[Federal Register Volume 62, Number 131 (Wednesday, July 9, 1997)]
[Rules and Regulations]
[Pages 36665-36671]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-17591]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[OPP-300509; FRL-5728-8]
RIN 2070-AB78


Lambda-cyhalothrin; Time-Limited Pesticide Tolerance

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: This regulation establishes a time-limited tolerance for the 
combined residues of lambda-cyhalothrin and its epimer in or on rice. 
The names for lambda-cyhalothrin and its epimer are as follows: Lambda-
cyhalothrin, a 1:1 mixture of (S)-alpha-cyano-3-phenoxybenzyl-(Z)-
(1R,3R)-3-(2-chloro-3,3,3-trifluoroprop-1-enyl) -2,2- 
dimethylcyclopropanecarboxylate and (R)-alpha-cyano-3-phenoxybenzyl-
(Z)-(1S,3S) -3-(2-chloro-3,3,3-trifluoroprop-1-enyl)-2,2-
dimethylcyclopropanecarboxylate and Epimer of lambda-cyhalothrin, a 1:1 
mixture of (S)-alpha-cyano-3-phenoxybenzyl-(Z)-(1S,3S)-3-(2-chloro-
3,3,3- trifluoroprop-1-enyl)-2,2-dimethylcyclopropanecarboxylate and 
(R)-alpha-cyano-3-phenoxybenzyl-(Z)-(1R,3R)-3-(2-chloro-3,3,3-
trifluoroprop-1-enyl)-2,2-dimethylcyclopropanecarboxylate. The Zeneca 
Ag Products requested this tolerance under the Federal Food, Drug and 
Cosmetic Act (FFDCA), as amended by the Food Quality Protection Act of 
1966 (Pub. L. 104-170). The tolerance will expire on November 15, 1997.

DATES: This regulation is effective July 9, 1997. Objections and 
requests for hearings must be received by EPA on or before September 8, 
1997.

ADDRESSES: Written objections and hearing requests, identified by the 
docket control number, [OPP-300509], must be submitted to: Hearing 
Clerk (1900), Environmental Protection Agency, Rm. M3708, 401 M St., 
SW., Washington, DC 20460. Fees accompanying objections and hearing 
requests shall be labeled ``Tolerance Petition Fees'' and forwarded to: 
EPA Headquarters Accounting Operations Branch, OPP (Tolerance Fees), 
P.O. Box 360277M, Pittsburgh, PA 15251. A copy of any objections and 
hearing requests filed withthe Hearing Clerk identified by the docket 
control number, [OPP-300509], must also be submitted to: Public 
Information and Records Integrity Branch, Information Resources and 
Services Division (7506C), Office of Pesticide Programs, Environmental 
Protection Agency, 401 M St., SW., Washington, DC 20460. In person, 
bring a copy of objections and hearing requests to Rm. 1132, CM #2, 
1921 Jefferson Davis Hwy., Arlington, VA.
    A copy of objections and hearing requests filed with the Hearing 
Clerk may also be submitted electronically by sending electronic mail 
(e-mail) to: [email protected]. Copies of objections and 
hearing requests must be submitted as an ASCII file avoiding the use of 
special characters and any form of encryption. Copies of objections and 
hearing requests will also be accepted on disks in WordPerfect 5.1 file 
format or ASCII file format. All copies of objections and hearing 
requests in electronic form must be identified by the docket control 
number [OPP-300509]. No Confidential Business Information (CBI) should 
be submitted through e-mail. Electronic copies of objections and 
hearing requests on this rule may be filed online at many Federal 
Depository Libraries.

FOR FURTHER INFORMATION CONTACT: By mail: George T. LaRocca, Product 
Manager (PM) 13, Registration Division (7505C), Office of Pesticide 
Programs, Environmental Protection Agency, 401 M St., SW., Washington, 
DC 20460. Office location, telephone number, and e-mail address: 
Crystal Mall #2, 1921 Jefferson Davis Hwy., Arlington, VA, (703) 308-
6100, e-mail: [email protected].

SUPPLEMENTARY INFORMATION: In the Federal Register of February 19, 1997 
(62 FR 7454; FRL-5585-5), EPA, issued a notice pursuant to section 408 
of the Federal Food, Drug, and Cosmetic Act (FFDCA), 21 U.S.C. 346a(e) 
announcing the filing of a pesticide petition (PP 6F4769) for tolerance 
by Zeneca Ag Products, 1800 Concord Pike, P.O. 15458, Wilmington, DE 
19850-5458. This notice included a summary of the petition prepared by 
Zeneca Ag Products, the registrant. There were no comments received in 
response to the notice of filing.
    The petition requested that 40 CFR 180.438 be amended by 
establishing a tolerance for combined residues of the insecticide 
lambda-cyhalothrin and its epimer (CAS NO. 91465-08-6; EPA Chemical NO. 
128867), in or on rice grain at 1.0 parts per million (ppm), rice straw 
at 1.75 ppm, rice hulls at 5.0 ppm. Subsequent to this filing EPA 
recommended that the tolerance on rice straw be rounded off to 1.8 ppm.

I. Risk Assessment and Statutory Findings

    New section 408(b)(2)(A)(i) of the FFDCA allows EPA to establish a 
tolerance (the legal limit for a pesticide chemical residue in or on a 
food) only if EPA determines that the tolerance is ``safe.'' Section 
408(b)(2)(A)(ii) defines ``safe'' to mean that ``there is a reasonable 
certainty that no harm will result from aggregate exposure to the 
pesticide chemical residue, including all anticipated dietary exposures 
and all other exposures for which there is reliable information.'' This 
includes exposure through drinking water and in residential settings, 
but does not include occupational exposure. Section 408(b)(2)(C) 
requires EPA to give special consideration to exposure of infants and 
children to the pesticide chemical residue in establishing a tolerance 
and to ``ensure that there is a reasonable certainty that no harm will 
result to infants and children from aggregate exposure to the pesticide 
chemical residue. . . .''
    EPA performs a number of analyses to determine the risks from 
aggregate exposure to pesticide residues. First, EPA determines the 
toxicity of pesticides based primarily on toxicological studies using 
laboratory animals. These studies address many adverse health effects, 
including (but not limited to) reproductive effects, developmental 
toxicity, toxicity to the nervous system, and carcinogenicity. Second, 
EPA examines exposure to the pesticide through the diet (e.g., food and 
drinking water) and through exposures that occur as a result of 
pesticide use in residential settings.

A. Toxicity

    1. Threshold and non-threshold effects. For many animal studies, a 
dose response relationship can be determined, which provides a dose 
that causes adverse effects (threshold effects) and doses causing no 
observed effects (the ``no-observed effect level'' or ``NOEL'').
    Once a study has been evaluated and the observed effects have been 
determined to be threshold effects, EPA generally divides the NOEL from 
the study with the lowest NOEL by an uncertainty factor (usually 100 or 
more) to determine the Reference Dose (RfD).

[[Page 36666]]

The RfD is a level at or below which daily aggregate exposure over a 
lifetime will not pose appreciable risks to human health. An 
uncertainty factor (sometimes called a ``safety factor'') of 100 is 
commonly used since it is assumed that people may be up to 10 times 
more sensitive to pesticides than the test animals, and that one person 
or subgroup of the population (such as infants and children) could be 
up to 10 times more sensitive to a pesticide than another. In addition, 
EPA assesses the potential risks to infants and children based on the 
weight of the evidence of the toxicology studies and determines whether 
an additional uncertainty factor is warranted. Thus, an aggregate daily 
exposure to a pesticide residue at or below the RfD (expressed as 100 % 
or less of the RfD) is generally considered acceptable by EPA. EPA 
generally uses the RfD to evaluate the chronic risks posed by pesticide 
exposure. For shorter term risks, EPA calculates a margin of exposure 
(MOE) by dividing the estimated human exposure into the NOEL from the 
appropriate animal study. Commonly, EPA finds MOEs lower than 100 to be 
unacceptable. This 100-fold MOE is based on the same rationale as the 
100-fold uncertainty factor.
    Lifetime feeding studies in two species of laboratory animals are 
conducted to screen pesticides for cancer effects. When evidence of 
increased cancer is noted in these studies, the Agency conducts a 
weight of the evidence review of all relevant toxicological data 
including short-term and mutagenicity studies and structure activity 
relationship. Once a pesticide has been classified as a potential human 
carcinogen, different types of risk assessments (e.g., linear low dose 
extrapolations or MOE calculation based on the appropriate NOEL) will 
be carried out based on the nature of the carcinogenic response and the 
Agency's knowledge of its mode of action.
    2. Differences in toxic effect due to exposure duration. The 
toxicological effects of a pesticide can vary with different exposure 
durations. EPA considers the entire toxicity data base, and based on 
the effects seen for different durations and routes of exposure, 
determines which risk assessments should be done to assure that the 
public is adequately protected from any pesticide exposure scenario. 
Both short and long durations of exposure are always considered. 
Typically, risk assessments include ``acute'', ``short-term'', 
``intermediate term'', and ``chronic'' risks. These assessments are 
defined by the Agency as follows.
    Acute risk, by the Agency's definition, results from 1-day 
consumption of food and water, and reflects toxicity which could be 
expressed following a single oral exposure to the pesticide residues. 
High end exposure to food and water residues are typically assumed.
    Short-term risk results from exposure to the pesticide for a period 
of 1-7 days, and therefore overlaps with the acute risk assessment. 
Historically, this risk assessment was intended to address primarily 
dermal and inhalation exposure which could result, for example, from 
residential pesticide applications. However, since enaction of FQPA, 
this assessment has been expanded to include both dietary and non-
dietary sources of exposure, and will typically consider exposure from 
food, water, and residential uses when reliable data are available. In 
this assessment, risks from average food and water exposure, and high-
end residential exposure, are aggregated. High-end exposures from all 3 
sources are not typically added because of the very low probability of 
this occurring in most cases, and because the other conservative 
assumptions built into the assessment assure adequate protection of 
public health. However, for cases in which high-end exposure can 
reasonably be expected from multiple sources (e.g. frequent and 
widespread homeowner use in a specific geographical area), multiple 
high-end risks will be aggregated and presented as part of the 
comprehensive risk assessment/characterization. Since the toxicological 
endpoint considered in this assessment reflects exposure over a period 
of at least 7 days, an additional degree of conservatism is built into 
the assessment; i.e., the risk assessment nominally covers 1-7 days 
exposure, and the toxicological endpoint/NOEL is selected to be 
adequate for at least 7 days of exposure. (Toxicity results at lower 
levels when the dosing duration is increased.)
    Intermediate-term risk results from exposure for 7 days to several 
months. This assessment is handled in a manner similar to the short-
term risk assessment.
    Chronic risk assessment describes risk which could result from 
several months to a lifetime of exposure. For this assessment, risks 
are aggregated considering average exposure from all sources for 
representative population subgroups including infants and children.

B. Aggregate Exposure

    In examining aggregate exposure, FFDCA section 408 requires that 
EPA take into account available and reliable information concerning 
exposure from the pesticide residue in the food in question, residues 
in other foods for which there are tolerances, residues in groundwater 
or surface water that is consumed as drinking water, and other non-
occupational exposures through pesticide use in gardens, lawns, or 
buildings (residential and other indoor uses). Dietary exposure to 
residues of a pesticide in a food commodity are estimated by 
multiplying the average daily consumption of the food forms of that 
commodity by the tolerance level or the anticipated pesticide residue 
level. The Theoretical Maximum Residue Contribution (TMRC) is an 
estimate of the level of residues consumed daily if each food item 
contained pesticide residues equal to the tolerance. In evaluating food 
exposures, EPA takes into account varying consumption patterns of major 
identifiable subgroups of consumers, including infants and children. 
The TMRC is a ``worstcase'' estimate since it is based on the 
assumptions that food contains pesticide residues at the tolerance 
level and that 100% of the crop is treated by pesticides that have 
established tolerances. If the TMRC exceeds the RfD or poses a lifetime 
cancer risk that is greater than approximately one in a million, EPA 
attempts to derive a more accurate exposure estimate for the pesticide 
by evaluating additional types of information (anticipated residue data 
and/or percent of crop treated data) which show, generally, that 
pesticide residues in most foods when they are eaten are well below 
established tolerances.

II. Aggregate Risk Assessment and Determination of Safety

    Consistent with section 408(b)(2)(D), EPA has reviewed the 
available scientific data and other relevant information in support of 
this action, EPA has sufficient data to assess the hazards of lambda-
cyhalothrin and its epimer, and to make a determination on aggregate 
exposure, consistent with section 408(b)(2), for a time-limited 
tolerance for combined residues of lambda-cyhalothrin and its epimer on 
rice grain at 1.0 ppm, rice straw at 1.8 ppm, and rice hulls at 5.0 
ppm. EPA's assessment of the dietary exposures and risks associated 
with establishing the tolerance follows.

A. Toxicological Profile

    EPA has evaluated the available toxicity data and considered its 
validity, completeness, and reliability as well as the relationship of 
the results of the studies to human risk. EPA has also considered 
available information

[[Page 36667]]

concerning the variability of the sensitivities of major identifiable 
subgroups of consumers, including infants and children. The nature of 
the toxic effects caused by lambda-cyhalothrin are discussed below.
    1. Acute toxicity. Acute toxicity studies with the technical 
gradeof the active ingredient lambda-cyahothrin: oral LD50 
in the rat of 79 mg/kg (males) and 56 mg/kg (females), dermal 
LD50 in the rat of 632 mg/kg (males) and 696 mg/kg females, 
primary eye irritation study showed mild irritation and primary dermal 
irritation study showed no irritation.
    2. Genotoxicity. The following genotoxicity tests were all 
negative: a gene mutation assay (Ames), a mouse micronucleus assay, an 
in-vitro cytogenetics assay, and a gene mutation study in mouse 
lymphoma cells.
    3. A three-generation reproduction study in rats fed diets 
containing 0, 10, 30, and 100 ppm with no developmental toxicity 
observed at 100 ppm, the highest dose tested. The maternal NOEL and 
LOEL (lowest observed effect level) for the study are established at 30 
(1.5 mg/kg/day) and 100 ppm (5 mg/kg/day), respectively, based upon 
decreased parental body weight gain. The reproductive NOEL and LOEL are 
established at 30 (1.5 mg/kg/day) and 100 ppm (5 mg/kg/day), 
respectively, based on decreased pup weight gain during weaning.
    4. A developmental toxicity study in rats given gavage doses of 0, 
5, 10, and 15 mg/kg/day with no developmental toxicity observed under 
the conditions of the study. The developmental NOEL is greater than 15 
mg/kg/day, the highest dose tested. The maternal NOEL and LOEL are 
established at 10 and 15 mg/kg/day, respectively, based on reduced body 
weight gain.
    5. A developmental toxicity study in rabbits given gavage doses of 
0, 3, 10, and 30 mg/kg/day with no developmental toxicity observed 
under the conditions of the study. The maternal NOEL and LOEL are 
established at 10 and 30 mg/kg/day, respectively based on decreased 
body weight gain. The developmental NOEL is greater than 30 mg/kg/day, 
the highest dose tested.
    6. A 90-day feeding study in rats fed doses of 0, 10, 50 and 250 
ppm with a NOEL of 50 ppm and a LOEL of 250 ppm based on body weight 
gain reduction.
    7. A 21-day study in rabbits exposed dermally to doses of 0, 10, 
100, and 1,000 mg/kg/day, 6 hours/day, 5 days/week with a systemic NOEL 
>1,000 mg/kg/kg. There were no clinical signs of systemic toxicity at 
any dose level tested.
    8. A 12-month feeding study in dogs fed dose (by capsule) levels of 
0, 0.1, 0.5, 3.5 mg/kg/day with a NOEL of 0.1 mg/kg/day. The LOEL for 
this study is established at 0.5 mg/kg/day based upon clinical signs of 
neurotoxicity.
    9. A 24-month chronic feeding/carcinogenicity study with rats fed 
diets containing 0, 10, 50, and 250 ppm. The NOEL was established at 50 
ppm and LOEL at 250 ppm based on reduced body weight gain. There were 
no carcinogenic effects observed under the conditions of the study.
    10. A carcinogenicity study in mice fed dose levels of 0, 20, 100, 
or 500 ppm (0, 3, 15, or 75 mg/kg/day) in the diet for 2 years. A 
systemic NOEL was established at 100 ppm and systemic LOEL at 500 ppm 
based on decreased body weight gain in males throughout the study at 
500 ppm. The EPA has classified lambda-cyhalothrin as a Group D 
carcinogen (not classifiable due to an equivocal finding in this 
study). No treatment-related carcinogenic effects were observed under 
the conditions of the study.
    11. Animal metabolism. Metabolism studies in rats demonstrated that 
distribution patterns and excretion rates in multiple oral dose studies 
are similar to single-dose studies. Accumulation of unchanged compound 
in fat upon chronic administration with slow elimination. Otherwise, 
lambda-cyhalothrin was rapidly metabolized and excreted. The metabolism 
of lambda-cyhalothrin in livestock has been studied in the goat, 
chicken, and cow. Unchanged lambda-cyhalothrin is the major residue 
component of toxicological concern in meat and milk.

B. Toxicological Endpoints

    1. Acute toxicity. No endpoint was selected by EPA to assess acute 
dietary risk. EPA determined that this risk assessment was not required 
since there was no acute dietary end point of concern.
    2. Short - and intermediate - term toxicity. As part of the hazard 
assessment process, EPA reviews the available toxicological database to 
determine the endpoints of concern for non-dietary exposure. For short- 
and intermediate-term inhalation margin of exposure (MOE) calculations, 
EPA used a NOEL of 0.3 g/l (0.05 mg/kg/day) from the 21-day 
inhalation toxicity study in rats. The LEL of 3.3 g/l was 
based on decreased body weight gains and clinical signs of toxicity 
including paw flicking, tail erections and tiptoe gait. EPA did not 
select an end point for short and intermediate term dermal exposure 
since in the 21-day dermal toxicity study, the NOEL was >1,000 mg/kg/
day (limit dose).
    3. Toxicity endpoint for dietary exposure--Chronic toxicity. EPA 
has established the reference dose (RfD) for lambda-cyhalothrin at 
0.001 milligrams/kilogram/day (mg/kg/day). This RfD is based on on a 1-
year oral study in dogs with a NOEL of 0.1 mg/kg/day and an uncertainty 
factor (UF) of 100. The LEL of 0.5 mg/kg/day was based on clinical 
signs of neurotoxicity (convulsions, ataxia, muscle tremors) and a 
slight increase in liquid feces.
    4. Carcinogenicity. Based on the available carcinogenicity studies 
in two rodent species, lambda-cyhalothrin has been classified as a 
Group ``D'' chemical, ``not classifiable as to human carcinogenicity.'' 
Although lambda-cyhalothrin was not shown to be carcinogenic in either 
the mouse or rat, the EPA Hazard Evaluation Division (HED) RfD/PEER 
review committee based the ``D'' classification on: (1) lambda-
cyhalothrin was not tested at adequate dose levels for carcinogenicity 
testing in the mouse, and (2) the equivocal nature of the findings with 
regard to the incidence of mammary adenocarcinomas. No additional 
cancer studies are being required at this time.

C. Exposures and Risks

    1. From food and feed uses. The primary source of human exposure to 
lambda-cyhalothrin will be from ingestion of both raw and processed 
food commodities treated with lambda-cyhalothrin. Time-limited 
tolerances have been established in 40 CFR 180.438, 40 CFR 185.3765 and 
40 CFR 186.3765 for combined residues of lambda-cyhalothrin and its 
epimer in or on a variety of food commodities. Risk assessments were 
conducted by EPA to assess dietary exposures and risks from lambda-
cyhalothrin as follows:
    i.  Acute exposure and risk. An acute risk assessment was not 
conducted because the Agency has not identified an acute dietary 
endpoint of concern for lambda-cyhalothrin.
    ii. Chronic exposure and risk. For purposes of assessing the 
potential chronic dietary and risk exposure estimates (DRES) for 
lambda-cyhalothrin on rice, EPA estimated chronic dietary exposure 
based on anticipated residues and percent crop treated (7% for rice) 
for several, but not all, commodities. The existing lambda-cyhalothrin 
tolerances plus the proposed rice use resulted in an Anticipated 
Residue Contribution (ARC) that is equivalent to the following 
percentages of the RfD:


[[Page 36668]]



                                                                        
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                                                 Percent of the RfD     
------------------------------------------------------------------------
U.S. Population...........................  22%                         
Nursing Infants (<1 year old).............  25%                         
Non-Nursing Infants (<1 year old).........  70%                         
Children (1-6 years old)..................  50%                         
Children (7-12 years old).................  33%                         
Hispanics.................................  24%                         
Non-hispanic Others.......................  27%                         
------------------------------------------------------------------------

    The subgroups listed above are: (1) the U.S. population (48 
states); (2) those for infants and children; and, (3) the other 
subgroups for which the percentage of the RfD occupied is greater than 
that occupied by the subgroup U.S population (48 states). As indicated 
above the proposed lambda-cyhalothrin tolerances result in an ARC that 
is up to 70% of the RfD for the most sensitive subpopulation (non-
nursing infants (<1 year old)). The general population is 22 percent of 
the RfD.
    Section 408(b)(2)(F) allows the Agency too use data on the actual 
percent of crop treated when establishing a tolerance only where the 
Agency can make the following findings: (1) that the data used are 
reliable and provide a valid basis for showing the percentage of food 
derived from a crop that is likely to contain residues; (2) that the 
exposure estimate does not underestimate the exposure for any 
significant subpopulation and; (3) where data on regional pesticide use 
and food consumption are available, that the exposure estimate does not 
understate exposure for any regional population. In addition the Agency 
must provide for periodic evaluation of any estimates used.
    Percent of crop treated estimates are derived from federal and 
market survey data. EPA considers these data reliable. Typically a 
range of estimates are supplied and the upper end of this range is used 
for the exposure assessment. By using this upper end estimate of 
percent crop treated, EPA is reasonably certain that exposure is not 
underestimated for any significant subpopulation. Further, regional 
consumption information is taken into account through EPA's computer-
based model for evaluating the exposure of significant subpopulations 
including several regional groups. Review of this regional data allows 
EPA to be reasonably certain that no regional population is exposed to 
residue levels higher than those estimated by EPA. EPA has made these 
findings when appropriate with respect to the proposed tolerance of 
lambda-cyhalothrin on rice. EPA has not provided for periodic 
reevaluation of the data on percent crop treated for lambda-cyhalothrin 
because this tolerance has a time-limitation.
    2. From drinking water. Because the Agency lacks sufficient water-
related exposure data to complete a comprehensive drinking water risk 
assessment for many pesticides, EPA has commenced and nearly completed 
a process to identify a reasonable yet conservative bounding figure for 
the potential contribution of water-related exposure to the aggregate 
risk posed by a pesticide. In developing the bounding figure, EPA 
estimated residue levels in water for a number of specific pesticides 
using various data sources. The Agency then applied the estimated 
residue levels, in conjunction with appropriate toxicological endpoints 
(RfD's or acute dietary NOEL's) and assumptions about body weight and 
consumption, to calculate, for each pesticide, the increment of 
aggregate risk contributed by consumption of contaminated water. While 
EPA has not yet pinpointed the appropriate bounding figure for exposure 
from contaminated water, the ranges the Agency is continuing to examine 
are all below the level that would cause lambda-cyhalothrin to exceed 
the RfD if the tolerance being considered in this document were 
granted. The Agency has therefore concluded that the potential 
exposures associated with lambda-cyhalothrin in water, even at the 
higher levels the Agency is considering as a conservative upper bound, 
would not prevent the Agency from determining that there is a 
reasonable certainty of no harm if the tolerance is granted.
    3. From non-dietary exposure. Lambda-cyhalothrin is currently 
registered for use on the following residential non-food sites: general 
indoor/outdoor pest control (crack/crevice/spot), termiticide, 
ornamental plants and lawns around homes, parks, recreation areas and 
athletic fields, and golf course turf. Application of this pesticide in 
and around these sites is mainly limited to commercial applicators.
    EPA lacks sufficient residential-related exposure data to complete 
a comprehensive residential risk assessment for many pesticides, 
including lambda-cyhalothrin. However, due to the following facts: (1) 
that lambda-cyhalothrin has a low vapor pressure (2  x  10-
10 torr); (2) there are no acute toxicity endpoints 
identified; (3) no short- or intermediate-term dermal toxicity endpoint 
was identified; (4) high worker inhalation MOEs (which ranged from 
1,000 to 6,800); and (5) the percentage of the RfD that is occupied by 
the pending and registered uses of this chemical is below 100; EPA has 
concluded that non-dietary, non-occupational uses of lambda-cyhalothrin 
would not pose a risk that exceeds EPA's level of concern.
    4. Cumulative exposure to substances with common mechanism of 
toxicity. Section 408(b)(2)(D)(v) requires that, when considering 
whether to establish, modify, or revoke a tolerance, the Agency 
consider ``available information'' concerning the cumulative effects of 
a particular pesticide's residues and ``other substances that have a 
common mechanism of toxicity.'' The Agency believes that ``available 
information'' in this context might include not only toxicity, 
chemistry, and exposure data, but also scientific policies and 
methodologies for understanding common mechanisms of toxicity and 
conducting cumulative risk assessments. For most pesticides, although 
the Agency has some information in its files that may turn out to be 
helpful in eventually determining whether a pesticide shares a common 
mechanism of toxicity with any other substances, EPA does not at this 
time have the methodologies to resolve the complex scientific issues 
concerning common mechanism of toxicity in a meaningful way. EPA has 
begun a pilot process to study this issue further through the 
examination of particular classes of pesticides. The Agency hopes that 
the results of this pilot process will increase the Agency's scientific 
understanding of this question such that EPA will be able to develop 
and apply scientific principles for better determining which chemicals 
have a common mechanism of toxicity and evaluating the cumulative 
effects of such chemicals. The Agency anticipates, however, that even 
as its understanding of the science of common mechanisms increases, 
decisions on specific classes of chemicals will be heavily dependent on 
chemical specific data, much of which may not be presently available.
    Although at present the Agency does not know how to apply the 
information in its files concerning common mechanism issues to most 
risk assessments, there are pesticides as to which the common mechanism 
issues can be resolved. These pesticides include pesticides that are 
toxicologically dissimilar to existing chemical substances (in which 
case the Agency can conclude that it is unlikely that a pesticide 
shares a common mechanism of activity with other substances) and 
pesticides that produce a common toxic metabolite (in which case common 
mechanism of activity will be assumed).

[[Page 36669]]

    Although lambda-cyhalothrin is structurally similar to other 
members of the synthetic pyrethroid class of insecticides, EPA does not 
have, at this time, available data to determine whether lambda-
cyhalothrin has a common mechanism of toxicity with other substances or 
how to include this pesticide in a cumulative risk assessment. Unlike 
other pesticides for which EPA has followed a cumulative risk approach 
based on a common mechanism of toxicity, lambda-cyhalothrin does not 
appear to have a toxic metabolite produced by other substances. For the 
purposes of this tolerance action, therefore, EPA has not assumed that 
lambda-cyhalothrin has a common mechanism of toxicity with other 
substances.

C. Aggregate Risks and Determination of Safety for U.S. Population

    1. Acute risks. As indicated above, a risk assessment was not 
conducted because EPA has not identified an acute toxicity dietary 
endpoint for lambda-cyhalothrin.
    2. Chronic risk. Using the exposure assumptions and risks described 
above, and taking into account the completeness and reliability of the 
toxicity data, EPA has concluded that dietary exposure to lambda-
cyhalothrin will utilize 22% of the RfD for the U.S. population. EPA 
generally has no concern for exposures below 100% of the RfD because 
the RfD represents the level at or below which daily aggregate dietary 
exposure over a lifetime will not pose appreciable risks to human 
health. Despite the potential for exposure to lambda-cyhalothrin in 
drinking water and via residential uses, EPA does not expect the 
aggregate exposure to exceed 100% of the RfD. EPA concludes that there 
is a reasonable certainty that no harm will result from aggregate 
exposure to lambda-cyhalothrin residues.

D. Aggregate Cancer Risk for U.S. Population

    Lambda-cyhalothrin has been classified by EPA as a Group ``D'' 
chemical, ``not classifiable as to human carcinogenicity''. Therefore, 
this risk assessment was not conducted.

E. Aggregate Risks and Determination of Safety for Infants and Children

    In assessing the potential for additional sensitivity of infants 
and children to residues of lambda-cyhalothrin, EPA considered data 
from developmental toxicity studies in rats and rabbits and a 3-
generation reproductive toxicity study in rats. The developmental 
toxicity studies are designed to evaluate adverse effects on the 
developing organism resulting from maternal pesticide exposure during 
prenatal development. Reproduction studies provide information relating 
to pre- and post-natal effects from exposure to the pesticide, 
information on the reproductive capability of mating animals, and data 
on systemic toxicity.
    FFDCA section 408 provides that EPA shall apply an additional 
tenfold margin of safety for infants and children in the case of 
threshold effects to account for pre-and post-natal toxicity and the 
completeness of the database unless EPA determines that a different 
margin of safety will be safe for infants and children. Margins of 
safety are incorporated into EPA risk assessments either directly 
through use of a margin of exposure analysis or through using 
uncertainty (safety) factors in calculating a dose level that poses no 
appreciable risk to humans. In either case, EPA generally defines the 
level of appreciable risk as exposure that is greater than 1/100 of the 
no observed effect level (NOEL) in the animal study appropriate to the 
particular risk assessment. This 100-fold uncertainty (safety) factor 
is designed to account for inter-species extrapolation and intra-
species variability. EPA believes that reliable data support using the 
standard 100-fold factor when EPA has a complete data base under 
existing guidelines and when the severity of the effect in infants or 
children or the potency or unusual toxic properties of a compound do 
not raise concerns regarding the adequacy of the standard factor.
    1. Developmental toxicity studies. a. From the developmental 
toxicity study in rats, the maternal (systemic) NOEL was 10 mg/kg/day. 
The maternal LEL of 15 mg/kg/day was based on decreased body weight 
gain and decreased food consumption. The developmental (fetal) NOEL was 
>15 mg/kg/day at the highest dose tested (HDT).
    b. From the developmental toxicity study in rabbits, the maternal 
(systemic) NOEL was 10 mg/kg/day. The maternal LEL of 30 mg/kg/day was 
based on decreased body weight gain. The developmental (fetal) NOEL was 
30 mg/kg/day (HDT).
    2. Reproductive toxicity studies. From the 3-generation 
reproductive toxicity study in rats, both the parental (systemic) and 
reproductive (pup) NOEL's were 1.5 mg/kg/day. Both the parental 
(systemic) and reproductive (pup) LEL's were 5 mg/kg/day. They were 
based on a significant decrease in parental body weight (systemic) or a 
significant decrease in pup body weight.
    3. Pre- and post-natal sensitivity.The toxicology data base for 
lambda-cyhalothrin is complete with respect to current toxicological 
data requirements. There are no pre- or post-natal toxicity concerns 
for infants and children, based on the results of the rat and rabbit 
developmental toxicity studies and the 3-generation reproductive 
toxicity study in rats.
    Based on the above, EPA concludes that reliable data support the 
use of the standard 100-fold margin of uncertainty factor and that an 
additional uncertainty factor is not warranted at this time.
    4. Acute risk. This risk assessment was not conducted because 
EPAhas not identified an acute toxicity dietary endpoint of concern for 
lambda-cyhalothrin.
    5. Chronic risk. Using the exposure assumptions described above, 
EPA has concluded that the percent of the RfD that will be utilized by 
dietary exposure to residues of lambda-cyhalothrin ranges from 25% for 
nursing infants less than one year old, up to 70% for non-nursing 
infants less than 1 year old. Despite the potential for exposure to 
lambda-cyhalothrin in drinking water and via residential uses, EPA does 
not expect the aggregate exposure to exceed 100% of the RfD. Therefore, 
taking into account the completeness and reliability of the toxicity 
data and the conservative exposure assessment, EPA concludes that there 
is a reasonable certainty that no harm will result to infants and 
children from aggregate exposure to lambda-cyhalothrin residues.

III. Other Considerations

A. Endocrine Effects

    EPA is required to develop a screening program to determine whether 
certain substances (including all pesticides and inerts) ``may have an 
effect in humans that is similar to an effect produced by a naturally 
occurring estrogen, or such other endocrine effect...''. The Agency is 
currently working with interested stakeholders, including other 
government agencies, public interest groups, industry and research 
scientists in developing a screening and testing program and a priority 
setting scheme to implement this program. Congress has allowed 3 years 
from the passage of FQPA (August 3, 1999) to implement this program. At 
that time, EPA may require further testing of this active ingredient 
and end use products for endocrine disrupter effects.

B. Metabolism In Plants and Animals

    The metabolism of lambda-cyhalothrin in plants and animals is

[[Page 36670]]

adequately understood for the purpose of this tolerance. EPA has 
determined that plant and animal metabolites do not need to appear in 
the tolerance expression at this time. The residues to be regulated are 
lambda-cyhalothrin and its epimer as specified in 40 CFR 180.438.

C. Magnitude of Residues

    Field residue data reflecting the application of lambda-cyhalothrin 
to rice are acceptable in quantity and quality and location in support 
of the proposed tolerances on rice grain, rice hulls, and rice straw. 
The existing tolerances for meat, milk, poultry and eggs are based on 
the transfer of residues from a worse-case diet consisting of various 
animal feed items containing residues of lambda-cyhalothrin and its 
epimer. No increase in the dietary burden of poultry and ruminants is 
expected from use on rice. Therefore, any secondary residues that might 
result in milk, meat, poultry and eggs would be covered by the existing 
tolerances on these commodities.

D. Analytical Enforcement Methodology

    There is a practical analytical method available for determination 
of residues of lambda-cyhalothrin and its epimer. Adequate enforcement 
methodology (gas chromatography/electron capture detector) for plant 
and animal commodities is available to enforce the tolerances. EPA will 
provide information on this method to FDA. In the interim, the 
analytical method is available to anyone who is interested in pesticide 
residue enforcement from: By mail, Calvin Furlow, Public Information 
and Records Integrity Branch, Information Resources and Services 
Division (7506C), Office of Pesticide Programs, Environmental 
Protection Agency, 401 M St. SW., Washington, DC 20460. Office location 
and telephone number: Crystal Mall #2, Rm 1128, 1921 Jefferson Davis 
Hwy., Arlington, VA 22202, 703-305-5805.

E. International Residue Limits

    There are no Codex, Canadian, or Mexican maximum residue limits 
(MRLs) for residues of lambda-cyhalothrin and its epimer in/on rice. 
Therefore, international harmonization is not an issue for this 
tolerance.

F. Rotational Crop Restrictions

    Studies submitted in support of lambda-cyhalothrin registration 
show that significant residues (<0.01 ppm) will not be present in crops 
rotated 30 days after application of parent lambda-cyhalothrin. No 
additional rotational crop data are needed to support current 
registered application rates.

IV. Conclusion

    A time limited tolerance is being established for lambda-
cyhalothrin and its epimer, in/or on rice grain at 1.0 ppm, rice straw 
at 1.8 ppm, and rice hulls at 5.0 ppm. Tolerances are time limited to 
allow development and review of drinking water and cumulative exposure 
data. Based upon the information and data considered EPA concludes that 
the proposed time limited tolerances will be safe. Therefore the 
tolerances are established as set forth in this document.

V. Objections and Hearing Requests

    The new FFDCA section 408(g) provides essentially the same process 
for persons to object'' to a tolerance regulation issued by EPA under 
new section 408(e) and (l)(6) as was provided in the old section 408 
and in section 409. However, the period for filing objections is 60 
days, rather than 30 days. EPA currently has procedural regulations 
which govern the submission of objections and hearing requests. These 
regulations will require some modification to reflect the new law. 
However, until those modifications can be made, EPA will continue to 
use those procedural regulations with appropriate adjustments to 
reflect the new law.
    Any person may, by September 8, 1997, file written objections to 
any aspect of this regulation and may also request a hearing on those 
objections. Objections and hearing requests must be filed with the 
Hearing Clerk, at the address given above (40 CFR 178.20). A copy of 
the objections and/or hearing requests filed with the Hearing Clerk 
should be submitted to the OPP docket for this rulemaking. The 
objections submitted must specify the provisions of the regulation 
deemed objectionable and the grounds for the objections (40 CFR 
178.25). Each objection must be accompanied by the fee prescribed by 40 
CFR 180.33(I). If a hearing is requested, the objections must include a 
statement of the factual issues on which a hearing is requested, the 
requestor's contentions on such issues, and a summary of any evidence 
relied upon by the requestor (40 CFR 178.27). A request for a hearing 
will be granted if the Administrator determines that the material 
submitted shows the following: There is genuine and substantial issue 
of fact; there is a reasonable possibility that available evidence 
identified by the requestor would, if established, resolve one or more 
of such issues in favor of the requestor, taking into account 
uncontested claims or facts to the contrary; and resolution of the 
factual issues in the manner sought by the requestor would be adequate 
to justify the action requested (40 CFR 178.32). Information submitted 
in connection with an objection or hearing request may be claimed 
confidential by marking any part or all of that information as 
Confidential Business Information (CBI). Information so marked will not 
be disclosed except in accordance with procedures set forth in 40 CFR 
part 2. A copy of the information that does not contain CBI must be 
submitted for inclusion in the public record. Information not marked 
confidential may be disclosed publicly by EPA without prior notice.

VI. Public Docket

    EPA has established a record for this rulemaking under docket 
control number [OPP-300509] (including any comments and data submitted 
electronically). A public version of this record, including printed, 
paper versions of electronic comments, which does not include any 
information claimed as CBI, is available for inspection from 8:30 a.m. 
to 4 p.m., Monday through Friday, excluding legal holidays. The public 
record is located in Room 1132 of the Public Information and Records 
Integrity Branch, Information Resources and Services Division (7506C), 
Office of Pesticide Programs, Environmental Protection Agency, Crystal 
Mall #2, 1921 Jefferson Davis Highway, Arlington, VA.
    Electronic comments may be sent directly to EPA at:
    [email protected].

    Electronic comments must be submitted as an ASCII file avoiding the 
use of special characters and any form of encryption.
    The official record for this rulemaking, as well as the public 
version, as described above will be kept in paper form. Accordingly, 
EPA will transfer any copies of objections and hearing requests 
received electronically into printed, paper form as they are received 
and will place the paper copies in the official rulemaking record which 
will also include all comments submitted directly in writing. The 
official rulemaking record is the paper record maintained at the 
Virginia address in ``ADDRESSES'' at the beginning of this document.

VII. Regulatory Assessment Requirements

    This final rule establishes a time limited tolerance under FFDCA 
section 408(d) in response to a petition

[[Page 36671]]

submitted to the Agency. The Office of Management and Budget (OMB) has 
exempted these types of actions from review under Executive Order 
12866, entitled Regulatory Planning and Review (58 FR 51735, October 4, 
1993). This final rule does not contain any information collections 
subject to OMB approval under the Paperwork Reduction Act (PRA), 44 
U.S.C. 3501 et seq., or impose any enforceable duty or contain any 
unfunded mandate as described under Title II of the Unfunded Mandates 
Reform Act of 1995 (UMRA) (Pub. L. 104-4). Nor does it require any 
prior consultation as specified by Executive Order 12875, entitled 
Enhancing the Intergovernmental Partnership (58 FR 58093, October 28, 
1993), or special considerations as required by Executive Order 12898, 
entitled Federal Actions to Address Environmental Justice in Minority 
Populations and Low-Income Populations (59 FR 7629, February 16, 1994), 
or require OMB review in accordance with Executive Order 13045, 
entitled Protection of Children from Environmental Health Risks and 
Safety Risks (62 FR 19885, April 23, 1997).
    In addition, since these tolerances and exemptions that are 
established on the basis of a petition under FFDCA section 408(d), such 
as the time limited tolerance in this final rule, do not require the 
issuance of a proposed rule, the requirements of the Regulatory 
Flexibility Act (RFA) (5 U.S.C. 601 et seq.) do not apply. 
Nevertheless, the Agency has previously assessed whether establishing 
tolerances, exemptions from tolerances, raising tolerance levels or 
expanding exemptions might adversely impact small entities and 
concluded, as a generic matter, that there is no adverse economic 
impact. The factual basis for the Agency's generic certification for 
tolerance actions published on May 4, 1981 (46 FR 24950) and was 
provided to the Chief Counsel for Advocacy of the Small Business 
Administration.

VIII. Submission to Congress and the General Accounting Office

    Under 5 U.S.C. 801(a)(1)(A), as added by the Small Business 
Regulatory Enforcement Fairness Act of 1996, the Agency has submitted a 
report containing this rule and other required information to the U.S. 
Senate, the U.S. House of Representatives, and the Comptroller General 
of the General Accounting Office prior to publication of this rule in 
today's Federal Register. This is not a ``major rule'' as defined by 5 
U.S.C. 804(2).

List of Subjects in 40 CFR Part 180

    Environmental protection, Administrative practice and procedure, 
Agricultural commodities, Pesticides and pests, Reporting and 
recordkeeping requirements.

    Dated: June 25, 1997.

James Jones,
Acting Director, Registration Division, Office of Pesticide Programs.

    Therefore, 40 CFR chapter I is amended as follows:

PART 180 [AMENDED]

    1. The authority citation for part 180 continues to read as 
follows:

    Authority : 21 U.S.C. 346a and 371.

    2. Section 180.438 is revised to read as follows:


Sec. 180.438  Lambda-cyhalothrin; tolerances for residues.

    (a) General. Time limited tolerances are established for residues 
of the insecticide lambda-cyhalothrin, a 1:1 mixture of (S)-alpha-
cyano-3-phenoxybenzyl-(Z)-(1R,3R)-3-(2-chloro-3,3,3-trifluoroprop-1-
enyl) -2,2- dimethylcyclopropanecarboxylate and (R)-alpha-cyano-3-
phenoxybenzyl-(Z)-(1S,3S)-3-(2-chloro-3,3,3-trifluoroprop-1-enyl)-2,2-
dimethylcyclopropanecarboxylate and the Epimer of lambda-cyhalothrin, a 
1:1 mixture of (S)-alpha-cyano-3-phenoxybenzyl-(Z)-(1S,3S)-3-(2-chloro-
3,3,3- trifluoroprop-1-enyl)-2,2-dimethylcyclopropanecarboxylate and 
(R)-alpha-cyano-3-phenoxybenzyl-(Z)-(1R,3R)-3-(2-chloro-3,3,3-
trifluoroprop-1-enyl)-2,2-dimethylcyclopropanecarboxylate on plants, as 
indicated in the following table. The tolerance will expire on the date 
specified in the following table.

                                                                        
------------------------------------------------------------------------
                                                          Expiration/   
            Commodity              Parts per million    Revocation Date 
------------------------------------------------------------------------
Rice grain......................  1.0                 November 15, 1997 
Rice straw......................  1.8                 November 15, 1997 
Rice, Hulls.....................  5.0                 November 15, 1997 
------------------------------------------------------------------------

    (b) Section 18 emergency exemptions. [Reserved]
    (c) Tolerances with regional registrations. [Reserved]
    (d) Indirect or inadvertent residues. [Reserved]

[FR Doc. 97-17591 Filed 7-8-97; 8:45 am]
BILLING CODE 6560-50-F