[Federal Register Volume 59, Number 17 (Wednesday, January 26, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-1615]
[[Page Unknown]]
[Federal Register: January 26, 1994]
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ENVIRONMENTAL PROTECTION AGENCY
[OPP-50573; FRL-4755-1]
Arthropod Pheromones in Solid Matrix Dispensers; Experimental Use
Permits
AGENCY: Environmental Protection Agency (EPA)
ACTION: Notice.
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SUMMARY: EPA is announcing in this notice that it is expanding the
acreage cut-off for when an Experimental Use Permit (EUP) is required
under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA)
from 10 acres to 250 acres for a class of biological pesticides. This
class of pesticides covers arthropod pheromone products in solid matrix
dispensers used at rates at or below a total use rate of 150 grams
active ingredient (AI)/acre/year. Tests conducted on these pheromone
formulations under the conditions specified in this notice would not
require an EUP at acreages up to and including 250 acres. Tests
conducted on acreages exceeding 250 acres would require an EUP.
FOR FURTHER INFORMATION CONTACT: By mail: Phil Hutton, Registration
Division, (7505C), Environmental Protection Agency, 401 M St., SW.,
Washington, DC 20460. Office location and telephone number: Rm. 213,
Crystal Mall #2, 1921 Jefferson Davis Highway, Arlington, VA, 707-305-
7690.
SUPPLEMENTARY INFORMATION:
I. Introduction
In keeping with the Administrator's commitment to reduce the use of
higher risk pesticides and provide incentives for the adoption of
lower-risk pest management methods, EPA is announcing in this notice a
new policy of allowing testing of pheromones in solid matrix dispensers
(e.g., twist ties, plastic tapes, and ropes) on no more than 250 acres
to proceed without an EUP. EPA recognizes that alternative pest control
strategies, integrated pest management, and reduced risk pesticides,
such as pheromones in solid matrix dispensers, are fundamental elements
of an overall program to reduce risks to humans and the environment.
Insect species utilize certain volatile compounds, semiochemicals,
and pheromones, to communicate with each other (e.g., to locate and
attract mates or give alarm). For purposes of this notice, EPA defines
a semiochemical as a chemical that transmits messages between living
organisms. A pheromone, which is a type of semiochemical, is defined as
a compound produced by an arthropod which, alone or in combination with
other such compounds, modifies the behavior of other individuals of the
same species (40 CFR 152.25(b)(1)). Even very low amounts of these
naturally occurring volatile compounds can confuse normal insect
behavior thus interrupting mating and preventing reproduction.
These chemicals may pose a relatively low risk alternative for
managing insect pest populations. The use of semiochemicals, including
pheromones, to attract and trap insects has been a viable pest
management technology for a considerable period of time. In 1979, EPA
first registered pheromones for use in traps for the purpose of mass
trapping Japanese Beetles. Since then, the Agency has registered
approximately 30 semiochemical pesticides with approximately 20 active
ingredients being Lepidoptera pheromones.
It was in the late 1970s that EPA recognized that biochemical
pesticides, including pheromones, were inherently different from most
broad spectrum conventional pesticides and encouraged their development
and registration, considering them to be potentially lower risk
alternatives to conventional synthetic products on the market. The
development of reduced safety data requirements currently in place for
the registration of biochemical pesticides is based on the Agency's
classification of a biochemical pesticide by two criteria: (1) The
compound's non-toxic mode of action on the target pest, and (2) the
natural occurrence of the compound. While not criteria for biochemical
classification, arthropod pheromone products also have a low use rate,
usually below 20 grams per acre, and target species specificity,
therefore less expected environmental impact than other pesticides.
The conditions under which an EUP, the first step in the regulation
process, is required and the data which is required for an EUP
application are major areas of concern by researchers and producers of
pheromone pesticide products. A 1987 survey of companies actively
involved in the registration of pheromones and companies that have
considered and rejected pheromone development indicated that industry
considered data requirements for pheromones to be excessive given the
relatively safe nature of these substances, their extremely low rate of
application, and their short persistence. Furthermore, it was noted
that the applicant must incur the costs of developing most of the data
to obtain an EUP, a stage in the product's development often too early
to tell whether the pheromone is viable as a pesticide product. Given
the limited earning potential of pheromone products, such testing costs
tend to be prohibitively expensive; this is in addition to the high
initial production costs of the pheromones themselves.
Over the years, industry has suggested several changes in EPA rules
and procedures to aid the development and ease the regulatory standards
for pheromones and similar semiochemicals. The Agency is now at a point
where it believes there is a sufficient body of information in the
public literature and has adequate data available on arthropod
pheromones, and is now taking steps toward this end.
Today's notice announces a new agency policy of allowing pheromones
in solid matrix dispensers to be tested on acreages not exceeding 250
acres of land under the conditions specified in this notice without an
EUP. This policy only applies to arthropod pheromones in solid matrix
dispensers, as defined in this notice, applied at rates not to exceed
150 grams AI/acre/year.
Conditional relief consisting of exemption from regulation under
FIFRA has previously been granted by EPA for pheromone traps in which
the pheromones are the sole active ingredient(s) (See 40 CFR
152.25(b)). In addition, EPA, on its own initiative, issued a proposed
rule in the Federal Register of December 8, 1993 (58 FR 64538), which
proposes to exempt from the requirement of a tolerance under the
Federal Food, Drug, and Cosmetic Act (FFDCA) the residues of arthropod
pheromones resulting from the use of these substances in solid matrix
dispensers with an annual application rate limitation of 150 grams AI/
acre/year for pest control in or on all raw agricultural commodities.
The scope of pheromone products exempted by this tolerance proposal
would be the same as the scope of products subject to this notice. EPA
currently is considering whether to take additional actions to grant
further regulatory relief for other types of pheromone products. If EPA
determines that any such regulatory relief is warranted, EPA would
announce such a decision in a future Federal Register notice.
II. Statutory and Regulatory Authority
Section 5 of FIFRA, 7 U.S.C. 136c and 40 CFR part 172 provide for
issuance by the Agency of EUP's for the testing of new, unregistered,
pesticides or registered pesticides being tested for new uses, in which
the purpose is only to determine its value for pesticide purposes or to
determine its toxicity or other properties. Such permits are generally
issued for large-scale testing of pesticides on more than 10 acres.
Contained within the scope of the regulation, however, is the
presumption that small-scale testing, i.e., on not more than 10 acres
of land, does not require an EUP provided that the crops are destroyed
or an appropriate tolerance is in place (40 CFR 172.3(a)). This
presumption, however, is caveated not to preclude experimental testing
on larger areas in certain circumstances where the purpose of the large
acreage test is only to determine the substance's value for pesticidal
purposes or to determine its toxicity or other properties, and no
benefit from pest control is expected (40 CFR 172.3(b)). EPA issued in
the Federal Register of January 22, 1993 (58 FR 5878), a proposed
amendment to 40 CFR part 172. The proposed amendment would, among other
things, modify Sec. 172.3 to clarify that the determination of whether
an EUP is required is based on risk considerations. The amendment would
provide that tests conducted on not more than 10 acres of land are
presumed not to involve unreasonable risks, and therefore, do not
require an EUP.
EPA believes that pheromone products in solid matrix dispensers
must be tested at acreages larger than 10 acres and as large as 250
acres to determine the products' value for pesticidal purposes. The 10
acre presumption in 40 CFR 172.3(a) is appropriate for most substances,
which can be tested to determine their value for pesticidal purposes at
small acreages below 10 acres. Due to the unique characteristics of
pheromones in solid matrix dispensers, however, these products must be
tested at much larger acreages. Most pheromone uses involve mating
disruption. Unlike traditional toxicants which usually focus on killing
the immature insect (which often does the most damage), pheromones act
upon the adult.
Insects use pheromones to locate potential mates. When pheromones
are introduced over an area by man as a pest control technique, the
insects become confused by the seemingly ubiquitous presence of the
guiding compound and therefore cannot find a suitable mate. When
successful, pheromone applications result in reduced mating, lower
insemination rates, and therefore lower population densities in the
next generation. The evaluation of pheromones cannot be accomplished on
small acreages because the treated area must be of sufficient size to
account for the natural flight range of the target pests, such that
already mated females flying into the test area do not skew the results
of the study. This problem does not occur for most traditional toxicant
pesticides which usually target the immature stage as these earlier
life stages do not possess the capability of flight.
An additional factor necessitating larger acreages is the volatile
nature of most pheromone compounds. It is unfeasible to adequately
separate treatments with small plots. For these reasons pheromones are
usually tested in plot sizes ranging from 20 to 60 acres, depending
upon the nature of the treated site and the pest in question. To
provide scientifically sound information, it is generally conceded that
four to six replications are necessary to validate the findings. Thus,
the position that 250 acres should be sufficient to determine the value
for pesticidal purposes of most pheromones. Moreover, as discussed in
the section entitled ``Exposure and Effect,'' below, EPA believes that
pheromones in solid matrix dispensers tested on no more than 250 acres
and at maximum application rates of 150 grams AI/acre/year will not
cause unreasonable adverse effects on the environment.
III. Exposure and Effect
Since 1986, EPA has reviewed many arthropod-active pheromone
products and has extensively reviewed pheromone toxicology data from
the public literature. Based on this information, discussed more fully
below, EPA believes that field tests conducted with pheromones in solid
matrix dispensers and under the conditions outlined in this policy,
will not cause unreasonable adverse effects on the environment. This
conclusion is based on a number of factors, including the generally low
toxicity and high volatility of pheromones, the low environmental and
human exposure expected from pheromones used in solid matrix
dispensers, and the low application rates and limited acreage required
by this policy. Although the natural background level of pheromones in
the atmosphere has never directly been determined, atmospheric levels
for some pheromones have been estimated for peak population levels
based on the pheromone emission rates for individual female arthropods.
These estimated values range widely since they can be based on the
amount of pheromone present in extracted glands or the measured
emission rate and depend on what is considered the adult population
during a peak pest infestation. To safeguard for the lack of data on
natural background levels, EPA has determined to set an upper limit on
the total amount of active ingredient released per acre per year from
solid matrix dispensers at 150 gm. The upper limit rate is necessary to
ensure that pheromones used in solid matrix dispensers do not result in
increased levels of pheromones beyond natural background levels.
The current upper limit for the application of a biochemical active
ingredient lacking significant toxic effects that does not require the
submission of residue data is 20 grams AI/acre (40 CFR
158.690(b)(2)(B)). To facilitate testing of pheromones for pesticidal
purposes, the Agency is setting a more realistic upper limit for the
amount of active ingredient released during a season before an EUP is
required. The Agency has found that given the low expected toxicity and
high volatility of arthropod pheromones, an upper limit of 150 grams
AI/acre/year is adequate for testing a pheromone product's feasibility
and efficacy while still protecting public health, nontarget organisms
and the environment from unreasonable risks from compound levels which
may be above ambient natural productions. These application rates
encompass the majority of pheromone uses seen by the Agency to date.
IV. Human Health
The study results and submitted data available to date have
indicated the following: acute oral toxicity - (LD50 > 5,000 mg/kg
category IV (nontoxic)); acute dermal toxicity (LD50 > 2,000 mg/kg
category IV, (nontoxic)), acute inhalation toxicity (LD50
generally > 5 mg/L- category III-IV, practically (nontoxic)); no
evidence of mutagenicity (Ames Salmonella assay); and minimal eye and
skin irritation.
EPA has reviewed the results of submitted mammalian toxicology
studies for the pheromone products registered to date and also
pheromone toxicology data from the public literature. The majority of
the compounds registered to date (26 of 31) have been Lepidopteran
(e.g. butterfly and moth) pheromones. These registered pheromones fall
within a well defined class of chemical structures: aliphatic compounds
with straight chains from 9 to 18 carbons in length and up to 3 double
bonds, and ending in an acetate, alcohol, aldehyde functional group.
Pheromones have been discovered with other chemical structures
including compounds with ketone, epoxide, lactone, terpenoid, pyrazine,
pyran, and aromatic structures. In 1983, when EPA promulgated the
exemption for pheromones used in traps, the Agency did not distinguish
between the rather restricted class of chemicals produced by
Lepidopteran species and pheromones with different chemical structures
produced by other arthropod species (e.g. beetles, flies, and mites)
for use in traps. Because the proposed interpretation that the use of
pheromones in solid matrix dispensers at an annual rate of up to 150 gm
AI/acre represents the same human risk as the use of pheromones in
traps, EPA does not believe there is a reason to distinguish between
chemical classes of pheromones for pheromones in solid matrix
dispensers.
While the toxicology data base for pheromones with structures
outside the well defined aliphatic Lepidopteran pheromones, such as
aromatic compounds, is not as extensive, there is no indication of
significant toxic effects to mammalian species from those compounds
registered to date. The literature indicates that some aromatic
pheromone compounds could be potentially toxic due to structural
similarities to other aromatic compounds. The data available to date on
both Lepidopteran and other arthropod pheromones, including several
aromatic pheromones, however, have indicated no mammalian toxicity at
the limit dose levels.
The volatility of these compounds also predicts that little, if
any, of the released compound will actually be associated with the
crop. Studies to measure the natural background levels of insect
pheromones in the environment or in or on fruit indicate little or no
detectable residues. When pheromone residue analyses were done on fruit
treated with from 129 to 141 gm AI/acre, no residues could be found
with a detection limit of 2 to 5 ppb (Refs. 1 and 2). The current
regulations provide that, in the absence of any significant toxic
effects, residue analysis can be required when biochemical pesticides
are applied above 20 gm AI/acre (40 CFR 158.690(b)). The Agency
recognizes that the 150 gm AI/acre/yr rate is well above the 20 gm/acre
limit triggering a food residue analysis. However, the negligible
exposure for pheromones in dispensers, the natural occurrence of these
compounds, their rapid biodegradation, high volatility and low worker
exposure associated with solid matrix dispensers justify raising the
limit for when an EUP is required for testing these volatile
biochemical pesticides.
Moreover, the Agency believes that an upper limit of 150 gm AI/
acre/year for pheromones labeled for use in dispensers as described
below does not present a significant risk of dietary exposure due to
the unlikelihood of direct contact with food and the low probability of
deposition on food or feed following atmospheric dilution. EPA, on its
own initiative, issued a proposed rule in the Federal Register of
December 8, 1993 (58 FR 64538), which proposes to exempt from the
requirement of a tolerance under the Federal Food, Drug, and Cosmetic
Act (FFDCA) the residues of arthropod pheromones resulting from the use
of these substances in solid matrix dispensers with an annual
application rate limitation of 150 grams AI/acre/year for pest control
in or on all raw agricultural commodities. However, until this
exemption from the requirements of a tolerance becomes a final rule
(anticipated in February 1994), a temporary tolerance and EUP
application will be required if the treated crop enters channels of
trade. A final rule establishing an exemption from the requirements of
a tolerance for inert ingredients of retrievably sized semiochemical
dispensers composed of polymeric matrix materials was published in the
Federal Register of December 8, 1993 (58 FR 64493).
V. Ecological Effects
Wildlife toxicity data indicate: high toxicity to aquatic
invertebrates and moderate toxicity to fish, but practically no
toxicity to birds tested. Data for one Lepidopteran pheromone indicate
low toxicity to avian bobwhite quail (acute oral LD50 of >2,000
mg/kg of body weight and dietary LC50 of >5,000 mg/kg). However,
this pheromone had a freshwater aquatic invertebrate (Daphnia magna)
LC50 of between the solubility limit of 0.2 mg/l and a calculated
LC50 of 0.58 mg/l. Observations of oily surface films at higher
test concentrations confirmed the low solubility of the test material.
The conclusion was that this pheromone was highly toxic to Daphnia and
that the calculated LC50 supported this conclusion. Whether the
mortality was due to the pheromone in solution or a film on the water
was not determined. Another Lepidopteran pheromone was found to be
moderately toxic to both Daphnia magna (LC50 8.6 mg/l) and the
freshwater rainbow trout (LC50 5.9 mg/l). These results are
sufficient to demonstrate the potential toxicity of Lepidopteran
pheromones to nontarget aquatic organisms.
Although pheromones may be in matrix dispensers, rates of
dissociation from matrices into water are not known. Refined petroleum
oils which form films at the water surface are registered by the Agency
as pesticides for control of mosquito larvae and pupae. Pesticidal
oils, which may comprise some of these products, kill by arresting
invertebrate respiration and affect interfacial tension at the water
surface upon which various arthropods depend for functions including
feeding, movement, and reproduction. To minimize the potential toxic
effects on aquatic organisms, the pheromone formulations in solid
polymeric matrix retrievably sized dispensers should be for terrestrial
use only and the experimental use should not include use in or around
marshes, swamps, rivers, streams, ponds, lakes, estuaries, flood
plains, or drainage ditches. They should not be allowed to wash or
drain into water.
Despite the toxicity to aquatic organisms from pheromones, EPA
believes that risks to aquatic organisms for tests conducted under the
conditions outlined in this notice are low. Pheromones in solid matrix
dispensers would not be expected to be used in water. In addition, many
of the solid matrix dispensers of the type covered by this policy are
typically affixed to trees or plants or other fixed objects, and thus,
are not likely to end up in bodies of water.
Broadcast application is not included in this notice because the
Agency does not have sufficient information on the levels of exposure
from pheromones which are broadcast.
VI. Solid Matrix Dispensers
Solid matrix dispensers, as defined in this notice, include, but
are not limited to: Rubber septa dispensers, trilaminate sheets, tapes,
tags, wafers, macrocapillary devices, such as long tubes or fibers,
twist ties, or ropes which are placed by hand in the field and are of
such and construction that they are readily seen. This policy does not
apply to the following formulations: Liquid flowables, microcapsules,
microcapillary straws, granular powder, flakes, or confetti
formulations which are sprayed or broadcast over an area; and cigarette
filters or unprotected ropes which generally contain the active
ingredient on the outer surface of the unit. The dispensers must not be
of a size, odor, taste or have other characteristics making them
attractive to wildlife that potentially could collect or eat them.
Devices like netting, webbing, loose filaments, and adhesives capable
of trapping or ensnaring nontarget organisms such as birds also would
not be covered by this policy. If inadvertently eaten, these dispensers
should be nontoxic and readily pass through an animal digestive system
without causing blockage or puncture.
VII. Agency Determinations
EPA has determined, pursuant to 40 CFR 172.3, to expand the land
use limitation for testing for pesticidal value without the need for an
EUP from 10 acres to 250 acres for arthropod pheromones in solid matrix
dispensers using no more than 150 grams AI/acre/year. This
determination is based both on a finding that tests conducted under the
conditions outlined will not cause unreasonable adverse effects on the
environment and on EPA's belief that it is necessary to test pheromones
in solid matrix dispensers on large acreages (i.e., larger than 10
acres) to determine their value for pesticidal purposes. EPA retains
the authority under 40 CFR 172.3 to require EUP's, on a case-by-case
basis, for tests conducted on acreages smaller than 250 acres if EPA
determines that the test is not being conducted only for the purpose of
determining the pheromone's value for pesticidal purposes or if EPA
determines that the test may cause unreasonable adverse effects on the
environment in the absence of agency oversight in the form of an EUP.
Today's notice only addresses EPA's policy with regard to EUP's for
pheromones in solid matrix dispensers. This notice does not in any way
obviate the need to obtain a tolerance under the FFDCA before using a
pheromone product for food or feed use. EPA intends to address use of
pheromones in solid matrix dispensers on food or feed crops with an
exemption from the requirement for a tolerance under FFDCA. Such a
proposed exemption was published in the Federal Register of December 8,
1993 (58 FR 64538). Moreover, EPA has published a final rule exempting
certain inert ingredients used in solid matrix dispensers from the
requirement of tolerance (December 8, 1993, 58 FR 64493).
Today's notice in no way affects the need to obtain an EUP for
tests conducted on more than 10 acres with formulations of pheromones
products other than those described in the notice (i.e., pheromone
formulations which are physically smaller than solid matrix dispensers,
such as sprayables). EUP's will continue to be required for tests
conducted on more than 10 acres using non-solid matrix dispenser
formulations.
EPA currently is considering whether to take additional actions to
grant further regulatory relief for other types of pheromone products.
If EPA determines that any such regulatory relief is warranted, EPA
would announce such a decision in a future Federal Register notice.
VIII. References
(1) Spittler, T. D.; Leichtweis, H. C.; Dennehy, T. J. (1988).
Biorational Control of Crop Pest by Mating Disruption; Residue Analyses
of Z-9-Dodecen-1-yl Acetate and Z-11-Tetradecenyl-1-yl Acetate in
Grapes. In: Biotechnology for Crop Protection, P. Hedin, J. J. Menn and
R. Hollingworth (eds.) ACS Symposium Series, 379:430-436.
(2) Spittler, T. D., Leichtweis, H. C., Kirsch, P. (1992).
Exposure, Fate and Potential Residues in Food of Applied Lepidopteran
Pheromones. In: Insect Pheromones and Other Behaviour-Modifying
Chemicals: Application and Regulation, R. L. Ridgeway, M. Inscoe and H.
Arn (eds.), BCPC Monograph No. 51, pp. 93-108.
Dated: January 19, 1994.
Stephanie R. Irene,
Acting Director, Registration Division, Office of Pesticide Programs.
[FR Doc. 94-1615 Filed 1-25-94; 8:45 am]
BILLING CODE 6560-50-F
