to applicators might be reduced were considered by the Agency based on
their potential to reduce levels of dermal exposure, the primary sources of
risks for this use. Due to the application method involved, the wearing of
long-sleeved shirts and long pants, and impermeable neoprene gloves,
aprons, and boots could viably reduce dermal exposure. The Agency has
determined that requiring applicators .0 wear long-sleeved shirts, long
pants, impermeable gloves, aprons, and boots would reduce dermal exposure
to the hands, trunk, and legs, which are the crucial points of exposure.
The estimated reduction in risks to be achieved via these risk-reduction
measures is given in Table IV-3. The Agency also is in the process
of evaluating suitable disposal or recycling requirements for the used
iincane product. The Agency solicits comments in this area and will
address it mere scecificallv in ?D 4.
1) Acoiicatcrs: Recuire that acolioatcrs wear lone-
sleeved work shirts, Icr.c cants , and impermeable (r.eocrene) elbow- ler.cth
cloves.
-------
2) Inhabitants: Measures shor~_ofcancellation not
practicable.
For use on structures iindane (0.5 percent w/w
lindane in water) is applied with a paint brush for small areas or applied
with a coarse spray for large areas. These procedures subject applicators
to dermal and respiratory exposure estimated at 558 - 1,116 mg/yr and 13 -
36 mg/yr respectively. Inhabitants are subjected to respiratory exposure
estimated at 60.48 mg/yr. At this level of exposure cancer risks are
estimated at 4.4 x 10 - 3.8 x 10 (applicators) and 4.6 x 10
(inhabitants). 'Margins of safety are estimated at 3 (applicators and
inhabitants) for acute toxicity and 416 (.applicators) and 5 (inhabitants)
for fetotoxicity.
Measures short of cancellation by which exposure
and risk to applicators might be reduced were selected for consideration
based on their viability as means to reduce levels of dermal and respira-
tory exposure. Crucial points of dermal exposure for applicators are the
arms, legs, and hands. Protective clothing requirements comprised of
long-sleeved shirts, long pants, and impermeable (neoprene) elbow-length
gloves would reduce the dermal contact to these crucial areas. The
estimated reduction in risks to be achieved via these risk-reduction
measures are given in Table IV-3.
i. Pineaooies
For use on pineapples lindane is applied by injection
via hoses from a supply tank regulated by pressure valves into the soil at
a depth of 3 to 78 inches under the planting line. Applicator exposure to
lindane is possible only through inhalation of vapors. Dermal exposure
does not occur since the application procedure prevents applicator exposure
via splashing or mists> Respiratory exposure to lindane for applicators is
estimated at 5.6 }j 10 mg/yr. At this exposure level cancer risks are
estimated at 10 ". Because current application procedures already
minimize exposure, no risk-reduction measures specific to this use were
considered ac-clica
Recuirs mat veterinarian
applicators wear protective clothing and impermeable (neocrer.e) apronjs and
albov~1ancth cloves.
This use of lindane subjects applicators to dermal
exposure estimated at 0.0312 mg/yr; respiratory exposure is negligible. At
this level of exposure, cancer risk is estimated at 2-4 x 10 and
margins of safety at 2.5 x 10 (fetotoxicity) and 1.3 x 10" (acute
effects).
-------
Protective measures by which exposure and risk to
veterinarian applicators might be reduced were selected for consideration
based on their viabilitv as means to reduce dermal exposure. Elbow-length
impermeable (neoorene) gloves and impermeable aprons worn over pror.act.ive
clothing would reduce dermal exposure to the hands, forearms, and torso,
the crucial points of contact. The reductions in risk anticipated via
these measures are given in Table IV-3. For home applicators, risk
reduction measures short of cancellation are deemed impracticable.
2) ?lea Collar, Dog Dusts, and Doc Shampoo
Lindane flea collars, dog dusts, and cog shampoos
are used primarily in the home by private pet owners. Risk-reduction
measures snort of cancellation are deemed impracticable.
k. Household Uses: Shelf paper, floor wax, general
purpose household spray, and smoke fumigation devices.
In connection with lindane household products, risk-
reduction measures short of cancellation are deemed impracticable.
1. Minor iJses
In connection with the various minor uses of lindane,
no submissions concerning benefits have been received, nor have Agency
efforts discovered any pertinent information. In the absence of data to
the contrary, the Agency has necessarily assumed that the economic
benefits involved are negligible. In view of the numerous, diverse minor
uses at issue and the apparently negligible benefits involved, the
development of use-specific risk-reduction measures short of
cancellation is deemed imcracticable.
-------
V. Proposed Regulatory Decision
As stated in Subsection IV.C, the Agency has developed three basic
regulatory options to be considered with respect to pesticide products
containing lindane:
1. Continue registration without restriction.
2. Cancel registration unless the terras and conditions of
registration are amended.
3. Cancel registration.
Subsection V.A below proceeds with a use-by-use analysis of the
risk/benefit impacts of the regulatory options. Subsection V.3 summarizes
the course of action which the Agency proposes to adopt and implement.
A. Risk/Benefit Analysis of Regulatory Options, Use-by-Use
1. Hardwood Logs and Lumber
If registrations of lindane products for use in the
hardwood logs and lumber industry were continued without restriction
(Option 1), an estimated 2/400 applicators would continue to be exposed to
lindane via. dip or spray treatments.,, Cancer risks to these applicators
would remain at an estimated 2.6x10 ~, and margins of safety would remain
approximately 11 (acute toxicity) and 22 (fetotoxicity). Under Option 1
•the benefits associated with this use, estimated at $147 million, would
likewise continue unaffected.
If registrations of lindane for use in the hardwood logs and
lumber industry wars continued with amended terms and conditions (Option
2), the following provisions would apply. All pesticide prcducts containing
lindane would be classified for restricted use, and applicator certification
would be required. The warnings to users, to women, and to parents
specified in Subsection IV.C.I.a would be required to appear on the labels
of all lindane products. Applicators would be required to wear impermeable
protective clothing (elbow-length neoprene cloves, neoprsne aprons, and
necprene boots), (Refer to Table IV-1.) Via these risk-reductioc
measures, cancer risks could be reduced from an estimated 2.6x10 ~ to
5.9x10 and margins of safety increased from 11 to 42 (acute toxicity)
and frcm 22 to S3 (fetotoxicity) . (Refer to Table IV-3.) The provisions
of Option 2 are expected to have a minimal impact on economic benefits.
If registrations of lindans oroducts for use In the hardwood
logs and lumber industry were cancelled (Option 2], ail iindane-related
risks to actlicators would be eliminated. The economic impacts whicn wouid
result frcm cancellation of this use are estimated at $147 million.
Presently, r.o alternative chemicals ara registered.
Having evaluated the cancer, acute toxic, and fetctoxic
risks cosed to acnlicators lr. conjunction with lindane use in the hardwccc.
-------
logs and lumber industry, the Agency has determined than continued,
unrestricted registration (Option 1) is unjustifiable. Option 2 would be
acceptable in this instance only if the reduced risks thereby achieved
were decidedly outweighed by benefits. Given the substantial risks which
would remain even if specified risk-reduction measures were implemented
(Table IV-3), the Agency's determination is that Option 2 would fail to
reduce risks to a level which would be outweighed by benefits and that
cancellation (Option 3) is warranted.
While the prospective long-term risks outweigh benefits ever
when the provisions of Option 2 are taken into account, the following
considerations lead the Agency to recommend cancellation to take effect
after a chase-out/interim period. As discussed in Subsection III.C.2., no
alternative chemicals are registered to control ambrosia beetles or
flat-headed and roundheaded borers , which are the pests of main economic
importance to the industry. Nor ars non-chemical methods available which
can viably control the target pests. Due to this lack of alternatives,
economic impacts estimated at $147 million are expected to fall to the
hardwood logs and lumber industry, which is characterized by a large numbei
of small, family-owned mills. Impacts are expected to fall primarily to
southern mills because that is where the insect problem is -.ost prevalent.
The possibility of mill closings is thereby raised.—
To encourage technological development of a suitable aiterna-
tive(s) fcr'use in the hardwood logs and lumber industry, and thereby to
moderate the major economic impacts expected to result from an immediate
cancellation, the Agency proposes cancellation to take effect after two
years, during which time ail of the amended terms and conditions cf
registration specified under Option 2 would apply. This time frame
reflects the Agency's best judgment regarding the time period necessary to
register an appropriate alternative. The Agency has received some
information that chlorpyrifos is a pesticide whose biological activity is
similar to lindane's and will provide adequate control for insect pests
found in hardwood logs and lumber. Chlorpyrifos has been registered for
use on live trees in forests and would therefore be expected to control
target pests in felled trees and cut lumber.
?I?SA and related regulations require the Agency ~o consida:
both the risks and the benefits associated with the uses of pesticides.
The proposed decision to cancel this use of lindane after two years, and
in the interim to amend the terms and conditions of registration, repre-
sents the Agency's best determination, taking into account the risks and
the benefits associated with iir.dane use in the hardwood legs and lumber
industry. As discussed above, the major economic impacts expected in
connection with an immediate cancellation can therabv be averted. Because
exposure to a-oolicators would be reduced from an estimated 40 vears
-------
(estimated lifetime exposure) to 2 years, cancer risk to applicators
wearing jjmpermeable protective clothing would be reduced from 6.9 :< 10
to 3.9 x 10 . Because during the 2-year phase-out/interim period,
applicators would be required to wear the impermeable protective clothing
specified under Option 2, margins of safety would be increased from roughly
11 to 42 (acute toxicity) and from 22 to 33 (fetotoxicity).
To recapitulate, the Agency proposes that lindane use in the
hardwood logs and lumber industry be cancelled to take effect after two
years in order to allow for the development/registration of a suitable
•alternative(s). During this 2-year phase-out/intsrim period, all of the
amended terms and conditions of registration specified under Option 2 will
apply.
2. Seed Treatments
If registrations of lindane products for use as a seed
treatment were continued without restriction (Option 1), an estimated
130,000 aoolicators would continue to be excosed to lindane.. Cancer risks
— " —3
to these applicators would remain at an estimated 3.3 X 10 , and
margins of safety would remain approximately 14 (acute toxicity) and 23
(fetotoxicity}. However, these calculations apply only to adults. Minors
are commonly involved in seed treatment application practices. Because
children are believed to be more susceptible to the toxic effects of
lindane than are adults, the MOS for children in connection with acute
effects is likely to be considerably lower. Under Option 1, the
unquantifiable econcmic benefits associated with iindane use as a seed
treatment would likewise continue unaffacted.
If registrations of lindane for use as a seed treatment were
continued with amended terms and conditions (Option 2), the following
provisions would apply. All pesticide products containing lindane would be
classified for restricted use, and applicator certification would be
required. The warnings to users, to women, and to parents specified in
Subsection IV.C.I.a would be required to appear on the labels of ail lindane
products. Applicators would be required to wear protective clothing (long-
sleeved shirts, long pants, gloves, and disposable paper masks). (Refer to
Table IV-1.) Via these risk-reduction measures, cancer risks could be
— D —O
reduced from an estimated 3.3 X 10 to 5.0 X 10 , and margins of
safety increased from 14 to 220 (acute toxicity) and from 23 to 440
( fetotoxicity) . (P.efer to Table IV-3 . ) The provisions of Option 2 are
expected to have a minimal impact on econcmic benefits.
The Acencv's evaluation of the imcacts of cancellation
(Option 3) of lindane seed treatment has bssn hampered by the lack of
benefits information submitted by the U.S. Department of Agriculture and
other- interested groups. Mevertheless, certain conclusions can be drawn.
For com acreage, ciazinon is an inexpensive alternative that is effective
against most com pests, and henca adverse economic impacts in corn are not
extected to occur. For small crains and other crocs, the benefits
situation is more crobiematical; civen the lack of aitarnatives. On
account of the lack of biological inf orrr.ation, the Agency has been unable
-------
to predict with any confidence the likelihood of ir.fastation or the loss
from given levels cf infestation, assuming no pesticide treatment. The
Agency dees believe, however, that based on the way in which lindar.e works
to protect: th.e ur.sprouted seed, it is basically an insurance treat.-7.enu and,
as such, is unlikely to be effective where heavy infestation occurs. Hence
the risks posed by corn seed treatment strongly outweigh the small benefits
for' that crop.
For the remaining seed treatment uses, the regulatory
decision is a difficult one. After careful consideration the Agency has
concluded that the risks cf use on these crops even reduced by protective
measures outweigh the benefits of use insofar as the benefits are presently
known and therefore recoiriEier.es cancellation. The Agency invites the agri-
cultural community and other interested groups during the comment period to
focus particular attention on the benefits of lindane seed treatment en
small grains, dry peas and lentils and the potential of developing alterna-
tives. The Agency will reevaluate its proposed decision in light of the
comments received.
Having evaluated the cancer, fetotoxic, and acute toxic
risks posed to applicators as well as the dietary cancer risk to the
general public in conjunction with lindane use as a seed treatment, the
Agency has determined that continued, unrestricted registration (Option 1)
is unjustifiable. Option 2, which would continue registrations with
amended terms and conditions, would be acceptable in this instance only if
the reduced risks thereby achieved were decidedly outweighed by benefits.
Given the ur.quantif iabie benefits associated with this use, however, and
given the substantial risks, including a dietary cancer risk (Table II-5),
which would remain even if specified risk-reduction measures were
implemented, an Agency determination that the benefits associated with
lindane seed treatment are of sufficient macnitude as to outweich risks
.,,_,.., , . ..."•/ ," , . . '
wouid be r-icnlv ssecu.La-.ive in casis,— The Acer.cv r.as tnererore
2/
— Data in tne Agency's possession indicate tnat r.eitner ciazincr. nor
chiorpyrifos poses unreasonable adverse effects.
- .-.egistraticr.s of heptachlor are being phased cut en the basis cf
carcincgenicity.
— The Agency points cut that the burden cf prcof with respect to the
benefits of a pesticide as used for its intended purpose lies with the
registrants. A general lack of data concerning the frequency of wire-
worm infestation and ccmoarati'.'e data ccncernir.c the extent cf crco
damace and vieid loss attributable to the tarcat tests, with and withcui
lindane seed treatment, contributed to the trctcsed cancellation. Any
-------
determined that Option 2 is unacceptable and that cancellation (Option 3)
is warranted. The Agency recommends than Option 3 be implemented with the
call for additional information and cancellation of registrations of
lindane products for use as a seed treatment is hereby proposed.
3. Avocados
If registrations of lindane products for use on Florida
avocados were continued without restriction (Option 1), an estimated 275
applicators would continue to be exposed to lindane via high-exposure spray
treatments. Cancer risks to these aoolicators would remain at an estimated
—4 —
6.2 X 10 , and margins of safety would remain very low: approximately 4
(acute tcxicity) and 7 (fetotoxicity). Under Option 1, the economic
benefits, estimated at S3.7 million associated with lindane use on Florida
avocados would likewise continue unaffected.
If registrations of lindane for use on avocados were
continued with amended terms and conditions (Option 2), the following
provisions would apply. All pesticide products containing lindane would be
classified for restricted use, and applicator certification would be
required. The warnings to users, to women, and to parents specified in
Subsection IV.C.I.a would be required to appear on the labels of all
lindane products. Applicators would be required either to wear protective
clothing (long-sleeved shirts, long pants, and wide-brimmed hats) and
impermeable gloves or to employ a roof-type shelter on machinery being
used. (Refer to Table IV-1 . ) Given the climate conditions of Florida,
however, whether protective clothing would in fact be worn is admittedly
cruestionable. Via these risk-reduction .measures , cancer risks could
—4 —o
theoretically be reduced frcm 6.2 X 10 to 2 X 10 , and margins of
safety increased frcm 4 to 15 (acute toxicity) and from 7 to 31
(fetotoxicity). (Refer to Table IV-3.) The provisions of Option 2 are
expected to have a minimal impact en economic benefits.
If registrations of lindane products for use on avocados
wers cancelled (Option 3), all lindane-related risks co applicators as well
as a cancer dietary risk would be eliminated. The economic impacts which
would result frcm cancellation of this use ara estimated, based on the
projections of local experts, at 53.7 million and would be experienced by
Florida growers,— assuming no change in grading standards. Although
no chemical alternatives are currently registered for mirid control,
several premising alternatives (such as acephate) are undergoing testing.
Preliminary indications suggest that these chemicals may prove efficacious
for mirid control. Parathicn, presently used only in California, is
available for control of webbincrworrs . Anticicatad losses
5/ As noted in Subsection III.S.3, this estimate rslias heavily u~or.
information provided by persons with expertise in Florida avocado
production and assumes that their projections of crop loss are
accurata. No data are available concsrninc tha extent of viald
loss attributable to mirids, with and wi-hcut iindane spray
-------
are strictly from lack of mirid control. Because California produces
almost 80 percent of the nation's avocados,—7 no impact on -he
availability of avocados nationwide is expected, and should the gracing
standard for avocados be amended there could be no significant impact
resulting from cancellation.
Having evaluated the cancer, fetotoxic, and acute toxic
risks posed to applicators in conjuncticn with lindane use en avccadcs,
the Agency has determined, chat these risks are unacceptably high and that
continued, unrestricted registration (Option 1) is unjustifiable. Option 2,
which would continue registrations with amended terns and conditions, would
be acceptable in this instance only if the reduced risks thereby achieved
were decidedly outweighed by benefits. Given the high level of exposure
associated with this use of iindane, however, substantial risks would
remain even if the specific provisions of Option 2 were implemented. Also
these low margins of safety and high cancer probability are not offset by
firmly substantiated benefits attributable to iindar.e as an anti-mirid
pesticide.— The Agency has therefore determined that Option 2 is
unacceptbie and that cancellation (Option 3} is warranted. Option 3 is
hereby recommended, and cancellation of registrations of lindane products
for use on avocados is proposed.
4. Ornamentals
If registrations of lindane products for use on ornamentals
were continued without restrictions (Option 1 ) , an estimated 30-1,200
professional applicators and an estimated 75,000 homeowner/applicators
would continue to be exposed to iindane via spray treatments to control
corers, thrips, and iaafmir.ers on a variety of floral and foliage plants
and woody ornamentals.. Cancer risks to these aooiicatcrs would remain at
. " ~3 " " -3 - j
an estimated 2.4 X 10 (homeowners) and 7.3 X 10 to 2.9 X 10
(commercial users), and margins of safety would remain approximately 47
for homeowners ar.d 5-16 for commercial users (acute toxicity) and 94 for
homeowners and 12-31 for commercial users (fetotcxicity). However, these
calculations apply only to adults. .Margins of safety for acuta effects in
children involved in application processes are likely to be considerably
lower. Under Option 1, the aconcmic benefits associated with lindane use
on ornamentals, roughly estimated at $20.e million fcr commercial growers
of ornamentals, would likewise continue unaffacted.
Pesticide use by California avocado growers is very limited, and
California has not reported using iincar.e in avocado groves.
The Agency is aware that the Agricultural Research and Education
Center of the University of Florida is currantly conducting
pesticide field trials on the avccado/mirid/lir.dane issue. The
experiments ire scheduled for completion in
-------
If registrations of lindane for use on ornamentals were
continued with amended terras and conditions (Option 2), the following
provisions would, apply. For commercial use, all pesticide products
containing lindane would be classified for restricted use, and applicator
certification would be required. The warnings to users, to worsen, and to
parents specified in Subsection IV.C.I.a would be required to appear on
the labels of all lindane products. Commercial applicators would be
required to wear protective clothing, impermeable gloves, and a respirator.
Via these risk-reduction measures cancer risks for commercial applicators
could be reduced from an estimated 7.3 X 10 - 2.9 X 10 to -4.1 X 10
-3.8 X 10 and margins of safety could he increased from. 5-16 to 41-
125 (acute toxicity) and from 12-31 to 8-3-25 (f atotoxicity) . (Refer to
•Table IV-3 . )
For home use, homeowner/applicators would be required to
wear protective clothing (long-sleeved shirts and long pants) and elbcw-
length impermeable gloves. Via these risk-reduction measures cancer risks
to homeowner/applicators could be reduced frcra an estimated 2.4 x 10 to
5.0 x 10 and margins of safety could be increased from 47 to 132 (acute
toxicity) and 94 to 335 (fetotoxicity). (Kefar to Table IV-3.) The
provisions of Option 2 are expected to have a minimal impact on economic
benefits.
If registrations of lindane products for use on ornament: a is
were cancelled (Option 3), all lindane-related risks to applicators would
be eliminated. The economic impacts which would result from cancellation
of this use are estimated at 520.6 million to commercial growers of
ornamentals. Impacts to homeowners would be largely aesthetic and such
are not cuantifiable. In areas where borer infestations are oarticularly
oroblamatic, homeowners misht be forced to abandon cajrtain soecies of wccdv
'd /
ornamentals or to employ professional pest control."" Presently,
lindane is the only pesticide registered t:o control ail borers on woody
ornamentals. Although alternative pesticides are generally available for
pest control on floral and foliage plants, only two alternative pesticides,
chiorpyrifos and andosulfan, are registered for borer control on woody
ornamentals. — However, these two alternative pesticides ara effective
on.lv on selected soecies of ornamentals.
— The cos- of professional treatment would range from roughly 320.00
to 555.00 per treatment per yard (Memo 13303.
9 /
— Data available to the Agencv indj_cazs that neither cr.lcr'ovri.rcs r.cr
endos'ilfan coses unreasonable adverse effects.
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Because the risks and benefits associated with lindane 'use
by commercial growers of ornamentals differ from those associated with
homeowner use, tha Agency has necessarily considered these two applications
separately. Regarding commercial applications, the Agency has evaluated
the cancer, fetotoxic, and acute toxic risks posed to applicators and has
determined that under current use patterns, risks decidedly outweigh
benefits. Continued, unrestricted registration has therefore been found
unjustifiable. At the opposite end of the regulatory spectrum,
cancellation (Option 3! would eliminate all lindane-related risks to the
professional applicators involved. In view of the economic impacts
(estimated at 20.5 million) expected to fall to commercial growers of
ornamentals as a result of a lindane cancellation, however, and in view of
the substantial reductions in risk which can be achieved by measures short
of cancellation (Table IV-3), the Agency has concluded that Option 3 does
not represent an appropriate risk/benefit determination in this instance.
Ooticn 2 is therefore recommended. The Agency herebv orcposes that
registrations of lindane products for use on commercial ornamentals ba
continued with the amended terms and conditions specified.
Regarding home applications, the Agency has evaluated the
multiple risks posed to homeowner/applicators and has again determined that
under current use patterns, benefits are clearly outweighed by risks arid
that Option 1 (continued, unrestricted registration) is therefore
unjustifiable. Although if rigorously implemented, the provisions of
Option 2 (continued registration with amended terms and conditions) would
measurably reduce risks to homeowner/applicators, Option 2 would not reduce
risks to a level which would ensure no adverse effects to the large number
of persons involved. It is Questionable, moreover, whether the orotactive
clothing requirements of this option are practicable in connection with
homeowners. In view of the risks which would continue to be posed to
homeowner/applicators even when the risk-reduction provisions of Option 2
are taken into account, and in view of the largely aesthetic benefits
involved, the Agency has determined that Option 2 fails to reduce risks to
a level which is outweighed by benefits. Option 3 (cancellation) is
therefore reccmmendac. The Agency hereby proposes that registrations of
iindane oroducts intended for home ornamental use be cancelled. —
10 /
— The Agency's risk/benefit determination concerning homeowr.er use of
lindane on ornamentals was based on the application of lindane as a
spray (typical rormuiatJion: 0.^ percent w/w ..means soiutr.cn) .
Tha Agency is aware of a 2-peroent paste formulation -hat is also
registered for use on ornamentals. However, the Acencv has r.o data
certaininc to usace, aooiicator exposure, or benefits uccn which to
evaluate this croduct. Anv additional information on this
formulation submitted io the Agency will be taken into account in
the final decision to be issued in Position document 4.
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5. Curcurbits
If registrations of lindane products for use on cucurbits
were continued without restrictions (Option 1), an estimated 950
applicators would continue to be exposed to iindane via treatments with row
cron boom soravers aoolvina a 0.06 w/w (Iindane weicht to water) sorav_.
- _ - ^ - - - - - - - =.0
ror tr.ese applicators, estimated car.car risk would remain at 4.1 X 10
and margins of safety would remain approximately 2500 (fetotoxicity) and
12SO (acute toxicity). Under Option 1, the benefits associated with lindens
use on cucurbits would regain unaffected. The economic benefits associated
with this use axe estimated at 2.4 million collars for Florida, South
Carolina, arid Georgia. —
If registrations of Iindane products for use on cucurbits
were continued with amended terns and conditions (Option 2), the following
provisions would apply. All pesticide products containing Iindane would be
recuired to disolav the label warnings specified in Subsection IV. C.1.a.
Lindane products would be classified for restricted use, and applicator
certification would be recuired. Acolicators would be required to wear
protective clothing (long-sleeved work shirts and long pants). (Refer to
Table IV-1.)
Implementation of these risk-reduction measures would reduce
car.csr risks from 4.1 X 10 to 4.0 X 10 and increase estimated
margins of safety from 2500 to 25,000 (fetotoxicity) and from 1250 to
12-,500 (acute effects). (Refer to Table IV-2 . ) The provisions of this
oction are expected to entail no significant imoact on economic cenerits<
If registration of Iindane products for use on cucurbits
were cancelled (Cctior. 3), all risks associated with Iindane would ce
eliminated. For the reasons discussed in Chapter III, cancellation of
Iindane would not result in significantly decreased yields. Furthermore,
the minor impacts projected for increased treatment costs of alternatives,
$175,000, may be high insofar as it assumes that the growers in certain
areas will switch to methcmvi which is bv far the most extensive
alternative.
The Agency has evaluated the cancer, fetotcxic, and acute
toxic risks posed to applicators in conjunction with Iindane use on
(Option 1) is unjustifiable. Even if the risk reduction measures of Option
2 were adopted, the risks would still outweigh the benefits. Accordingly,
the Acencv has selected Cotion 3 - Cancellation.
'_]_/ Data concerning use on cucurbits is available only for Florida,
-------
o . Christmas Trees
If registrations of lincar.e products for use on Christmas
trees were con ringed without restriction (Option 1), an estimated 10,000
asoiicators (crivate Christmas tree orowers ) would cqn-tir.ua to be excosed
" ~ ~ * I tL /
to -Li.nca.-ie via foliar, stu.~p, and trur.k treatments. ~ Car.oer risks to
these applicators would remain at an estimated 3.7 X 10 to 6.3 X 10
margins of safety would remain at a ranee of 2-37 (acute toxicity) and 4-75
( f etotoxicity ) . Under Option 1, the economic benefits ( uncuantif ied)
associated with lincar.e use on Christmas trees would likewise continue
unaf f ected .
ns of iir.dane for use on Christmas trees were
continued with amended terns and conditions (Option 2), the following
provisions w-ouic apply. All pesticide products containing lindane would b
classified for restricted use, and applicator certification would be
required. The warnings to users, to woman, and to parents scecified in
Subsection ~/.C.1.a would be required to appear on the labels of ail
lincar.e products. Applicators would be required to wear protective
clothing and imcermeable (neoorer.e) acrons, boots, and elbow-length gloves
(Refer to Table IV-1.) Via these risk-reduction measures , .cancer risks
-3 -4
couia se reduced , from an estimated 3.7 x 10 - 5.3 X 10 to 2 . 0 X
10 - 1 . 7 X 10 , ar.d margins of safety increased from 2-37 to 8-70
(acute toxicity) from 4-75 to 15-139 ( f etotoxicity ). (Kefer to Table IV-
3 . ) The provisions of Option 2 are expected to have a mininai impact on
economic benefits .
If regst
trees were cancelled (Option 2], ail iindane-relatad risks to applicators
would be eliminated. Given a lack of data on annual usage, rhe economic
Impacts which would result from cancellation of this use were u_-.cuar.tif i-
ahie . Based on a qualitative analysis, however, the Ager.cy projects that
these inpacts will be r.inor , although it is possible that certain indivicuaj
growers night experience :najor impacts. Cxyderr.eton-aethyi , which is
approximately 1.2 to 2 tir\es the cost per acre of lincar.e, is available to
control one of the target cests , white oine weevils . Chemical control can
also be supplemented by non-chemical cultural practices what should provide
control over the insect population.
Having evaluated the car.cer , fetotoxic, and acute toxic
risks cosed to aoolicators in conjunction with lindane use on Christmas
trees, the .-.cency has determined that continued, 'unrestricted recistrstion
\Cption ', } is ur.jusriiia.bie. Option 2, which would continue registrations
with amended ter-.s and cor.dizions , would be acceptable in this instance
industrv wera unavailable. •
-------
only ir the reduced risks thereby achieved wers decidedly outweighed by
benefits. Given the uncuantifiable benefits associated with this use
together with the availability of chemical and non-chemical alternatives,
and given the risks which would remain even if specified risk-reduction
measures were implemented, the Agency's determination is that Option 2 is
unacceptable and that cancellation (Option 3) is warranted. The Agency
therefore recommends that Option 3 be implemented, a_nd cancellation of
registrations of iindane products for use on Christmas trees is hereby
oroccsed.
ir registrations or iincane procucts ror use on pecans
were continued without restriction (Option 1), an estimated 1200 applicators
would continue to be exposed to Iindane via high-exposure spray treatments.
Cancer risks to these applicators would remain at an estimated 3.1 x 10 ,
and margins of safety would remain very lev,: approximately 4 (acute
tcxicity) and 7 (fetotoxicity). under Option 1, the economic benefits,
estimated at $1.4 million, associated with Iindane usa en pecans would
likewise continue unaffected.
If recistrations of Iindane for use on oecans were continued
with amended terms and conditions (Option 2), the following provisions
would apply. Ail pesticide products containing iindane would be classified
for restricted use, and applicator certification would be 'required. The
warnings to users, and to women, and to parents specified in subsection
IV.C.I.a would be required to apcear on the labels of ail Iindane products.
Applicators would be recruired 1) to wear protective clothing (long-slesved
shirts, long pants, and wide-brimmed hats) and elbow-length impermeable
(neoprene) cloves, or 2 ) to employ z. roof-type shelter on machinery being
used. (Refer to Table IV-1.} Via these risk-reduction measures, cancer
risks to applicators could be reduced from 3 . 1 :< 10 to 7.5 x 10 ,
and margins of safety increased from 4 to 15 (acuta tcxicity) and fro.- / to
31 ( fatotoxicity} . (?,afar to Table IV-3 . } The provisions of Option 2 are
expected to have a very miner impact on economic benefits.
If registraticns of Iindane products for use on pecans were
cancelled (Option 3), ail iindane-rsiated risks to applicators as well as
dietary cancer risk to the general public as a result of this use of the
cesticide would be eliminated. The economic imcacts resulting rrcm tne can-
cellation of the use would be neciigible. Snccsulfan is currentlv reels-
tared for cecar.s in Mississipci 'under JURA 24(c) and has federally
sndosuifan can be recistersd .and used as a substitute in -ost areas wnere
... . . . ' -;/
iinoane is crurrentiv usea. ~
alternatives c-cse ur.resscnabie adverse errects.
-------
Having evaluated the cancer, acute toxic, and fetotoxic
risks cosed to aoolicators the Agency has determined that these risks are
unacceptabiy high and that continued, 'unrestricted registration (Option 1)
is unjustifiable. Option 2, which would continue registration with amended
terms and conditions, would be acceptable in this instance only if the
reduced risks thereby achieved were decidedly outweighed by benefits.
Given the minor economic benefits, associated with this use, and given the
substantial exposure and risk which would remain even if specified risk-
reduction measures were rigorously implemented, the Agency's determination
is that Option 2 is unacceptable and that cancellation (Option 3) is
warranted. The Agency therefore recommends that Option 3 be implemented,
and cancellation of recistration of iindana products for use on pecans is
hereby proposed.
3. Forestry
If registrations of lindane products for 'use in forestry
were continued without restriction (Option 1), an estimated 1000 applicators
would continue to be exposed to lindane via spray treatments• Cancer risks
to these applicators would remain at an estimated 1.9 x 10 and margins
of safety would remain approximately 36 (fetotoxicity) and IS (acute
toxicity). Under Option 1, the economic benefits (unquantifiabie}
associated with lindane use in forestry would likewise continue unaffected.
If registrations of lindana for use in forestry were
continued with amended terms and conditions (Option 2], the following terms
and conditions would acpiy. All zestici-de products containing iincar.e
would be classified for restricted use, and applicator certification wcuio
be. required. The warnings to users, to woman, and to parents specified in
Subsection IV.C.I.a would be required to appear on the labels of ail iindane
products. Applicators would be required to wear protective clothing and
aibow-iencth imcermaabie (neoorene) gloves. (?,efer to Table IV-'.) These
are the game protective clothing recuiremer.ts set by the U.S. Tcrest
Service. — Via these risk-reduction measures, cancer risks could be
reduced from an estimated 1.9 x 10 to 5 .5 x 10 "*, and margins of
safety increased from 36 to 42 (fetotoxicity} and 13 to 21 (acute toxicity).
(Refer to Table IV-3.) The orovisions of Cation 2 are sxoected to have a
If registrations of iindane for use in forestry were
cancalisd ,'Ccticr. 3) , ail iindane—related risks to acoiicatcrs vcu_-r. oe
u.S, Department of Acriculture Forest Service, Southeast
Southeastern L'nitsd States."
-------
which would result frcn
However, the Agency projects that impacts wcuid be borne by Southern
forestry, primarily by private land owners. Wo impact could be determinad
rcr seed orchards and naval stcres-oroducir.g trees . ?.ecistered alternative
chemicals include endosulfan and dicrotoohcs. Recent test results indicate
that chlorpyrifos is likely to be more effective than iindane for use in
forestry. Cultural practices can also be employed to supplement these
cheaiical alternatives.
Having evaluated the cancer, fetotoxic, and acute toxic
risks posed to applicators in conjunction with iindane use in forestry, the
Agency has determined that continued, 'unrestricted registration (Option 1)
is unjustifiable. Option 2, which would continue registrations with
amended terms and conditions, would be acceptable in this instance only if
the reduced risks thereby achieved were decidedly outweighed by benefits.
Given the unquantifiable benefits associated with this use together with
the availability cf alternatives, and given the substantial risks whicn
would remain even if specified risk—reduction measures were implemented,
the Agency's determination is that Option 2 is unacceptable and that
cancellation (Option 3) is warranted. The Agency therefore recommends that
Option 3 be implemented and proposes that registrations of iindane products
for use in forestry be cancelled. The Agency makes this reccrrjr.endation
for ail forestrv uses othar than those associated with brcadscale blow
downs of trees. In such a case, aerial application of Iindane would result
j_n lower application risks and benefit would be high. The Agency solicits
comments on this and will provide a specific position in ?D 4.
9. Livestock
If registrations of Iindane products for 'use en livestock
were continued without restrictions (Option i), an estimated 250,000
applicators would continue to be exposed to Iindane via dip and spray-
treatments. Sstimatsd cancer risks to these applicators would remain 5.0 x
10 ~" and margins of safety would remain 415 (f atotoxicity) and 208 (acute
tcxicity; with no change in the risks associated with dietary exposure.
Under this option, the benefits associated with Iindane use on livestock,
estimated at Si,083,400, would likewise remain unaffected-
If registrations of iindane products for use en livestock
were continued with amended terms and conditions (Option 2), tne roncwir.c
provisions would aooiy. Lindane oroducts would be classified for
products would be required to display the label warnings to users, to
wccien, and to parents specified in Subsection "7 . C . 1 . a . Applicators wcuic
oe required to wear orotective ciothina and impermeable (necorene) arrcns,
boots, and elbow-length giovas. (xefar to Table IV-1.) Implementation of
5.0 x 10 to 1.3 x 10 " and increase ~ar~ir.s of safetv frcm 415 to
IV-2 . ) These "revisions are extected to have -s. neciicibla imcact en
econcmic benefits.
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iz registrations or pesticice prccucts containing iincane
for use on livestock were cancelled (Option 3), ail iir.dane-reiated risks
to applicators would be eliminated. Alternative chemicals would have to be
substituted for iindane, resulting in a total economic impact estimated, at
31,083,400.00. This represents a minor economic impact, entailing no
effect on oroduction yield or auality. However, alternatives are not as
effective as lindane for control of mites, and a cancellation would leave
users without any acecruata means of controlling mites on livestock. A
recent publication by the National Academy of Science (Lar.gford, 1980)
documents the recent soread of scabies among cattle in crowded commercial
feedlots and recommends the use of lindane because a single application is
effective in controlling mites. Alternatives, including coumaphos ana
phosmet, are less effective, recuire multiple abdications, and are
believed to lead to cenetioaiiv induced resistance. The only otner
alternative for mite control is tcxaphene, which has been presumed to pose
unreasonable adverse effects and is currently under ?_?A?. review.
Having evaluated the cancer, fetotoxic, and acute toxic
risks posed to applicators as well as the dietary cancer risk posed to the
general public in conjunction with lindane use on livestock, the Agency has
determined that continued, unrestricted registration (Option 1) is unjusti-
fiable. Cancellation (Option 3) would eliminate ail exposure and risk
associated with this use of lindane. However, Option 3 would be warranted
only if measures short of cancellation would not suffice to reduce risks to
a level which is outweighed by benefits. Given the benefits associated
with iincane usa against mites which infest livestock, and given the
decreased risks associated with the implementation of the specified risk
reduction measures, the Acencv's determination is that cancellation (Ccticn
3) is unwarranted. The Agency therefore recommends that Option 2 oe
implemented and that registrations of iindane products for use on livestock
be continued with specified asended terms and conditions.
10. Structures
If registrations of lindane products for use in structures
were continued without restriction (Option 1), an estimated 40,000
inhabitants (10,000-12,000 houses) and 300-1000 applicators would continue
to be exposed to lindane. Cancer risks to these inhabitants ate applicators
would remain an estimated 4.6 x 10 and 4.4 x "0 "to 3.3 x 10
respectively. Margins of safety for inhabitants would remain approximately
3 (acute toxicity) and 415 (fetotoxicity), while these for applicators
would remain approximately 2 (acute toxicity; and 3 ;fstotcxicity} . These
children are likely to be considerably lower. Under Cpticn 1, the economic
benefits (unquantiflad) associated with lindane use on structures would
likewise continue unaffected-
continued with amendsd tsrms and conditions (Ctticn
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Iindane products. Anoiicators would be reouired to wear trotactive
clothing, elbow-length impermeable (naoprane) glovas and s. respirator.
(Refer to Table IV-1.) Via these risk reduction measures, cancer risks to
applicators couidbe reduced from an astimated 4.4x10 -3.3x10"
to 1.2 x 10 - 2.5 x 10 , and margins of safety increased from 3 to
13 (acute tcxicity) and from 5 to 3" (fetotexicity). Risks to residents
ana their children would remain unchanged. The provisions of Option 2 are
expected to have a minimal impact on econcmic benefits.
If registrations cf iindane products for use on structures
were cancelled (Option 3), all iindane-related risks to applicators and to
residents would be eliminated. The economic impact of cancelling the
structural use of iindane is likely to be slight because infestation can be
prevented or retarded by finishing wood surfaces, where feasible, and
because, in the event of infestation,^3C? is available as an effective and
economically competitive alternative.-— The conclusion that cancel-
lation of the powder post beetle use of Iindane will cause minimal economic
impact is supported by the fact that powder post beetle infestations spread
slowly, and that not all infestations require treatment to prevent economic
damage.
Having evaluated the cancer, fetotoxic, and acute toxic, and
fatotoxic risks posed to applicators and to residents, especially children,
in conjunction with Iindane use on structures, the Agency has determined
that continued, unrestricted, registration (Option 1) is unjustifiable.
Option 2, which would continue registrations with amended terms and
conditions, would be acceptable in this instance only if the reduced risks
thereby achieved were cecidedlv cutweicned bv benefits. Given the
unquantifiab-ie benefits associated with this use, and given the substantial
risks which would remain even if specified risk-reduction measures were
implemented, th-a Agency's determination is that Option'2 is unacceptable
and that cancellation (Option 3) is warranted. The Agency therefore
recommends that Option 3 be implemented, and cancellation cf registrations
of iindane products for use en structures is hereby proposed.
1 1 . Pineapples
If registrations of iindane products for use in Hawaiian
oineaopie fields were continued without restriction (Option 1), an
estimated !,SOO workers would continue to be exposed -o iindana primarily
via innaiation. However, anticipated hourly excosura (5 x 10 } is so
is estimated at 10 '", and margins of safety at 4.3 x 10' (acute
effects) and 2.3 x 10 (fetctoxicity). "near Cpticn 1, the benefits
-------
If registrations cf iir.dane for use on Hawaiian oir.eacoie
fields were continued with amended terms ar.d concisions (Option 2), tne
following provisions would apply. Ail pesticide products containing
lindanewould be classified for restricted use, ar.d applicator certification
would be required. The warnings to users, to women, and to parents
soecified in Subsection IV.C.I.a would be required to appear or. the labels
of all lindaneproducts. Although no measurable reductions in risk can be
attributed to these provisions, the Agency maintains that restricted use
classification and requirements for applicator certification and label
warnincs are orudentorscautior.ary measures in any instance involving
potential exposure, howeversmaii, to lincane. The provisions of Option 2
are axcectad to have a negligible impact on acor.crr.ic benefits •
If registrations cf lindane for usa in Hawaiian pineapple
fields were cancelled (Option 3), all exposure to applicators would be
eliminated. The Hawaiian Pineapple Growers Association has estimated that
if iir.dane were unavailable for use on pineapples, the Hawaiian pineapple
industry would have to aisorb an economic loss cf 51,103,367 (1977 dollars)
over each 4-year production cvcle. Cancellation of this use would mean
that growers would have no method cf syrr.phyiid control in cases of late
infestations or adverse soil conditions. At present, there are no non-
chemical methods of controlling symphyiids. Certain soil fumigants which
orimariiv control neinatoces heio to control svmchvlids, but these have no
..,". .. - ""," To/
resicuai action ana orrer no protection against _ate inrestatior.s . ~
Moreover, soil fumicants vacorize off the fields in very moist or
improperly prepared soil.
Because the cancer, fetotcxic, and acute toxic risks
associated with lindane use on aineaoole fields are so low as to oe
statistically insignificant, and because no acceptable alternatives are
available which can replace lindane in its roie in dual soil treatments,
the Agency has determined that benefits outweigh risks even though quanti-
fiable benefits (51,013,357 •; 1977 dollars; over =ach -1-year production
cycle) are considered minor. Cancellation (Cpticn 3) is therefore inappro-
priate. Given the scecial sensitivitv oc childrsn to the toxic effects o-
iindane, however, and given the susceptibility of •inborn children to the
fetotcxic effects of the pesticide, continued registration ;Cpticn ')
seems imprudent even though exposure and risk are very lew. However, since
applicators already are required to use protective cicthing when using
f'imiganto, additional requirements are unwarranted because of the
extrameiv low carcinccenic risk. Therefore, the Agencv racommenc
continued registraticn with the general labeling precautions spec
iindane.
CLbrccicchlorocrc-ane (3BC?), athviene cibrcmice >'ZC3), Teicne, and
-------
12. ?et Uses
a . Dog Washes
Lincar.e dog washes are currer.tiv available for use bv
both veterinarians and orivate oet owners. If recistratior.s were continued
without restriction (Option 1), an estimated 15,000,000 non-veterinarian
applicators and an estimated 130,000 veterinarian applicators would
continue to be exposed to iindane in connection with this use. Cancer
risks to these applicators would remain at approximately 2.4 x 10
(Post-application cancer risk is estimated at 7 :< 10 .) Margins-of
safety would remain roughly 2.5 x 10 (fetotoxicity) and 1.3 x 10
(acute effects). (Post-application margins of safety are estimated at 1.4
x 10 [fetotoxicityj and 0.7 x 10^ [acute effects].) However, these
calculations apply only to adults. Margins of safety for acute effects in
children are likely to be considerably lower. Under Option 1, the benefits
(unquantifiable but assessed in qualitative terms as minor) associated witn
tnis use wou^ d continue '--na ^-1" °. c t ~d •
Ir registrations were continued with amended terms and
conditions (Option 2), the following provisions would apply. The warnings
to users, to women, to parents specified in Subsection IV.C.I.a would be
recuired to atcear on the labels of iindane doc washes. Lincar.e cog wasnes
would be classified for restricted use, the products would be designated
for veterinarian apnlication oniv, and veterinarians would be required to
obtain applicator certification. In addition, veterinarian applicators
would be required to wear protective clothing ar.c impermeable aprons and
elbow-length cloves. (Refer -o Table ~/-i.) Cancer risks to veterinarian
apciicators would thereby be reduced for an estimated 2.4 x 10 to 4.3 x
10 , and margins of safetv for fetctaxicitv and acute effects would be
increased to 1.2 x 10" and 5.2 x 10 respective!-/ (Table IV-3).
Because pet owners would no longer be allowed to apply Iindane doc washes,
nazard to this coouiaticn would be limited to oost-aoolication exposure.
If registrations were cancelled (Option 3), exposure
and risk to both oet owners ar.c veterinarians would be eliminated. In
economic terms, the Impact (ur.quantif iabie) of this cancellation is
expected to be minor. To cancel Iindane doc washes, however, would be to
remove from the market the pesticide reportedly most effective against
scabies (mange;-causing mites. A
(Langford, 12SO).
-------
In the absence of ar.v ecuallv affective alternative to iinclar.e for us-e
against scabies-causing mites, however, the Agency has concluded that
Option 3 is likewise unacceptable. Option 2 is therefore recommended. The
Agency proposes that registrations of iindane dog washes be continued with
the specific amended terms and conditions of registration designated above.
o- Flea Collars, joe Dusts, and Coc Shamcoos
If registrations cf lindane flea collars, dog dusts,
and dog shampoos were continued without restriction (Option 1), ar>.
undetermined -unbar of pet owners, including children, would continue to be
exposed to iincans in connection with these primarily non-veterinarian
uses. — Cancer risks would remain at an estimated 2 :< 10 (flea
collars), 1.5 x 10 "" for applicators and 1,9 x 10 post-application
(dog dusts), and 3.6 x 10 for applicators and 2 x 10 post-
application (doc shampoos).
Margins cf safety for fetotoxicity would remain roughly
3 :< 10 (fisa collars), 33,000 (dog dusts), and 16,555 (dog shampoos). -
Margins of safety for acute effects would remain approximately 1 .-J x 10
(flea collars), 41,500 (cog dusts), and 3,333 (dog shampoos). Post-
application y.CS for dog dusts and dog sham.pccs would remain at 5250
(fatotoxicity) and 4530 (acute effects) and 3S40 (fetotoxicity) and 1920
(acute effects), respectively. However, these calculations apply only to
adults. Marcins of safety for acute effects in children are likely to be
considerably lower. Cnder Option 1, the benefits (un qua ntifi able but
projected as minor) associated with these pet uses would likewise continue
unaffected.
If recistratlor.s were continued with amended terms and
conditions (Option 2), the warnings to users, to wcmen, and to parents
specified in Subsection IV.C.1.a would be recuired to artear on the labels
of ail iindane flea collars, dog dusts, and dog shampoos. Altncugr. no
measurable reduction in risk can be attributed to warninc labels, the
A—er.cv considers warning statements to be a reasonable crecauticnary
measure in any instance invciving exposure to lindane. Label warninc
If recistrations of these ret uses wore cancelled
(Cpticn 3), exposure and risk to pet owners wculd be eliminated. Given tne
general availabili-v of effective alternatives, the imract cf thess cancel-
lations is extected to ba very minor, though no ruantitative assessment was
_r. tne concentratrcns necessarv lor cest centra-, _rncan= is
tOAtc to cats, but net to docs. Cr.lv Chi: currently reccmmer.ds
-means for usa acainst flaas en cats .
-------
The Agencv has evaluated the cancer, fete-toxic, and
acute toxic risks posed to users and especially to children in connection
with lindane flea collars, dog dusts, and. dog shampoos and determined that
continued, 'unrestricted registration (Option 1) is unjustifiable. Given 1)
the imoracticaiity of any provision short of cancellation which could bring
about .cneasursbie reductions in exposure and risk, 2) the likelihood that
children are exc-osed- to lindane via these pet uses, and- 3) the -minimal
benefits involved, the Agency's determination is that Option 2 (continued
registration with amended terms and conditions) is likewise unacceptable.
Cancellation (Option 3) is therefore proposed. The Agency recommends that
registrations of iindane flea collars, cog dusts, and dog shampoos ee
cancelled.
13. Household uses
c. General Purpose Household Soray
d. Smoke Fumieration Devices
If registrations of lindane shelf paper, fleer wax,
General c-urccsa household sorav, and smoke rustication devices were
continued without restriction (Cotion 1), a large number of users and their
children would continue to be exposed- to lindane in connection witn tnese
household uses. ~' Cancer risks would remain at approximately 3.9 :<
10 " (shelf paper), S..7 :< 10 (floor wax), 6.0 x 10 ' (household
spray), and 1.1 x 10 (smoke fumigation devices). Margins of safety fcr
fetctcxicitv would re-main roughlv 5,000 (shelf paper), 1,250 (floor wax),
3.S x 10 (household spray), and 700 ( sir.cka fumigation devices). Margins
of safety for acuta effects would remain roughly 3,OCO (shelf paper;, 62~
( f locr wax), 1.9 x 10 (household soray), and 350 (smoke fumigation
•devices). However, these calculations apply only to adults. Margins o~
safety for acute effects in children are likelv to ba considerably lower.
under Gcticn 1 , the benefits (uncuantif iabie but crojected as very mir-cr)
associated with lindane household uses would likewise continue ';^naf f ected.
If registrations of iindana household uses were
continued with amended terms and conditions (Cpticn 2), the warnings to
users, to women, -and to parents specified in Subsection .17. C. '. . a wcu_c c-e
required to appear on the labels of ail lindane creducts intended for
paper is 11,000,000. The number cf persons exposed to fleer wax
is estimated at '00,000,000. The number of cerscns execsed
-------
If registrations of iindane shelf paper, floor wax,
general purpose household spray, and smoke fumigation were cancelled
(Option 3), all iir.dar.e-reiatsd risks to users would be eliminated. The
economic impact of these cancellations is axpected to be minor, though da
lij.i~at.ions have precluded quantitative assessment. Numerous alternatives
to linear.** for these household purposes ars currently available, including
dianinon , maiathicn, naphthalene, paradichiorobenzene , methoxychlcr , and
dichiorvos .
Having evaluated the cancer, fetotoxic, and acute toxic
risks pcsad to users and especially to children in connection with lindane
household uses, the Agency has determined that continued, unrestricted
registration (Option 1) is unjustif lable . In view of 1) the ^.practicality
of any provision short of cancellation which could measurably reduce
exposure and risk, 2) the inevitable exposure of children in connection
with these household uses, and 2} the minimal benefits involved, the
Agency's determination is that Option 2 (continued registration with
amended terns and conditions) is likewise unacceptable. Cancellation
(Coticn 3) is therefore recommended. The Ager.cv oroooses that registrations
or iincane shelf paper, floor wax, general purpose household spray, and
smoke fumicaticn devices be cancelled.
14 . Minor usas
a . M-L no r 'J 5 a s Specific?. 1 ly Under ?.g v lew •
1 } Industrial rjse .'-'.cth Scrav
2) Uninhabited Builc.inc Insect Sorav
3} Zmctv Stcrace Bin F~c Strav
If r scis tra tions of the above named miner uses
were continued without registration (Option 1), an undetermined numJter of
aooiicators would continue to be extcsed to lindane. ;-ost-appIication
axtos'urs is also involved wherever industrial moth scrav is used. Cancer
~ 3 ~ 3
ris.-;3 would remain at " .3 x !0 for aooiicatcrs and ' . " x 10 for
post-application exposure (rncth spray), 1.9 x 10 " ( ^ininhabi ted building
insect spray), and 3.5 x 10 (empty storage bir. fee spray,1. Margins of
safety for f 2 tctoxicitv would remain at 2 x iO and 500 '.moth sorav :
apoii~atcr and post-application exposure, respectively), 135 ( 'ininhaoitac.
safety for acute effects would remain at 5 .x 10 and 4JC .moth spray:
applicator and post-application exposure, respectively;, c£ { uninhaoiteo
1, the benefits ; -uncuantif iable but oro'.ected as minor, associated with
these uses would likewise continue ur.aff acted.
it r e c i s t r a t i c " s w e r ^ c c *~ 1 1 ~ u e d w ~- " ~. am* e "^ d e d t e r m s
_^' _^_4;J_'— l_t^ ' r~- *-^ ,' _ _ ^ \ „ '^ ^ _r^l •^^,.,__, _,.,.^....,' «^ ^_.— • ••", • ' ' — — -»^-".. "".-*^l
«..O ^.^'.H.C.^.u.^^^;.^ '.. ^ T2 ^. — O * » *. s i _ .. , 5 _O_— v^ iv_.^CJ ^__/v_ci__Vj..i f*^, ~. „ v. z~ •- -* ^. t • ...^-
-------
v» czn3ii y cLnci ^*o c-cijrsjrz'^s stDSC'^jLsci ^ ^ 3LIJDS^"""tuLor T"V 0 1 2. woxi^ '"^ '"*'o "*"^<~-i7~i ~^^ ~^
appear or. the labels of these products. The provisions of Option 2 are
expected to have a negligible imract en economic benefits.
If registrations wara cancelled (Option 3), all
exposure ar.d risk associated with these minor uses would be eliminated. No
data concerning the economic benefits of these uses are available to the
Agency. In the absence of such information, given the lengthy public
notice and the attempts by the EJr.V'USDA/State assessment team to obtain
data the Agency must proceed on the assumption that ths economic impacts of
these cancellations would be sini~al.
*n r/j_ev/ or tne ca.ncer / retotox—c , and acute tcx~c
risks oosed to applicators in conjunction with those r\incr uses which are
specifically under review, ar.d in view of the ir.inisal benefits involved,
the Acencv has ceta.rr.ined that neither Ootion 1 (continued, unrestricted
registration) nor Option 2 (continued registration with amended terns and
conditions) is justifiable. Option 3 (cancellation) is therefore
reconiaended, The Agency proposes that registrations of the ainor uses of
lindane be cancelled.
b, gther^J-lincr Uses
In addition to chose minor uses of lindane specifically
under review, the numerous other minor uses of lindane are reccnmencad ;or
cancellation. These include use of lindane on lettuce, rnushrocms,
tomatoes, apples, apricots, asparagus, broccoli, Brussels sprouts, cabbage,
cauliflower, celery, cherries, ccilards, eggplants, grapes, guavas, kale,
kohlrabi, r.ancoes, tr.ustard greens, nectarines, okra, onions, peacr.es,
—^ 3* JT "5 / C^-S ^^"::'"r"S ™! 1 ^ • *~i •£: ~ r^ ", t* z". f *i r" ''""Ct:vS ;~"C.1'"^ W« ~* *" ~^~"" "^ S '"'"^O o'^'SS C"2.'r"sZ*
Together these croo uses likely account for a- sizable proportion or tne
dietary intake and risk (Table II-5).
3. Sumciajrv of Prcpcsad ?.egulatcrv Sacisior.
1 . Hardwood Locs and Lurrh-er
Option 3. Cancel rsclstrations to take effect after two
racuirsc. Specified warnings to users, to wccsn, and to parents :r.ust
appear en the labels of all lindane products. —' .Applicators will be
-cots, and eibow-iencth neotrene cicves).
-------
Option 3 . Cancel registrations •
3. Ayecaccs
Cpticn 3. Cancel registrations.
4. Orr.aiTisr.~i Is
a . CoB-j.erciai Us a
Option 2. Cor.tir.ua registrations with the following arne-dec
terzis and conditions of registration, lir.dans products for ccrrcrierc^ai i.iS2
will b« classified for restricted. U3a, and applicator cartificaticn will be
racuirad. Specified war~incs to users, to wcraen, and to pa.rsr.ts ricst
appear or. the labels of all lir.dane products. Cc~~.=rcial applicators will
be rscruired to wear trctscti"/e clcthir.a (lor.c-siaeved work shirts ar.d -or.g
pants), slbcw-iar.gth jjsip-errr.eable (neoprana) cloves, and a respirator.
b . Hor.eowr.er Us a
Option 3. Cancal racistratior.s.
5. Cucurbits
Octicn 3. Cancel raciscraticr.s ,
CT3tJ.cn 3. Cancsl racriscratior.s
:arr.s ar.d ccr.citior.s of registration. lindar.e prccucts w^__ -e
-------
Option. 2. Continue registracicr.s wi~h tha following
air.endriant to the tar-;S an-d conditions of registration. Specified warnings
to users, ~o women / and to parents ."nusc accear en the labels of ail lindana
produces .
12. Pst^ Us as
a. . Dec Washes
Option 2. Continue recistz'aticns with the follcwinc
amended terras and conditions, Lir.dana produc-s will be classified ;'or
rss~xicted use and iiraitsd to vatarinarian aaolications onlv; acnlicator
certification will be rscniired. Soecified warnings to users, co women, ana
to parents rr^jjst acceaj;' on ths labels of all lindane orcducts • Vatarinarian
acolicatcrs will be recuired to wear protective clothing (long-sleeved work
shirts and long pants), elbow- lang-ch i-r.perneable (~eoprene) gloves and
neoprane aprons.
h- Flsa Collars , Doc Dusts, and Doa Sh^ain'ooos
Option 3. Cancel registrations •
1 3 . Ho use h o 1 a U s e s
Option 3 . Cancel registrations .
Cotion 3 . Cancel recisr.ration3 .
-------
Lir.dane : Position Document 2/3
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14
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14
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'*>' CO .i. JT I. C CTS W , ^ . 1 S J~<3 . ' J'" 3 CS_m~i.:i j_SC™ S "^ 3^ '"* r1 X3.C (*3 " S " " ~'-'.-
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ISA
19
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Burroughs Weiicccr.a Cac-.p3.ny
Burroughs Wailccrua Ccnpanv"
Raed and Carr.rich rha.rr.aceu-icals
Con.c.insr.t:al Chsnisca Corocra
[451 ?.2d 331 (7-.: Cir Occka
33
Paper
.-.coxsr Chaff..-.-a.
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