[Federal Register Volume 72, Number 54 (Wednesday, March 21, 2007)]
[Rules and Regulations]
[Pages 13174-13179]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 07-1386]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[EPA-HQ-OPP-2006-0325; FRL-8117-9]


6-Benzyladenine; Exemption from the Requirement of a Tolerance

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: This regulation establishes an exemption from the requirement 
of a tolerance for residues of the biochemical pesticide, 6-
benzyladenine (6-BA), in or on pear when applied/used as a plant 
regulator. Valent BioSciences Corporation (Valent) submitted a petition 
to EPA under the Federal Food, Drug, and Cosmetic Act (FFDCA), as 
amended by the Food Quality Protection Act of 1996 (FQPA), requesting 
an exemption from the requirement of a tolerance. This regulation 
eliminates the need to establish a maximum permissible level for 
residues of 6-benzyladenine.

DATES: This regulation is effective March 21, 2007. Objections and 
requests for hearings must be received on or before May 21, 2007, and 
must be filed in accordance with the instructions provided in 40 CFR 
part 178 (see also Unit I.C. of the SUPPLEMENTARY INFORMATION).

ADDRESSES: EPA has established a docket for this action under docket 
identification (ID) number EPA-HQ-OPP-2006-0325. All documents in the 
docket are listed in the index for the docket. Although listed in the 
index, some information is not publicly available, e.g., Confidential 
Business Information (CBI) or other information whose disclosure is 
restricted by statute. Certain other material, such as copyrighted 
material, is not placed on the Internet and will be publicly available 
only in hard copy form. Publicly available docket materials are 
available in the electronic docket at http://www.regulations.gov, or, 
if only available in hard copy, at the OPP Regulatory Public Docket in 
Rm. S-4400, One Potomac Yard (South Bldg.), 2777 S. Crystal Dr., 
Arlington, VA. The Docket Facility is open from 8:30 a.m. to 4 p.m., 
Monday through Friday, excluding legal holidays. The Docket telephone 
number is (703) 305-5805.

FOR FURTHER INFORMATION CONTACT: Denise Greenway, Biopesticides and 
Pollution Prevention Division (7511P), Environmental Protection Agency, 
1200 Pennsylvania Ave., NW., Washington, DC 20460-0001; telephone 
number: (703) 308-8263; e-mail address: [email protected].

SUPPLEMENTARY INFORMATION:

[[Page 13175]]

I. General Information

A. Does This Action Apply to Me?

    You may be potentially affected by this action if you are an 
agricultural producer, food manufacturer, or pesticide manufacturer. 
Potentially affected entities may include, but are not limited to:
     Crop production (NAICS code 111).
     Animal production (NAICS code 112).
     Food manufacturing (NAICS code 311).
     Pesticide manufacturing (NAICS code 32532).
    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 this unit could also be 
affected. The North American Industrial Classification System (NAICS) 
codes have been provided to assist you and others in determining 
whether this action might apply to certain entities. If you have any 
questions regarding the applicability of this action to a particular 
entity, consult the person listed under FOR FURTHER INFORMATION 
CONTACT.

B. How Can I Access Electronic Copies of this Document?

    In addition to accessing an electronic copy of this Federal 
Register document through the electronic docket at http://www.regulations.gov, you may access this ``Federal Register'' document 
electronically through the EPA Internet under the ``Federal Register'' 
listings at http://www.epa.gov/fedrgstr. You may also access a 
frequently updated electronic version of 40 CFR part 180 through the 
Government Printing Office's pilot e-CFR site at http://www.gpoaccess.gov/ecfr.

C. Can I File an Objection or Hearing Request?

    Under section 408(g) of the FFDCA, as amended by the FQPA, any 
person may file an objection to any aspect of this regulation and may 
also request a hearing on those objections. The EPA procedural 
regulations which govern the submission of objections and requests for 
hearings appear in 40 CFR part 178. You must file your objection or 
request a hearing on this regulation in accordance with the 
instructions provided in 40 CFR part 178. To ensure proper receipt by 
EPA, you must identify docket ID number EPA-HQ-OPP-2006-0325 in the 
subject line on the first page of your submission. All requests must be 
in writing, and must be mailed or delivered to the Hearing Clerk on or 
before May 21, 2007.
    In addition to filing an objection or hearing request with the 
Hearing Clerk as described in 40 CFR part 178, please submit a copy of 
the filing that does not contain any CBI for inclusion in the public 
docket that is described in ADDRESSES. Information not marked 
confidential pursuant to 40 CFR part 2 may be disclosed publicly by EPA 
without prior notice. Submit your copies, identified by docket ID 
number EPA-HQ-OPP-2006-0325, by one of the following methods.
     Federal eRulemaking Portal: http://www.regulations.gov. 
Follow the on-line instructions for submitting comments.
     Mail: Office of Pesticide Programs (OPP) Regulatory Public 
Docket (7502P), Environmental Protection Agency, 1200 Pennsylvania 
Ave., NW., Washington, DC 20460-0001.
     Delivery: OPP Regulatory Public Docket (7502P), 
Environmental Protection Agency, Rm. S-4400, One Potomac Yard (South 
Bldg.), 2777 S. Crystal Dr., Arlington, VA. Deliveries are only 
accepted during the Docket's normal hours of operation (8:30 a.m. to 4 
p.m., Monday through Friday, excluding legal holidays). Special 
arrangements should be made for deliveries of boxed information. The 
Docket telephone number is (703) 305-5805.

II. Background and Statutory Findings

    In the Federal Register of April 19, 2006 (71 FR 20100) (FRL-8058-
1), EPA issued a notice pursuant to section 408(d)(3) of the FFDCA, 21 
U.S.C. 346a(d)(3), announcing the filing of a pesticide tolerance 
petition (PP 6F7035) by Valent BioSciences Corporation (Valent), 870 
Technology Way, Libertyville, IL 60048-6316. The petition requested 
that 40 CFR part 180 (specifically, Sec.  180.1150) be amended by 
establishing an exemption from the requirement of a tolerance for 
residues of 6-benzyladenine (6-BA) in or on pear when applied at a rate 
of <=182 grams of active ingredient per acre per season. The electronic 
docket (EPA-HQ-OPP-2006-0325) for this notice includes a summary of the 
petition prepared by the petitioner, Valent. Previously, on April 2, 
2004 (69 FR 17304; FRL-7347-6), EPA issued a final rule granting a 
permanent exemption from the requirement of a tolerance for residues of 
6-BA in or on pistachio when applied at a rate of <=60 grams of active 
ingredient per acre per season, and the existing permanent tolerance 
exemption for apple was amended to expand the uses (by adding a post-
bloom-applied stand-alone fruitlet thinner use) and increase the 
permissible application rate to <=182 grams of active ingredient per 
acre per season. Both apple and the subject new crop, pear, are pome 
fruit and, therefore, botanically similar. The two crops are grown in 
the same climatic/geographic regions, and are similarly cultivated. For 
both crops, 6-BA is applied for the same purpose, on the same schedule, 
at the same application rate and with the same 86-day pre-harvest 
interval restriction. Based on these similarities, the Agency has 
determined for the purpose of establishing the requested tolerance 
exemption that previously-submitted and reviewed information and data 
supporting the current tolerance exemption for apple will apply equally 
to the new crop, pear. In submitting this petition, therefore, Valent 
is relying on information previously submitted in connection with 
seeking and obtaining the tolerance exemption for the expanded use of 
6-BA on apple, which was summarized in the April 2, 2004, final rule, 
and also on new data summarized in the cited petition summary (i.e., PP 
6F7035). New data submitted to the Agency by Valent on October 20, 2004 
and summarized by the company in the current petition are a two-
generation rat reproduction study, which is data not required for U.S. 
registration of this biochemical active ingredient, but rather was 
conducted to satisfy the registration requirements of other countries 
and submitted by the petitioner to augment the Agency's 6-BA data base.
    In response to EPA's April 19, 2006 notice, no comments were 
submitted in accordance with the instructions for submitting comments 
set forth in the notice. However, one informal comment was received 
from a private citizen who opposed issuance of a final rule. The 
commenter expressed concern regarding the hazard associated with plant 
regulator use in general, stated the unsupported belief that more 
testing needs to be done, and was generally opposed to the 
establishment of an exemption from the requirement of a tolerance as 
proposed in the subject pesticide tolerance petition for 6-BA. The 
Agency understands and recognizes that some individuals believe that 
pesticides, which include plant regulators, should be banned 
completely. Notwithstanding such beliefs, pursuant to its authority 
under the FFDCA, EPA has conducted a comprehensive assessment of 6-BA 
and has concluded that there is a reasonable certainty that no harm 
will result from dietary exposure to this chemical when its use is 
limited by the specified maximum application rates.
    Section 408(c)(2)(A)(i) of the FFDCA allows EPA to establish an 
exemption

[[Page 13176]]

from the requirement for a tolerance (the legal limit for a pesticide 
chemical residue in or on a food) only if EPA determines that the 
exemption is ``safe.'' Section 408(c)(2)(A)(ii) of the FFDCA 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. Pursuant to section 408(c)(2)(B) of the FFDCA, 
in establishing or maintaining in effect an exemption from the 
requirement of a tolerance, EPA must take into account the factors set 
forth in section 408(b)(2)(C) of the FFDCA, which require EPA to give 
special consideration to exposure of infants and children to the 
pesticide chemical residue in establishing a tolerance and to ``ensure 
that there is a reasonable certainty that no harm will result to 
infants and children from aggregate exposure to the pesticide chemical 
residue.... '' Additionally, section 408(b)(2)(D) of the FFDCA requires 
that the Agency consider ``available information concerning the 
cumulative effects of a particular pesticide's residues '' and ``other 
substances that have a common mechanism of toxicity.''
    EPA performs a number of analyses to determine the risks from 
aggregate exposure to pesticide residues. First, EPA determines the 
toxicity of pesticides. Second, EPA examines exposure to the pesticide 
through food, drinking water, and through other exposures that occur as 
a result of pesticide use in residential settings.

III. Toxicological Profile

    Consistent with section 408(b)(2)(D) of the FFDCA, EPA has reviewed 
the available scientific data and other relevant information in support 
of this action and considered its validity, completeness, and 
reliability and the relationship of this information 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 toxicological profile for 6-BA was published by the Agency in 
the June 1994 N6-Benzyladenine (synonymous with the subject active 
ingredient, 6-benzyladenine) Reregistration Eligibility Decision (RED) 
document (http://www.epa.gov/oppsrrd1/REDs/old_reds/n6benzyladenine.pdf). The summarized values and categories for the 
various, previously reviewed studies for the technical active 
ingredient are presented here.
    1. Acute toxicity. Toxicity Category III was assigned to the acute 
oral toxicity study in the rat (lethal dose (LD)50 = 1.3 
grams/kilogram (g/kg)), and in the eye irritation study in the rabbit 
(moderate irritant). Toxicity Category IV (the least toxic category) 
was assigned to the acute dermal toxicity study in the rabbit 
(LD50 >5 g/kg), the acute inhalation toxicity study in the 
rat (lethal concentration (LC)50 = 5.2 milligrams/liter (mg/
L)), and to the dermal irritation study in the rabbit (slight 
irritant). Additionally, from a dermal sensitization study in the 
guinea pig, it was determined that 6-BA is not a dermal sensitizer. 
There have been no reported incidents of hypersensitivity directly 
linked to 6-BA. Nevertheless, to comply with section 6(a)(2) of the 
Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), any 
incident of hypersensitivity associated with the use of this pesticide 
must be reported to the Agency.
    2. Genotoxicity. From three mutagenicity studies (Ames test, mouse 
micronucleus assay, and unscheduled DNA synthesis assay in the rat), it 
was determined that 6-BA is not mutagenic.
    3. Developmental toxicity. The no observed adverse effect levels 
(NOAEL) and the lowest observed adverse effect levels (LOAEL) for 
maternal and developmental toxicity in rats, respectively, were found 
to be 50 and 175 milligrams/kilogram body weight/day (mg/kg bwt/day), 
respectively.
    4. Subchronic toxicity. For rats of both sexes, the NOAEL was 
approximately 111 mg/kg bwt/day and the LOAEL was approximately 304 mg/
kg bwt/day.
    In addition to the previously reviewed studies discussed above, a 
two-generation rat reproduction study was relied upon by Valent to 
support the current petition to establish an exemption from the 
requirement of a tolerance for residues of 6-BA in or on pear. The 
lowest-LOAEL for parental systemic toxicity of technical 6-BA is 750 
ppm (58.6-70.4 mg/kg bwt/day) and is based on reduced body weight and 
weight gain in F0 and F1 male rats\1\.The NOAEL 
is 400 ppm (31.5-37.5 mg/kg bwt/day)\1\ . This systemic adult endpoint 
was used in the dietary risk assessment. Although the systemic endpoint 
is similar to that used in previous occupational risk assessments, the 
previous toxicological endpoint (40 mg/kg bwt/day) has been modified to 
more precisely reflect the composition of test diets, rat body weights, 
and food consumption estimates\1\.
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    \1\ USEPA. N6-Benzyladenine: Review of Information for an 
Exemption from the Requirement of a Tolerance. K. R. Carlson to D. 
Greenway; December 5, 2006.
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    Because only systemic and no reproductive effects were observed, 
the LOAEL for reproductive toxicity of technical 6-BA in rats could not 
be determined. The NOAEL, therefore, is >1,500 ppm (115.7-144.2 mg/kg 
bwt/day for males and 133.0-139.2 mg/kg bwt/day for females), the 
highest dose tested\1\.
    The LOAEL for offspring toxicity of technical 6-BA in rats is 750 
ppm (66.7-68.1 mg/kg bwt/day) and is based on decreased body weight and 
weight gain in F1 and F2 male and female pups. 
The NOAEL is 400 ppm (35.8-36.0 mg/kg bwt/day)\1\.
    Uncertainty factors for inter- and intra-species variation (10X 
each) and subchronic to chronic extrapolation (3X) were used to modify 
the toxicity NOAEL.

IV. Aggregate Exposures

    In examining aggregate exposure, section 408 of the FFDCA directs 
EPA to consider available information concerning exposures from the 
pesticide residue in food and all other non-occupational exposures, 
including drinking water from ground water or surface water and 
exposure through pesticide use in gardens, lawns, or buildings 
(residential and other indoor uses).

A. Dietary Exposure

    1. Food. Apple field trials yielded acceptable magnitude of the 
residue data. In apples, residues of 6-BA were consistently near the 
limit of quantitation (LOQ). However, the residue levels for processed 
commodities did not increase relative to those on the raw commodity, 
and were below the LOQ. The apple field data are adequate to support 
the tolerance exemption for pear, limited by a maximum application rate 
of <=182 grams of active ingredient per acre per season, because of the 
shared physical, compositional and cultural characteristics of the two 
botanically similar pome fruits, which also are grown in the same 
climatic/geographic regions. The proposed use pattern; low application 
rate, frequency and timing; and 86-day pre-harvest interval are 
identical for apple and pear. Because application precedes harvest by 
approximately 2.5 months for apple and pear, the potential for dietary 
exposure is reduced. Due to the low anticipated dietary intake of 6-BA 
residues relative to the chronic and acute population adjusted doses 
(see Unit VI.), and the

[[Page 13177]]

fact that actual exposure will probably be considerably less because 
the dietary exposure analysis was based on worst-case assumptions (such 
as conservatively assuming: That 100% of the crop is treated, that non-
detected or 2 mg/L at 20[deg] C, and detections in ground water are not 
expected. Together, these data indicate that residues are not expected 
in drinking water.

B. Other Non-Occupational Exposure

    The potential for non-dietary, non-occupational exposure to 6-BA 
residues for the general population, including infants and children, is 
unlikely because the uses, both those currently allowed and the one 
currently being established, are limited to applications in certain 
tree fruit and nut tree orchards. Additionally, because 6-BA is a 
naturally-occurring cytokinin plant regulator (having been detected in 
all higher plants tested for its presence), it is a normal part of the 
human diet. Moreover, the proposed use rates are well below the 
toxicity NOAELs (see Unit III.), and the residues resulting from 
applications made in accordance with the proposed use rates indicate 
dietary exposures that are <1.0% of the chronic and acute population 
adjusted doses. Therefore, not only is there a great likelihood of 
prior exposure for most, if not all, individuals to 6-BA, due to its 
natural presence in food crops, the data submitted also demonstrate 
that any incremental increased exposure due to the proposed use would 
be negligible due to the lack of residue in comparison with the 
toxicity NOAELs.

V. Cumulative Effects

    Section 408(b)(2)(D)(v) of FFDCA 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.'' These considerations include the 
possible cumulative effects of such residues on infants and children.
    EPA does not have, at this time, available data to suggest whether 
6-BA has a common mechanism of toxicity with other substances. Unlike 
other pesticides for which EPA has followed a cumulative risk approach 
based on a common mechanism of toxicity, EPA has not made a common 
mechanism of toxicity finding as to 6-BA and any other substances and 
6-BA 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 6-BA has a common mechanism of toxicity with other 
substances. For information regarding EPA's efforts to determine which 
chemicals have a common mechanism of toxicity and to evaluate the 
cumulative effects of such chemicals, see the policy statements 
released by EPA's Office of Pesticide Programs concerning common 
mechanism determinations and procedures for cumulating effects from 
substances found to have a common mechanism on EPA's web site at http://www.epa.gov/pesticides/cumulative/.

VI. Determination of Safety for U.S. Population, Infants and Children

A. U.S. Population

    When assessing the contributions of apple and pistachio, the 
Agency's analysis estimated that the chronic exposures for the overall 
U.S. population was 0.000002 mg/kg/day (<1.0% of the chronic population 
adjusted dose (cPAD))\1\. Similarly, the acute dietary estimated 
exposure was 0.000069 mg/kg/day (<1.0% of the acute population adjusted 
dose (aPAD)) for the overall U.S. population. Critical exposure 
commodity analysis showed that apple juice contributed the most to 
dietary exposure for the overall population. Dietary exposure to 6-BA 
residues in or on pear did not add significantly to the current dietary 
exposure to 6-BA from its use in or on apple or pistachio. Due to the 
low anticipated dietary intake of 6-BA residues relative to the chronic 
and acute population adjusted doses, and the fact that actual exposure 
will probably be considerably less because the dietary exposure 
analysis was made based on worst-case assumptions (such as 
conservatively assuming: That 100% of the crop is treated, that non-
detected or