PMEP Home Page --> Pesticide Active Ingredient Information --> Insecticides and Miticides --> DDT to famphur (Warbex) --> esbiothrin --> esbiothrin Pesticide Petition Filing 10/99

esbiothrin Pesticide Petition Filing 10/99


[Federal Register: October 15, 1999 (Volume 64, Number 199)]
[Notices]               
[Page 55914-55921]
>From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr15oc99-71]                         

-----------------------------------------------------------------------

ENVIRONMENTAL PROTECTION AGENCY

[PF-891; FRL-6099-6]

 
Notice of Filing Pesticide Petitions To Establish a Tolerance for 
Certain Pesticide Chemicals in or on Food

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice.

-----------------------------------------------------------------------

SUMMARY: This notice announces the initial filing of pesticide 
petitions proposing the establishment of regulations for residues of 
certain pesticide chemicals in or on various food commodities.

DATES: Comments, identified by docket control number PF-891, must be 
received on or before November 15, 1999.

ADDRESSES: Comments may be submitted by mail, electronically, or in 
person. Please follow the detailed instructions for each method as 
provided in Unit I.C. of the ``SUPPLEMENTARY INFORMATION'' section. To 
ensure proper receipt by EPA, it is imperative that you identify docket 
control number PF-891 in the subject line on the first page of your 
response.

FOR FURTHER INFORMATION CONTACT: The product manager listed in the 
table below:

----------------------------------------------------------------------------------------------------------------
                                      Office location/telephone
          Product Manager               number/e-mail address             Address           Petition number(s)
----------------------------------------------------------------------------------------------------------------
Ann Sibold.........................  Rm. 212, CM #2, 703-305-     1921 Jefferson Davis    PP 6H5743
                                      6502, e-mail:                Hwy, Arlington, VA
                                      sibold.ann@epamail.epa.gov
                                      .
William Sproat.....................  Rm. 6044, CM #2, 703-308-    Do.                     PP 9F6043
                                      8587, e-mail:
                                      sproat.william@epamail.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:


------------------------------------------------------------------------
                                                          Examples of
           Categories                    NAICS            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 in the ``FOR FURTHER INFORMATION 
CONTACT'' section.

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'' and then look up the entry for this document under the 
``Federal Register--Environmental Documents.'' You can also go directly 
to the Federal Register listings at http://www.epa.gov/fedrgstr/.
    2. In person. The Agency has established an official record for 
this action under docket control number PF-891. The official record 
consists of the documents specifically referenced in this action, any 
public comments received during an applicable comment period, 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), Rm. 119, 
Crystal Mall #2, 1921 Jefferson Davis Highway, 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.

C. How and to Whom Do I Submit Comments?

    You may submit comments through the mail, in person, or 
electronically. To ensure proper receipt by EPA, it is imperative that 
you identify docket control number PF-891 in the subject line on the 
first page of your response.
    1. By mail. Submit your comments to: Public Information and Records 
Integrity Branch (PIRIB), Information Resources and Services Division 
(7502C), Office of Pesticide Programs, Environmental Protection Agency, 
401 M St., SW., Washington, DC 20460.
    2. In person or by courier. Deliver your comments to: Public 
Information and Records Integrity Branch (PIRIB), Information Resources 
and Services Division (7502C), Office of Pesticide Programs (OPP), 
Environmental Protection Agency, Rm. 119, Crystal Mall #2, 1921 
Jefferson Davis Highway, Arlington, VA. The PIRIB is open from 8:30 
a.m. to 4 p.m., Monday through Friday, excluding legal holidays. The 
PIRIB telephone number is (703) 305-5805.
    3.  Electronically. You may submit your comments electronically by 
E-mail to: ``opp-docket@epa.gov ,'' or you can submit a computer disk 
as described above. Do not submit any information electronically that 
you consider to be CBI. Avoid the use of special characters

[[Page 55915]]

and any form of encryption. Electronic submissions will be accepted in 
Wordperfect 5.1/6.1 or ASCII file format. All comments in electronic 
form must be identified by docket control number PF-891. Electronic 
comments may also be filed online at many Federal Depository Libraries.

D. How Should I Handle CBI That I Want To Submit to the Agency?

    Do not submit any information electronically that you consider to 
be CBI. You may claim information that you submit to EPA in response to 
this document as CBI 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. In addition to one complete 
version of the comment that includes any information claimed as CBI, a 
copy of the comment that does not contain the information claimed as 
CBI must be submitted for inclusion in the public version of the 
official record. Information not marked confidential will be included 
in the public version of the official record without prior notice. If 
you have any questions about CBI or the procedures for claiming CBI, 
please consult the person identified in the ``FOR FURTHER INFORMATION 
CONTACT'' section.

E. What Should I Consider as I Prepare My Comments for EPA?

    You may find the following suggestions helpful for preparing your 
comments:
     1. Explain your views as clearly as possible.
     2. Describe any assumptions that you used.
     3. Provide copies of any technical information and/or data you 
used that support your views.
     4. If you estimate potential burden or costs, explain how you 
arrived at the estimate that you provide.
     5. Provide specific examples to illustrate your concerns.
     6. Make sure to submit your comments by the deadline in this 
notice.
     7. To ensure proper receipt by EPA, be sure to identify the docket 
control number assigned to this action in the subject line on the first 
page of your response. You may also provide the name, date, and Federal 
Register citation.

II. What Action Is the Agency Taking?

    EPA has received pesticide petitions as follows proposing the 
establishment and/or amendment of regulations for residues of certain 
pesticide chemicals in or on various food commodities under section 408 
of the Federal Food, Drug, and Comestic Act (FFDCA), 21 U.S.C. 346a. 
EPA has determined that these petitions contain 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.

List of Subjects

    Environmental protection, Agricultural commodities, Feed additives, 
Food additives, Pesticides and pests, Reporting and recordkeeping 
requirements.

    Dated: October 7, 1999.

James Jones,

Director, Registration Division, Office of Pesticide Programs.

Summaries of Petitions

    The petitioner summaries of the pesticide petitions are printed 
below as required by section 408(d)(3) of the FFDCA. The summaries of 
the petitions were prepared by the petitioners and represent the views 
of the petitioners. EPA is publishing the petition summaries verbatim 
without editing them in any way. The petition summary announces the 
availability of a description of the analytical methods available to 
EPA for the detection and measurement of the pesticide chemical 
residues or an explanation of why no such method is needed.

1. AgrEvo Environmental Health

PP 6H5743

    EPA has received a pesticide petition (PP 6H5743) from AgrEvo 
Environmental Health, 95 Chestnut Ridge Road, Montvale, NJ 07645 
proposing, pursuant to section 408(d) of the Federal Food, Drug, and 
Cosmetic Act, 21 U.S.C. 346a(d), to amend 40 CFR part 180 by 
establishing a tolerance for residues of esbiothrin and S-bioallethrin 
in or on food/feed items as a result of applications in food/feed 
handling establishments at 1.0 parts per million (ppm). EPA has 
determined that the petition contains data or information regarding the 
elements set forth in section 408(d)(2) of the FFDCA; 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.

A. Residue Chemistry

    1. Plant metabolism. The nature of the residues of esbiothrin and 
S-bioallethrin in plants relevant to the establishment of a food/feed 
additive tolerance is adequately understood. Metabolism data have been 
generated on tomatoes, wheat and lettuce as well as samples of these 
stored commodities. All degradates found from the metabolism samples 
had structures consistent with photoproducts of allethrin. Only very 
minor amounts of cleavage products were found, indicating that 
metabolic or abiotic cleavage was not occurring to any great extent. In 
view of the known rapid photodegradation of allethrin and related 
compounds, it is most likely that these products arose from photolysis, 
rather than metabolism. No metabolites of toxicological concern were 
identified. Therefore, the only residue of concern is allethrin.
    2. Analytical method. Analytical methods for determining residues 
of allethrin in a variety of food commodities have been developed and 
submitted to the Agency. These methods use gas chromatography (GC) with 
quantitation by an electron capture detector (ECD) for determination of 
total allethrin residues. These methods have been validated and are 
appropriate for the determination of allethrin residues in a variety of 
food commodities after application in food/feed handling 
establishments.
    3. Magnitude of residues. The magnitude of the residue study 
demonstrated that residues of esbiothrin and S-bioallethrin are not 
expected to exceed the proposed tolerance level of 1.0 ppm as a result 
of the use of these compounds in food/feed handling establishments.

B. Toxicological Profile

    1. Acute toxicity--i. S-bioallethrin. The acute rat oral 
LD<INF>50</INF> of S-bioallethrin was 574 milligrams/kilograms (mg/kg) 
(males) and 413 mg/kg (females) when administered in PEG 200 and 607 
mg/kg (males) and 497 mg/kg (females) when administered in corn oil. 
The acute rabbit dermal LD<INF>50</INF> was greater than 2,000 mg/kg. 
The acute rat inhalation LC<INF>50</INF> was 1.26 milligrams per liter 
(mg/L). S-bioallethrin was found to be slightly irritating to rabbit 
eyes, non-irritating to rabbit skin, and did not elicit a sensitizing 
response in guinea pigs.
    ii. Esbiothrin. The acute oral LD<INF>50</INF> of esbiothrin in 
rats was 432.3 mg/kg (males) and 378 mg/kg (females). The acute dermal 
LD<INF>50</INF> in rabbits was greater than 2,000 mg/kg. The acute 
inhalation LC<INF>50</INF> in rats was 2.59 mg/L. Esbiothrin

[[Page 55916]]

was found to be non-irritating to rabbit eyes, slightly irritating to 
rabbit skin, and did not elicit a sensitizing response in guinea pigs.
    2. Genotoxicity. No indication of genotoxicity was noted in a 
battery of in vivo and in vitro studies conducted with either S-
bioallethrin or esbiothrin.
    3. Reproductive and developmental toxicity--i. S-bioallethrin. In a 
rat developmental toxicity study, animals were administered S-
bioallethrin at 0, 5, 20, and 80 mg/kg/day during gestation days 6-15. 
Maternal mortality, tremors, piloerection and body weight (bwt) changes 
were observed. No evidence of developmental toxicity was observed. The 
maternal no observed adverse effect levels (NOAEL) was 20 mg/kg/day. 
The developmental NOAEL was 80 mg/kg/day.
    In a rabbit developmental toxicity study, animals were administered 
S-bioallethrin at 0, 5, 50, or 200 mg/kg/day during gestation days 6-
19. Tremors and reduced bwts and food consumption were reported. The 
maternal NOAEL was 50 mg/kg/day. Some evidence of slight developmental 
delay and an associated increased incidence of extra ribs and vertebrae 
were noted at the 200 mg/kg/day level. However these findings were only 
observed at the maternally toxic dose. The developmental NOAEL was 50 
mg/kg/day.
    ii. Esbiothrin. In a developmental toxicity study, rats were 
administered 0, 5, 25, and 125 mg/kg/day esbiothrin during gestation 
days 6-15. The maternal NOAEL was 25 mg/kg/day based on mortality and 
excess salivation, urine staining of the abdominal fur, tremors, body 
jerks and hypersensitivity to sound. There were no indications of 
developmental toxicity. The developmental NOAEL was 125 mg/kg/day.
    In a rabbit developmental toxicity study, animals were administered 
esbiothrin at 0, 30, 100, and 300 mg/kg/day during gestation days 6-18. 
The maternal NOAEL was 100 mg/kg/day based on deaths, tremors, 
decreased motor activity, and ataxia. There were no indications of 
developmental toxicity. The developmental NOAEL was 300 mg/kg/day.
    In a 2-generation reproduction study, esbiothrin was administered 
to rats at dietary concentrations of 0, 70, 200, 600, and 1,800 ppm. 
Decreased body weights (bwts) and mortality were observed in F1 
parental animals. Slight decreases in pup viability and pup weights 
were observed only in the F1 generation and were confined to four 
litters in the high dose group. The reproductive NOAEL was 600 ppm or 
50.4 mg/kg/day.
    4. Subchronic toxicity--i. S-bioallethrin. A 28-day dermal toxicity 
study was conducted with S-bioallethrin applied to the backs of rats at 
0, 10, 100, or 1,000 mg/kg/day for 6 hours/exposure 5 days/week for a 
total of 28 exposures. There were no treatment-related effects 
observed. The NOAEL was 1,000 mg/kg/day.
    A 28-day rat inhalation study was conducted with S-bioallethrin at 
analytical concentrations of 0 (air only), 0.0051, 0.025, and 0.073 mg/
L. Animals were exposed for 6 hours/day, 5 days/week for a total of 4 
weeks. Intermittent limb tremors, walking on ``tip toes,'' hunched 
posture, aggressive behavior and vocalizing when handled were observed 
at 0.025 and 0.073 mg/L. The NOAEL was 0.0051 mg/L.
    In a 90-day feeding study, rats were administered S-bioallethrin at 
dietary concentrations of 0, 250, 500, 2,000, and 8,000 ppm. Reduced 
bwt gain, food and water consumption, and increased absolute and 
relative liver and thyroid weights were observed at 2,000 ppm and 
higher. Various microscopic findings were reported for liver, kidneys 
and the thyroid. The NOAEL was 250 ppm or 18.5 mg/kg/day.
    In a 90-day feeding study, beagle dogs were administered S-
bioallethrin at dietary concentrations of 0, 400, 1,000, and 2,250 ppm. 
Decreased bwt gains, muscle tremors, wasted body condition, and 
intermittent incidences of decreased activity, hunched posture, 
diarrhea, and increased absolute and relative liver weights were 
observed. Histopathologic examination of the liver revealed 
centrilobular hepatocyte enlargement. The NOAEL was 1,000 ppm (38.54 
mg/kg/day).
    ii. Esbiothrin. In a 21-day dermal toxicity study, rabbits were 
exposed to 0, 40, 200 and 1,000 mg/kg esbiothrin for 6 hours/day for 5 
days/week for 3 weeks. There were no treatment-related systemic 
effects. Dermal effects were noted at all dose levels. The NOAEL for 
systemic toxicity was 1,000 mg/kg/day highest dose tested (HDT).
    5. Chronic toxicity. In a 2-year toxicity/oncogenicity study, rats 
were administered 0, 100, 500, 1,500, or 4,500 ppm esbiothrin in the 
diet. Decreased bwt gain, increased liver enzymes and cholesterol 
levels, increased liver weights, hepatocellular hypertrophy and hepatic 
cell degeneration and necrosis were observed. There was no evidence of 
oncogenicity. The NOAEL was 500 ppm (27 mg/kg/day).
    A 2-year toxicity/oncogenicity study was conducted with esbiothrin 
in mice at dietary concentrations of 0, 50, 250, or 1,250 ppm 
esbiothrin. Increased absolute and relative liver weights were 
observed. There was no evidence of oncogenicity. The NOAEL was 1,250 
ppm (214.3 mg/kg/day).
    In a 1-year feeding study, beagle dogs were administered dietary 
concentrations of 0, 80, 400, and 2,000 ppm esbiothrin. There were no 
toxicologically significant effects observed. The NOAEL for this study 
was 2,000 ppm (69.9 mg/kg/day).
    6. Animal metabolism. It appears that absorption of the allethrins 
is dependent upon the vehicle and route of administration. However, 
once absorbed, the allethrins are readily excreted. The dermal 
absorption determined from a rat dermal absorption study was 
approximately 25% when administered in an aromatic hydrocarbon vehicle.
    7. Endocrine disruption. No special studies have been conducted to 
investigate the potential of esbiothrin or S-bioallethrin to induce 
estrogenic or other endocrine effects. However, the standard battery of 
required toxicity studies has been completed. The studies include an 
evaluation of the potential effects on reproduction and development and 
an evaluation of the pathology of the endocrine organs following 
repeated or long-term exposure. These studies are generally considered 
to be sufficient to detect any endocrine effects, yet no such effects 
were detected. Thus, the potential for esbiothrin or S-bioallethrin to 
produce any significant endocrine effects is considered to be minimal.

C. Aggregate Exposure

    Esbiothrin and S-bioallethrin are broad-spectrum insecticides used 
to control various pests in domestic indoor and outdoor areas 
(including use on pets), commercial and industrial food use areas and 
on ornamental plants. Thus, aggregate non-occupational exposure would 
include exposures resulting from non-food uses in addition to 
consumption of potential residues in food and water.
    Both mixtures possess similar qualitative toxicologic profiles, but 
the overall weight of evidence indicates that the d-trans of d isomer 
is the most toxicologically significant isomer in these mixtures. 
Consequently, after converting into S-bioallethrin equivalents from 
esbiothrin data, or vice versa, based on the relative proportions of d-
trans of d, the toxicity data for these mixtures can be used 
interchangeably.
    1. Dietary exposure--Food. Since there are no agricultural uses 
with these active ingredients, an acute dietary exposure was not 
evaluated. According to EPA guidelines, food handling establishment 
uses should only be

[[Page 55917]]

evaluated for chronic dietary exposure. Potential chronic dietary 
exposures from food commodities under the proposed food and feed 
additive tolerance for esbiothrin and S-bioallethrin were estimated 
using the Exposure 1 software system (TAS, Inc.) and the 1977-78 USDA 
consumption data. Dietary risk assessment was conducted in a tiered 
approach whereby three scenarios were evaluated. The first scenario 
assumed 100% of all food and feed handling establishments (FHE) are 
treated with S-bioallethrin or esbiothrin and that all residues from 
these treatments are at the proposed tolerance level (1 ppm). The 
second scenario assumes that 100% of the FHE are treated and all 
residues are at the proposed tolerance level except where actual 
residue data are available. The third scenario assumes that, more 
realistically, only 25% of the FHE are treated and all residues are at 
the proposed tolerance level except for where actual residue data 
exist.
    2. Drinking water. Exposure via drinking water is expected to be 
negligible since esbiothrin and S-bioallethrin are neither persistent 
in the environment nor likely to leach. As is characteristic of 
pyrethroids, the allethrins bind strongly to soil and will not be 
leached out by water. Further, this pyrethroid is rapidly degraded 
under environmental conditions (in soil, water and in the presence of 
sunlight). The half-life of esbiothrin and S-bioallethrin is 
approximately 7-15 minutes in sunlight and no more than 2 hours in 
total darkness. Due to these properties, no residues in drinking water 
are expected to be present.
    3. Non-dietary exposure. As noted above, esbiothrin and S-
bioallethrin are broad-spectrum insecticides developed for use in non-
agricultural applications including indoor foggers, insect mats and 
coils, household commercial and institutional insect killers; food and 
feed handling applications, commercial non- food/feed sites, pet 
applications and greenhouse/ornamental applications. To evaluate non-
dietary exposure, the ``flea infestation control,'' scenario was chosen 
to represent a plausible but worst-case non-dietary (indoor and 
outdoor) non-occupational exposure. This scenario provides a situation 
where S-bioallethrin and/or esbiothrin is commonly used and one in 
which both can be used concurrently for a multitude of uses, e.g. spot 
treatment of infested indoor surfaces such as carpets and rugs, 
treatment of pets and treatment of animal housing. This hypothetical 
situation provides a very conservative, upper bound estimate of 
potential non-dietary exposures. Consequently, if health risks are 
acceptable under these conditions, the potential risks associated with 
other more likely scenarios would also be acceptable.
    Aggregate short-term risk was calculated by combining the risk 
calculated for the ``flea infestation'' scenario (non-dietary risk) 
with the chronic dietary risk analyses. As indicated previously, S-
bioallethrin and esbiothrin possess similar qualitative toxicity 
profiles. Due to their isomeric mixtures, the product toxicity data for 
either product can be converted to the other after the appropriate 
conversions have been made based on relative proportions of the d-trans 
of d isomer content. For risk assessment purposes, S-bioallethrin will 
be used to assess the risk of S-bioallethrin and esbiothrin since it 
contains a greater proportion of the more toxicologically significant 
isomer, d-trans of d. As a result of using the data in this manner, a 
conservative, worst-case evaluation can be made.

D. Cumulative Effects

    At the present time, there are insufficient data available to allow 
AgrEvo to properly evaluate the potential for cumulative effects from 
the various pyrethroids now being used, or from any other chemicals 
that may have similar mechanisms of toxicity. Furthermore, because of 
the need to utilize data from multiple registrants, such an analysis 
cannot be conducted by a single registrant. AgrEvo is currently 
participating in a joint industry effort to evaluate the potential 
aggregate risks from exposure to all pyrethroids but the results from 
this evaluation are not yet available.
    As an interim measure, AgrEvo has evaluated the potential 
cumulative risks associated with exposure to three products in the 
allethrin series: bioallethrin, esbiothrin, and S-bioallethrin. These 
products contain varying proportions of d-trans chrysanthemate ester of 
d- and l-allethrolone (d-trans d and d-trans l). The uses for these 
products are very similar except that no food uses are being proposed 
for bioallethrin. The use rates for the three products differ based on 
relative efficacy which appears to be related to the percentage of the 
most active isomer (d-trans d). The risk assessments conducted in 
support of this petition were based on the worst-case assumption that 
all residues were from S-bioallethrin, the product with the highest 
percentage of the most active isomer. Therefore, the potential 
cumulative risks associated with a combination of all three of these 
products would actually be lower than those presented here.

E. Safety Determination

    1. U.S. population. The combined toxicity and residue data base for 
esbiothrin and S-bioallethrin is considered to be valid, reliable and 
essentially complete. No evidence of oncogenicity has been observed. In 
accordance with EPA's ``Toxicology Endpoint Selection Process'' 
Guidance Document, the toxicology endpoint from the S-bioallethrin 
acute neurotoxicity study, 30 mg/kg, was used to evaluate acute non-
dietary risk. According to current EPA policy, residues from Food 
Handling Establishment uses are only evaluated for potential chronic 
dietary risk. AgrEvo is proposing a RfD of 0.226 mg/kg bwt/day to 
evaluate chronic dietary risk for S-bioallethrin and esbiothrin. This 
RfD is based on the NOAEL from the esbiothrin rat chronic toxicity/
oncogenicity study with a 100-fold safety factor to account for 
interspecies extrapolation and intraspecies variation. The S-
bioallethrin NOAEL served as a worst-case scenario because it contains 
the largest amount of d-trans of d isomer by weight.
    The potential chronic dietary exposure for the overall U.S. 
population under the three scenarios as described in section D utilize 
the following portions of the RfD: 10.73% for scenario 1 (100% FHE 
treated and all residues at the proposed tolerance level); 5.28% for 
the second scenario (100% FHE treated and all residues at proposed 
tolerance level except where actual data exist) and 1.32% of the third 
scenario (treatment of only 25% of FHE and residues at proposed 
tolerance except where actual data exist). There is generally no 
concern for chronic exposures below 100% of the RfD since it represents 
the level at or below which no appreciable risks to human health is 
posed.
    Using an upper bound estimate of potential non-dietary exposure 
from a worst-case scenario (flea treatment) results in a margin of 
exposure (MOE) of approximately 610,000 for adults with S-bioallethrin 
and approximately 510,000 for esbiothrin.
    Utilizing the scenario of chronic dietary exposure with an upper 
bound estimate of potential non-dietary exposure from a worst-case 
scenario (flea treatment), the resulting MOE for aggregate exposure to 
S-bioallethrin is 9,800 for the adult population and 8,100 for 
esbiothrin for the same population group.
    There is generally no concern for MOEs greater than 100 or 
utilization of less than 100% RfD. Therefore, there is

[[Page 55918]]

reasonable certainty that no harm will result to the U.S. population in 
general from aggregate exposure to S-bioallethrin or esbiothrin.
    2. Infants and children. Data from developmental toxicity studies 
in rats and rabbits and multi-generation reproduction studies in rats 
are generally used to assess the potential for increased sensitivity of 
infants and children. The developmental toxicity studies are designed 
to evaluate adverse effects on the developing organism resulting from 
pesticide exposure during prenatal development. Reproduction studies 
provide information relating to reproductive and other effects on 
adults and offspring from prenatal and postnatal exposure to the 
pesticide. None of the studies conducted with S-bioallethrin or 
esbiothrin indicated evidence of developmental or reproductive effects 
resulting from exposure to either material at non-maternally toxic 
doses.
    FFDCA section 408 provides that EPA may apply an additional safety 
factor for infants and children in the case of threshold effects to 
account for prenatal and postnatal toxicity and the completeness of the 
data base. Based on the current toxicological data requirements, the 
data base relative to prenatal and postnatal effects in children is 
complete. No indication of increased susceptibility to younger animals 
was noted in the developmental or reproduction studies at non-
maternally toxic doses or in the majority of studies with other 
pyrethroids. Therefore, use of the S-bioallethrin acute neurotoxicity 
NOAEL of 30 mg/kg for short-term risk, and the proposed RfD of 0.226 
mg/kg/day for assessing chronic aggregate risk to infants and children 
is appropriate and an additional uncertainty factor is not warranted.
    Using the dietary exposure assumptions described above in section 
D, the first scenario utilizes 41.98% of RfD for non-nursing infants (< 
1-year) and 26.14% of RfD for children 1-6 years. The second scenario 
utilizes 11.96% of the RfD for non-nursing infants < 1-year and 11.54% 
of RfD for children 1-6 years. The third scenario utilizes 2.96% of RfD 
for non-nursing infants < 1-year and 2.88% of the RfD for children 1-6 
years. There is generally no concern for chronic exposures below 100% 
of the RfD since it represents the level at or below which no 
appreciable risks to human health is posed.
    Using an upper bound estimate of potential non-dietary exposures 
for a worst case scenario (flea infestation) results in a MOE of 2,300 
for infants less than 1-year old for S-bioallethrin and 1,900 for 
esbiothrin. A MOE of 2,400 for children 1-6 years was noted for S-
bioallethrin and a MOE of 2,000 for esbiothrin.
    Utilizing the scenario of chronic dietary exposure with an upper 
bound estimate of potential non-dietary exposure from a worst case 
scenario (flea infestation), it can be seen that for aggregate exposure 
to S-bioallethrin and esbiothrin, the MOE for infants less than 1-year 
is 1,500 for S-bioallethrin and 1,200 for esbiothrin. For children 1-6 
years, the MOE's are 1,600 for S- bioallethrin and 1,300 for 
esbiothrin.
    As noted for the U.S. population, these compounds have a very short 
half-life in light and in darkness. These products are metabolized 
rapidly from the body and based on general practices, are applied not 
more than once per month. Based on these properties and use patterns, 
real-life exposures would be acute in nature and at much lower levels 
than used in this assessment.
    There is generally no concern for MOE's greater than 100, or less 
than 100% utilization of RfD. Therefore, there is reasonable certainty 
that no harm will result to the most sensitive population subgroup, 
described as non-nursing infants less than 1-year and children 1-6 
years, from aggregate exposure to esbiothrin and S-bioallethrin.

F. International Tolerances

    Esbiothrin and S-bioallethrin are broad spectrum insecticides used 
throughout the world to control pests of ornamental plants, household, 
commercial and industrial areas (indoor and outdoor). There are 
currently no maximum residue limits (MRLs) for esbiothrin or S-
bioallethrin.


[FR Doc. 99-26971 Filed 10-14-99; 8:45 am]
BILLING CODE 6560-50-F