62308 Federal Register / Vol. 62, No. 225 / Friday, November 21, 1997 / Notices

C. Aggregate Exposure

1. Dietary exposure— Food. For

purposes of assessing the potential

dietary exposure under the proposed

tolerances, Novartis has estimated

aggregate exposure based on the

theoretical maximum residue

contribution (TMRC) from the

benoxacor tolerance of 0.01 ppm in or

on raw agricultural commodities for

which tolerances have been established

for metolachlor. In conducting this

exposure assessment, Novartis has made

very conservative assumptions--100% of

all raw agricultural products for which

tolerances have been established for

metolachlor will contain benoxacor

residues and those residues would be at

the level of the tolerance (0.01 ppm)

which result in an overestimate of

human exposure.

2. Drinking water. Although

benoxacor is mobile and hydrolyzes

slowly at low pHs, it rapidly degrades

in the soil (half-life of 49 days under

aerobic conditions and 70 days

anaerobically). Based on this data,

Novartis does not anticipate exposure to

residues of benoxacor in drinking water.

This is supported by extensive

experience with metolachlor, where in

large scale ground water monitoring

studies, metolachlor has been detected

in less than 4% of the samples with the

typical value being 1 ppb or less. Since

benoxacor is formulated as a 1 to 30

ratio with metolachlor, (maximum of 0.2

pounds benoxacor per acre) the

presence of benoxacor in groundwater is

highly unlikely. The EPA has not

established a Maximum Concentration

Level for residues of benoxacor in

drinking water.

3. Non-dietary exposure. Novartis has

evaluated the estimated nonoccupational exposure to benoxacor and

based on its low use rate concludes that

the potential for non-occupational

exposure to the general population is

unlikely except for the potential

residues in food crops discussed above.

Benoxacor is used only on agricultural

crops and is not used in or around the

home.

D. Cumulative Effects

Novartis also considered the potential

for cumulative effects of benoxacor and

other substances that have a common

mechanism of toxicity. Novartis

concluded that consideration of a

common mechanism of toxicity is not

appropriate at this time. Novartis does

not have any reliable information to

indicate that toxic effects seen at high

doses of benoxacor (generalized liver

toxicity, nephrotoxicity and the

occurrence of forestomach tumors in an

organ not present in humans) would be

cumulative with those of any other

chemical compounds; thus Novartis is

considering only the potential risks of

benoxacor in its aggregate exposure

assessment.

E. Safety Determination

1. U.S. population. Using the

conservative exposure assumptions

described above and based on the

completeness and reliability of the

toxicity data base for benoxacor,

Novartis has calculated that aggregate

exposure to benoxacor will utilize 4.7%

of the RfD for the U.S. population based

on chronic toxicity endpoints and only

0.4% based on a margin of exposure

assessment and a carcinogenic NOEL of

4.2 mg/kg/day. EPA generally has no

concern for exposures below 100

percent 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. Novartis concludes

that there is a reasonable certainty that

no harm will result from aggregate

exposure to benoxacor residues.

2. Infants and children. Using the

same conservative exposure

assumptions used for the determination

in the general population, Novartis has

concluded that the percent of the RfD

that will be utilized by aggregate

exposure to residues of benoxacor is

5.3% for nursing infants less than 1 year

old, 20.2% for non-nursing infants,

11.9% for children 1-6 years old and

7.7% for children 7-12 years old. These

worst case estimates are likely at least

4 times greater than actual values when

considering that benoxacor residues

have not been detected at the limit of

quantitation of 0.005 ppm (tolerance is

0.01 ppm) and using a more realistic

market share of 50% rather than the

conservative 100%. Therefore, based on

the completeness and reliability of the

toxicity data base and the conservative

exposure assessment, Novartis

concludes that there is a reasonable

certainty that no harm will result to

infants and children from aggregate

exposure to benoxacor residues.

F. International Tolerances

A maximum residue level has not

been established for benoxacor by the

Codex Alimentarius Commission.

[FR Doc. 97–30659 Filed 11–20–97; 8:45 am]

BILLING CODE 6560–50–F

ENVIRONMENTAL PROTECTION

AGENCY

[FRL–5925–9]

Availability of Draft Document on

Information for States on Developing

Affordability Criteria for Drinking Water

AGENCY: Environmental Protection

Agency.

ACTION: Notice of document availability.

SUMMARY: The Environmental Protection

Agency is making available for public

comment a draft document entitled

Information for States on Developing

Affordability Criteria for Drinking

Water. The Safe Drinking Water Act

Amendments of 1996 require the

Agency to publish information to assist

states in developing affordability

criteria. To meet the statutory schedule,

this information must be published by

February 6, 1998. The draft document

being made available today was

developed by a diverse working group

of stakeholders under the auspices of

the National Drinking Water Advisory

Council (NDWAC). The full NDWAC

reviewed this draft and recommended it

to EPA as a draft to be made available

for public comment. EPA invites

interested members of the public to

submit comments on the draft

document. EPA will consider public

comments and publish a final document

by the February 6, 1998, statutory

deadline.

DATES: Submit comments on or before

December 31, 1997.

ADDRESSES: Address all comments

concerning this draft document to Peter

E. Shanaghan, Small Systems

Coordinator, Office of Ground Water

and Drinking Water, Mail Code 4606,

401 M Street SW., Washington, DC

20460.

FOR FURTHER INFORMATION CONTACT:

Peter E. Shanaghan, 202–260–5813 or

shanaghan.peter@epamail.epa.gov.

SUPPLEMENTARY INFORMATION: A copy of

the draft document may be obtained by

calling the Safe Drinking Water Hotline

at 1–800–426–4791. The hotline

operates Monday through Friday, 9:00

a.m.–5:30 p.m. (EST). The document

may also be downloaded from EPA’s

homepage, http://www.epa.gov/

OGWDW.

Elizabeth Fellows,

Acting Director, Office of Ground Water and

Drinking Water.

[FR Doc. 97–30660 Filed 11–20–97; 8:45 am]

BILLING CODE 6560–50–M