United States
Environmental Protection
Agency
Prevention, Pesticides
And Toxic Substances
(7508C)
EPA-738-F-02-011
Revised April 2004
vvEPA R.E.D. FACTS
Pesticide
Reregistration
Lindane
All pesticides sold or distributed in the United States must be registered by
EPA, based on scientific studies showing that they can be used without posing
unreasonable risks to people or the environment. Because of advances in
scientific knowledge, the law requires that pesticides which were first registered
before November 1, 1984, be reregistered to ensure that they meet today's more
stringent standards.
In evaluating pesticides for reregistration, EPA obtains and reviews a
complete set of studies from pesticide producers, describing the human health and
environmental effects of each pesticide. To implement provisions of the Rxxl
Quality Protection Act of 1996, EPA considers'the special sensitivity of iniants
and children to pesticides, as well as aggregate exposure of the public to pesticide
residues from all sources, and the cumulative effects of pesticides and other
compounds with common mechanisms of toxicity. The Agency assesses the risk
associated with the use of the pesticide, and develops mitigation measures or
regulatory controls to effectively reduce each pesticide's risks. ER\ then
reregisters pesticides that meet the safety standard of the EQPA and can be used
without posing unreasonable risks to human health or the environment.
When a pesticide is eligible for reregistration, EPA explains the basis for its
decision in a Reregistration Eligibility Decision (RED) document. This feet sheet
summarizes the information in the RED document for the reregistration of
lindane.
Use Profile Lindane is an organochlorine insecticide used as a pre-plant seed treatment
for barley, corn, oats, rye, sorghum, and wheat. The pesticide is formulated into
dust, emulsifiable concentrate, flowable concentrate, and liquid ready-to-use
products. Lindane is applied to seeds using the following equipment: liquid seed
treater, planter/seed box, air seed treater, canister tube applicator, and slurry-type
seedtreater. Approximately 233,000 Ibs of active ingredient of lindane are used
annually for seed treatment.
Lindane is also currently approved by the U.S. Food and Drug
Administration (FDA) for use in pharmaceutical products intended to control head
lice and scabies (mites) in humans.
xx-a
73BF02 011
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Regulatory
History
Human Health
Assessment
Lindane was first registered as a pesticide in the U.S. in the 1940's for use
on a wide variety of food crops, ornamentals, livestock, homeowner, and other
sites. In 1977, EPA initiated for lindane a Rebuttable Presumption Against
Registration (RB\R) review, now called a Special Review. The lindane RB\R
was triggered based on questions of oncogenicity, fetotoxicity/ teratogenicity,
reproductive effects, its potential to cause blood dyscrasias, and acute toxicity to
wildlife. EPA published Position Documents (PDs) in 1977 through 1983,
resulting in the cancellation of certain uses of lindane.
EPA. issued a Registration Standard for lindane in September 1985, which
included a Data Call-In (DCI) requiring submission of additional data to support
the lindane registration and address exposure concerns from treated structures and
animals. After issuance of the 1985 Registration Standard, many of the registered
uses of lindane were cancelled, resulting in only seed treatment use on six crops
(barley, corn, oats, rye, sorghum, and wheat) that still remain registered and
subject to rcregistration.
Toxicity
Lindane primarily affects the nervous system. In acute, subchronic, and
developmental neurotoxicity studies and chronic toxicity/oncogenicity studies,
lindane was found to cause neurotoxic effects. Lindane also appears to cause
kidney (renal) and liver (hepatic) toxicity. In addition, there is some evidence
that lindane may act as an endocrine disruptor; however, further investigation is
necessary to ascertain the relevance and impact of such findings on public health.
In 2001, ER\ classified lindane as having "suggestive evidence of
carcinogeniciry, but not sufficient to assess human carcinogenic potential" based
on an increased incidence of benign lung tumors in female mice only. Therefore,
pursuant to Agency cancer guidelines, cancer risks were not quantified.
Dietary Exposure
EPA assessed dietary risk by estimating exposure to lindane residues from
consumption of food and drinking water that can occur over a single-day (acute)
or longer (chronic). The acute and chronic dietary (food) risks are less than
100% of the acute Population Adjusted Dose for the general U.S. population and
all population subgroups. Infants (< 1 year)-and children (1-6 years) were the
most highly exposed population subgroup for acute and chronic exposure,
respectively.
Because lindane persists in the environment and has long-range
atmospheric transport potential, the Agency performed a supplementary chronic
dietary risk assessment for the subsistence diets of indigenous peoples of the
Arctic region of the U.S. (Alaska) who rely heavily on game for their food
source. For indigenous people of Alaska, the chronic dietary risks are generally
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Human Health
Assessment
Continued
not of concern, and although the Agency does not have information on a typical
day's diet to assess acute dietary risk, limited residue data indicates that acute
dietary risks are unlikely to be of concern.
Drinking water exposure to lindane can occur through ground and surface
water contamination. EPA used models to conduct a screening-level assessment
of potential high-end estimates of lindane concentrations in surface and ground
water sources of drinking water from seed treatment uses.
Pharmaceutical Use Risk
Lindane has been approved by the FDA as a prescription drug to treat lice
and scabies. EB\ has conducted an assessment of these uses to determine the
risk of a lice or scabies treatment. Based on the Agency's current understanding
of available data, the Agency does not believe that lindane pharmaceutical
products used for treatment of lice pose human health risks of concern, when
used in accordance with directions provided on the label. However, based on
other blood-level analyses, the Agency cannot conclude at this time with
reasonable certainty that exposure to lindane through scabies treatment will not
result in unacceptable exposure and risk.
Risk from All Registered Pesticide Lindane Exposures
To assess risks from all lindane exposures, the Agency combined risk from
food and drinking water exposure only, because there are no registered
residential or other non-occupational uses of lindane that need to be considered
for regulatory purposes at this time. POT the agricultural seed treatment uses of
lindane, both acute and chronic estimated drinking water concentrations are below
the corresponding drinking water level of comparisons (DWLOCs) for all
drinking water sources, and are not of concern to the Agency.
Occupational Exposure
Occupational exposure to lindane occurs either on-farm.or at commercial
seed treatment facilities to farmers or workers who mix, load and/or apply
lindane as a seed treatment, and persons who handle or plant treated seed. Based
on the Agency's assessment, on-farm handling of the lindane dust formulation to
mix/load and plant treated seed result in risks of concern. Because of the lower
seed planting rate, the on-farm treatment of corn and sorghum seeds with the
lindane dust formulation is permitted, provided additional personal protective
equipment (PPE) is utilized. Commercial treatment of seeds with the liquid
formulation for all registered uses is permitted. Also, the Agency has no risk
concerns for post-application exposures to agricultural workers, and no risk
mitigation measures are necessary beyond a 24-hour restricted entry interval
(REI). However, provided the soil is not disturbed and there is no contact with
the treated seeds, workers may enter the planted field during the 24-hour REI,
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Environmental ERVs ecological risk assessment for lindane suggests that the use of
Assessment l^1^3116 can result in adverse acute and chronic effects to terrestrial organisms,
and adverse acute effects to aquatic organisms. Lindane is also a potential
endocrine disrupter in birds, mammals, and possibly fish.
Avian (dietary) aversion toxicity studies and a field study suggest that birds
are repelled by treated seeds; hence, the Agency believes that the risk to birds by
treating certain seeds with lindane are lower and not of concern. Moreover, the
Agency believes that the risks for local populations of mammals in areas where
lindane treated seeds are planted are low, and that mammals may be similarly
averse to eating seeds treated with lindane. Although the assessment indicates
acute risks of concern for freshwater fish and invertebrates, and estuarine marine
invertebrates, the screening-level model used to assess these risks has likely
produced highly conservative estimates which overestimated the environmental
concentrations and resulting risks to aquatic species. Actual aquatic risks are
expected to be lower and not of concern, and the Agency is requiring data to
confirm this determination.
Risk Mitigation
Measures
To mitigate human health and ecological risks of concern for lindane, the
following measures are to be implemented:
• On-farm treatment of wheat, barley, oats, and rye with the lindane dust
formulation is prohibited;
• Maximum application rate for corn is reduced to 0.0558 Ib ai/100 Ib seed;
• Workers must wear double layer clothing (coveralls over long-sleeved shirt
and long pants, chemical-resistant footwear), chemical-resistant gloves, and
a dust/mist respirator for on-iarm treatment of corn and sorghum seeds
only with the dust formulation;
• A 24-hour REI is necessary for all seed treatment uses;
• All lindane end-use product labels must specify a 30-day plantback interval
for leafy vegetables and a 12-month plantback interval for all other
unregistered crops. The registrant may also conduct a confined
accumulation of rotational crops (OPPTS 860.1850) study to show that
these plantback intervals can be reduced.
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Additional Data
Required
EPA is requiring the submission of the following additional generic data to
confirm the regulatory decision for lindane:
• OPPTS 830.6314 Oxidation/reduction: chemical incompatibility
• OPPTS 830.6317 Storage stability
• OPPTS 830.7050 UV/Vfeible light absorption
• OPPTS 860.1300 Nature of residue (plant metabolism study)
• OPPTS 835.SS01 Seed leaching
Additional studies are currently reserved and may be required, pending
results of the studies listed above. See the lindane RED document for norther
details.
The Agency also is requiring product-specific data, including product
chemistry and acute toxicity studies, and revised Confidential Statements of
Formula (CSFs).
Regulatory
Conclusion
EPA has determined that all existing tolerances for lindane should be
revoked. These tolerances are no longer necessary because all lindane products
for which the tolerances were originally established have been canceled. EPA. has
also determined that a number of changes to the terms and conditions of
registration of the seed treatment products are necessary to prevent
"unreasonable adverse effects on the environment." EPA has identified additional
data needed to characterize lindane metabolites in order to complete its
assessment of potential dietary risks. Finally, EPA has determined that the use of
lindane for seed treatment is likely to result in residues in raw agricultural
commodities derived from plants grown from seeds treated with lindane.
Therefore, new tolerances are required before the currently registered lindane
products may be reregistered. In sum, lindane seed treatment products would be
eligible for reregistration if the registrants make the changes to the registration
terms and conditions specified in the RED document, provide the required data,
and EPA is able to establish all required tolerances for residues of lindane in
food.
EPA notes that the establishment of new tolerances for the seed treatment
uses of lindane is conditioned on: 1) the receipt and review of additional data to
characterize lindane metabolites; and 2) ERVs ability to make a determination
that establishing the new tolerances meets the safety standard in Federal Rxxl,
Drug and Cosmetic Act (FFDCA). EPA is considering whether the statute
requires the Agency to include in its safety assessment those exposures resulting
from the use of lindane in pharmaceutical products.
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For More EPA is requesting public comments on the Reregistration Eligibility
Information ^)ec^s'on (RED) document for lindane during a 60-day public comment period, as
announced in a Notice of Availability published in the Federal Register on
September 25, 2002. You may access this federal Register notice on the Internet
through ERVs website at http://www.epa.gov/fedrgstr/ .
The Federal Register notice describes how to access the RED and related
documents and submit comments, including how to use ERVs electronic public
docket and comment system, EPA Dockets. EPA Dockets is available on the
Internet at http: //www. epa. gov/edocket/. Electronic copies of the RED and all
supporting documents related to the Agency's decision on lindane are available on
the internet and can be accessed at http://www.epa.gov/reregistration/lindane .
Printed copies of the RED document and feet sheet are available from
EPA's National Service Center for Environmental Publications (EPA/NSCEP),
PO Box 42419, Cincinnati, OH 45242-2419, telephone 1-800490-9198; fex
513489-8695.
Following the comment period, the lindane RED document also will be
available from the National Technical Information Service (NTIS), 5285 ft>rt
Royal Road, Springfield, VA 22161, telephone 1-800-553-6847, or 703-605-
6000.
For more information about EBVs pesticide reregistration program, the ""
lindane RED, or reregistration of individual products containing lindane, please
contact ERVs Office of Ffesticide Programs, Special Review and Reregistration
Division at 703-308-8000, or visit our website at http://www.epa.gov/pesticides/.
Fbr information about the health effects of pesticides, or for assistance in
recognizing and managing pesticide poisoning symptoms, please contact the
National Raticide Information Center (NPIQ. Call toll-free 1-800-858-7378,
from 6:30 am to 4:30 pm Pacific Time, or 9:30 am to 7:30 pm Eastern Standard
Time, seven days a week. Their Internet address is http://npic.orst.edu.
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