Document ID: EPA-HQ-OPP-2008-0606-0002
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2008-11-12T05:00Z

<EPA BIOPESTICIDES AND POLLUTION PREVENTION DIVISION COMPANY NOTICE OF
FILING FOR PESTICIDE PETITIONS PUBLISHED IN THE FEDERAL REGISTER  >

<EPA Biopesticides and Pollution Prevention Division contact: [Linda
Hollis (703) 308-8733]>

 

<INSTRUCTIONS:  Please utilize this outline in preparing the pesticide
petition.  In cases where the outline element does not apply, please
insert “NA-Remove” and maintain the outline. Please do not change
the margins, font, or format in your pesticide petition. Simply replace
the instructions that appear in green, i.e., “[insert company
name],” with the information specific to your action.>

<SUBMISSION: E-mail the completed template to: hollis.linda@epa.gov.>

<TEMPLATE:>

<[Luxembourg-Pamol Inc.]>

<[Insert petition number]>

<	EPA has received a pesticide petition ([insert petition number]) from
[Luxembourg-Pamol Inc.], [5100 Poplar Ave., Suite 2700, Memphis, TN
38137] 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 part 180.>

<(Options (pick one)>

<	1. by establishing a tolerance for residues of [NA-Remove]>

<	2. to establish an exemption from the requirement of a tolerance for
[NA- Remove]>

	

<	3. to establish an amendment/expansion of an existing tolerance
exemption for the>

<(Options (pick one)>

<	1. microbial pesticide  [NA-Remove]>

<	2. biochemical pesticide [phosphorous acid and its ammonium, sodium,
and potassium salts]>

	

<	3. plant-pesticide [NA-Remove] in or on [NA-Remove].>

<	Pursuant to section 408(d)(2)(A)(i) of  FFDCA, as amended,
[Luxembourg-Pamol Inc.] has submitted the following summary of
information, data, and arguments in support of their pesticide petition.
This summary was prepared by [Luxembourg-Pamol Inc.] and EPA has not
fully evaluated the merits of the pesticide petition. The summary may
have been edited by EPA if the terminology used was unclear, the summary
contained extraneous material, or the summary unintentionally made the
reader conclude that the findings reflected EPA’s position and not the
position of the petitioner.>

<I. [Luxembourg-Pamol Inc.]  Petition Summary>

<	[Insert petition number]>

<A. Product Name and Proposed Use Practices>

<	[ProPhyt-PHC is proposed as a post-harvest agricultural fungicide
treatment on citrus. Anticipated application of phosphorous acid and it
salts to citrus will be carried out as a post-harvest drench or dip. The
use rate for these types of applications is projected to be as a
4,000-12,000 ppm solution. The phosphorous acid may also be added to the
hot water solution which is applied prior to waxing.]>

<B. Product Identity/Chemistry>

<	1. Identity of the pesticide and corresponding residues. [Phosphorous
acid and its ammonium, sodium, and potassium salts are active
ingredients in numerous products registered by EPA as fungicides.  These
products are used also as fertilizer compounds in significant quantities
in the U.S.]>

<	2. Magnitude of residues at the time of harvest and method used to
determine the residue. [Phosphorous acid is a naturally-occurring
compound, commonly found as a salt.  Phosphorous is a required substance
in the metabolism of all living organisms. It is an integral building
block of both ribonucleic (RNA) and deoxyribonucleic acids (DNA).
Phosphates also play a critical role in energy transfer in metabolic
pathways. The fact that phosphate plays a key role in the metabolism of
all living cells, it completely dissociates in water, and its low acute
toxicity are among the reasons why EPA does not regulate residues of
phosphorous acid arising from the pre-harvest application of fungicides
containing salts of phosphorous acid as active ingredients. As such,
Luxembourg-Pamol Inc. does not have magnitude of residue data, nor is an
analytical method for the determination of residues appropriate.]>

<	3. A statement of why an analytical method of detecting and measuring
the levels of the pesticide residue are not needed. [Luxembourg-Pamol
Inc. is seeking to amend the current tolerance exemption for phosphorous
acid and its salts. As such, an analytical method is not provided.]>

<C. Mammalian Toxicological Profile>

<	[The toxicity profile for phosphorous acid and its ammonium, potassium
and sodium salts has already been assessed for its pesticidal use by the
Agency and published in support of the tolerance exemption for residues
of phosphorous acid in or on all food commodities when used as an
agricultural fungicide. For the purposes of this tolerance exemption
amendment, the Agency has relied on the data and/or information
previously submitted and has reassessed that data in order to evaluate
the request to add post-harvest uses to the tolerance exemption.
Additionally, the Agency has reviewed publicly available data and
information on phosphoric acid, which is chemically and structurally
similar to phosphorous acid. The Agency has stated that it believes that
in combination, the data and other information relied upon for this
tolerance exemption supports its conclusion that there is reasonable
certainty of no harm that will result from the post-harvest treatment of
potatoes with phosphorous acid when used according to the recommended
application rate.>

In the original tolerance exemption publication, the Agency also pointed
to the fact that human toxicity from consumption of crops treated with
phosphorous acid fertilizers would be well known, if it occurred. The
lack of reported dietary toxicity from consumption of crops treated with
phosphorous acid fertilizers is supporting evidence that use of
phosphorous acid applications as a fungicide should not result in
dietary toxicity. EPA does not require residue chemistry data in cases
where the toxicity is so low and the use pattern will result in
exposures much lower than the highest dose tested without an effect. 

Acute toxicity. To support the tolerance established for post-harvest
application to stored potatoes, EPA relied on acute toxicity data that
was developed with a 53.8% end-use product.  Luxembourg proposes to
conduct the risk assessment for the current tolerance exemption petition
based on acute toxicity studies that were conducted with a 54.5%
solution (ProPhyt, EPA Reg. No. 42519-22).  These data were submitted in
support of Luxembourg’s current EPA registrations containing potassium
salt of phosphorous acid. The toxicological profile of the 54.5%
solution of phosphorous acid is briefly summarized as follows: 

Acute oral (rat) toxicity: LD50 >5,000 mg/kg body weight (bw). The acute
oral toxicity was found to be greater than the highest tested dose.  No
deaths occurred. Normal gains in body weight were observed and no
abnormalities were noted at necropsy. There were no adverse effects
reported at 5,000 mg/kg bw. The test material is classified as Toxicity
Category IV for acute oral toxicity, which is the lowest category
available, representing low toxicity.

Acute dermal (rat) toxicity: LD50 >4,000 mg/kg bw. No deaths were
recorded. No signs of systemic toxicity or skin irritation were noted.
All animals showed expected weight gain and no abnormalities were noted
at necropsy.  There were no adverse effects reported at 4,000 mg/kg bw. 
A similar product with a concentration of 53.8% that was previously
relied upon by the Agency for the post-harvest potato risk assessment
did not show dermal toxicity in rats when a dose of 5,000 mg/kg was
used.  According to these findings (see Federal Register, Vol. 71, No.
163; August, 2006), the test material is classified as Toxicity Category
IV for acute dermal toxicity, which is the lowest category available,
representing low toxicity. 

 

Acute inhalation (rat) toxicity: LC50 >5.05 mg/l.  All rats recovered
from hunched posture, pilo-erection, and red/brown staining around the
eyes and snout. Rats appeared normal one day after the exposure. Normal
body weight gain was noted. With the exception of one male, which showed
dark foci on the lungs, no abnormalities were observed at necropsy.  The
test material is classified as Toxicity Category IV for acute inhalation
toxicity, which is the lowest category available, representing low
toxicity.

Primary eye irritation (rabbit): The product was found to be slightly
irritating to the eyes of rabbits.  All ocular effects cleared within
seven days.  The test material is classified as Toxicity Category III
for eye irritation.

Acute dermal irritation (rabbit): The product did not produce any dermal
irritation in rabbits.  The test material is classified as Toxicity
Category IV for dermal irritation.

Skin sensitization (guinea pigs): The product was not positive in guinea
pigs when tested for skin sensitization [the sensitization rate was 0%
(0/8)] and is classified as a non-sensitizer. 

Developmental, reproductive, chronic and carcinogenic effects.  As part
of the original tolerance exemption that was published on October 5,
2000 [65 FR 59348], and again, in the further assessment of the
information presented in the tolerance exemption to allow for
post-harvest application to stored potatoes, EPA accepted the following
rationale regarding the potential for phosphorous acid and its salts to
cause long-term developmental, reproductive, chronic, or carcinogenic
effects: There is adequate information available from literature sources
to characterize the toxicity of phosphorous acid. Phosphorous acid can
affect human health through inhalation of mist, ingestion, and contact
with the skin and eyes. In a concentrated form, it will cause corrosive
effects (burns or irreversible damage) to the eyes, skin, throat,
digestive tract, upper respiratory tract and nose. Signs of overexposure
to this chemical are severe burning of eyes and skin, possible nausea
and vomiting, coughing, burning and tightness of the chest and shortness
of breath. Based on corrosivity and the current use patterns for the
mineral acids, EPA did not require these studies as part of the
Reregistration Eligibility Decision (RED) on the Mineral Acids (EPA
738-R-029; December 1993).]

<D. Aggregate Exposure>

<	1. Dietary exposure. [No dietary exposure is expected. When
phosphorous acid is applied to growing crops in the environment, it
rapidly dissociates to form hydrogen and phosphite ions. The fact that
the phosphorous acid at the time of post-harvest treatment has not been
oxidized to its degradates is clear and it is unknown how much this
oxidation process reduces the potential dietary exposure to phosphorous
acid under the conditions of post-harvest treatment. However, even with
these uncertainties, the Agency has stated that it believes that when
phosphorous acid is used as a post-harvest treatment at the recommended
application rate (on potatoes), the remaining residues of PA on stored
potatoes will not increase toxicity or add any new dietary exposure or
risks and the toxicity of phosphorous acid would still be classified in
category IV (which is low toxicity) and will be safe. This is also the
case with the much lower rates applied post-harvest to citrus.]>

<	i. Food. [The Agency has determined that post-harvest treatment of
phosphorous acid to stored potatoes at the typical application rate
evaluated by the Agency may reduce any new anticipated exposure to
phosphorous acid. However, even if dietary exposure is not reduced, the
Agency has stated that it believes, based on its reassessment of the
data and information, that post-harvest application of phosphorous acid
to potatoes is safe. The proposed application of phosphorous acid and
its ammonium, sodium and potassium salts as a post-harvest fungicide to
citrus, with a use rate of 4,000-12,000 ppm is three to nine-fold below
the established tolerance on potatoes. Moreover, dietary exposure to
phosphorous acid and its salts when applied to citrus is likely to be
significantly lower than dietary exposure from consumption of potatoes
because the rind of citrus fruit is far less commonly consumed than the
pulp and juice portions, while the Agency’s assessment of the
post-harvest use of phosphorous acid and its salts on potatoes assumed
that the entire potato (skin and flesh) would be consumed.]>

<	ii. Drinking water. [No significant drinking water exposure is
expected to result from phosphorous acid when applied as a post-harvest
treatment to citrus because phosphorous acid rapidly degrades, is very
soluble in water and is applied in storage facilities.]>

<	2. Non-dietary exposure. [There are no residential, school or day care
uses proposed for this product. Since the proposed use pattern is for
post-harvest treatment on citrus, the potential for non-occupational,
non-dietary exposures to phosphorous acid by the general population,
including infants and children, is highly unlikely. Further, even if
persons were exposed via the non-occupational route, the low toxicity
from a dilute application such as the one evaluated by the Agency on
potatoes and proposed on citrus is safe and the primary hazards
associated with concentrated phosphorous acid (corrosivity and
irritation) will be significantly reduced because the end use products
are diluted and the residues following application are very low.]>

<E. Cumulative Effects>

<	[In assessing both the pre-harvest tolerance exemption published in
2000 and the post-harvest potato tolerance in 2006, the Agency
considered all available information that related to the cumulative
effect of pesticide residues of  phosphorous acid and residues of other
materials having a common mechanism of toxicity. Especially important in
these assessments is the effect potential residues may have on infants
and children. The Agency concluded the following: BPPD (EPA) has
considered the potential for cumulative effects of phosphorous acid and
other substances in relation to a common mechanism of toxicity.
Phosphorous acid may share a common metabolic mechanism with other salts
of phosphorous acid (such as calcium); however, due to the low order of
toxicity and lack of reported dietary toxicity associated with the use
of phosphorous fertilizers on crops, no cumulative effect from the use
of phosphorous acid is expected. The proposed post-harvest application
rate on citrus is significantly below the tolerance levels allowed on
potatoes; therefore, there should be no risk of cumulative effects with
this material when applied post-harvest to citrus.]>

<F. Safety Determination>

<	1. U.S. population. [With respect to the potential for harmful effects
of phosphorous acid in the U.S. population and, in particular, the
segment of the population that includes infants and children, the Agency
has accepted the following rationale. Aggregate exposure to phosphorous
acid is expected to be minimal. There is very little potential for
exposure to phosphorous acid in drinking water and from non-dietary,
non-occupational exposures. This chemical will be applied post-harvest
to the rind of citrus which is not commonly consumed by any segment of
the population, especially infants or children. Once released into the
environment, the chemical rapidly dissociates to form hydrogen and
phosphite ions. The hydrogen ions affect pH, but this is moderated by
natural means. Many phosphite salts are generally recognized as safe
(GRAS). Therefore, the health risk to humans is negligible based on the
low toxicity of these ions and a low application rate for the active
ingredient, and one can conclude that there is a reasonable certainty
that no harm will result from aggregate exposure to phosphorous acid.]>

<	2. Infants and children. [With respect to infants and children, the
Agency has accepted the following rationale. Aggregate exposure to
phosphorous acid is expected to be minimal. There is very little
potential for exposure to phosphorous acid in drinking water and from
non-dietary, non-occupational exposures. This chemical will be applied
to agricultural food crops. Once released into the environment, the
chemical rapidly dissociates to form hydrogen and phosphite ions. The
hydrogen ions affect pH, but this is moderated by natural means. Many
phosphite salts are ‘GRAS.’ Therefore, the health risk to humans is
negligible based on the low toxicity of (the subject end-use product)
and these ions and a low application rate for the active ingredient. One
can conclude that there is a reasonable certainty that no harm will
result to infants and children from aggregate exposure to phosphorous
acid residues.]>

<G. Effects on the Immune and Endocrine Systems>

<	[In 2006, the Agency determined that there is no evidence that
phosphorous acid affects the immune system, functions in a manner
similar to any known hormone, or that it acts as an endocrine
disruptor.]>

<H. Existing Tolerances>

<	[As previously referenced, EPA has established a maximum tolerance
level of 35,600 ppm for use of phosphorous acid as a post-harvest
treatment of potatoes at 40 CFR 180.1210. All pre-harvest agricultural
food uses of phosphorous acid and its salts are exempt from the
requirement of a tolerance.]>

<I. International Tolerances>

<	[No maximum residue levels (MRLs) have been established for phophorous
acid by the Codex Alimentarius Commission (CODEX).]>

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