 

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:

[Verdesian Life Sciences, LLC]

[Insert petition number]

	EPA has received a pesticide petition ([insert petition number]) from
[Verdesian Life Sciences, LLC], [1001 Winstead Drive, Suite 480, Cary,
NC 27513] 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,
calcium, 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, [Verdesian
Life Sciences, LLC] has submitted the following summary of information,
data, and arguments in support of their pesticide petition. This summary
was prepared by [Verdesian Life Sciences, LLC] 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. [Verdesian Life Sciences, LLC]  Petition Summary

	[Insert petition number] 

A. Product Name and Proposed Use Practices

	[Calciphite is proposed as a pre- and post-harvest treatment on all
food commodities when used in accordance with good agricultural
practices and in or on potatoes when applied as a post-harvest treatment
at 35,600 ppm or less phosphorous acid.]

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 pesticide products registered by EPA as a pre-
and post-harvest agricultural fungicide.  These products as well as the
calcium salt of phosphorous acids are also used 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- and post-harvest application of
fungicides containing salts of phosphorous acid as active ingredients. 
Therefore, no magnitude of residue data, nor is an analytical method for
the determination of residues required.]

	3. A statement of why an analytical method of detecting and measuring
the levels of the pesticide residue are not needed. [Phosphorous acid is
currently exempt from tolerance; therefore, an analytical method is not
required by EPA.]

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
for pre- and post-harvest application of phosphorous acid in or on all
food commodities when used as an agricultural fungicide.  

EPA has recognized the chemical and biological equivalence of calcium,
sodium and potassium phosphorous acid salts, which is based on classical
inorganic chemistry.  Both the alkali (potassium and sodium) and
alkaline (calcium) earth metal salts are fully ionized in aqueous
solution to both their cationic and anionic components.  The only
difference between calcium and potassium is the valence of the cation.

Potassium and calcium salts derived from acids (e.g., sulfates,
phosphates, phosphites, hydrochlorides, carbonates, etc.) are widespread
in nature as mineral constituents of soil and rocks.  Both calcium and
potassium are non-toxic and are essential for the well-being of human
metabolism and homeostasis.  Additionally, in support of the biological
equivalence of mono- and di-potassium and calcium phosphite salts, it
should be taken into account that minute residues of these salts, if
ingested, would generate, due to the hydrochloric acid in the highly
acidic human stomach, minute quantities of phosphorous acid and
potassium and calcium chlorite salts.  In minute quantities, neither
potassium chloride nor calcium chloride, would be expected to be toxic
since both are categorized as EPA Class III toxicity.

Thus based on the comparable biological equivalence of the fully ionized
mono- and di-potassium and calcium phosphite salts, it follows that the
toxicology and properties of mono- and di-potassium salts can be bridged
to the calcium salts.  

For the purposes of this tolerance exemption amendment, Verdesian Life
Sciences, LLC is relying upon data and/or information previously
submitted to EPA, and also on the EPA reassessments recently completed
to add post-harvest uses.  Additionally, Verdesian Life Sciences, LLC is
also relying upon any publicly available data and information that EPA
used on phosphoric acid, which is chemically and structurally similar to
phosphorous acid.  The Agency stated that it believes that in
combination, the data and other information relied upon for the existing
tolerance exemption, supports its conclusion that there is reasonable
certainty of no harm that will result from the pre- and post-harvest
uses of phosphorous acid when used according to the recommended
application rate.  Additionally, based on Federal Register comments from
EPA, there is further support that there is reasonable certainty of no
harm that will result from the post-harvest treatment with a phosphorous
acid calcium salt end-use product.

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. Verdesian Life Sciences, LLC is relying upon acute
toxicity studies that were conducted with a 99% solution (Fungi-Phite DF
MUP, EPA Reg. No. 73771-6).  The toxicological profile of Fungi Phite DF
is briefly summarized as follows: 

Acute oral (rat) toxicity: LD50 2661 mg/kg body weight (bw). 

Acute dermal (rat) toxicity: LD50 >5,050 mg/kg bw. 

Acute inhalation (rat) toxicity: LC50 >0.66 mg/l.  

Primary eye irritation (rabbit): The product was found to be moderately
irritating to the eyes of rabbits.  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 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, 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. [In the Federal Register Notice dated October 5,
2000 (65 FR 59346) (FRL-6599-1), EPA noted the establishment of an
exemption from the requirement of a tolerance for residues of
phosphorous acid and its ammonium, sodium and potassium salts in or on
all food commodities when used as an agricultural fungicide on food
crops.  This regulation eliminated the need to establish maximum
permissible levels for residues of phosphorous acid and its ammonium,
sodium and potassium salts.

On August 23, 2006, in the Federal Register (71 FR 36731-36736) (FRL
8084-3), EPA established an exemption from the requirement of a
tolerance for residues of phosphorous acid and its ammonium, sodium, and
potassium salts in or on all food commodities to allow for post-harvest
application to stored potatoes at 35,600 ppm or less of phosphorus acid.
 The regulation eliminated the need to establish maximum permissible
levels for residues of phosphorous acid and its ammonium, sodium and
potassium salts.

As previously noted, calcium salts of phosphorus acid are similar in
functionality to other salts, in particular potassium salts.  The key
difference between the two salt types is their oxidations states, which
should not be a factor, as the main pesticidal component of the active
ingredient are the phosphites, not their cations.  The Agency feels that
it is logical for the tolerance exemption to include other salts of
phosphorus acid that are similar in composition and residue profile.]

	i. Food. [Phosphorous acid rapidly dissociates to form hydrogen and
phosphite ions when applied to growing crops in the environment and
therefore, it has already been established that no dietary exposure is
expected from pre-harvest applications.  The degradates of phosphorous
acid, hydrogen and phosphite ions are important nutrients for plants and
animals.  Formation of these degradates however, may be compromised when
phosphorous acid is applied as a post-harvest treatment.  Since
post-harvest treatment of phosphorous acid to most agricultural
commodities is likely to occur in indoor storage facilities, the
oxidation process of phosphorous acid will most likely be slowed down. 
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 believes that when
phosphorous acid is used as a post-harvest treatment at the recommended
application rate, the remaining residues of phosphorous acid will not
increase toxicity or add any new dietary exposure or risks and the
toxicity of phosphorous acid would still be considered to have a low
toxicity and will be considered safe.]

	ii. Drinking water. [No significant drinking water exposure is expected
to result from phosphorous acid when applied as a pre- and post-harvest
treatment to agricultural commodities, because phosphorous acid rapidly
dissociates to form hydrogen and phosphite ions and is very soluble in
water.  The hydrogen ions affect pH, but this is moderated by natural
means.]

	2. Non-dietary exposure. [There are no residential, school or day care
uses proposed for this product.  Since the proposed use pattern is for
pre- and post-harvest treatment on agricultural commodities, 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 agricultural commodities and
potatoes 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 tolerance exemption 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.]

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 pre- and
post-harvest treatment to agricultural commodities.  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
pre- and post-harvest treatment to agricultural commodities.  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 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

	[EPA has established a tolerance exemption for phosphorous acid under
40 CFR 180.1210.  All pre- and post-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 phosphorous
acid by the Codex Alimentarius Commission (CODEX).]

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