Federal Register / Vol. 66, No. 106 / Friday, June 1, 2001 / Rules and Regulations 29705

363 Recorded Delivery Fee

The recorded delivery fee is $2.10 and

is in addition to postage and other

special service fees, if applicable.

* * * * *

Stanley F. Mires,

Chief Counsel, Legislative.

[FR Doc. 01–13704 Filed 5–31–01; 8:45 am]

BILLING CODE 7710–12–U

ENVIRONMENTAL PROTECTION

AGENCY

40 CFR Part 52

[MO 0129–1129; FRL–6989–6]

Approval and Promulgation of Air

Quality Implementation Plans;

Missouri; Withdrawal of Direct Final

Rule

AGENCY: Environmental Protection

Agency (EPA).

ACTION: Withdrawal of direct final rule.

SUMMARY: On April 6, 2001 (66 FR

18198), EPA published a direct final

approval of a revision to the Missouri

State Implementation Plan (SIP) which

pertained to the Missouri construction

permitting rule. The direct final action

was published without prior proposal

because EPA anticipated no adverse

comment. EPA stated in the direct final

rule that if EPA received adverse

comment by May 7, 2001, EPA would

publish a timely withdrawal in the

Federal Register. EPA subsequently

received adverse comments on the

direct final rule. Therefore, EPA is

withdrawing the direct final approval.

EPA will address the comments in a

subsequent final action based on the

parallel proposal also published on

April 6, 2001 (66 FR 18223). As stated

in the parallel proposal, EPA will not

institute a second comment period on

this action.

EFFECTIVE DATE: The direct final rule

published on April 6, 2001, is

withdrawn as of June 1, 2001.

FOR FURTHER INFORMATION CONTACT:

Wayne Kaiser at (913) 551–7603.

List of Subjects in 40 CFR Part 52

Environmental protection, Air

pollution control, Intergovernmental

relations, Ozone, Particulate matter,

Reporting and recordkeeping

requirements.

Dated: May 23, 2001.

Nat Scurry,

Acting Regional Administrator, Region 7.

Accordingly, the revision to 40 CFR

52. 1320, published in the Federal

Register April 6, 2001 (66 FR 18198),

which was to become effective June 5,

2001, is withdrawn.

[FR Doc. 01–13775 Filed 5–31–01; 8:45 am]

BILLING CODE 6560–50–P

ENVIRONMENTAL PROTECTION

AGENCY

40 CFR Part 180

[OPP–301128; FRL–6781–5]

RIN 2070–AB78

Prohexadione Calcium; Pesticide

Tolerance

AGENCY: Environmental Protection

Agency (EPA).

ACTION: Final rule.

SUMMARY: This regulation establishes a

tolerance for residues of prohexadione

calcium (calcium 3-oxido-5-oxo-4-

propionylcyclohex-3-enecarboxylate) in

or on grass forage, grass hay, grass straw

and grass seed screenings. K-I Chemical

U.S.A. Inc. requested these tolerances

under the Federal Food, Drug, and

Cosmetic Act, as amended by the Food

Quality Protection Act of 1996.

DATES: This regulation is effective June

1, 2001. Objections and requests for

hearings, identified by docket control

number OPP–301128, must be received

by EPA on or before July 31, 2001.

ADDRESSES: Written objections and

hearing requests may be submitted by

mail, in person, or by courier. Please

follow the detailed instructions for each

method as provided in Unit VI. of

theSUPPLEMENTARY INFORMATION. To

ensure proper receipt by EPA, your

objections and hearing requests must

identify docket control number OPP–

301128 in the subject line on the first

page of your response.

FOR FURTHER INFORMATION CONTACT: By

mail: Cynthia Giles-Parker (PM 22),

Registration Division (7505C), Office of

Pesticide Programs, Environmental

Protection Agency, 1200 Pennsylvania

Ave., NW., Washington, DC 20460;

telephone number: (703) 305–7740; and

e-mail address: gilesparker.cynthia@epa.gov.

SUPPLEMENTARY INFORMATION:

I. General Information

A. Does this Action Apply to Me?

You may be affected by this action if

you are an agricultural producer, food

manufacturer, or pesticide

manufacturer. Potentially affected

categories and entities may include, but

are not limited to:

Categories NAICS

codes

Examples of Potentially Affected Entities

Industry 111 Crop production

112 Animal production

311 Food manufacturing

32532 Pesticide manufacturing

This listing is not intended to be

exhaustive, but rather provides a guide

for readers regarding entities likely to be

affected by this action. Other types of

entities not listed in the table could also

be affected. The North American

Industrial Classification System

(NAICS) codes have been provided to

assist you and others in determining

whether or not this action might apply

to certain entities. If you have questions

regarding the applicability of this action

to a particular entity, consult the person

listed under FOR FURTHER INFORMATION

CONTACT.

B. How Can I Get Additional

Information, Including Copies of this

Document and Other Related

Documents?

1. Electronically. You may obtain

electronic copies of this document, and

certain other related documents that

might be available electronically, from

the EPA Internet Home Page at http://

www.epa.gov/. To access this

document, on the Home Page select

‘‘Laws and Regulations,’’ ‘‘Regulations

and Proposed Rules,’’ and then look up

the entry for this document under the

‘‘Federal Register—Environmental

Documents.’’ You can also go directly to

theFederal Register listings at http://

www.epa.gov/fedrgstr/. To access the

OPPTS Harmonized Guidelines

referenced in this document, go directly

to the guidelines at http://www.epa.gov/

opptsfrs/home/guidelin.htm.

2. In person. The Agency has

established an official record for this

action under docket control number

OPP–301128. The official record

consists of the documents specifically

referenced in this action, and other

information related to this action,

including any information claimed as

Confidential Business Information (CBI).

This official record includes the

documents that are physically located in

the docket, as well as the documents

that are referenced in those documents.

The public version of the official record

does not include any information

claimed as CBI. The public version of

the official record, which includes

printed, paper versions of any electronic

comments submitted during an

applicable comment period is available

for inspection in the Public Information

and Records Integrity Branch (PIRIB),

29706 Federal Register / Vol. 66, No. 106 / Friday, June 1, 2001 / Rules and Regulations

Rm. 119, Crystal Mall #2, 1921 Jefferson

Davis Hwy., Arlington, VA, from 8:30

a.m. to 4 p.m., Monday through Friday,

excluding legal holidays. The PIRIB

telephone number is (703) 305–5805.

II. Background and Statutory Findings

In the Federal Register of March 28,

2001 (66 FR 16921) (FRL–6769–9), EPA

issued a notice pursuant to section 408

of the Federal Food, Drug, and Cosmetic

Act (FFDCA), 21 U.S.C. 346a as

amended by the Food Quality Protection

Act of 1996 (FQPA) (Public Law 104–

170) announcing the filing of a pesticide

petition (PP) for tolerance by K-I

Chemical U.S.A. Inc., Westchester

Financial Center, 11 Martine Avenue,

9th Floor, White Plains, NY, 10606. This

notice included a summary of the

petition prepared by K-I Chemical

U.S.A. Inc., the registrant. There were

no comments received in response to

the notice of filing.

The petition requested that 40 CFR

180.547 be amended by establishing a

tolerance for residues of the plant

growth regulator prohexadione calcium,

calcium 3-oxido-5-oxo-4-

propionylcyclohex-3-enecarboxylate in

or on grass forage at 0.10 part per

million (ppm), grass hay at 0.10 ppm,

grass straw at 1.2 ppm and grass seed

screenings at 3.5 ppm.

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. For

further discussion of the regulatory

requirements of section 408 and a

complete description of the risk

assessment process, see the final rule on

Bifenthrin Pesticide Tolerances (62 FR

62961, November 26, 1997) (FRL–5754–

7).

III. 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 and to make a determination

on aggregate exposure, consistent with

section 408(b)(2), for a tolerance for

residues of prohexadione calcium,

calcium 3-oxido-5-oxo-4-

propionylcyclohex-3-enecarboxylate in

or on grass forage at 0.10 ppm, grass hay

at 0.10 ppm, grass straw at 1.2 ppm and

grass seed screenings at 3.5 ppm. EPA’s

assessment of 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 prohexadione

calcium are discussed in the following

Table 1 as well as the no observed

adverse effect level (NOAEL) and the

lowest observed adverse effect level

(LOAEL) from the toxicity studies

reviewed.

TABLE 1.—SUBCHRONIC, CHRONIC, AND OTHER TOXICITY

Guideline No./ Study Type Results

870.3100 90–Day oral toxicity rodents (rat) NOAEL: Males: 73.1 mg/kg/day; Females: 80.4 mg/kg/day LOAEL:

Males: 734 mg/kg/day; Females: 815 mg/kg/day based on squamous cell hyperplasia of the forestomach.

870.3100 90–Day oral toxicity rodents (mouse) NOAEL: Males: ≥10,244 mg/kg/day; Females: ≥11,916 mg/kg/day

(highest dose tested)LOAEL: Males: >10,244 mg/kg/day; Females:

>11,916 mg/kg/day

870.3150 90–Day oral toxicity in nonrodents (dog) NOAEL = 80 mg/kg/day LOAEL = 400 mg/kg/day based on moderate

cortical areas of dilated basophilic tubules in the kidneys and decreased potassium levels.

870.3200 21/28–Day dermal toxicity DATA GAP

870.3250 90–Day dermal toxicity NA

870.3700a Prenatal developmental toxicity in rodents (rat) Maternal NOAEL ≥1,000 mg/kg/day (limit dose)LOAEL = Not observed Developmental NOAEL ≥1,000 mg/kg/day (limit dose)

LOAEL = Not observed

870.3700b Prenatal developmental toxicity in nonrodents (rabbit) Maternal NOAEL = 40 mg/kg/dayLOAEL = 200 mg/kg/day based on

increased mortality,abortions, and decreased maternal body weight

gain.Developmental NOAEL ≥200 mg/kg/day LOAEL = Not observed(Due to severe mortality at 750 mg/kg/day, 200 mg/kg/day

wasdeemed the high dose for evaluation)

870.3700b Prenatal developmentaltoxicity in nonrodents (rabbit) Maternal NOAEL = ≥150 mg/kg/day LOAEL = Not observed Developmental NOAEL ≥150 mg/kg/day LOAEL = Not observed

Federal Register / Vol. 66, No. 106 / Friday, June 1, 2001 / Rules and Regulations 29707

TABLE 1.—SUBCHRONIC, CHRONIC, AND OTHER TOXICITY—Continued

Guideline No./ Study Type Results

870.3700b Prenatal developmentaltoxicity in nonrodents (rabbit) Maternal NOAEL = 100 mg/kg/dayLOAEL = 350 mg/kg/day based on

premature deliveries.Developmental NOAEL ≥350 mg/kg/day

LOAEL = Not observed

870.38002–Generation Reproductionand fertility effects rats Parental/Systemic NOAEL = 35.5 mg/kg/dayLOAEL = 385 mg/kg/day

based on increased mortality.Reproductive NOAEL ≥3,850 mg/kg/

dayLOAEL >3,850 mg/kg/dayOffspring NOAEL = 385 mg/kg/

dayLOAEL = 3850 mg/kg/day based on decreased pup body

weight.

870.4100 Chronic toxicity dogs NOAEL = 20 mg/kg/day LOAEL = 200 mg/kg/daybased on

histopathological changes in thekidneys and increased urinary

volumeand sodium concentrations.

870.4300 Chronictoxicity/carcinogenicity rats NOAEL = 93.9 mg/kg/dayLOAEL = 469 mg/kg/day based on decreased WBC in males.No evidence of carcinogenicity

870.4200 Carcinogenicity mice NOAEL = 279 mg/kg/dayLOAEL = 2847 mg/kg/day based on decreased bodyweight gain and food utilization andmicroscopic

changes in the stomachs of males.No evidence of carcinogenicity

870.5100 Bacterial reversemutation assay (Ames test) Negative with and without S–9activation up to the highest dose tested

(5,000 μg/plate).

870.5300In vitro mammalian gene mutation assay Negative with S–9 activationup to 475 μg/mL. Negative without S–

9activation up to 500 μg/mL. Compound testedto concentrations

limited by solubility.

870.5375In vitro mammalian chromosomeaberration (Chinese

Hampster Ovary (CHO) cells)

Increase in polyploidy in theabsence of S9 activation at 500 μg/mL

for6 hours at the 24–hour cell harvest time;effect not observed after

treatments of 24–or 48–hours. No increase in aberrationfrequency

at any concentration orharvest time with or without S9. Compound

wastested up to concentrations limited by solubility.

870.5385 In vivomammalian chromosome aberration (rat bone marrow

cells)

Negative at 6, 24, and48–hour sacrifices. Compound testedto the

limit dose.

870.5395 Mammalian erythrocytemicronucleus test Negative at 24, 48, and 72 hour sacrifices. Noincrease in the frequency of micronucleatedpolychromatic erythrocytes in bone marrow.

870.5550 UDS in primary rat hepatocytes Negative up to cytotoxic concentration (500 μg/mL).

870.5500 Rec assay withBacillus subtilis Negative for DNA damage when tested upto the limit dose (5,000 μg/

mL) both with and without S9.

870.6200a Acute neurotoxicityscreening battery NOAEL ≥2,000 mg/kg LOAEL = Not observed

870.6200b Subchronic neurotoxicityscreening battery NOAEL ≥1148 (M) or 1348(F) mg/kg/day LOAEL = Not observed

870.6300 Developmental neurotoxicity NA

870.7485 Metabolism and pharmacokinetics Following oral treatment of rats,prohexadione calcium was

rapidlyabsorbed with highest tissue/carcassconcentrations obtained

within30 minutes; however, absorptionbecame saturated at the

highest dose.The test material did not accumulatein the tissues.

For low dose animals,renal excretion was the primary route

ofelimination. At the high dose, fecalexcretion became the primary

route ofelimination. The primary excreta(both feces and urine) metabolite wasidentified as the free acid.

870.7600 Dermal penetration NA

B. Toxicological Endpoints

The dose at which no adverse effects

are observed (the NOAEL) from the

toxicology study identified as

appropriate for use in risk assessment is

used to estimate the toxicological level

of concern (LOC). However, the lowest

dose at which adverse effects of concern

are identified (the LOAEL) is sometimes

used for risk assessment if no NOAEL

was achieved in the toxicology study

selected. An uncertainty factor (UF) is

applied to reflect uncertainties inherent

in the extrapolation from laboratory

animal data to humans and in the

variations in sensitivity among members

of the human population as well as

other unknowns. An UF of 100 is

routinely used, 10× to account for

29708 Federal Register / Vol. 66, No. 106 / Friday, June 1, 2001 / Rules and Regulations

interspecies differences and 10× for

intraspecies differences.

For dietary risk assessment (other

than cancer) the Agency uses the UF to

calculate an acute or chronic reference

dose (acute RfD or chronic RfD) where

the RfD is equal to the NOAEL divided

by the appropriate UF (RfD = NOAEL/

UF). Where an additional safety factor is

retained due to concerns unique to the

FQPA, this additional factor is applied

to the RfD by dividing the RfD by such

additional factor. The acute or chronic

Population Adjusted Dose (aPAD or

cPAD) is a modification of the RfD to

accommodate this type of FQPA Safety

Factor.

For non-dietary risk assessments

(other than cancer) the UF is used to

determine the LOC. For example, when

100 is the appropriate UF (10× to

account for interspecies differences and

10× for intraspecies differences) the

LOC is 100. To estimate risk, a ratio of

the NOAEL to exposures (margin of

exposure (MOE) = NOAEL/exposure) is

calculated and compared to the LOC.

The linear default risk methodology

(Q*) is the primary method currently

used by the Agency to quantify

carcinogenic risk. The Q* approach

assumes that any amount of exposure

will lead to some degree of cancer risk.

A Q* is calculated and used to estimate

risk which represents a probability of

occurrence of additional cancer cases

(e.g., risk is expressed as 1 × 10–6 or one

in a million). Under certain specific

circumstances, MOE calculations will

be used for the carcinogenic risk

assessment. In this non-linear approach,

a ‘‘point of departure’’ is identified

below which carcinogenic effects are

not expected. The point of departure is

typically a NOAEL based on an

endpoint related to cancer effects

though it may be a different value

derived from the dose response curve.

To estimate risk, a ratio of the point of

departure to exposure (MOEcancer= point

of departure/exposures) is calculated. A

summary of the toxicological endpoints

for prohexadione calcium used for

human risk assessment is shown in the

following Table 2:

TABLE 2.—SUMMARY OF TOXICOLOGICAL DOSE AND ENDPOINTS FOR PROHEXADIONE CALCIUM FOR USE IN HUMAN RISK

ASSESSMENT

Exposure Scenario Dose Used in Risk Assessment, UF

FQPA SF and LOC for Risk

Assessment Study and Toxicological Effects

Acute Dietary NA NA no adverse effects of concern observed in oral, developmental, and

neurotoxicity studies in rats and

rabbits, attributable to a single exposure dose

Chronic Dietary NOAEL= 80 mg/kg/day UF

= 100 Chronic RfD =

0.80 mg/kg/day

FQPA SF = 1× cPAD = chronic RfD FQPA SF = 0.80 mg/

kg/day

Subchronic & chronic toxicity-dog

LOAEL = 200 mg/kg/day based on

histopathological changes in the

kidneys (dilated basophilic tubules)

and clinical chemistry changes

Short-Term Dermal (1–7 days) (Occupational/Residential)Oral Maternal NOAEL =

100 mg/kg/day Estimated

dermal absorption rate

25%

LOC for MOE = 100 (Occupational)Developmental toxicity- rabbit Maternal LOAEL = 350 mg/kg/day based

on premature deliveries

Intermediate-Term Dermal (1 week –

several months) (Occupational/Residential)

Oral NOAEL = 80 mg/kg/

day Estimated absorption

rate 25%

LOC for MOE =100 (Occupational)Subchronic toxicity-dog LOAEL = 400

mg/kg/day based on moderate cortical areas of dilated basophilic tubules in the kidneys and decreased

potassium levels

Long-Term Dermal (several months –

lifetime) (Occupational/Residential)

Oral NOAEL = 80 mg/kg/

day Estimated absorption

rate 25%

LOC for MOE = 100 (Occupational)Subchronic & chronic toxicity-dog

LOAEL = 200 mg/kg/day based on

histopathological changes in the

kidneys (dilated basophilic tubules)

and clinical chemistry changes

Short-Term Inhalation (1–7 days) (Occupational/Residential)Oral Maternal NOAEL= 100

mg/kg/day (inhalation absorption rate = 100%)

LOC for MOE = 100 (Occupational)Developmental toxicity- rabbit LOAEL

= 350 mg/kg/day based on premature deliveries

Intermediate-Term Inhalation (1 week

– several months) (Occupational/

Residential)

Oral NOAEL= 80 mg/kg/

day (inhalation absorption rate = 100%)

LOC for MOE = 100 (Occupational)Subchronic toxicity-dog LOAEL = 400

mg/kg/day based on moderate cortical areas of dilated basophilic tubules in the kidneys and decreased

potassium levels

Long-Term Inhalation(several months

– lifetime)(Occupational/Residential)

Oral NOAEL= 80 mg/kg/

day (inhalation absorption rate = 100%)

LOC for MOE = 100 (Occupational)Subchronic & chronic toxicity-dog

LOAEL = 200 mg/kg/day based on

histopathological changes in the

kidneys (dilated basophilic tubules)

and clinical chemistry changes

Federal Register / Vol. 66, No. 106 / Friday, June 1, 2001 / Rules and Regulations 29709

TABLE 2.—SUMMARY OF TOXICOLOGICAL DOSE AND ENDPOINTS FOR PROHEXADIONE CALCIUM FOR USE IN HUMAN RISK

ASSESSMENT—Continued

Exposure Scenario Dose Used in Risk Assessment, UF

FQPA SF and LOC for Risk

Assessment Study and Toxicological Effects

Cancer (oral, dermal, inhalation) Not likely human carcinogenNA No evidence of carcinogenic potential,

therefore, cancer risk assessment

is not required

C. Exposure Assessment

1. Dietary exposure from food and

feed uses. Tolerances have been

established (40 CFR 180.547) for the

residues of prohexadione calcium, in or

on a variety of raw agricultural

commodities. Risk assessments were

conducted by EPA to assess dietary

exposures from prohexadione calcium

in food as follows:

i. Acute exposure. Acute dietary risk

assessments are performed for a fooduse pesticide if a toxicological study has

indicated the possibility of an effect of

concern occurring as a result of a one

day or single exposure. An acute dietary

risk assessment was not performed

because there were no adverse effects of

concern observed in neurotoxicity

studies, oral toxicology studies,

including maternal toxicity in the

developmental toxicity studies in rats

and rabbits, that were attributable to a

single exposure dose.

ii. Chronic exposure. In conducting

this chronic dietary risk assessment the

Dietary Exposure Evaluation Model

(DEEMM) analysis evaluated the

individual food consumption as

reported by respondents in the USDA

1989–1992 nationwide Continuing

Surveys of Food Intake by Individuals

(CSFII) and accumulated exposure to

the chemical for each commodity. The

following assumptions were made for

the chronic exposure assessments:

Tolerance level residues (pome fruit,

peanuts, animal feeds) and 100% CT

was assumed for all commodities.

Residues were not found to concentrate

in processed apples; therefore,

concentration factors were not used

(apple juice, cider).

iii. Cancer. In accordance with the

EPA Draft Guidelines for Carcinogen

Risk Assessment (July, 1999),

prohexadione calcium is classified as

not likely to be carcinogenic to humans

by all routes of exposure based upon

lack of evidence of carcinogenicity in

rats and mice.

2. Dietary exposure from drinking

water. The Agency lacks sufficient

monitoring exposure data to complete a

comprehensive dietary exposure

analysis and risk assessment for

prohexadione calcium in drinking

water. Because the Agency does not

have comprehensive monitoring data,

drinking water concentration estimates

are made by reliance on simulation or

modeling taking into account data on

the physical characteristics of

prohexadione calcium.

The Agency uses the Generic

Estimated Environmental Concentration

(GENEEC) or the Pesticide Root Zone/

Exposure Analysis Modeling System

(PRZM/EXAMS) to estimate pesticide

concentrations in surface water and SCIGROW, which predicts pesticide

concentrations in groundwater. In

general, EPA will use GENEEC (a tier 1

model) before using PRZM/EXAMS (a

tier 2 model) for a screening-level

assessment for surface water. The

GENEEC model is a subset of the PRZM/

EXAMS model that uses a specific highend runoff scenario for pesticides.

GENEEC incorporates a farm pond

scenario, while PRZM/EXAMS

incorporates an index reservoir

environment in place of the previous

pond scenario. The PRZM/EXAMS

model includes a percent crop area

factor as an adjustment to account for

the maximum percent crop coverage

within a watershed or drainage basin.

None of these models include

consideration of the impact processing

(mixing, dilution, or treatment) of raw

water for distribution as drinking water

would likely have on the removal of

pesticides from the source water. The

primary use of these models by the

Agency at this stage is to provide a

coarse screen for sorting out pesticides

for which it is highly unlikely that

drinking water concentrations would

ever exceed human health levels of

concern.

Since the models used are considered

to be screening tools in the risk

assessment process, the Agency does

not use estimated environmental

concentrations (EECs) from these

models to quantify drinking water

exposure and risk as a %RfD or %PAD.

Instead drinking water levels of

comparison (DWLOCs) are calculated

and used as a point of comparison

against the model estimates of a

pesticide’s concentration in water.

DWLOCs are theoretical upper limits on

a pesticide’s concentration in drinking

water in light of total aggregate exposure

to a pesticide in food, and from

residential uses. Since DWLOCs address

total aggregate exposure to

prohexadione calcium they are further

discussed in the aggregate risk sections

below.

Based on the GENEEC and SCI-GROW

models the estimated environmental

concentrations (EECs) of prohexadione

calcium for acute exposures are

estimated to be 35.6 parts per billion

(ppb) for surface water and 0.001 ppb

for ground water. The EECs for chronic

exposures are estimated to be 7.73 ppb

for surface water and 0.001 ppb for

ground water.

3. From non-dietary exposure. The

term ‘‘residential exposure’’ is used in

this document to refer to nonoccupational, non-dietary exposure

(e.g., for lawn and garden pest control,

indoor pest control, termiticides, and

flea and tick control on pets).

Prohexadione calcium is not registered

for use on any sites that would result in

residential exposure.

4. Cumulative exposure to substances

with a 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.’’

EPA does not have, at this time,

available data to determine whether

prohexadione calcium 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, prohexadione

calcium 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 prohexadione calcium has

a common mechanism of toxicity with

other substances. For information

regarding EPA’s efforts to determine

which chemicals have a common

mechanism of toxicity and to evaluate

the cumulative effects of such

chemicals, see the final rule for

29710 Federal Register / Vol. 66, No. 106 / Friday, June 1, 2001 / Rules and Regulations

Bifenthrin Pesticide Tolerances (62 FR

62961, November 26, 1997).

D. Safety Factor for Infants and

Children

1. In general. 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 prenatal

and postnatal toxicity and the

completeness of the data base on

toxicity and exposure 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 (MOE) analysis or through

using uncertainty (safety) factors in

calculating a dose level that poses no

appreciable risk to humans.

2. Prenatal and postnatal sensitivity.

The prenatal and postnatal toxicology

data base for prohexadione is adequate

for FQPA considerations. The results of

these studies indicated no quantitative

or qualitative increase in susceptibility

of rats or rabbits to in utero and/or

postnatal exposure to prohexadione. A

developmental neurotoxicity study is

not required.

3. Conclusion. There is a complete

toxicity data base for prohexadione

calcium and exposure data are complete

or are estimated based on data that

reasonably accounts for potential

exposures. The FQPA Safety Factor is

1× (reduced from 10×). In assessing the

risk posed by prohexadione calcium the

safety factor could be removed because:

(i) The prenatal and postnatal toxicology

data base is complete, there is no

indication of increased susceptibility,

and a developmental neurotoxicity

study is not required, and (ii) the food

and drinking water exposure

assessments will not underestimate the

potential exposures for infants and

children from the use of prohexadione

calcium (currently there are no

proposed residential uses and, therefore,

non-occupational exposure is not

expected).

E. Aggregate Risks and Determination of

Safety

To estimate total aggregate exposure

to a pesticide from food, drinking water,

and residential uses, the Agency

calculates DWLOCs which are used as a

point of comparison against the model

estimates of a pesticide’s concentration

in water (EECs). DWLOC values are not

regulatory standards for drinking water.

DWLOCs are theoretical upper limits on

a pesticide’s concentration in drinking

water in light of total aggregate exposure

to a pesticide in food and residential

uses. In calculating a DWLOC, the

Agency determines how much of the

acceptable exposure (i.e., the PAD) is

available for exposure through drinking

water [e.g., allowable chronic water

exposure (mg/kg/day) = cPAD - (average

food + residential exposure). This

allowable exposure through drinking

water is used to calculate a DWLOC.

A DWLOC will vary depending on the

toxic endpoint, drinking water

consumption, and body weights. Default

body weights and consumption values

as used by the USEPA Office of Water

are used to calculate DWLOCs: 2L/70 kg

(adult male), 2L/60 kg (adult female),

and 1L/10 kg (child). Default body

weights and drinking water

consumption values vary on an

individual basis. This variation will be

taken into account in more refined

screening-level and quantitative

drinking water exposure assessments.

Different populations will have different

DWLOCs. Generally, a DWLOC is

calculated for each type of risk

assessment used: acute, short-term,

intermediate-term, chronic, and cancer.

When EECs for surface water and

groundwater are less than the calculated

DWLOCs, OPP concludes with

reasonable certainty that exposures to

the pesticide in drinking water (when

considered along with other sources of

exposure for which OPP has reliable

data) would not result in unacceptable

levels of aggregate human health risk at

this time. Because OPP considers the

aggregate risk resulting from multiple

exposure pathways associated with a

pesticide’s uses, levels of comparison in

drinking water may vary as those uses

change. If new uses are added in the

future, OPP will reassess the potential

impacts of residues of the pesticide in

drinking water as a part of the aggregate

risk assessment process.

1. Acute risk. Acute dietary risk

assessment is not expected because

there were no adverse effects of concern

observed in neurotoxicity studies, oral

toxicology studies, including maternal

toxicity in the developmental toxicity

studies in rats and rabbits, that were

attributable to a single exposure dose.

2. Chronic risk. Using the exposure

assumptions described in this unit for

chronic exposure, EPA has concluded

that exposure to prohexadione calcium

from food will utilize < 1 % of the cPAD

for the U.S. population, 2% of the cPAD

for all infants (<1 year old) and 2% of

th cPAD for children 1–6 years of age.

There are no residential uses for

prohexadione calcium that result in

chronic residential exposure to

prohexadione calcium. In addition,

there is potential for chronic dietary

exposure to prohexadione calcium in

drinking water. After calculating

DWLOCs and comparing them to the

EECs for surface and ground water, EPA

does not expect the aggregate exposure

to exceed 100% of the cPAD, as shown

in the following Table 3:

TABLE 3.—AGGREGATE RISK ASSESSMENT FOR CHRONIC (NON- CANCER) EXPOSURE TO PROHEXADIONE CALCIUM

Population Subgroup cPAD mg/kg/day %cPAD (Food) Surface Water

EEC (ppb)

Ground Water EEC

(ppb)

Chronic DWLOC

(ppb)

U.S. Population 0.80 < 1 7.73 0.001 28,000

All Infants (< 1 year old) 0.80 2 7.73 0.001 8,000

Children 1–6 years old 0.80 2 7.73 0.001 8,000

Females 13–50 years old 0.80 < 1 7.73 0.001 24,000

3. Short-term risk. Short-term

aggregate exposure takes into account

residential exposure plus chronic

exposure to food and water (considered

to be a background exposure level).

Prohexadione calcium is not registered

for use on any sites that would result in

residential exposure. Therefore, the

aggregate risk is the sum of the risk from

food and water, which do not exceed

the Agency’s level of concern.

4. Intermediate-term risk.

Intermediate-term aggregate exposure

takes into account residential exposure

plus chronic exposure to food and water

(considered to be a background

exposure level). Prohexadione calcium

is not registered for use on any sites that

would result in residential exposure.

Therefore, the aggregate risk is the sum

of the risk from food and water, which

do not exceed the Agency’s level of

concern.

Federal Register / Vol. 66, No. 106 / Friday, June 1, 2001 / Rules and Regulations 29711

5. Aggregate cancer risk for U.S.

population. Prohexadione calcium is

classified as not likely to be

carcinogenic to humans by all routes of

exposure based upon lack of evidence of

carcinogenicity in rats and mice,

therefore, no cancer risk is expected.

6. Determination of safety. Based on

these risk assessments, EPA concludes

that there is a reasonable certainty that

no harm will result to the general

population, and to infants and children

from aggregate exposure to

prohexadione calcium residues.

IV. Other Considerations

A. Analytical Enforcement Methodology

Adequate enforcement methodology

(gas chromatography and mass selective

detector) is available to enforce the

tolerance expression. The method may

be requested from: Calvin Furlow,

PRRIB, IRSD (7502C), Office of Pesticide

Programs, Environmental Protection

Agency, 1200 Pennsylvania Ave., NW,

Washington, DC 20460; telephone

number: (703) 305–5229; e-mail address:

furlow.calvin@epa.gov.

B. International Residue Limits

There is neither a Codex proposal, nor

Canadian or Mexican limits for residues

of prohexadione calcium in/on plant or

livestock commodities.

C. Conditions

A 21–day dermal toxicity study in

rabbits (OPPTS 870.3200) is required.

V. Conclusion

Therefore, the tolerance is established

for residues of prohexadione calcium,

calcium 3-oxido-5-oxo-4-

propionylcyclohex-3-enecarboxylate in

or on grass forage at 0.10 ppm, grass hay

at 0.10 ppm, grass straw at 1.2 ppm and

grass seed screenings at 3.5 ppm.

VI. Objections and Hearing Requests

Under section 408(g) of the FFDCA, as

amended by the FQPA, any person may

file an objection to any aspect of this

regulation and may also request a

hearing on those objections. The EPA

procedural regulations which govern the

submission of objections and requests

for hearings appear in 40 CFR part 178.

Although the procedures in those

regulations require some modification to

reflect the amendments made to the

FFDCA by the FQPA of 1996, EPA will

continue to use those procedures, with

appropriate adjustments, until the

necessary modifications can be made.

The new section 408(g) provides

essentially the same process for persons

to ‘‘object’’ to a regulation for an

exemption from the requirement of a

tolerance issued by EPA under new

section 408(d), as was provided in the

old FFDCA sections 408 and 409.

However, the period for filing objections

is now 60 days, rather than 30 days.

A. What Do I Need to Do to File an

Objection or Request a Hearing?

You must file your objection or

request a hearing on this regulation in

accordance with the instructions

provided in this unit and in 40 CFR part

178. To ensure proper receipt by EPA,

you must identify docket control

number OPP–301128 in the subject line

on the first page of your submission. All

requests must be in writing, and must be

mailed or delivered to the Hearing Clerk

on or before July 31, 2001.

1. Filing the request. Your objection

must specify the specific provisions in

the regulation that you object to, and the

grounds for the objections (40 CFR

178.25). If a hearing is requested, the

objections must include a statement of

the factual issues(s) on which a hearing

is requested, the requestor’s contentions

on such issues, and a summary of any

evidence relied upon by the objector (40

CFR 178.27). Information submitted in

connection with an objection or hearing

request may be claimed confidential by

marking any part or all of that

information as 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.

Mail your written request to: Office of

the Hearing Clerk (1900), Environmental

Protection Agency, 1200 Pennsylvania

Ave., NW., Washington, DC 20460. You

may also deliver your request to the

Office of the Hearing Clerk in Rm. C400,

Waterside Mall, 401 M St., SW.,

Washington, DC 20460. The Office of

the Hearing Clerk is open from 8 a.m.

to 4 p.m., Monday through Friday,

excluding legal holidays. The telephone

number for the Office of the Hearing

Clerk is (202) 260–4865.

2. Tolerance fee payment. If you file

an objection or request a hearing, you

must also pay the fee prescribed by 40

CFR 180.33(i) or request a waiver of that

fee pursuant to 40 CFR 180.33(m). You

must mail the fee to: EPA Headquarters

Accounting Operations Branch, Office

of Pesticide Programs, P.O. Box

360277M, Pittsburgh, PA 15251. Please

identify the fee submission by labeling

it ‘‘Tolerance Petition Fees.’’

EPA is authorized to waive any fee

requirement ‘‘when in the judgement of

the Administrator such a waiver or

refund is equitable and not contrary to

the purpose of this subsection.’’ For

additional information regarding the

waiver of these fees, you may contact

James Tompkins by phone at (703) 305–

5697, by e-mail at

tompkins.jim@epa.gov, or by mailing a

request for information to Mr. Tompkins

at Registration Division (7505C), Office

of Pesticide Programs, Environmental

Protection Agency, 1200 Pennsylvania

Ave., NW., Washington, DC 20460.

If you would like to request a waiver

of the tolerance objection fees, you must

mail your request for such a waiver to:

James Hollins, Information Resources

and Services Division (7502C), Office of

Pesticide Programs, Environmental

Protection Agency, 1200 Pennsylvania

Ave., NW., Washington, DC 20460.

3. Copies for the Docket. In addition

to filing an objection or hearing request

with the Hearing Clerk as described in

Unit VI.A., you should also send a copy

of your request to the PIRIB for its

inclusion in the official record that is

described in Unit I.B.2. Mail your

copies, identified by docket control

number OPP–301128, to: Public

Information and Records Integrity

Branch, Information Resources and

Services Division (7502C), Office of

Pesticide Programs, Environmental

Protection Agency, 1200 Pennsylvania

Ave., NW., Washington, DC 20460. In

person or by courier, bring a copy to the

location of the PIRIB described in Unit

I.B.2. You may also send an electronic

copy of your request via e-mail to: oppdocket@epa.gov. Please use an ASCII

file format and avoid the use of special

characters and any form of encryption.

Copies of electronic objections and

hearing requests will also be accepted

on disks in WordPerfect 6.1/8.0 or

ASCII file format. Do not include any

CBI in your electronic copy. You may

also submit an electronic copy of your

request at many Federal Depository

Libraries.

B. When Will the Agency Grant a

Request for a Hearing?

A request for a hearing will be granted

if the Administrator determines that the

material submitted shows the following:

There is a 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(s) in the manner sought by the

requestor would be adequate to justify

the action requested (40 CFR 178.32).

29712 Federal Register / Vol. 66, No. 106 / Friday, June 1, 2001 / Rules and Regulations

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) (Public

Law 104–4). Nor does it require any

special considerations under Executive

Order 12898, entitled Federal Actions to

Address Environmental Justice in

Minority Populations and Low-Income

Populations (59 FR 7629, February 16,

1994); or OMB review or any Agency

action under Executive Order 13045,

entitled Protection of Children from

Environmental Health Risks and Safety

Risks (62 FR 19885, April 23, 1997).

This action does not involve any

technical standards that would require

Agency consideration of voluntary

consensus standards pursuant to section

12(d) of the National Technology

Transfer and Advancement Act of 1995

(NTTAA), Public Law 104–113, section

12(d) (15 U.S.C. 272 note). Since

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. In addition, the

Agency has determined that this action

will not have a substantial direct effect

on States, on the relationship between

the national government and the States,

or on the distribution of power and

responsibilities among the various

levels of government, as specified in

Executive Order 13132, entitled

Federalism(64 FR 43255, August 10,

1999). Executive Order 13132 requires

EPA to develop an accountable process

to ensure ‘‘meaningful and timely input

by State and local officials in the

development of regulatory policies that

have federalism implications.’’ ‘‘Policies

that have federalism implications’’ is

defined in the Executive Order to

include regulations that have

‘‘substantial direct effects on the States,

on the relationship between the national

government and the States, or on the

distribution of power and

responsibilities among the various

levels of government.’’ This final rule

directly regulates growers, food

processors, food handlers and food

retailers, not States. This action does not

alter the relationships or distribution of

power and responsibilities established

by Congress in the preemption

provisions of FFDCA section 408(n)(4).

For these same reasons, the Agency has

determined that this rule does not have

any tribal implications as described in

Executive Order 13175, entitled

Consultation and Coordination with

Indian Tribal Governments (65 FR

67249, November 6, 2000). Executive

Order 13175, requires EPA to develop

an accountable process to ensure

meaningful and timely input by tribal

officials in the development of

regulatory policies that have tribal

implications. Policies that have tribal

implications is defined in the Executive

Order to include regulations that have

substantial direct effects on one or more

Indian Tribes, on the relationship

between the Federal government and

the Indian tribes, or on the distribution

of power and responsibilities between

the Federal government and Indian

tribes. This rule will not have

substantial direct effects on tribal

governments, on the relationship

between the Federal government and

Indian tribes, as specified in Executive

Order 13175. Thus, Executive Order

13175 does not apply to this rule.

VIII. Submission to Congress and the

Comptroller General

The Congressional Review Act, 5

U.S.C. 801 et seq., as added by the Small

Business Regulatory Enforcement

Fairness Act of 1996, generally provides

that before a rule may take effect, the

agency promulgating the rule must

submit a rule report, which includes a

copy of the rule, to each House of the

Congress and to the Comptroller General

of the United States. EPA will submit 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 United

States prior to publication of this final

rule in the Federal Register. This final

rule 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: May 16, 2001.

James Jones,

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. 321(q), 346(a) and

371.

2. Section 180.547 is amended by

alphabetically adding commodities to

the table in paragraph (a) to read as

follows:

§ 180.547 Prohexadione calcium;

tolerances for residues.

(a) * * *

Commodity Parts per million

*****

Grass, forage1 0.10 ppm

Grass, hay1 0.10 ppm

Grass, seed screenings1 3.5 ppm

Grass, straw1 1.2 ppm

*****

1Registration is limited to grasses grown for

seed.

* * * * *

[FR Doc. 01–13774 Filed 5–31–01; 8:45 am]

BILLING CODE 6560–50–S

ENVIRONMENTAL PROTECTION

AGENCY

40 CFR Part 271

[FRL–6938–8]

Maryland: Final Authorization of State

Hazardous Waste Management

Program Revisions

AGENCY: Environmental Protection

Agency (EPA).

ACTION: Immediate final rule.

SUMMARY: The State of Maryland (State)

has applied to EPA for Final

authorization of changes to its

hazardous waste program under the

Resource Conservation and Recovery

Act (RCRA). EPA has determined that

these changes satisfy all requirements

needed to qualify for Final

authorization, and is authorizing the

State’s changes through this immediate

final action. EPA is publishing this rule

to authorize the changes without a prior

proposal because we view this as a

routine program change and do not

expect comments that oppose it. Unless

we get written comments which oppose

this authorization during the comment

period, the decision to authorize