[Federal Register Volume 60, Number 26 (Wednesday, February 8, 1995)]
[Proposed Rules]
[Pages 7509-7511]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-3206]



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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 180

[PP 5F4427/P606; FRL-4936-6]
RIN 2070-AC18


Pesticide Tolerance for Chlorpyrifos

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: EPA proposes to establish a time-limited tolerance for 
residues of the insecticide chlorpyrifos [O,O-diethyl O-(3,5,6-
trichloro-2-pyridyl) phosphorothioate] in or on the raw agricultural 
commodities oats and barley when blended together in a mixture 
containing 97% oats and 3% barley. The proposal to establish maximum 
permissible levels for residues of the insecticide was requested in a 
petition submitted by General Mills.

DATES: Comments, identified by the document control number, [PP 5F4427/
P606], must be received on or before March 10, 1995.

ADDRESSES: By mail, submit written comments to: Public Response and 
Program Resources Branch, Field Operations Division (7506C), Office of 
Pesticide Programs, Environmental Protection Agency, 401 M St., SW., 
Washington, DC 20460. In person, bring comments to: Rm. 1132, CM #2, 
1921 Jefferson Davis Hwy., Arlington, VA 22202.
    Information submitted as a comment concerning this notice 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 comment 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. All 
written comments will be available for public inspection in Rm. 1132 at 
the address given above, from 8 a.m. to 4 p.m., Monday through Friday, 
excluding legal holidays.

FOR FURTHER INFORMATION CONTACT: By mail: Dennis H. Edwards, Jr., 
Product Manager (PM) 19, Registration Division (7505C), Environmental 
Protection Agency, 401 M St., SW., Washington, DC 20460. Office 
location and telephone number: Rm. 207, CM #2, 1921 Jefferson Davis 
Hwy., Arlington, VA 22202, (703)-305-6386.

SUPPLEMENTARY INFORMATION: EPA issued a notice, published in the 
Federal Register of November 21, 1994 (59 FR 60013), which announced 
that General Mills had submitted pesticide petition (PP) 5F4427 to EPA 
requesting that the Administrator, pursuant to section 408(e) of the 
Federal Food, Drug, and Cosmetic Act (FFDCA), 21 U.S.C. 346a, amend 40 
CFR 180.342 by establishing a tolerance for residues of the insecticide 
chlorpyrifos in or on the raw agricultural commodity oats at 15 ppm, 
provided that such tolerance applies only to oats that were treated 
post-harvest with chlorpyrifos on or before June 15, 1994; that such 
tolerance applies only to oats to be used as animal feed or as a 
constituent of animal feed; that, notwithstanding any other provision 
of law or regulation, this tolerance does not authorize the presence of 
residues of chlorpyrifos in any human food item made from such treated 
oats, other than residues resulting from the use of the oats for animal 
feed purposes; and that such tolerance expires on December 31, 1996.
    Chlorpyrifos is registered under the Federal Insecticide, 
Fungicide, and Rodenticide Act (FIFRA) for application to many growing 
crops; associated tolerance regulations have been established under the 
FFDCA. It is not, however, registered for use on oats or for treatment 
of stored grain. A pest control operator under contract to General 
Mills improperly treated stored oats and fraudulently claimed to have 
used a different pesticide, chlorpyrifos-methyl, that is registered for 
use on stored grains such as oats. The illegal residues were discovered 
by a routine FDA inspection. Processed food products manufactured from 
improperly treated oats were determined by the Agency not to be a human 
health hazard and those that had entered commerce were not recalled. 
Processed products that had not yet entered commerce were retained by 
General Mills and subsequently destroyed. Approximately 18 million 
bushels of stored unmilled oats treated with chlorpyrifos are at 
present controlled by General Mills or its customers. Although the 
Agency has determined that the use of the stored oats for the 
production of food does not constitute a human health hazard, no 
approval has been sought by General Mills to use the treated oats for 
human food purposes.
    Chlorpyrifos is registered for use on other crops that are used for 
livestock or poultry feed purposes. General Mills has submitted data to 
demonstrate that the use of treated oats for livestock or poultry feed 
will not yield residues in meat, milk, or eggs that exceed existing 
tolerances for chlorpyrifos in these commodities. To ensure that the 
oats will be unacceptable for human food production, General Mills has 
stated that they will be blended to include not less than 3% barley and 
97% oats. Accordingly, the definition of the raw agricultural commodity 
in the petition has been amended to ``oats and barley when blended 
together in a mixture containing 97% oats and 3% barley.''
    There were no comments or requests for a referral to an advisory 
committee received in response to the notice of filing.
    The data submitted in the petition and other relevant material have 
been evaluated. Toxicological data considered in support of the 
proposed tolerance include:
    1. A 2-year dog feeding study with a no-observed-effect-level 
(NOEL) for systemic effects of 1.0 milligram (mg)/ kilogram (kg)/day 
and lowest-effect- level (LEL) (increased liver weight) of 3.0 mg/kg/
day. The NOELs for cholinesterase (ChE) inhibition were as follows: 
0.01 mg/kg/day for plasma, 0.1 mg/kg/day for red blood cells, and 1.0 
mg/kg/day for brain cells. Levels tested were 0, 0.01, 0.03, 0.1, 1.0, 
and 3 mg/kg/day. [[Page 7510]] 
    2. A voluntary human study with chronic ChE NOEL of 0.03 mg/kg/day 
(based on 20 days of exposure at this level).
    3. A 2-year mouse chronic toxicity/carcinogenicity study with a 
NOEL of 15 ppm for systemic effects (equivalent to 2.25 mg/kg/day) and 
no carcinogenic effects observed under the conditions of the study at 
all levels tested (0, 0.5, 5, and 15 ppm, equivalent to 0.075, 0.75, 
and 2.25 mg/kg/day).
    4. A voluntary human study with acute ChE NOEL of 0.10 mg/kg/day 
(based on daily single-dose exposures of 0, 0.014, 0.03, or 0.10 mg/kg/
day) determined at 1, 3, 6, and 9 days of treatment.
    5. A 2-year rat feeding/carcinogenicity study with ChE NOEL of 0.1 
and LEL of 1.0 mg/kg/day (based on decreased plasma and brain ChE 
activity), and a systemic NOEL of 1.0 mg/kg/day and LEL of 10 mg/kg/day 
(based on decreased erythrocyte and hemoglobin values and increased 
platelet count during the first year). There were no observed 
carcinogenic effects at the levels tested (0.05, 0.1, 1.0, and 10 mg/
kg/day) under the conditions of the study. Chlorpyrifos is classified 
as a Group E chemical (no evidence of carcinogenicity).
    6. A three-generation reproduction study in rats with no 
reproductive effects observed at the dietary levels tested (0, 0.1, 
0.3, and 1.0 mg/kg/day).
    7. Two rat developmental toxicity studies: one negative for 
developmental toxicity at all dose levels (levels tested were 0.1, 3.0, 
and 15.0 mg/kg/day); and one with maternal NOEL of 15 mg/kg/day and 
developmental NOEL of 2.5 mg/kg/day (levels tested, by gavage, were 0, 
0.5, 2.5, and 15 mg/kg/day).
    8. A mouse developmental toxicity study with a teratogenic NOEL 
greater than 25 mg/kg/day (highest dose tested) and a developmental 
fetotoxic NOEL of 10 mg/kg/day and LEL of 25 mg/kg/day (decreased fetal 
length and increased skeletal variants).
    9. A developmental toxicity study in rabbits with maternal and 
developmental NOELs of 81 mg/kg/day, and maternal and developmental 
LELs of 140 mg/kg/day (based on maternal decreased food consumption on 
gestation day 15 to 19, and body weight loss during the dosing period 
followed by a compensatory weight gain; and based on a slight reduction 
in fetal weights and crown-rump lengths, and fetal increased incidence 
of unossified fifth sternebrae and/or xiphisternum). Levels tested were 
0, 1, 9, 81, and 140 mg/kg/day.
    10. An acute delayed neurotoxicity study in the hen that was 
negative at 50 and 100 mg/kg/day.
    11. Several mutagenicity studies which were all negative. These 
include an Ames assay, two Chinese hamster ovary cell mutation assays, 
a micronucleus assay for chromosomal aberration, an in vitro 
chromosomal aberration assay with and without enzymatic activation, and 
an unscheduled DNA synthesis assay.
    12. A general metabolism study in rats shows that the major 
metabolite of chlorpyrifos is 3,5,6-trichloro-2-pyridinol (TCP). The 
studies listed below were conducted to demonstrate that TCP is less 
toxic than chlorpyrifos and is not a ChE inhibitor.
    a. A 90-day rat feeding study with a systemic NOEL of 30 mg/kg/day. 
Levels tested were 0, 10, 30, and 100 mg/kg/day.
    b. A rat developmental toxicity study with no developmental 
toxicity observed at the dosages tested (0, 50, 100, and 150 mg/kg/
day).
    c. Mutagenicity studies (including an Ames assay and an unscheduled 
DNA synthesis assay) were negative for mutagenic effects.
    Based on the above studies, the Agency has concluded that the TCP 
metabolite is not of toxicological concern.
    For the assessment of chronic dietary risk, the reference dose 
(RfD) based on the human voluntary ChE study (ChE NOEL of 0.03 mg/kg/
day) and using a 10-fold uncertainty factor is calculated to be 0.003 
mg/kg of body weight/day. Tolerances for food uses appear in 40 CFR 
180.342 and 40 CFR 185.1000. The Dietary Risk Exposure Section (DRES) 
used, when justified and appropriate, anticipated residues rather than 
published tolerance values, and data regarding percent crop treated 
(when less than 100%). The anticipated residue contribution (ARC) from 
published uses of chlorpyrifos is 0.000860 mg/kg of body weight/day for 
the overall U.S. population. This represents 28.7% of the RfD. None of 
the DRES subgroups has an exposure that exceeds the RfD. The population 
subgroup most highly exposed is nonnursing infants, less than 1 year 
old, with an ARC from published uses of 0.002147 mg/kg of body weight/
day, 71.6% of the RfD. The next most highly exposed population subgroup 
is children, 1 to 6 years old, with an ARC from published uses of 
0.001914 mg/kg of body weight/day, 63.8% of the RfD. The proposed 
tolerance on oats does not raise the ARC as a percentage of the RfD 
because the oats are not to be used for human food and any secondary 
residues occurring in milk, eggs, or meat of livestock and poultry will 
fall within existing tolerances for these commodities. The ARC was 
calculated assuming tolerance level residues of chlorpyrifos on these 
commodities.
    The DRES detailed acute analysis estimates the distribution of 
single-day exposures for the overall U.S. population and certain 
subgroups. The analysis evaluates individual food consumption as 
reported by respondents in the USDA 1977-1978 Nationwide Food 
Consumption Survey (NFCS) and accumulates exposure to the chemical for 
each commodity. Each analysis assumes uniform distribution of 
chlorpyrifos in the commodity (oats). Since the toxicological endpoint 
to which exposure is being compared in this analysis is neurotoxicity, 
four human population subgroups (infants, less than 1 year old; 
children, 1 to 12 years old; females, 13 years old and older; males, 13 
years old and older), as well as the overall population, are of 
interest.
    The Margin of Exposure (MOE) is a measure of how close the high-end 
exposure comes to the NOEL and is calculated as the ratio of the NOEL 
to the exposure. (NOEL/exposure = MOE.) For neurotoxicity, the Agency 
is generally not concerned unless the MOE is below 10 when the NOEL is 
based on human data. For the overall population the calculated MOE at 
high end (top-most eaters--defined as the top 0.5% of the population in 
terms of consumption) as a result of all commodities, other than oats, 
treated with chlorpyrifos is less than 10. In the overall population 6% 
of consumers have an MOE less than 10.
    The DRES analysis to estimate the potential increased risk of 
neurotoxicity resulting from residues of chlorpyrifos in meat, poultry, 
eggs, and milk obtained from animals fed treated oats indicates that 
the MOE is greater than 10 for the overall U.S. population and for each 
of the 4 population subgroups. The calculated MOE at high end (top-most 
eaters--in this case defined as the top 0.5% of the population/
subpopulation in terms of consumption) for the overall population is 
33; for infants, less than 1 year old it is 20; for children, 1 to 12 
years old it is 25; for females, 13 years old and older it is 83; and 
for males, 13 years old and older it is 71.
    The Margin of Exposure estimates are considered conservative 
because a major assumption is that the high-end eater consumed only 
meat, poultry, eggs, and/or milk from animals fed only oats containing 
chlorpyrifos residues. The increase in calculated estimates of acute 
[[Page 7511]] risk from chlorpyrifos residues as a result of the 
proposed temporary tolerance would be negligible.
    The petition for a tolerance has resulted from a misuse of 
chlorpyrifos, and the Agency does not generally grant a tolerance to 
cover misuse. The following points, however, were considered. The 
petitioner was not directly responsible for the misuse. Although human 
food produced from the treated chlorpyrifos was not determined by the 
Agency to be a human health hazard, the petitioner has not sought 
approval for use of the treated oats as human food and destroyed all 
human food made from the treated oats that had not entered commerce. 
The tolerance is time limited. Finally, if this tolerance is not 
approved, 18 million bushels of oats, or approximately 15% of the 
privately held U.S. stocks, will have to be destroyed despite EPA's 
conclusion that use of the oats as an animal feed protects the public 
health.
    To ensure that the oats are used as an animal feed, EPA has amended 
the commodity definition from ``the raw agricultural commodity oats'' 
to ``the raw agricultural commodities oats and barley when blended 
together in a mixture containing 97% oats and 3% barley.'' Blending 
barley with oats will make the oats unsuitable for milling to produce 
human food. The petitioner has agreed to blend barley into the treated 
oats prior to sale or distribution.
    The nature of the residue in plants and animals is adequately 
understood. Adequate methodology is available for enforcement purposes 
and for analysis of chlorpyrifos in oat grain. The FDA Pestrack data 
base (PAM Vol. I, January, 1994) indicates that complete recovery has 
been obtained for chlorpyrifos under FDA multiresidue methods 302 and 
303, and partial recovery has been obtained with method 304.
    The pesticide is considered useful for the purpose for which the 
tolerance is sought.
    There are currently no actions pending against continued 
registration of this chemical.
    Based on the information and data considered, the Agency has 
determined that the tolerance established by amending 40 CFR 180 would 
protect the public health. Therefore, it is proposed that the tolerance 
be established as set forth below.
    Any person who has registered or submitted an application for 
registration of a pesticide, under the Federal Insecticide, Fungicide, 
and Rodenticide Act (FIFRA) as amended, which contains any of the 
ingredients listed herein, may request within 30 days after publication 
of this document in the Federal Register that this rulemaking proposal 
be referred to an Advisory Committee in accordance with section 408(e) 
of the FFDCA.
    Interested persons are invited to submit written comments on the 
proposed regulation. Comments must bear a notation indicating the 
document control number, [PP 5F4427/P606]. All written comments filed 
in response to this petition will be available in the Public Response 
and Program Resources Branch, at the address given above, from 8 a.m. 
to 4 p.m., Monday through Friday, except legal holidays.
    Under Executive Order 12866 (58 FR 51735, Oct. 4, 1993), the Agency 
must determine whether the regulatory action is ``significant'' and 
therefore subject to all the requirements of the Executive Order (i.e., 
Regulatory Impact Analysis, review by the Office of Management and 
Budget (OMB)). Under section 3(f), the order defines ``significant'' as 
those actions likely to lead to a rule (1) having an annual effect on 
the economy of $100 million or more, or adversely and materially 
affecting a sector of the economy, productivity, competition, jobs, the 
environment, public health or safety, or State, local or tribal 
governments or communities (also known as ``economically 
significant''); (2) creating serious inconsistency or otherwise 
interfering with an action taken or planned by another agency; (3) 
materially altering the budgetary impacts of entitlement, grants, user 
fees, or loan programs; or (4) raising novel legal or policy issues 
arising out of legal mandates, the President's priorities, or the 
principles set forth in this Executive Order.
    Pursuant to the terms of this Executive Order, EPA has determined 
that this rule is not ``significant'' and is therefore not subject to 
OMB review.
    Pursuant to the requirements of the Regulatory Flexibility Act 
(Pub. L. 96-54, 94 Stat. 1164, 5 U.S.C. 601-612), the Administrator has 
determined that regulations establishing new tolerances or raising 
tolerance levels or establishing exemptions from tolerance requirements 
do not have a significant economic impact on a substantial number of 
small entities. A certification statement to this effect was published 
in the Federal Register of May 4, 1981 (46 FR 24950).

List of Subjects in 40 CFR Part 180

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

Dated: February 1, 1995.

Stephen L. Johnson,
Director, Registration Division, Office of Pesticide Programs.
    Therefore, it is proposed that 40 CFR part 180 be 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. In Sec. 180.342, by adding new paragraph (f), to read as 
follows:


Sec. 180.342   Chlorpyrifos; tolerances for residues.

* * * * *
    (f) A tolerance of 15 ppm is established for residues of the 
pesticide chlorpyrifos [O,O-diethyl O-(3,5,6-trichloro-2-pyridyl) 
phosphorothioate] in or on the raw agricultural commodities oats and 
barley when blended together as a mixture containing 97% oats and 3% 
barley.
    (1) Such tolerance applies only to oats that were treated post-
harvest with chlorpyrifos on or before June 15, 1994.
    (2) Such tolerance applies only to oats to be used as animal feed 
or as a constituent of animal feed.
    (3) Notwithstanding any other provision of law or regulation, this 
tolerance does not authorize the presence of residues of chlorpyrifos 
in any human food item made from such treated oats, other than residues 
resulting from the use of the oats for animal feed purposes.
    (4) Such tolerance expires on December 31, 1996.

[FR Doc. 95-3206 Filed 2-3-95; 5:06 pm]
BILLING CODE 6560-50-F