[Federal Register Volume 62, Number 29 (Wednesday, February 12, 1997)]
[Notices]
[Pages 6526-6528]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-3645]


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ENVIRONMENTAL PROTECTION AGENCY
[PF-704; FRL-5586-5]


Entek; Pesticide Tolerance Petition Filing

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice of filing.

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SUMMARY: This notice announces the initial filing of a pesticide 
petition proposing the establishment of tolerances for residues of 
carbon disulfide in or on almond nutmeats, almond hulls, peaches and 
plums (fresh prunes). This notice includes a summary of the petition 
that was prepared by the petitioner, Entek Corporation.

DATES: Comments, identified by the docket number [PF-704], must be 
received on or before, March 14, 1997.

ADDRESSES: By mail, submit written comments to: Public Response and 
Program Resources Branch, Field Operations Division (7506C), Office of 
Pesticide Programs, Environmental Protection Agency, 401 M St., SW., 
Washington, DC 20460. In person, bring comments to Rm. 1132, CM #2, 
1921 Jefferson Davis Highway, Arlington, VA.
    Comments and data may also be submitted electronically be sending 
electronic mail (e-mail) to: [email protected]. Electronic 
comments must be submitted as an ASCII file avoiding the use of special 
characters and any form of encryption. Comments and data will also be 
accepted on disks in WordPerfect in 5.1 file format or ASCII file 
format. All comments and data in electronic form must be identified by 
docket number [PF-704]. Electronic comments on this notice may be filed 
online at many Federal Depository Libraries. Additional information on 
electronic submissions can be found in Unit II. of this document.
    Information submitted as a comment concerning this document may be 
claimed confidential by marking any part or all of that information as 
``Confidential Business Information'' (CBI). CBI should not be 
submitted through e-mail. Information marked as CBI will not be 
disclosed except in accordance with procedures set forth in 40 CFR part 
2. A copy of the comment that does not contain CBI must be submitted 
for inclusion in the public record. Information not marked confidential 
may be disclosed publicly by EPA without prior notice. All written 
comments will be available for public inspection in Rm. 1132 at the 
address given above, from 8:30 a.m. to 4 p.m., Monday through Friday, 
excluding legal holidays.

FOR FURTHER INFORMATION CONTACT: Cynthia Giles-Parker, Product Manager 
(22), 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: Rm. 229, CM #2, 
1921 Jefferson Davis Highway, Arlington, VA, 703-305-5540, e-mail: 
[email protected].

SUPPLEMENTARY INFORMATION: EPA has received a pesticide petition (PP 
5F4482) from Entek Corporation, P.O. Box 458, Brea, CA 92822, proposing 
pursuant to section 408(d) of the Federal Food, Drug and Cosmetic Act 
(FFDCA), 21 U.S.C. 346a(d), to amend 40 CFR 180.467 by establishing a 
tolerance, at 0.1 part per million (ppm), for residues of the fumigant 
carbon disulfide resulting from the soil application of sodium 
tetrathiocarbonate in or on the raw agricultural commodities almond 
nutmeats, almond hulls, peaches and plumes (fresh prunes). The proposed 
analytical method is gas chromatography using a sulfur specific 
detector. EPA has determined that the petition contains data or 
information regarding the elements set forth in section 408(d)(2); 
however, EPA has not fully evaluated the sufficiency of the submitted 
data at this time or whether the data supports granting of the 
petition. Additional data may be needed before EPA rules on the 
petition.
    As required by section 408(d) of the FFDCA, as recently amended by 
the Food Quality Protection Act (Pub. L. 104-170), Entek Corporation 
included in the petition a summary of the petition and authorization 
for the summary to be published in the Federal Register in a notice of 
receipt of the petition. The summary represents the views of Entek 
Corporation. EPA is in the process of evaluating the petition. As 
required by section 408(d)(3) EPA is including the summary as a part of 
this notice of filing. EPA has made minor edits to the summary for the 
purpose of clarity.

I. Entek's Petition Summary

A. Residue Chemistry

    1. Plant metabolism. Radiolabel metabolism studies, using 14C 
labeled sodium tetrathiocarbonate, were conducted with potatoes and 
tomatoes. The studies established that sodium tetrathiocarbonate 
rapidly degrades in soil and plants and the resulting residues are 
carbon disulfide (CS2), free and bound. No other residues of 
concern were identified in the radiolabel or other residue chemistry 
studies submitted by the petitioner.
    2. Analytical method. An adequate analytical method for detecting 
free and bound CS2 residues in plants is available. The method has 
been validated by EPA. In brief, plant material is blended with water 
in a sealed container. Aliquots of the gas and liquid phases are 
removed and the free CS2 content is determined by purge-and-trap 
gas chromatography using a sulfur-specific detector. A sample of the 
liquid phase, purged for free CS2, is subjected to hot acid 
hydrolysis followed by purge-and-trap gas chromatography in order to 
measure the bound CS2 content. In general, the limit of detection 
for the analytical method is 0.5 ppb and the limit of quantitation is 
1.7 parts per billion (ppb).
    3. Magnitude of residues. Two field trials were conducted for each 
crop (peaches, plums and almonds). Trials were all conducted in 
California since it is the predominant growing area for each of the 
requested raw agricultural commodities (RACs) and the petitioner has 
proposed to limit use of Enzone (the product containing 
sodium tetrathiocarbonate) to Arizona, California, Oregon, and 
Washington. In each trial, sodium tetrathiocarbonate was applied in 
amounts equal to or greater than the maximum label rate and 
pretreatment, control and treatment samples were analyzed for free and 
bound CS2.
    In the plum and peach trials, very low levels (<20 ppb) of free and 
bound CS2 were observed in pretreated, control and treatment 
samples. In both almond trials, very low levels of free or bound 
CS2 (< 10 ppb) were observed in almond nutmeats. In one of the 
almond trials, unusually high levels of bound CS2 (from 567-6,761 
ppb) were observed in control and treated almond hull

[[Page 6527]]

samples. The petitioner believes that these atypical levels were most 
likely due to high natural occurrence or drift of an ethylene 
bisdithiocarbamate (EBDC) pesticide from a nearby source.
    Rigorous statistical analysis of the sample data clearly showed 
that there is no increase in CS2 (free or bound) above background 
levels for treated almond, pear or plum trees when compared to 
untreated or control trees.

B. Toxicological Profile

    1. Acute toxicity. Technical sodium tetrathiocarbonate (32% active 
ingredient) is moderately toxic by the oral route, with a combined 
acute oral LD50 of 631 milligrams/kilograms (mg/kg) in the rat. 
Technical sodium tetrathiocarbonate is practically nontoxic by dermal 
application (acute dermal LD50 > 2,000 mg/kg) and slightly toxic 
after a 4-hour inhalation exposure (acute LC50 is 4.73 mg/L 
(males) and 3.17 mg/L (females). Technical sodium tetrathiocarbonate is 
corrosive to skin and eyes but is not a dermal sensitizer.
    2. Genotoxicity. In the bacterial gene mutation test (Ames) 
technical sodium tetrathiocarbonate was negative, with or without 
metabolic activation. Technical sodium tetrathiocarbonate was also 
negative in a mammalian gene mutation assay (CHO/HGPRT), with or 
without metabolic activation. In the chromosome aberration assay, 
technical sodium tetrathiocarbonate gave a weakly positive result under 
activation conditions. Technical sodium tetrathiocarbonate was negative 
in the unscheduled DNA Synthesis assay. On the basis of the 
mutagenicity battery, Entek concludes that sodium tetrathiocarbonate is 
not mutagenic or genotoxic.
    3. Developmental toxicity. Developmental toxicity studies with 
sodium tetrathiocarbonate were performed in the rat and rabbit. In the 
rat study, pregnant rats were administered sodium tetrathiocarbonate at 
doses of 0, 150, 400, 450 and 500 mg/kg/day on gestation days 6 through 
15. Necropsy examinations of the animals that died and animals that 
survived to final sacrifice did not reveal any lesions which could be 
attributed to sodium tetrathiocarbonate. Treatment with 150, 400 or 450 
mg/kg/day of sodium tetrathiocarbonate did not alter fetal, skeletal or 
visceral development. The developmental toxicity no observed effect 
level (NOEL) for this study is 450 mg/kg/day. In the rabbit study, 
pregnant rabbits were administered sodium tetrathiocarbonate at doses 
of 0, 75, 150 and 185 mg/kg/day on days 7-19 of gestation. 
Developmental effects (elevated resorptions and increased post-
implantation loss) were observed at 185 mg/kg/day; developmental 
effects were not observed at the lower dose levels. The developmental 
toxicity no observed effect level (NOEL) for this study is 150 mg/kg/
day.
    Entek has requested waivers for several of the toxicology studies 
that are normally required for crop tolerances. These include: 90-day 
oral toxicity study (rat and dog); 2-generation reproduction (rat); 
chronic toxicity study (rat and dog); oncogenicity (rat and mouse) and 
general metabolism. The basis for the waiver request is that the 
natural or background levels of CS2, either free or bound, are not 
increased from the application of sodium tetrathiocarbonate to almonds, 
peaches or plums.
    In 1987, an oral reference dose (RfD) of 0.1 mg/kg/day for CS2 
was established by EPA's Integrated Risk Information System (IRIS).

C. Aggregate Exposure

    1. Dietary exposure-- i. Food. Extensive residue data compiled by 
the petitioner and information in the public literature has shown a 
natural occurring dietary CS2 level (bound and free) of 
approximately 10-20 ppb. Assuming a dietary intake of 3,000 g/day, the 
daily intake of CS2 is approximately 0.06 mg/day. The use of 
sodium tetrathiocarbonate on almonds, peaches or plums is not 
anticipated to add to the daily intake of CS2 since, as noted 
above, no increases in CS2 residues above background levels were 
observed in the residue trials. It should also be noted that there was 
no increase above background CS2 levels for the crops (grapes and 
citrus) currently covered by a tolerance.
    ii. Drinking water. Two state-of-art prospective ground water 
monitoring studies were conducted for sodium tetrathiocarbonate. In 
both studies, sodium tetrathiocarbonate was applied above very shallow 
aquifers (3-7 ft. below the surface) and the ground water was analyzed 
for CS2. The studies demonstrated that CS2, from sodium 
tetrathiocarbonate application, is not a residual ground water 
contaminant.
    2. Non-dietary exposure. Carbon disulfide is an industrial chemical 
used in the manufacture of rayon fibers; in the production of cellulose 
and rubber chemicals; as a solvent for cleaning and extraction; as an 
extractant for olive oil and in the production of adhesives. 
Accordingly, workers in these industries may be exposed to low levels 
of CS2 in the air. The daily exposure limit is 20 ppm (8-hr time 
weight average).

D. Cumulative Effects

    There is no reliable information to indicate that carbon disulfide 
has a common mechanism of toxicity with any other chemical compound.

E. Safety Determination

    1. U.S. population. Since the use of sodium tetrathiocarbonate on 
almonds, peaches and plums is not anticipated to contribute to CS2 
exposures, Entek concludes that there is a reasonable certainty that no 
harm will result from sodium tetrathiocarbonate application to these 
RACs.
    2. Infants and children. Entek also concludes that there is a 
reasonable certainty that no harm will result to infants and children 
since no increase in infant or child exposure to CS2 will result 
from the application of sodium tetrathiocarbonate on almonds, peaches 
and plums.

F. International Tolerances

    There are no Codex maximum residue levels [MRLs] established for 
residues of carbon disulfide resulting from the application of sodium 
tetrathiocarbonate.

II. Public Record

    A record has been established for this notice under docket number 
[PF-704] including comments and data submitted electronically as 
described below). 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 Response and Program 
Resources Branch, Field Operations Division (7506C), Office of 
Pesticide Programs, Environmental Protection Agency, Crystal Mall #2, 
1921 Jefferson Davis Highway, Arlington, VA.
    Electronic comments can be sent directly to EPA at:
    [email protected]
    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 all comments 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 address

[[Page 6528]]

in ``ADDRESSES'' at the beginning of this document.

List of Subjects

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

    Dated: February 7, 1997.

Donald R. Stubbs,

Acting Director, Registration Division, Office of Pesticide Programs.

[FR Doc. 97-3645 Filed 2-11-97; 8:45 am]
BILLING CODE 6560-50-F