55778 Federal Register / Vol. 62, No. 204 / Wednesday, October 22, 1997 / Rules and Regulations

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 180.495 is amended as

follows:

a. By adding a heading to paragraph

(a).

b. In paragraph (b) by adding a

heading and alphabetically adding the

following commodities.

c. Paragraphs (c) and (d) are added

and reserved with headings.

§ 180.495 Spinosad; tolerances for

residues.

(a) General. [Reserved]

(b) Section 18 emergency exemptions.

* * *

Commodity Parts per million Expiration/Revocation Date

Brassica (Cole) Leafy Vegetables Crop Group (5) ............................. 10.0 9/30/98

* * * * * * *

Fruiting Vegetables (except Cucurbits) Crop Group (8) ..................... 0.25 9/30/98

Leafy Vegetables (except Brassica vegetables) Crop Group (4) ....... 10.0 9/30/98

Tomato paste ....................................................................................... 0.50 9/30/98

(c) Tolerances with regional

registrations. [Reserved]

(d) Indirect or inadvertent residues.

[Reserved]

[FR Doc. 97–27727 Filed 10–21–97; 8:45 am]

BILLING CODE 6560–50–F

ENVIRONMENTAL PROTECTION

AGENCY

40 CFR Part 180

[OPP–300548; FRL–5742–5]

RIN 2070–AB78

Pyrithiobac Sodium Salt; Time-Limited

Pesticide Tolerance

AGENCY: Environmental Protection

Agency (EPA).

ACTION: Final rule.

SUMMARY: This regulation extends the

time-limited tolerance for residues of

the herbicide pyrithiobac sodium salt

(sodium 2-chloro-6-[(4,6-

dimethoxypyrimidin-2-yl)thio]benzoate)

in or on cottonseed at 0.02 parts per

million (ppm). E.I. du Pont de Nemours

& Co., Inc., 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 September 30, 1999.

DATES: This regulation is effective

October 22, 1997. Objections and

requests for hearings must be received

by EPA on or before December 22, 1997.

ADDRESSES: Written objections and

hearing requests, identified by the

docket control number, [OPP–300548],

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 with the Hearing Clerk identified

by the docket control number, [OPP–

300548], 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: oppdocket@epamail.epa.gov. 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–

300548]. 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: James A. Tompkins, 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) 305–5697, e-mail:

tompkins.james@epamail.epa.gov.

SUPPLEMENTARY INFORMATION: In the

Federal Register of July 11, 1997 (62 FR

37241)(FRL–5728–7), 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

4F4391) for tolerance by E.I. du Pont de

Nemours & Co., Inc., Barley Mill Plaza,

P.O. Box 80038, Wilmington, DE 19880–

0038. This notice included a summary

of the petition prepared by du Pont.

There were two comments received in

response to the notice of filing from

cotton growers urging the extension of

the time limited tolerance.

The petition requested that 40 CFR

180.487 be amended by extending the

time-limited tolerance for residues of

the herbicide pyrithiobac sodium salt

(sodium 2-chloro-6-[(4,6-

dimethoxypyrimidin-2-yl)thio]benzoate)

in or on cottonseed at 0.02 ppm. This

tolerance will expire on September 30,

1999.

In the Federal Register of October 25,

1995 (60 FR 54607)(FRL–4982–8), EPA

established a time limited tolerance for

residues of the herbicide pyrithiobac

sodium in or on cottonseed at 0.02 ppm.

The time limited tolerance will expire

on September 30, 1997.

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
Federal Register / Vol. 62, No. 204 / Wednesday, October 22, 1997 / Rules and Regulations 55779

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).

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 percent

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 three

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 ‘‘worst case’’

estimate since it is based on the

assumptions that food contains

pesticide residues at the tolerance level
55780 Federal Register / Vol. 62, No. 204 / Wednesday, October 22, 1997 / Rules and Regulations

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.

Percent of crop treated estimates are

derived from Federal and private market

survey data. Typically, a range of

estimates are supplied and the upper

end of this range is assumed for the

exposure assessment. By using this

upper end estimate of percent of crop

treated, the Agency is reasonably certain

that exposure is not understated for any

significant subpopulation group.

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, to pesticide

residues. For this pesticide, the most

highly exposed population subgroup

(children 1 to 6) was not regionally

based.

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 pyrithiobac sodium and to

make a determination on aggregate

exposure, consistent with section

408(b)(2), for a time-limited tolerance

for residues of pyrithiobac sodium on

cottonseed at 0.02 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

concerning the variability of the

sensitivities of major identifiable

subgroups of consumers, including

infants and children. The nature of the

toxic effects caused by pyrithiobac

sodium salt are discussed below.

1. A rat acute oral study with a LD50

of 3,300 milligrams (mg)/kilogram (kg)

for males and a LD50 3,200 mg/kg for

females.

2. A 90–day rat feeding study with a

No Observed Effect Level (NOEL) of 50

ppm (3.25 mg/kg/day for males and 4.14

mg/kg/day for females) and a Lowest

Observed Effect Level (LOEL) of 500

ppm (31.8 mg/kg/day for males and 40.5

mg/kg/day for females), based on

decrease body weight gains and

increased rate of hepatic B-oxidation in

males.

3. A 90–day mouse feeding study with

a NOEL of 500 ppm (83.1 mg/kg/day for

males and 112 mg/kg/day for females)

and a LOEL of 1,500 ppm (263 mg/kg/

day for males and 384 mg/kg/day for

females) based on increased liver weight

and an increased incidence of

hepatocellular hypertrophy in males

and decreased neutrophil count in

females.

4. A 3–month dog feeding study with

a NOEL of 5,000 ppm (165 mg/kg/day)

and a LOEL of 20,000 ppm (626 mg/kg/

day), based on decrease red blood cell

count, hemoglobin, and hematocrit in

females and increased liver weight in

both sexes.

5. A 21–day rat dermal study with a

Dermal Irritation NOEL of 50 mg/kg/day

and a dermal irritation LOEL of 500 mg/

kg/day based on increased incidence of

erythema and edema, and with a

systemic dermal NOEL of 500 mg/kg/

day and a Systemic Dermal LOEL of

1,200 mg/kg/day based on body weight

gain inhibition.

6. A 90–day rat neurotoxicity

screening battery with a systemic NOEL

of 7,000 ppm (466 mg/kg/day for males

and 588 mg/kg/day for females) and a

systemic LOEL of 20,000 ppm (1376 mg/

kg/day for males and 1,609 mg/kg/day

for females), based on decreased hind

grip strength and increased foot spay in

males, and a neurotoxicity NOEL of

20,000 ppm [Highest Dose Tested

(HDT)].

7. A 78–week dietary carcinogenicity

study in mice with a NOEL of 1,500

ppm 217 mg/kg/day (males) and 319

mg/kg/day (females) and a LOEL of

5,000 ppm 745 mg/kg/day (males) and

1,101 mg/kg/day (females) based on

decreased body weight/gain in both

sexes, treatment related increase in the

incidence of foci/focus of hepatocellular

alternation in males, and increased

incidence of glomerulonephropathy

murine in both sexes, and an increased

incidence of infarct in the kidney and

keratopathy of the eyes. There was

evidence of carcinogenicity based on

significant differences in the pair-wise

comparisons of hepatocellular

adenomas and combined adenoma/

carcinoma in the 150 and 1,500 dose

groups (but not at the high dose of 5,000

ppm) with the controls. The

carcinogenic effects observed are

discussed below.

8. A 24–month rat chronic feeding/

carcinogenicity study with a systemic

NOEL of 1,500 ppm (58.7 mg/kg/day for

males and 278 mg/kg/day for females)

and a systemic LOEL of 5,000 ppm (200

mg/kg/day for males and 918 mg/kg/day

for females) based on decreases in body

weight, body weight gains and food

efficiency in females, increased

incidence of eye lesions in males and

females, mild changes in hematology

and urinalysis in both sexes, clinical

signs suggestive of urinary tract

dysfunction in males and females,

increased incidence of focal cystic

degeneration in the liver in males,

increased rate of hepatic peroxisomal Boxidation in males and an increased

incidence of inflammatory and

degenerative lesions in the kidney in

females. There was evidence of

carcinogenicity based on a significant

dose-related increasing trend in kidney

tubular combined adenoma/carcinoma

in male rats and a significant dose

related increasing trend in kidney

tubular bilateral and/or unilateral

adenomas in females. The carcinogenic

effects observed are discussed further

below.

9. A 1–year dog chronic feeding study

with a NOEL of 5,000 ppm (143 mg/kg/

day for males and 166 mg/kg/day for

females) and a LOEL of 20,000 ppm (580

mg/kg/day for males and 647 mg/kg/day

for females) based on decreases in body

weight gain and increased liver weight.

10. A two generation reproduction

study in rats with a maternal NOEL of

1,500 ppm (103 mg/kg/day) and a

maternal LOEL of 7,500 ppm (508 mg/

kg/day ppm), based on decreased body

weight/gain and food efficacy. The

Reproductive and Offspring NOEL is

7,500 ppm (508 mg/kg/day) and the

reproductive and offspring LOEL is

20,000 ppm (1,551 mg/kg/day), based on

decreased pup body weight.

11. A developmental toxicity study in

rabbits with a maternal and

developmental NOEL of 300 mg/kg and

a Maternal LOEL of 1,000 mg/kg based

on deaths, decreased body weight gain

and feed consumption, increased

incidence of clinical signs, and an

increase in abortions and a

developmental LOEL of 1,000 mg/kg,

based on decreased fetal body weight

gain.

12. A developmental toxicity study in

rats with a maternal NOEL 200 mg/kg

and a maternal LOEL of 600 mg/kg due

to increased incidence of peritoneal

staining. The developmental NOEL is

600 mg/kg and the developmental LOEL

is 1,800 mg/kg based on the increased

incidence of skeletal variations.
Federal Register / Vol. 62, No. 204 / Wednesday, October 22, 1997 / Rules and Regulations 55781

13. No evidence of gene mutation was

observed in a test for induction of

forward mutations at the HGPRT locus

in Chinese hamster ovary cells. No

evidence was observed for inducing

reverse gene mutation in two

independent assays with Salmonella

typhimurium with and without

mammalian metabolic activation.

Pyrithiobac sodium was negative for the

induction of micronuclei in the bone

marrow cells of mice, and negative for

induction of unscheduled DNA

synthesis in rat primary hepatocytes.

Pyrithiobac sodium was positive for

inducing chromosome aberrations assay

in human lymphocytes.

14. A rat metabolism study showed

that radio labeled pyrithiobac sodium is

excreted in urine and feces with > 90%

being eliminated within 48 hours. A sex

difference was observed in the excretion

and biotransformation. Females

excreted a greater amount of the

radiolabel in the urine than males

following all doing regimens, with a

corresponding lower amount being

eliminated in the feces compared to the

males.

B. Toxicological Endpoints

1. Acute toxicity. EPA has concluded

that no endpoint exists to suggest any

evidence of significant toxicity from 1–

day or single-event exposure.

2. Short - and intermediate - term

toxicity. EPA has concluded that

available evidence does not indicate any

evidence of significant toxicity from

short and intermediate term exposure.

3. Chronic toxicity. EPA has

established the RfD for pyrithiobac

sodium at 0.587 milligrams/kilogram/

day (mg/kg/day). This RfD is based on

the systemic NOEL of 58.7 mg/kg/day

for males in the rat chronic feeding

study with a 100-fold safety factor to

account for interspecies extrapolation

and intraspecies variability.

4. Carcinogenicity. The Health Effects

Division Carcinogenicity Peer Review

Committee has concluded that the

available data provide limited evidence

of the carcinogenicity of pyrithiobac

sodium in mice and rats and has

classified pyrithiobac sodium as a

Group C (possible human carcinogen

with limited evidence of carcinogenicity

in animals) in accordance with Agency

guidelines, published in the Federal

Register in 1986 (51 FR 33992,

September 24, 1986) and recommended

that for the purpose of risk

characterization, a low dose

extrapolation model should be applied

to the experimental animal tumor data

for quantification for human risk (Q1*).

This decision was based on liver

adenomas, carcinomas and combined

adenoma/carcinomas in the male mouse

and rare kidney tubular adenomas,

carcinomas and combined adenoma/

carcinomas in male rats. The unit risk,

Q1* (mg/kg/day)-1, of pyrithiobac

sodium is 1.05 × 10-3 (mg/kg/day)-1 in

human equivalents based on male

kidney tumors.

B. Exposures and Risks

1. From food and feed uses. Time

limited tolerances have been established

(40 CFR 180.487) for the residues of

pyrithiobac sodium in or on the raw

agricultural commodity cottonseed at

0.02 ppm until September 30, 1997.

Processing studies for cotton have

shown that pyrithiobac sodium does not

concentrate in cottonseed processed

commodities. Risk assessments were

conducted by EPA to assess dietary

exposures and risks from herbicide

pyrithiobac sodium salt (sodium 2-

chloro-6-[(4,6-dimethoxypyrimidin-2-

yl)thio]benzoate) as follows:

Based on the assumption that 100% of

the crop is treated with pyrithiobac

sodium, the upper bound limit of the

dietary carcinogenic risk is calculated in

the range of one incidence in a billion

(1.0 × 10-9).

Using the NOEL of 58.7 mg/kg/day

from the most sensitive species in the

rat chronic feeding study with a 100-

fold safety factor, the Reference Dose

(RfD) for systemic effects is 0.58 mg/kg/

day. The theoretical maximum residue

contribution (TMRC) from the

established and proposed tolerances is

0.000001 mg/kg/day and utilizes less

than 1 percent of the RfD for the overall

U.S. population. For exposure of the

most highly exposed subgroup in the

population, children 1 through 6 years

old, the TMRC is 0.000001 mg/kg/day

which is still less than 1 percent of the

RfD.

2. From drinking water. Pyrithiobac

sodium concentration in surface water

has been estimated by using the Generic

Expected Environmental Concentrations

(GENEEC) model. The worst case

exposure estimate for surface water is

7.76 parts per billion (ppb) and for

ground water is 0.778 ppb. Based on the

estimated exposures to pyrithiobac

sodium from drinking water, the

percentage of the RfD utilized for

children (1 through 6 years old) would

be 0.1% of the RfD. The exposure for the

general U.S. population would be less

than 0.1% of the RfD.

The worst case estimate for cancer

risk from the estimated residues of

pyrithiobac sodium in drinking water is

2.3 × 10-7 .

3. From non-dietary exposure. There

are no non-food uses of pyrithiobac

sodium currently registered under the

FIFRA, as amended. No non-dietary

exposures are expected for the general

population.

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).

EPA does not have, at this time,

available data to determine whether

pyrithiobac sodium salt has a common
55782 Federal Register / Vol. 62, No. 204 / Wednesday, October 22, 1997 / Rules and Regulations

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, pyrithiobac

sodium does not appear to produce a

toxic metabolite produced by other

substances. For the purposes of this

tolerance action, therefore, EPA has not

assumed that pyrithiobac sodium has a

common mechanism of toxicity with

other substances.

C. Aggregate Risks and Determination of

Safety for U.S. Population

1. Acute, short-term, and intermediate

term risk. EPA has concluded that no

endpoint exists to suggest any evidence

of significant toxicity from acute, shortterm or intermediate-term exposures

from the use of pyrithiobac sodium on

cotton.

2. Chronic risk. Using the exposure

assumptions described above, EPA has

concluded that aggregate exposure to

pyrithiobac sodium from food and

drinking water will utilize less than

0.1% of the RfD for the U.S. population.

For the major identifiable subgroup with

the highest aggregate exposure, children

(1 through 6 years old), the aggregate

exposure to pyrithiobac sodium from

food and drinking water will utilize less

than 0.2% of the RfD. 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.

D. Aggregate Cancer Risk for U.S.

Population

Based on the upper bound potency

factor (Q1*) of 1.05 × 10-3 (mg/kg/day)-1,

the aggregate upper bound lifetime

cancer risk from the use of pyrithiobac

sodium on cotton from worst case

estimates of residues in food and

drinking water is 2.3 × 10-7.

E. Aggregate Risks and Determination of

Safety for Infants and Children

1. Safety factor for infants and

children—a. In general. In assessing the

potential for additional sensitivity of

infants and children to residues of

pyrithiobac sodium, EPA considered

data from developmental toxicity

studies in the rat and rabbit and a twogeneration reproduction study in the rat.

The developmental toxicity studies are

designed to evaluate adverse effects on

the developing organism resulting from

pesticide exposure during prenatal

development to one or both parents.

Reproduction studies provide

information relating to effects from

exposure to the pesticide 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 MOE

analysis or through using uncertainty

(safety) factors in calculating a dose

level that poses no appreciable risk to

humans. EPA believes that reliable data

support using the standard MOE and

uncertainty factor (usually 100 for

combined inter- and intra-species

variability)) and not the additional

tenfold MOE/uncertainty 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 MOE/safety factor.

b. Developmental and Reproductive

toxicity studies. The pre- and post-natal

toxicology data base for pyrithiobac

sodium is complete with respect to

current toxicological data requirements.

The results of these studies indicate that

infants and children are not more

sensitive to exposure, based on the

results of the oral rat and rabbit

developmental toxicity studies and the

two-generation reproductive toxicity

study in rats. Therefore, EPA concludes

an additional tenfold safety factor is not

necessary.

2. Chronic risk. Using the

conservative exposure assumptions

described above, EPA has concluded

that aggregate exposure to pyrithiobac

sodium from food and drinking water

will utilize less than 0.2% of the RfD for

infants and children. 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. EPA concludes that

there is a reasonable certainty that no

harm will result to infants and children

from aggregate exposure to pyrithiobac

sodium residues.

III. Other Considerations

A. Metabolism In Plants and Animals

The metabolism of pyrithiobac

sodium in plants and animals is

adequately understood for purposes of

this tolerance.

B. Analytical Enforcement Methodology

An adequate analytical method, High

Pressure Liquid Chromatography - Ultra

Violet (HPLC-UV) with column

switching, is available for enforcement

purposes. Because of the long lead time

from establishing these tolerances to

publication of the enforcement

methodology in the Pesticide Analytical

Manual, Vol. II, the analytical

methodology is being made available in

the interim to anyone interested in

pesticide enforcement when requested

from: Calvin Furlow, Public Information

and Records Integrity Branch,

Information Resources and Records

Service (7506C), Office of Pesticide

Programs, Environmental Protection

Agency, 401 M St., SW., Washington,

DC 20460. Office location and telephone

number: Room 1130A, CM#2, 1921

Jefferson Davis Highway, Arlington, VA

22202, (703–305–5937).

C. Magnitude of Residues

The nature of the residue in plants is

adequately understood for the purposes

of this time-limited tolerance.

D. International Residue Limits

There are no Codex Alimentarius

Commission (Codex) Maximum Residue

Levels (MRLs) for pyrithiobac sodium.

IV. Conclusion

The analysis for pyrithiobac sodium

using tolerance level residues for all

population subgroups examined by EPA

shows the use on cotton will not cause

exposure at which the Agency believes

there is an appreciable risk. Based on

the information cited above, EPA has

determined that the extension of the

time limited tolerance for residues of

pyrithiobac sodium in cottonseed at

0.02 ppm until September 30, 1999 by

amending 40 CFR 180.487 will be safe;

therefore, the tolerances are extended as

set forth below.

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
Federal Register / Vol. 62, No. 204 / Wednesday, October 22, 1997 / Rules and Regulations 55783

those procedural regulations with

appropriate adjustments to reflect the

new law.

Any person may, by December 22,

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–300548] (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:

opp-docket@epamail.epa.gov.

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 tolerance

under FFDCA section 408(d) in

response to a petition 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 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: October 1, 1997.

Daniel M. Barolo,

Director, 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. By revising § 180.487 to read as

follows:

§ 180.487 Pyrithiobac sodium; tolerances

for residues.

(a) General. (1) Time-limited

tolerances are established for residues of

the herbicide, pyrithiobac-sodium,

sodium 2-chloro-6-[(4,6-

dimethoxypyrimidin-2-yl)thio]benzoate,

in or on the food commodities in the

table in paragraph (a)(2). The tolerance

will expire on the date specified in the

table.

(2) Residues in these commodities not

in excess of the established tolerance

resulting from the use described in the

following table remaining after

expiration of the time-limited tolerance
55784 Federal Register / Vol. 62, No. 204 / Wednesday, October 22, 1997 / Rules and Regulations

will not be considered to be actionable

if the herbicide is applied during the

term of and in accordance with the

provisions of paragraph (a) of this

section.

Commodity Parts per

million

Expiration/

revocation

date

Cottonseed ......... 0.02 Sept. 30,

1999

(b) Section 18 emergency exemptions.

[Reserved]

(c) Tolerances with regional

registrations. [Reserved]

(d) Indirect or inadvertent residues.

[Reserved]

[FR Doc. 97–27843 Filed 10–21–97; 8:45 am]

BILLING CODE 6560–50–F

ENVIRONMENTAL PROTECTION

AGENCY

40 CFR Parts 180 and 186

[OPP–300563; FRL–5748–9]

RIN 2070–AB78

Cyromazine; Pesticide Tolerances for

Emergency Exemptions

AGENCY: Environmental Protection

Agency (EPA).

ACTION: Final rule.

SUMMARY: This regulation establishes

time-limited tolerances for the

combined residues of cyromazine and

its metabolite melamine in or on the

meat, fat, and meat byproducts of

turkeys. This action is in response to

EPA’s granting of an emergency

exemption under section 18 of the

Federal Insecticide, Fungicide, and

Rodenticide Act authorizing use of the

pesticide on turkeys. This regulation

establishes a maximum permissible

level for residues of cyromazine and its

metabolite melamine in this food

commodity pursuant to section 408(l)(6)

of the Federal Food, Drug, and Cosmetic

Act, as amended by the Food Quality

Protection Act of 1996. These tolerances

will expire and are revoked on October

1, 1998.

DATES: This regulation is effective

October 22, 1997. Objections and

requests for hearings must be received

by EPA on or before December 22, 1997.

ADDRESSES: Written objections and

hearing requests, identified by the

docket control number, [OPP–300563],

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 with the Hearing Clerk identified

by the docket control number, [OPP–

300563], 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: oppdocket@epamail.epa.gov. 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–

300563]. 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: Andrew Ertman, 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) 308-9367, e-mail:

ertman.andrew@epamail.epa.gov.

SUPPLEMENTARY INFORMATION: EPA, on

its own initiative, pursuant to section

408(e) and (l)(6) of the Federal Food,

Drug, and Cosmetic Act (FFDCA), 21

U.S.C. 346a(e) and (l)(6), is establishing

tolerances for combined residues of the

insecticide (larvicide) cyromazine and

its metabolite melamine, in or on meat,

fat, and meat byproducts of turkeys at

0.05 part per million (ppm). These

tolerances will expire and are revoked

on October 1, 1998. EPA will publish a

document in the Federal Register to

remove the revoked tolerances from the

Code of Federal Regulations.

I. Background and Statutory Authority

The Food Quality Protection Act of

1996 (FQPA) (Pub. L. 104–170) was

signed into law August 3, 1996. FQPA

amends both the Federal Food, Drug,

and Cosmetic Act (FFDCA), 21 U.S.C.

301 et seq., and the Federal Insecticide,

Fungicide, and Rodenticide Act

(FIFRA), 7 U.S.C. 136 et seq . The FQPA

amendments went into effect

immediately. Among other things,

FQPA amends FFDCA to bring all EPA

pesticide tolerance-setting activities

under a new section 408 with a new

safety standard and new procedures.

These activities are described below and

discussed in greater detail in the final

rule establishing the time-limited

tolerance associated with the emergency

exemption for use of propiconazole on

sorghum (61 FR 58135, November 13,

1996)(FRL–5572–9).

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. . . .’’

Section 18 of FIFRA authorizes EPA

to exempt any Federal or State agency

from any provision of FIFRA, if EPA

determines that ‘‘emergency conditions

exist which require such exemption.’’

This provision was not amended by

FQPA. EPA has established regulations

governing such emergency exemptions

in 40 CFR part 166.

Section 408(l)(6) of the FFDCA

requires EPA to establish a time-limited

tolerance or exemption from the

requirement for a tolerance for pesticide

chemical residues in food that will

result from the use of a pesticide under

an emergency exemption granted by

EPA under section 18 of FIFRA. Such

tolerances can be established without

providing notice or period for public

comment.