Federal Register / Vol. 62, No. 168 / Friday, August 29, 1997 / Rules and Regulations 45735

Montana

(a) * * * October 1, 1998.

* * * * *

Nevada

(a) * * *

(b) * * * October 1, 1998.

(c) * * * October 1, 1998.

* * * * *

North Dakota

(a) * * * October 1, 1998.

* * * * *

Tennessee

(a) * * * October 1, 1998.

* * * * *

(e) * * * October 1, 1998.

Texas

(a) * * * Interim approval will expire

October 1, 1998. * * *

* * * * *

Virgin Islands

(a) * * * Interim approval will expire

October 1, 1998.

* * * * *

Washington

(a) * * * October 1, 1998.

(b) * * * October 1, 1998.

(c) * * * October 1, 1998.

(d) * * * October 1, 1998.

(e) * * * October 1, 1998.

(f) * * * October 1, 1998.

(g) * * * October 1, 1998.

(h) * * * October 1, 1998.

(i) * * * October 1, 1998.

* * * * *

Wisconsin

(a) * * * October 1, 1998.

* * * * *

Wyoming

(a) * * * October 1, 1998.

[FR Doc. 97–23033 Filed 8–28–97; 8:45 am]

BILLING CODE 6560–50–P

ENVIRONMENTAL PROTECTION

AGENCY

40 CFR Part 180

[OPP–300534; FRL–5738–7]

RIN 2070–AB78

Cyromazine; Pesticide Tolerances for

Emergency Exemptions

AGENCY: Environmental Protection

Agency (EPA).

ACTION: Final rule.

SUMMARY: This regulation establishes a

time-limited tolerance for combined

residues of cyromazine (N-cyclopropyl1,3,5-triazine-2,4,6-triamine) and its

metabolite, melamine (1,3,5-triazine2,4,6-triamine) in or on dry bulb onions.

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

onion seed in California. This regulation

establishes a maximum permissible

level for residues of cyromazine 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. The

tolerance will expire and is revoked on

July 31, 1998.

DATES: This regulation is effective

August 29, 1997. Objections and

requests for hearings must be received

by EPA on or before October 28, 1997.

ADDRESSES: Written objections and

hearing requests, identified by the

docket control number, [OPP–300534],

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–

300534], 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–

300534]. 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: Stephen Schaible, 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) 308-9362, e-mail:

schaible.stephen@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

a tolerance for combined residues of the

insecticide cyromazine (N-cyclopropyl1,3,5-triazine-2,4,6-triamine) and its

metabolite, melamine (1,3,5-triazine2,4,6-triamine), in or on dry bulb onions

at 0.3 part per million (ppm). This

tolerance will expire and is revoked on

July 31, 1998. EPA will publish a

document in the Federal Register to

remove the revoked tolerance 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
45736 Federal Register / Vol. 62, No. 168 / Friday, August 29, 1997 / Rules and Regulations

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.

Because decisions on section 18-

related tolerances must proceed before

EPA reaches closure on several policy

issues relating to interpretation and

implementation of the FQPA, EPA does

not intend for its actions on such

tolerance to set binding precedents for

the application of section 408 and the

new safety standard to other tolerances

and exemptions.

II. Emergency Exemption for

Cyromazine on Onion Seed and FFDCA

Tolerances

On February 6, 1997, the California

Environmental Protection Agency,

Department of Pesticide Regulation,

availed itself of the authority to declare

the existence of a crisis situation within

the state, thereby authorizing use under

FIFRA section 18 of cyromazine on

onion seed to control onion maggots

(Delia antiqua). Onion maggots damage

onion plants by tunneling and feeding

on the growing (underground bulbs and

stems; several generations of onion

maggots can mature within a single

season, thereby increasing the

magnitude of losses to growers. The

Applicant claims that resistance to

chlorpyrifos, the most effective

registered alternative control agent, has

developed in the onion maggot.

Utilization of alternative cultural

practices, such as crop rotation, has not

successfully controlled the onion

maggot without the use of chemical

control agents. Onion growers in the

states receiving seed are expected to

experience up to a 36% yield loss

without the use of cyromazine. EPA has

authorized under FIFRA section 18 the

use of cyromazine on onion seed for

control of onion maggot in California.

After having reviewed the submission,

EPA concurs that emergency conditions

exist for this state.

As part of its assessment of this

emergency exemption, EPA assessed the

potential risks presented by residues of

cyromazine in or on dry bulb onions as

a result of treatment of onion seed. In

doing so, EPA considered the new safety

standard in FFDCA section 408(b)(2),

and EPA decided that the necessary

tolerance under FFDCA section 408(l)(6)

would be consistent with the new safety

standard and with FIFRA section 18.

Consistent with the need to move

quickly on the emergency exemption in

order to address an urgent non-routine

situation and to ensure that the resulting

food is safe and lawful, EPA is issuing

this tolerance without notice and

opportunity for public comment under

section 408(e), as provided in section

408(l)(6). Although this tolerance will

expire and is revoked on July 31, 1998,

under FFDCA section 408(l)(5), residues

of the pesticide not in excess of the

amounts specified in the tolerance

remaining in or on dry bulb onions after

that date will not be unlawful, provided

the pesticide is applied in a manner that

was lawful under FIFRA. EPA will take

action to revoke this tolerance earlier if

any experience with, scientific data on,

or other relevant information on this

pesticide indicate that the residues are

not safe.

Because this tolerance is being

approved under emergency conditions

EPA has not made any decisions about

whether cyromazine meets EPA’s

registration requirements for use on

onion seed or whether a permanent

tolerance for this use would be

appropriate. Under these circumstances,

EPA does not believe that this tolerance

serves as a basis for registration of

cyromazine by a State for special local

needs under FIFRA section 24(c). Nor

does this tolerance serve as the basis for

any State other than California to use

this pesticide on this crop under section

18 of FIFRA without following all

provisions of section 18 as identified in

40 CFR part 166. For additional

information regarding the emergency

exemption for cyromazine, contact the

Agency’s Registration Division at the

address provided above.

III. Risk Assessment and Statutory

Findings

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
Federal Register / Vol. 62, No. 168 / Friday, August 29, 1997 / Rules and Regulations 45737

assessments (e.g., linear low dose

extrapolations or MOE calculation based

on the appropriate NOEL) will be

carried out based on the nature of the

carcinogenic response and the Agency’s

knowledge of its mode of action.

2. Differences in toxic effect due to

exposure duration. The toxicological

effects of a pesticide can vary with

different exposure durations. EPA

considers the entire toxicity data base,

and based on the effects seen for

different durations and routes of

exposure, determines which risk

assessments should be done to assure

that the public is adequately protected

from any pesticide exposure scenario.

Both short and long durations of

exposure are always considered.

Typically, risk assessments include

‘‘acute’’, ‘‘short-term’’, ‘‘intermediate

term’’, and ‘‘chronic’’ risks. These

assessments are defined by the Agency

as follows.

Acute risk, by the Agency’s definition,

results from 1-day consumption of food

and water, and reflects toxicity which

could be expressed following a single

oral exposure to the pesticide residues.

High end exposure to food and water

residues are typically assumed.

Short-term risk results from exposure

to the pesticide for a period of 1-7 days,

and therefore overlaps with the acute

risk assessment. Historically, this risk

assessment was intended to address

primarily dermal and inhalation

exposure which could result, for

example, from residential pesticide

applications. However, since enaction of

FQPA, this assessment has been

expanded to include both dietary and

non-dietary sources of exposure, and

will typically consider exposure from

food, water, and residential uses when

reliable data are available. In this

assessment, risks from average food and

water exposure, and high-end

residential exposure, are aggregated.

High-end exposures from all 3 sources

are not typically added because of the

very low probability of this occurring in

most cases, and because the other

conservative assumptions built into the

assessment assure adequate protection

of public health. However, for cases in

which high-end exposure can

reasonably be expected from multiple

sources (e.g. frequent and widespread

homeowner use in a specific

geographical area), multiple high-end

risks will be aggregated and presented

as part of the comprehensive risk

assessment/characterization. Since the

toxicological endpoint considered in

this assessment reflects exposure over a

period of at least 7 days, an additional

degree of conservatism is built into the

assessment; i.e., the risk assessment

nominally covers 1-7 days exposure,

and the toxicological endpoint/NOEL is

selected to be adequate for at least 7

days of exposure. (Toxicity results at

lower levels when the dosing duration

is increased.)

Intermediate-term risk results from

exposure for 7 days to several months.

This assessment is handled in a manner

similar to the short-term risk

assessment.

Chronic risk assessment describes risk

which could result from several months

to a lifetime of exposure. For this

assessment, risks are aggregated

considering average exposure from all

sources for representative population

subgroups including infants and

children.

B. Aggregate Exposure

In examining aggregate exposure,

FFDCA section 408 requires that EPA

take into account available and reliable

information concerning exposure from

the pesticide residue in the food in

question, residues in other foods for

which there are tolerances, residues in

groundwater or surface water that is

consumed as drinking water, and other

non-occupational exposures through

pesticide use in gardens, lawns, or

buildings (residential and other indoor

uses). Dietary exposure to residues of a

pesticide in a food commodity are

estimated by multiplying the average

daily consumption of the food forms of

that commodity by the tolerance level or

the anticipated pesticide residue level.

The Theoretical Maximum Residue

Contribution (TMRC) is an estimate of

the level of residues consumed daily if

each food item contained pesticide

residues equal to the tolerance. In

evaluating food exposures, EPA takes

into account varying consumption

patterns of major identifiable subgroups

of consumers, including infants and

children. The TMRC is a ‘‘worst case’’

estimate since it is based on the

assumptions that food contains

pesticide residues at the tolerance level

and that 100% of the crop is treated by

pesticides that have established

tolerances. If the TMRC exceeds the RfD

or poses a lifetime cancer risk that is

greater than approximately one in a

million, EPA attempts to derive a more

accurate exposure estimate for the

pesticide by evaluating additional types

of information (anticipated residue data

and/or percent of crop treated data)

which show, generally, that pesticide

residues in most foods when they are

eaten are well below established

tolerances.

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

non-nursing infants less than one year

old was not regionally based.

IV. 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 cyromazine and to make a

determination on aggregate exposure,

consistent with section 408(b)(2), for a

time-limited tolerance for combined

residues of cyromazine (N-cyclopropyl1,3,5-triazine-2,4,6-triamine and its

metabolite, melamine (1,3,5-triazine2,4,6-triamine on dry bulb onions at 0.3

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 cyromazine are

discussed below.

1. Acute toxicity. OPP has determined

that an acute dietary risk assessment is

not required for this chemical.

2. Short - and intermediate - term

toxicity. For short- and intermediateterm MOE calculations, the Agency

recommends use of the systemic NOEL

of 0.75 mg/kg/day from the 6-month dog

feeding study. At the Lowest Effect

Level (LEL) of 7.5 mg/kg/day, there were

changes in hematological parameters.

3. Chronic toxicity. EPA has

established the RfD for cyromazine at

0.0075 milligrams/kilogram/day (mg/kg/

day). This RfD is based on the NOEL of

0.75 mg/kg/day, taken from the 6-month

dog feeding study. Pronounced effects

on hematological parameters were

observed at the LEL of 7.5 mg/kg/day.
45738 Federal Register / Vol. 62, No. 168 / Friday, August 29, 1997 / Rules and Regulations

An uncertainty factor of 100 was

applied to account for both interspecies

and intraspecies variability.

4. Carcinogenicity. Cyromazine has

been classified as a Group E (evidence

of non-carcinogenicity for humans)

chemical by the Agency. Melamine, a

metabolite of cyromazine, has been

evaluated by the Carcinogenicity Peer

Review Committee (CPRC). The CPRC

concluded that melamine was not

amenable to classification using the

current Agency guidelines and chose to

describe the weight-of-the-evidence

using a narrative form. Based on

mechanistic evaluation of the only

tumors seen, those that occurred at

exceptionally high doses in the bladder

of male rats, it appears that humans are

not likely to be exposed to doses of

melamine that produce the urinary tract

toxicity that precedes and seems to lead

to the carcinogenic response in rats. The

CPRC concluded that it is unlikely that

melamine exposure would pose a

carcinogenic hazard to humans from

pesticidal usage of cyromazine.

B. Exposures and Risks

1. From food and feed uses.

Tolerances have been established (40

CFR 180.414) for the combined residues

of cyromazine (N-cyclopropyl-1,3,5-

triazine-2,4,6-triamine) and its

metabolite, melamine (1,3,5-triazine2,4,6-triamine), in or on a variety of raw

agricultural commodities. Though

tolerances exist for residues of

cyromazine in or on animal

commodities, there are no animal feed

items associated with the proposed use,

and no secondary residues in meat,

milk, poultry or eggs are expected. Risk

assessments were conducted by EPA to

assess dietary exposures and risks from

cyromazine as follows:

Chronic exposure and risk. Chronic

dietary exposure was calculated

assuming tolerance level residues for

published and proposed uses and

percent of crop treated refinements for

several commodities. While percent of

crop treated refinements were

incorporated into these ARC exposure

estimates, chronic risk is still

overestimated due to the use of

tolerance level residues.

2. From drinking water. Review of

available data indicates that cyromazine

and its metabolite, melamine, are

persistent and mobile. There is no

established Maximum Concentration

Level (MCL) for residues of cyromazine

in drinking water, nor have there been

drinking water Health Advisory Levels

issued for cyromazine. The ‘‘Pesticides

in Groundwater Database’’ has no

information concerning cyromazine.

Chronic exposure and risk. Because

the Agency lacks sufficient waterrelated exposure data to complete a

comprehensive drinking water risk

assessment for many pesticides, EPA

has commenced and nearly completed a

process to identify a reasonable yet

conservative bounding figure for the

potential contribution of water-related

exposure to the aggregate risk posed by

a pesticide. In developing the bounding

figure, EPA estimated residue levels in

water for a number of specific pesticides

using various data sources. The Agency

then applied the estimated residue

levels, in conjunction with appropriate

toxicological endpoints (RfD’s or acute

dietary NOEL’s) and assumptions about

body weight and consumption, to

calculate, for each pesticide, the

increment of aggregate risk contributed

by consumption of contaminated water.

While EPA has not yet pinpointed the

appropriate bounding figure for

exposure from contaminated water, the

ranges the Agency is continuing to

examine are all below the level that

would cause cyromazine to exceed the

RfD if the tolerance being considered in

this document were granted. The

Agency has therefore concluded that the

potential exposures associated with

cyromazine in water, even at the higher

levels the Agency is considering as a

conservative upper bound, would not

prevent the Agency from determining

that there is a reasonable certainty of no

harm if the tolerance is granted.

3. From non-dietary exposure.

Cyromazine is currently registered for

outdoor use on ornamentals. There are

no lawn or indoor residential uses.

i. Chronic exposure and risk. There

are residential uses of cyromazine and

the Agency acknowledges that there

may be chronic, non-occupational

exposure scenarios. EPA has identified

toxicity endpoints for chronic

residential risk assessment. However, no

acceptable, reliable exposure data to

assess this potential risk are available at

this time. Based on the low percentage

of the RfD occupied by aggregate dietary

exposure and in the best scientific

judgement of the Agency, chronic

exposure from residential uses will not

cause the aggregate risk from

cyromazine to exceed the Agency’s level

of concern.

ii. Short- and intermediate-term

exposure and risk. There are residential

uses of cyromazine and the Agency

acknowledges that there may be shortand intermediate-term, nonoccupational exposure scenarios. EPA

has identified toxicity endpoints for

short- and intermediate-term residential

risk assessment. However, no

acceptable, reliable exposure data to

assess these potential risks are available

at this time. Based on the low

percentage of the RfD occupied by

aggregate dietary exposure and in the

best scientific judgement of the Agency,

short- and intermediate-term exposure

from residential uses will not cause the

aggregate risk from cyromazine to

exceed the Agency’s level of concern.

4. Cumulative exposure to substances

with common mechanism of toxicity.

Section 408(b)(2)(D)(v) requires that,

when considering whether to establish,

modify, or revoke a tolerance, the

Agency consider ‘‘available

information’’ concerning the cumulative

effects of a particular pesticide’s

residues and ‘‘other substances that

have a common mechanism of toxicity.’’

The Agency believes that ‘‘available

information’’ in this context might

include not only toxicity, chemistry,

and exposure data, but also scientific

policies and methodologies for

understanding common mechanisms of

toxicity and conducting cumulative risk

assessments. For most pesticides,

although the Agency has some

information in its files that may turn out

to be helpful in eventually determining

whether a pesticide shares a common

mechanism of toxicity with any other

substances, EPA does not at this time

have the methodologies to resolve the

complex scientific issues concerning

common mechanism of toxicity in a

meaningful way. EPA has begun a pilot

process to study this issue further

through the examination of particular

classes of pesticides. The Agency hopes

that the results of this pilot process will

increase the Agency’s scientific

understanding of this question such that

EPA will be able to develop and apply

scientific principles for better

determining which chemicals have a

common mechanism of toxicity and

evaluating the cumulative effects of

such chemicals. The Agency anticipates,

however, that even as its understanding

of the science of common mechanisms

increases, decisions on specific classes

of chemicals will be heavily dependent

on chemical specific data, much of

which may not be presently available.

Although at present the Agency does

not know how to apply the information

in its files concerning common

mechanism issues to most risk

assessments, there are pesticides as to

which the common mechanism issues

can be resolved. These pesticides

include pesticides that are

toxicologically dissimilar to existing

chemical substances (in which case the

Agency can conclude that it is unlikely

that a pesticide shares a common

mechanism of activity with other

substances) and pesticides that produce
Federal Register / Vol. 62, No. 168 / Friday, August 29, 1997 / Rules and Regulations 45739

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

cyromazine 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,

cyromazine 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 cyromazine has a common

mechanism of toxicity with other

substances.

C. Aggregate Risks and Determination of

Safety for U.S. Population

1. Chronic risk. Using the ARC

exposure assumptions described above,

EPA has concluded that aggregate

exposure to cyromazine from food will

utilize 32% of the RfD for the U.S.

population. The major identifiable

subgroup with the highest aggregate

exposure is non-nursing infants less

than 1 year old (discussed below). EPA

generally has no concern for exposures

below 100% of the RfD because the RfD

represents the level at or below which

daily aggregate dietary exposure over a

lifetime will not pose appreciable risks

to human health. Despite the potential

for exposure to cyromazine in drinking

water and from non-dietary, nonoccupational exposure, EPA does not

expect the aggregate exposure to exceed

100% of the RfD. EPA concludes that

there is a reasonable certainty that no

harm will result from aggregate

exposure to cyromazine residues.

2. Short- and intermediate-term risk.

Short- and intermediate-term aggregate

exposure takes into account chronic

dietary food and water (considered to be

a background exposure level) plus

indoor and outdoor residential

exposure.

For short term MOE calculations, the

Agency recommended use of the

systemic NOEL of 0.75 mg/kg/day from

the 6-month dog feeding study.

The Agency typically considers

aggregate MOEs of greater than 100 to be

acceptable. Using ARC exposure

estimates and making conservative

assumptions for exposure from water

and residential routes of exposure, short

term aggregate MOEs were acceptable

for the U.S. and all population groups

evaluated. EPA concludes that there is

reasonable certainty that no harm to the

U.S. population will result from short

term aggregate exposure to cyromazine

residues.

D. Aggregate Cancer Risk for U.S.

Population

Cyromazine has been classified as a

Group E (evidence of noncarcinogenicity for humans) chemical

by the Agency. No risk assessment for

cancer effects was performed.

E. Aggregate Risks and Determination of

Safety for Infants and Children

1. Safety factor for infants and

children— i. In general. In assessing the

potential for additional sensitivity of

infants and children to residues of

cyromazine, EPA considered data from

developmental toxicity studies in the rat

and rabbit and a two-generation

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.

ii. Developmental toxicity studies. In

the rabbit developmental study, the

maternal (systemic) NOEL was 10 mg/

kg/day, the highest dose tested. In the

rat developmental study, the

developmental NOEL was identified at

300 mg/kg/day, while the maternal

NOEL was 100 mg/kg/day. Although

there were developmental findings at

600 mg/kg/day in rat fetuses, these

findings were not severe effects and

only occurred in the presence of

maternal toxicity.

iii. Reproductive toxicity study. In the

rat reproduction study, the parental

(systemic) and reproductive/

developmental NOELs were both

established at 50 mg/kg/day. A detailed

analysis of the study indicates that

slight pup effects (decreased pup

growth, decreased number of pups per

litter, and increased fetotoxicity)

occurred in the presence of slight

maternal toxicity (body weight loss).

iv. Pre- and post-natal sensitivity. The

results of the rat and rabbit

developmental studies did not

demonstrate any potential for additional

pre-natal sensitivity. In the rat

reproduction study, the parental and

reproductive/developmental NOELs

were both established at 50 mg/kg/day,

which suggests that there is no special

post-natal sensitivity to cyromazine.

v. Conclusion. Based on detailed

analysis of the toxicological data base

for cyromazine, the Agency concludes

that aggregate exposure to cyromazine

resulting from registered uses plus the

emergency exemption use does not

represent an unacceptable pre- or postnatal risk to infants and children. The

data support use of the standard

uncertainty factor of 100; an additional

uncertainty factor of 10 is not necessary

to be protective of infants and children.

2. Chronic risk. Using the

conservative exposure assumptions

described above, EPA has concluded

that aggregate exposure to cyromazine

from food will utilize 50% 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. Despite the potential

for exposure to cyromazine in drinking

water and from non-dietary, nonoccupational exposure, EPA does not

expect the aggregate exposure to exceed

100% of the RfD. EPA concludes that

there is a reasonable certainty that no

harm will result to infants and children

from aggregate exposure to cyromazine

residues.

3. Short- or intermediate-term risk.

For short term MOE calculations, the

Agency recommended use of the

systemic NOEL of 0.75 mg/kg/day from

the 6-month dog feeding study.

The Agency typically considers

aggregate MOEs of greater than 100 to be

acceptable. Using ARC dietary exposure

estimates and making conservative

assumptions for exposure from water

and residential routes of exposure, short

term aggregate MOEs were acceptable

for all infant and children population

groups evaluated. EPA concludes that

there is a reasonable certainty that no
45740 Federal Register / Vol. 62, No. 168 / Friday, August 29, 1997 / Rules and Regulations

harm will result to infants and children

from short term aggregate exposure to

cyromazine residues.

V. Other Considerations

A. Metabolism In Plants and Animals

The nature of the residue in plants is

adequately understood. The residue of

concern is cyromazine (N-cyclopropyl1,3,5-triazine-2,4,6-triamine) and its

metabolite, melamine (1,3,5-triazine2,4,6-triamine).

B. Analytical Enforcement Methodology

An adequate analytical method,

HPLC/UV method AG-408, has been

validated by the Agency and published

in PAM II.

C. Magnitude of Residues

Residues of cyromazine are not

expected to exceed 0.3 ppm in dry bulb

onions grown from onion seed treated

with cyromazine under the proposed

use.

D. International Residue Limits

There are currently no Codex,

Canadian or Mexican limits for residues

of cyromazine in or on onions.

Therefore, establishment of a timelimited tolerance will not pose a

concern for international

harmonization.

E. Rotational Crop Restrictions.

Tolerances are not yet established for

sweet corn and radishes as rotational

crops (a decision regarding petition

PP#6F3332 is currently pending with

the Agency). Until such tolerances are

established, rotation to sweet corn and

radishes is not permitted.

VI. Conclusion

Therefore, the tolerance is established

for combined residues of cyromazine

(N-cyclopropyl-1,3,5-triazine-2,4,6-

triamine) and its metabolite, melamine

(1,3,5-triazine-2,4,6-triamine) in dry

bulb onions at 0.3 ppm. In addition to

amending § 180.414 to establishing a

tolerance for use in dry bulb onions,

since the FQPA has eliminated the

distinctions between processed food

and feed commodities, § 180.414 is also

being revised to restructure the existing

tolerances.

VII. Objections and Hearing Requests

The new FFDCA section 408(g)

provides essentially the same process

for persons to ‘‘object’’ to a tolerance

regulation issued by EPA under new

section 408(e) and (l)(6) as was provided

in the old section 408 and in section

409. However, the period for filing

objections is 60 days, rather than 30

days. EPA currently has procedural

regulations which govern the

submission of objections and hearing

requests. These regulations will require

some modification to reflect the new

law. However, until those modifications

can be made, EPA will continue to use

those procedural regulations with

appropriate adjustments to reflect the

new law.

Any person may, by October 28, 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.

VIII. Public Docket

EPA has established a record for this

rulemaking under docket control

number [OPP–300534] (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 Hwy., 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.

IX. Regulatory Assessment

Requirements

This final rule establishes a tolerance

under FFDCA section 408. 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).
Federal Register / Vol. 62, No. 168 / Friday, August 29, 1997 / Rules and Regulations 45741

In addition, since these tolerances and

exemptions that are established under

FFDCA section 408 (1), 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.

X. 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: August 17, 1997.

James Jones,

Acting Director, Registration Division, Office

of Pesticide Programs.

Therefore, 40 CFR chapter I is

amended as follows:

PART 180—[AMENDED]

1. The authority citation for part 180

continues to read as follows:

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

2. Section 180.414 is revised to read

as follows:

§ 180.414 Cyromazine; tolerances for

residues.

(a) General. (1) Tolerances are

established for combined residues of the

insecticide cyromazine (N-cyclopropyl1,3,5-triazine-2,4,6-triamine) and its

metabolite melamine (1,3,5-triazine2,4,6-triamine) in or on the following

food commodities:

Commodity Parts per

million

Celery ........................................ 10.0

Cucurbit vegetables .................. 2.0

Eggs .......................................... 0.25

Leafy vegetables (except Brassica) ....................................... 10.0

Lettuce, head ............................ 5.0

Mushrooms ............................... 10.0

Peppers ..................................... 4.0

Tomato ...................................... 1.0

(2) Tolerances are established for

residues of the cyromazine metabolite

melamine (1,3,5-triazine-2,4,6-triamine)

in or on the following food

commodities:

Commodity Part per million

Fat, poultry (from chicken layer

hens and chicken breeder

hens only) .............................. 0.05

Meat, poultry (from chicken

layer hens and chicken

breeder hens only) ................ 0.05

Meat byproducts (from chicken

layer hens and chicken

breeder hens only) ................ 0.05

(3) Tolerances are established for

residues of the insecticide cyromazine

(N-cyclopropyl-1,3,5-triazine-2,4,6-

triamine) in or on the following food

commodities:

Commodity Part per million

Fat, poultry (from chicken layer

hens and chicken breeder

hens only) .............................. 0.05

Meat, poultry (from chicken

layer hens and chicken

breeder hens only) ................ 0.05

Meat byproducts (from chicken

layer hens and chicken

breeder hens only) ................ 0.05

(b) Section 18 emergency exemptions.

Time-limited tolerances are established

for the combined residues of the

insecticide cyromazine (N-cyclopropyl1,3,5-triazine-2,4,6-triamine) and its

metabolite, melamine (1,3,5-triazine2,4,6-triamine), in connection with use

of the pesticide under section 18

emergency exemption granted by EPA.

The tolerances are specified in the

following table. These tolerances expire

and are revoked on the date specified in

the table.

Commodity Parts per million Expiration/revocation date

Onion, dry bulb .................................................................................... 0.3 July 31, 1998

(c) Tolerances with regional

registrations. Tolerances with regional

registration, as defined in § 180.1(n), are

established for the combined residues of

the insecticide cyromazine (Ncyclopropyl-1,3,5-triazine-2,4,6-

triamine) and its metabolite melamine

(1,3,5-triazine-2,4,6-triamine),

calculated as cyromazine, in or on the

following food commodities:

Commodity Parts per

million

Cabbage, Chinese .................... 3.0

Commodity Parts per

million

Mustard, Chinese ...................... 3.0

(d) Indirect or inadvertent residues.

[Reserved]

[FR Doc. 97–23098 Filed 8–28–97; 8:45 am]

BILLING CODE 6560–50–F

ENVIRONMENTAL PROTECTION

AGENCY

40 CFR Part 180

[OPP–300532; FRL–5738–5]

RIN 2070–AB78

Desmedipham; Pesticide Tolerances

for Emergency Exemptions

AGENCY: Environmental Protection

Agency (EPA).

ACTION: Final rule.

SUMMARY: This regulation establishes a

time-limited tolerance for the herbicide

desmedipham in or on garden beet roots