Potassium Silicate; Exemption from the Requirement of a Tolerance, 34267-34272 [E6-8939]
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Federal Register / Vol. 71, No. 114 / Wednesday, June 14, 2006 / Rules and Regulations
distribution of power and
responsibilities between the Federal
government and Indian tribes, as
specified in Executive Order 13175.
Thus, Executive Order 13175 does not
apply to this rule.
The Congressional Review Act, 5
U.S.C. 801 et seq., as added by the Small
Business Regulatory Enforcement
Fairness Act of 1996, generally provides
that before a rule may take effect, the
agency promulgating the rule must
submit a rule report, which includes a
copy of the rule, to each House of the
Congress and to the Comptroller General
of the United States. EPA will submit a
report containing this rule and other
required information to the U.S. Senate,
the U.S. House of Representatives, and
the Comptroller General of the United
States prior to publication of this final
rule in the Federal Register. This final
rule is not a ‘‘major rule’’ as defined by
5 U.S.C. 804(2).
List of Subjects in 40 CFR Part 180
Environmental protection,
Administrative practice and procedure,
Agricultural commodities, Pesticides
and pests, Reporting and recordkeeping
requirements.
Dated: June 6, 2006.
James Jones,
Director, Office of Pesticide Programs.
Therefore, 40 CFR chapter I is
amended as follows:
I
PART180—[AMENDED]
1. The authority citation for part 180
continues to read as follows:
I
Authority : 21 U.S.C. 321(q), 346a and 371.
2. Section 180.1269 is added to
subpart D to read as follows:
I
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§ 180.1269 Bacillus mycoides Isolate J on
sugar beets: exemption from the
requirement of a tolerance.
Bacillus mycoides isolate J is
temporarily exempt from the
requirement of a tolerance when used as
a fungicide for control of Cercospora
Leaf Spot (Cercospora beticola) on sugar
beets. This temporary exemption from
the requirement of a tolerance expires
and is revoked on December 31, 2007.
BILLING CODE 6560–50–S
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40 CFR Part 180
[EPA–HQ–OPP–2006–0299; FRL–8069–6]
Potassium Silicate; Exemption from
the Requirement of a Tolerance
IX. Congressional Review Act
[FR Doc. E6–9282 Filed 6–13–06; 8:45 am]
ENVIRONMENTAL PROTECTION
AGENCY
Environmental Protection
Agency (EPA).
ACTION: Final rule.
AGENCY:
SUMMARY: This regulation establishes an
exemption from the requirement of a
tolerance for residues of potassium
silicate in or on all food commodities
when applied/used as a fungicide,
insecticide or miticide so long as the
potassium silicate is not applied at rates
exceeding 1% by weight in aqueous
solution and when used in accordance
with good agricultural practices. PQ
Corporation 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 potassium silicate.
DATES: This regulation is effective June
14, 2006. Objections and requests for
hearings must be received on or before
August 14, 2006, 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–2006–0299. 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
https://www.regulations.gov, or, if only
available in hard copy, at the OPP
Regulatory Public Docket in Rm. S-4400,
One Potomac Yard (South Building),
2777 S. Crystal Drive, Arlington, VA.
The Docket Facility is open from 8:30
a.m. to 4 p.m., Monday through Friday,
excluding legal holidays. The telephone
number for the Docket is (703) 305–
5805.
FOR FURTHER INFORMATION CONTACT:
Carol E. Frazer, Biopesticides and
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34267
Pollution Prevention Division (7511P),
Environmental Protection Agency, 1200
Pennsylvania Ave., NW., Washington,
DC 20460–0001; telephone number:
(703) 308–8810; e-mail address:
frazer.carol@epa.gov.
SUPPLEMENTARY INFORMATION:
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 https://
www.regulations.gov, you may access
this Federal Register document
electronically through the EPA Internet
under the ‘‘Federal Register’’ listings at
https://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 https://
www.gpoaccess.gov/ecfr.
C. Can I File an Objection or Hearing
Request?
Under section 408(g) of 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
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provided in 40 CFR part 178. To ensure
proper receipt by EPA, you must
identify docket ID number EPA–HQ–
OPP–2006–0299 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 August 14, 2006.
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–2006–0299, by one of
the following methods:
• Federal eRulemaking Portal: https://
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 Building), 2777 S.
Crystal Drive, 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
telephone number for the Docket is
(703) 305–5805.
II. Background and Statutory Findings
In the Federal Register of July 27,
2005 (70 FR 43417) (FRL–7719–5), EPA
issued a notice pursuant to section
408(d)(3) of FFDCA, 21 U.S.C.
346a(d)(3), announcing the filing of a
pesticide tolerance petition (PP 5F6905)
by PQ Corporation, P.O. Box 840 Valley
Forge, PA 19482–0840. The petition
requested that 40 CFR part 180 be
amended by establishing a temporary
exemption from the requirement of a
tolerance for residues of potassium
silicate. This notice included a
summary of the petition prepared by the
petitioner PQ Corporation. There were
no comments received in response to
the notice of filing.
Section 408(c)(2)(A)(I) of FFDCA
allows EPA to establish an exemption
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 FFDCA
defines ‘‘safe’’ to mean that ‘‘there is a
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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), 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), 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 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 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.
Potassium silicate is a synthetic
compound that is chemically the
potassium salt of silicic acid. It is
produced by combining pure silica sand
(SiO2) and potash (K2CO3 or NaCO3).
Silicic acid salts (i.e., silicates) are the
most common form of silicon. For the
purposes of this tolerance exemption,
the Agency has relied on the extensive
body of knowledge, data and/or
information from the public literature as
submitted by PQ Corporation and as
researched by the Agency which
document the similarity of silica (also
known as silicon dioxide) and
potassium silicate and support the
conclusion that there is reasonable
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certainty of no harm that will result
from the use of potassium silicate as an
agricultural pesticide.
Silicon dioxide (silica) has been
assessed for its pesticidal uses by the
Agency and it was determined that the
toxicity of this compound is moderate to
low and therefore, the human health
risk is low and not unreasonable.
Further, silicon dioxide is recognized by
the Food and Drug Administration
(FDA) to be a Generally-Recognized As
Safe (GRAS) substance, as a food
additive (21 CFR 182.90 and 182.1711).
Comprehensive reviews and risk
assessments have been conducted on
silicon dioxide (silica) and its related
soluble silicates with regard to its
toxicity to human health and have
concluded that silica and its soluble
silicates (potassium silicate) are low in
toxicity and the primary hazard of
concern is the corrosive nature of the
compound. The corrosive nature of
potassium silicate is not of a concern
when used as a very dilute solution (less
than or equal to 1%). The soluble
silicates include: potassium silicate,
sodium silicate and sodium
metasilicate, the latter of which the
Agency has exempted in diluted form
from the requirement of a tolerance for
use on all food commodities.
Additionally, the FDA has determined
that sodium silicate and potassium
silicate can be used interchangeably
which substantiates information in the
public literature that the compounds are
very similar.
The data submitted and reviewed on
the end use pesticide product
containing 29.1% w/w potassium
silicate caused moderate to low dermal
irritation and is classified as an eye
irritant due to the high pH of the
product. When used as a pesticide
(fungicide, insecticide and miticide) the
active ingredient is effective at very low
concentrations (less than or equal to
1%) and thus the dilution of the active
ingredient would reduce the risks to
pesticide users. Labeling of such
products with the appropriate protective
clothing, gloves and eyewear would
mitigate the risk of exposure to
potassium silicate on pesticide
applicators. Potassium silicate residues
which may result from its use as an
agricultural pesticide would be reduced
by washing or processing treated
commodities before their consumption;
this point is supported by the water
solubility of potassium silicate and the
possibility of it being washed off treated
surfaces by rainfall in the field. Further,
potassium silicate is neutralized by
stomach acid and primarily excreted in
the urine.
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Federal Register / Vol. 71, No. 114 / Wednesday, June 14, 2006 / Rules and Regulations
The components of potassium silicate
are potassium and silicon. Potassium is
found in the environment and is an
essential element in human and plant
nutrition. It is found in many fruits and
vegetables consumed by humans. A
common soil plant nutrient and
fertilizer (as K2O), potassium comprises
approximately 2.59% of the Earth’s
crust by weight. The primary source of
naturally-occurring soluble potassium is
from the weathering of potassium
containing minerals.
Silicon is ubiquitous in the
environment, the second most abundant
element in the lithosphere after oxygen.
A nutritional element, silica is required
for proper and strong growth of
mammalian bones. Silica is present
naturally in all plant stems and is
present in larger amounts in crops such
as rice and sugar cane. It comprises
approximately 31% of the Earth’s crust
by weight and is present as dissolved
silica, amorphous silica in the solid
phase (for example, silica and silica gel
(FDA GRAS chemicals), and silica
bound to organic matter. In the normal
range of soil pH, silicic acid is the major
silicate in soil water. In natural waters
most dissolved silica results from
weathering of silicate minerals.
Research demonstrates that commercial
soluble silicates rapidly degrade to
molecular forms that are
indistinguishable from natural dissolved
silica (IUCLID, 1995). Beach sand, for
example is comprised of nearly 100%
silica (Crop Protection handbook, 2003).
Additionally, silica is approved by the
FDA for use as an anti-caking agent in
food.
Potassium silicate immediately breaks
down in the presence of water to the
potassium and silicate ions which are
indistinguishable from natural
components. As stated above, potassium
silicate is produced by direct fusion of
precisely measured portions of pure
silica sand (SiO2) and potash (K2CO3) in
a fired furnace at temperatures above
1000°C. Solutions of potassium silicate
are produced by dissolving alkali silica
lumps in water at elevated
temperatures. Potassium silicate is
classified as GRAS by FDA (21 CFR
182.90 and 21 CFR 182.1711) for limited
use in canned potable water as a
corrosion inhibiting agent and the EPA
has exempted potassium silicate from
the requirement of a tolerance when
used as an inert ingredient, a surfactant,
emulsifier, wetting agent, stabilizer, or
inhibitor (40 CFR 180.910). Data and/or
information from the public literature
demonstrates a long history of safe use
of fertilizers containing potassium and
silica. (HERA 2005, NOSB/TAP, 2003
and the Silicon Dioxide and Silica Gel
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RED EPA, 1991, Kant, T., et al, 2003,
Savant N.K., et al., 1999). Fertilizers
used in the agricultural industry contain
plant nutrients and micronutrients such
as potassium and silicon. Potassium
silicate is approved by the USDA as a
fertilizer for conventional agriculture
and is used on a variety of crops
including rice, wheat, barley, sugar
cane, melons, grapes and cucurbits
(USDA/ERS, 2002, NOSB/TAP, 2003).
As mentioned above, silicon dioxide
and its soluble silicates which include
potassium silicate have been fully
characterized and assessed by the
Agency and other notable resources and
it has been concluded that silicon
dioxide and its related soluble silicates
exhibit moderate to low toxicity, the
Agency has therefore concluded there is
a reasonable certainty of no harm
resulting from the use of potassium
silicate as an agricultural pesticide. This
determination is based on information
from the literature which as stated
above document the similarity of silica
(also known as silicon dioxide) and
potassium silicate. This information
combined with the fact that the
components of potassium silicate
(potassium and silica) are already
naturally present in the stems of all
plants (silica) and naturally in foods
supports the Agency’s conclusion that
there is a reasonable certainty of no
harm resulting from the use of
potassium silicate as an agricultural
pesticide and exposure from the use of
potassium silicate as a pesticide will not
add to the exposure already present
from its natural occurrence, its presence
in foods, in the human diet and in the
environment.
A. Acute Toxicity
The registrant did not submit any
toxicity data testing the technical grade
of the active ingredient. Data waivers
were requested by the registrant and
granted by the Agency based on the
body of extensive knowledge from the
public literature and as researched by
the Agency. The toxicity of the soluble
silicates via oral toxicity, teratogenicity
and genotoxicity were tested on the
Technical Grade of the Active
Ingredient (TGAI) and reported and the
Agency has relied upon this information
to support its decision to grant the
waiver requests for these studies. Acute
toxicity data were submitted using the
end-use product as the test material
which is approximately aB dilution of
the technical grade of the active
ingredient. Requests for data waivers
were granted for additional toxicity
studies described below. These data
waiver requests were granted based on
the findings from comprehensive
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reviews and risk assessments conducted
on silicon dioxide (silica) and its related
soluble silicates (potassium silicate)
with regard to its toxicity to human
health and the conclusion that silicon
dioxide and its related soluble silicates
have moderate to low toxicity, and
therefore, the Agency concludes that
there is a reasonable certainty of no
harm resulting from the use of
potassium silicate. The data submitted
and waivers that were granted are as
follows:
Acute oral rat OPPTS Harmonized
Guideline 870.1100; Master Record
Identification (MRID) Number
46434903). LD50 = 5,000 milligrams/
kilogram (mg/kg) (29.1% potassium
silicate aqueous solution). The test
material is classified as a Toxicity
Category IV for acute oral toxicity and
demonstrates that a dilution of the
active ingredient to a level that is
comparable to the concentration of
potassium silicate in the proposed enduse product eliminates the potential of
the active ingredient to cause acute
toxic effects. There were no adverse
effects reported at 5,000 mg/kg.
Technical grade of the active
ingredient. A request to waive this data
requirement was submitted by the
registrant. The Agency has granted this
data waiver based on: (1) Data from the
public literature which shows soluble
silicates have a moderate to low acute
toxicity by the oral route (HERA 2005),
(2) potassium silicate, a soluble silicate
that is both chemically and
toxicologically similar to silicon dioxide
(silica) which has been fully
characterized, assessed, and therefore
determined by the Agency that silicon
dioxide and its related soluble silicates
pose no unreasonable adverse effects to
human health when used as an
agricultural pesticide and (3) potassium
and silica are already present in the
human diet as they are contained
naturally in various crops.
Acute dermal rat OPPTS 870.1200;
(MRID 4643902). LD50 = 5,000 mg/kg
(29.1% potassium silicate aqueous
solution). The test material is classified
as a Toxicity Category IV for acute
dermal toxicity and demonstrates that a
dilution of the active ingredient to a
level that is comparable to the
concentration of potassium silicate in
the proposed end use product will be
moderately irritating to the skin.
Technical grade of the active
ingredient. Section 158.690(c)(2)(I)
states this test is not required if the test
material is corrosive to skin. Therefore,
this test was not required. However, this
active ingredient is classified Toxicity
Category I on the basis of potential
dermal irritation effects.
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Acute inhalation rat OPPTS 870.1300;
(MRID 46434906). LC50 >2.06 milligrams
per liter (mg/L) (29.1% potassium
silicate aqueous solution). The test
material is classified as a Toxicity
Category IV for acute inhalation toxicity
and demonstrates that a dilution of the
active ingredient to a level that is
comparable to the concentration of
potassium silicate in the proposed end
use product will not cause acute
inhalation effects at greater than 2.06
mg/L.
Technical grade of the active
ingredient. This test is only required if
the product consists of a respirable
material. Since potassium silicate does
not consist of a respirable material
under normal conditions of use, this test
is not required.
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B. Genotoxicity, Immune Response,
Mutagenicity, Developmental,
Oncogenicity, Subchronic and Chronic
Toxicity
The applicant requested to waive the
data requirements below and submitted
a summary of public literature to satisfy
the data requirements for 90–day oral
toxicity (OPPTS 870.3100), genotoxicity
(OPPTS 870.5100; 870.5300; 870.5375),
teratogenicity (OPPTS 870.3700) and
immunotoxicity (OPPTS 880.3550) for
the active ingredient. Potassium silicate
waiver requests were submitted (MRID
46434701). As mentioned above, the
Agency has determined that the data
requirements were met by the
submission of public literature. The
public literature demonstrates that
potassium silicate has low toxicity by
the oral route when tested as the TGAI
because potassium silicate is
neutralized by stomach acid and
primarily excreted in the urine. The
high pH of the pesticide product may
cause eye and skin irritation to humans.
However, risks to humans will be
reduced by dilution of the pesticide
product and further mitigated by the use
of protective personal equipment.
IV. Aggregate Exposures
In examining aggregate exposure,
section 408 of FFDCA directs EPA to
consider available information
concerning exposures from the pesticide
residue in food and all other nonoccupational 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. Potassium is found in the
environment and is present in the cells
of humans and plants and is therefore
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an essential element in human and
plant nutrition. It is found in many
fruits and vegetables consumed by
humans. Humans require an adequate
supply of potassium from consumption
of foods for healthy growth and
development. Humans consume daily
many sources of potassium, including a
variety of fruits, vegetables and
beverages such as barley, bananas,
plums, apricots, strawberries, oranges,
apples, grapes, spinach, potatoes,
carrots, celery, tomatoes, lettuce,
cucumbers, milk, fruit juices, coffee,
white wine and light beers, etc. The
average potassium content of the above
fruits and vegetables ranges from 2.4 K/
kg (tomato) - 3.7 K/kg (banana).
As mentioned above, potassium is a
common soil plant nutrient and
fertilizer (as K2O), and comprises
approximately 2.59% of the Earth’s
crust by weight. Silicon is a ubiquitous
mineral nutrient in the environment
(soil, water) and the second most
abundant element in the lithosphere
after oxygen. A nutritional trace
element, silicon is required for proper
and strong growth and development of
mammalian bones. In plants, silicic acid
(Si(OH)4) is rapidly absorbed. Once
absorbed, silicic acid is readily
circulated throughout the plant and
deposited as silicon dioxide.
Consequently exposure to soluble silica
occurs on a daily basis and is a property
of all plant products in the human diet.
The concentration of silicon in
vegetable plants varies greatly with
cereals and grasses containing the
highest concentrations (0.2-2.0%).
Good agricultural practice when using
potassium silicate means it will most
likely be used in aqueous solutions
because application of pure potassium
silicate to crops is likely to be corrosive
to crops since the active ingredient is a
known corrosive. When applied to food
crops at concentrations not to exceed
1% by weight of potassium silicate in
aqueous solution, it is highly unlikely
there will be any residues of
significance in or on food.
Further dilution by tank mixing with
water of a pesticide product containing
the active ingredient at 29% w/w of
potassium silicate before application of
the pesticide reduces the amount of
active ingredient (to concentrations not
to exceed 1% active ingredient) that will
be on the crop.
Furthermore, potassium silicate
breaks down in the presence of water to
potassium and silicate ions, both of
which occur naturally in animals and
plants. Concentrations of potassium
silicate as a pesticide in foliar sprays
and nutrient solutions are dominated by
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silicic acid, which as mentioned above,
is readily absorbed by plants.
Therefore, given the use dilution of
the pesticide product and other good
agricultural practices as required on
product labels, the likely dietary
exposures to potassium silicate from the
pesticidal uses are not expected to add
significantly to those levels of
potassium silicate already found in
foods, beverages, and in drinking water
as a result of conventional agriculture
and its natural occurrence in the
environment.
2. Drinking water exposure. Because
potassium silicate breaks down into
potassium and silicate ions in the
presence of water, there will be no
residues of potassium silicate in
drinking water from its use as a
pesticide. The Agency does not expect
the resulting potassium and silicate ions
resulting from this breakdown process
will add significantly to the level of
potassium and silica presently in the
water.
Potassium and silicon dioxide are
ubiquitous in the environment, and the
uses of soluble silicates are widespread
in dishwashing soaps, other soaps, and
detergents. Potassium silicate is
classified by the FDA as a GRAS
substance (21 CFR 182.90 and 21 CFR
182.1711) for limited use in canned
potable water as a corrosion inhibiting
agent. Moreover, both potassium and
silicon are already present in natural
waters. The potassium (natural) content
of drinking water varies greatly
depending on its source and may be
larger in mineral and spa waters than
ordinary tap water. On average, the
daily water consumption by adults
supplies less than 0.1% of their
potassium intake (European Fertilizer
Manufacturers Association, 1997). In
natural waters most dissolved silica
results from weathering of silicate
minerals and it has been demonstrated
that commercial soluble silicates rapidly
degrade to molecular forms that are
indistinguishable from natural dissolved
silica. Therefore, because of the levels at
which potassium and silica (silicon
dioxide) are already present in the water
supply, the Agency does not expect that
the use of potassium silicate as a
pesticide will result in detectable
exposures aside from what is currently
in the environment.
B. Other Non-Occupational Exposure
1. Dermal exposure. Nonoccupational dermal exposures to
potassium silicate when used as a
pesticide are expected to be negligible
because it is limited to agricultural use.
2. Inhalation exposure. Nonoccupational inhalation exposures to
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potassium silicate when used as a
pesticide are expected to be negligible
because it is limited to agricultural use
and will be used as a spray.
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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 considers
available information concerning the
cumulative effects of a particular
pesticide’s residues and other
substances that have a common
mechanism of toxicity.
The information available at this time
indicates that potassium silicate when
applied to food crops at a rate less than
or equal to 1% of potassium silicate by
weight in aqueous solution does not
have a toxic effect. Therefore,
cumulative effects from the residues of
this product are not anticipated.
VI. Determination of Safety for U.S.
Population, Infants and Children
1. U.S. population. The Agency has
determined that there is reasonable
certainty that no harm will result to the
U.S. population from aggregated
exposure to residues of potassium
silicate when used in an aqueous
solution in which the potassium silicate
does not exceed 29.1% by weight. This
includes all anticipated dietary
exposures and other exposures for
which there is reliable information. The
Agency arrived at this conclusion based
on the anticipated low acute exposure
estimates from its pesticidal use, the
low mammalian toxicity in its diluted
form, the widespread exposure to
potassium and silica, from foods in the
human diet, and the similarity both
chemically and toxicologically to silicon
dioxide which has already been fully
characterized and assessed, and found
that there is reasonable certainty of no
harm that will result from the use of
silicon dioxide and its related soluble
silicates (potassium silicate) as an
agricultural pesticide.
2. Infants and children. FFDCA
section 408 provides that EPA shall
apply an additional tenfold margin of
exposure (MOE) for infants and children
in the case of threshold effects. Margins
of exposure are often referred to as
uncertainty or safety factors, and are
used to account for potential prenatal
and postnatal toxicity and any lack of
completeness of the data base. Based on
available data and other information,
EPA may determine that a different
MOE will define a level of concern for
infants and children or that a MOE
approach is not appropriate. Based on
all the available information the Agency
reviewed on potassium silicate,
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15:14 Jun 13, 2006
Jkt 208001
including a lack of threshold effects, the
Agency concluded that potassium
silicate, in its diluted form, is
practically non-toxic to mammals,
including infants and children. Since
there are no effects of concern, the
provision requiring an additional
margin of safety does not apply.
VII. Other Considerations
A. Endocrine Disruptors
Based on available data, no endocrine
system-related effects have been
identified with consumption of
potassium silicate. In addition, there is
no evidence to suggest that potassium
silicate functions in a manner similar to
any known hormone.
B. Analytical Method(s)
The Agency proposes to establish an
amendment to the exemption from the
requirement of a tolerance without any
numerical limitation for residues since
it has determined that residues resulting
from the pesticidal uses of potassium
silicate would be so low as to be
indistinguishable from the naturally
occurring silicates that are ubiquitous in
the environment.
C. Codex Maximum Residue Level
There are no Codex Maximum
Residue Levels for this chemical.
VIII. Conclusions
Based on the toxicology data
submitted, there is reasonable certainty
no harm will result to the U.S.
population including infants and
children from aggregate exposure of
residues of potassium silicate when the
product is used in accordance with good
agricultural practices. This includes all
anticipated dietary exposures and all
other exposures about which there is
reliable information. As a result, EPA
establishes an exemption from tolerance
requirements pursuant to FFDCA 408(c)
and (d) for residues of potassium silicate
in or on all food commodities so long
as the potassium silicate is not applied
to food crops at rates that exceed 1%
potassium silicate by weight in an
aqueous solution.
IX. Statutory and Executive Order
Reviews
This final rule establishes an
exemption from the tolerance
requirement under section 408(d) of
FFDCA in response to a petition
submitted to the Agency. The Office of
Management and Budget (OMB) has
exempted these types of actions from
review under Executive Order 12866,
entitled Regulatory Planning and
Review (58 FR 51735, October 4, 1993).
Because this rule has been exempted
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34271
from review under Executive Order
12866 due to its lack of significance,
this rule is not subject to Executive
Order 13211, Actions Concerning
Regulations That Significantly Affect
Energy Supply, Distribution, or Use (66
FR 28355, May 22, 2001). This final rule
does not contain any information
collections subject to OMB approval
under the Paperwork Reduction Act
(PRA), 44 U.S.C. 3501 et seq., or impose
any enforceable duty or contain any
unfunded mandate as described
underTitle II of the Unfunded Mandates
Reform Act of 1995 (UMRA) (Public
Law 104–4). Nor does it require any
special considerations under Executive
Order 12898, entitled Federal Actions to
Address Environmental Justice in
Minority Populations and Low-Income
Populations (59 FR 7629, February 16,
1994); or OMB review or any Agency
action under Executive Order 13045,
entitled Protection of Children from
Environmental Health Risks and Safety
Risks (62 FR 19885, April 23, 1997).
This action does not involve any
technical standards that would require
Agency consideration of voluntary
consensus standards pursuant to section
12(d) of the National Technology
Transfer and Advancement Act of 1995
(NTTAA), Public Law 104–113, section
12(d) (15 U.S.C. 272 note). Since
tolerances and exemptions that are
established on the basis of a petition
under section 408(d) of FFDCA, such as
the exemption in this final rule, do not
require the issuance of a proposed rule,
the requirements of the Regulatory
Flexibility Act (RFA) (5 U.S.C. 601 et
seq.) do not apply. The Agency hereby
certifies that this rule will not have
significant negative economic impact on
a substantial number of small entities.
In addition, the Agency has determined
that this action will not have a
substantial direct effect on States, on the
relationship between the national
government and the States, or on the
distribution of power and
responsibilities among the various
levels of government, as specified in
Executive Order 13132, entitled
Federalism (64 FR 43255, August 10,
1999). Executive Order 13132 requires
EPA to develop an accountable process
to ensure ‘‘meaningful and timely input
by State and local officials in the
development of regulatory policies that
have federalism implications.’’ ‘‘Policies
that have federalism implications’’ is
defined in the Executive order to
include regulations that have
‘‘substantial direct effects on the States,
on the relationship between the national
government and the States, or on the
distribution of power and
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Federal Register / Vol. 71, No. 114 / Wednesday, June 14, 2006 / Rules and Regulations
responsibilities among the various
levels of government.’’ This final rule
directly regulates growers, food
processors, food handlers and food
retailers, not States. This action does not
alter the relationships or distribution of
power and responsibilities established
by Congress in the preemption
provisions of section 408(n)(4) of
FFDCA. For these same reasons, the
Agency has determined that this rule
does not have any ‘‘tribal implications’’
as described in Executive Order 13175,
entitled Consultation and Coordination
with Indian Tribal Governments (65 FR
67249, November 6, 2000). Executive
Order 13175, requires EPA to develop
an accountable process to ensure
‘‘meaningful and timely input by tribal
officials in the development of
regulatory policies that have tribal
implications.’’ Policies that have tribal
implications’’ is defined in the
Executive order to include regulations
that have ‘‘substantial direct effects on
one or more Indian tribes, on the
relationship between the Federal
Government and the Indian tribes, or on
the distribution of power and
responsibilities between the Federal
Government and Indian tribes.’’ This
rule will not have substantial direct
effects on tribal governments, on the
relationship between the Federal
Government and Indian tribes, or on the
distribution of power and
responsibilities between the Federal
Government and Indian tribes, as
specified in Executive Order 13175.
Thus, Executive Order 13175 does not
apply to this rule.
Dated: May 31, 2006.
James Jones,
Director, Office of Pesticide Programs.
X. Congressional Review Act
The Federal Communications
Commission, on its own motion,
clarifies certain aspects of the
Implementation of the Commercial
Spectrum Enhancement Act and
Modernization of the Commission’s
Competitive Bidding Rules and
Procedures. Among other things, the
Commission clarifies that the expansion
of the unjust enrichment payment
schedule to ten years applies only to
licenses granted on or after April 25,
2006. This ensures that retroactive
penalties are not imposed on preexisting designated entities.
DATES: Effective June 14, 2006.
FOR FURTHER INFORMATION CONTACT:
Brian Carter at (202) 418–0660.
SUPPLEMENTARY INFORMATION: This is a
summary of the Order on
Reconsideration of the Second Report
and Order (Order on Reconsideration)
released on June 2, 2006. The complete
text of the Order on Reconsideration
including attachments and related
Commission documents is available for
mstockstill on PROD1PC61 with RULES
List of Subjects in 40 CFR Part 180
Environmental protection,
Administrative practice and procedure,
Agricultural commodities, Pesticides
and pests, Reporting and recordkeeping
requirements.
15:14 Jun 13, 2006
Jkt 208001
PART 180—AMENDED
1. The authority citation for part 180
continues to read as follows:
I
Authority: 21 U.S.C. 321(q), 346a and 371.
2. Section 180.1268 is added to
subpart D to read as follows:
I
§ 180.1268 Potassium silicate; exemption
from the requirement of a tolerance.
Potassium silicate is exempt from the
requirement of a tolerance in or on all
food commodities so long as the
potassium silicate is not applied at rates
exceeding 1% by weight in aqueous
solution and when used in accordance
with good agricultural practices.
[FR Doc. E6–8939 Filed 6–13–06; 8:45 am]
BILLING CODE 6560–50–S
FEDERAL COMMUNICATIONS
COMMISSION
47 CFR Part 1
[WT Docket No. 05–211; FCC 06–78]
Commercial Spectrum Enhancement
Act and Modernization of the
Commission’s Competitive Bidding
Rules and Procedures
Federal Communications
Commission.
ACTION: Final rule.
AGENCY:
SUMMARY:
The Congressional Review Act, 5
U.S.C. 801 et seq., as added by the Small
Business Regulatory Enforcement
Fairness Act of 1996, generally provides
that before a rule may take effect, the
agency promulgating the rule must
submit a rule report, which includes a
copy of the rule, to each House of the
Congress and to the Comptroller General
of the United States. EPA will submit a
report containing this rule and other
required information to the U.S. Senate,
the U.S. House of Representatives, and
the Comptroller General of the United
States prior to publication of this final
rule in the Federal Register. This final
rule is not a ‘‘major rule’’ as defined by
5 U.S.C. 804(2).
VerDate Aug<31>2005
Therefore, 40 CFR chapter I is
amended as follows:
I
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public inspection and copying from 8
a.m. to 4:30 p.m. Monday through
Thursday or from 8 a.m. to 11:30 a.m.
on Friday at the FCC Reference
Information Center, Portals II, 445 12th
Street, SW., Room CY–A257,
Washington, DC 20554. The Order on
Reconsideration and related
Commission documents may also be
purchased from the Commission’s
duplicating contractor, Best Copy and
Printing, Inc. (BCPI), Portals II, 445 12th
Street, SW., Room CY–B402,
Washington, DC 20554, telephone 202–
488–5300, facsimile 202–488–5563, or
you may contact BCPI at its Web site:
https://www.BCPIWEB.com. When
ordering documents from BCPI please
provide the appropriate FCC document
number, for example, FCC 06–78. The
Order on Reconsideration and related
documents are also available on the
Internet at the Commission’s Web site:
https://wireless.fcc.gov/auctions.
I. Introduction
1. The Commission, on its own
motion, released an Order on
Reconsideration which clarifies certain
aspects of the Implementation of the
Commercial Spectrum Enhancement
Act and Modernization of the
Commission’s Competitive Bidding
Rules and Procedures, Second Report
and Order (Designated Entity Second
Report and Order), 71 FR 26245, (May
4, 2006). The Commission also
addresses certain procedural issues
raised in filings submitted in response
to the Designated Entity Second Report
and Order.
II. Background
2. In the Further Notice of Proposed
Rule Making in this proceeding
(FNPRM), 71 FR 6992 (February 10,
2006), the Commission sought comment
on a proposal by a commenter that the
Commission restrict the award of
designated entity benefits to designated
entities that have material relationships
with large in-region incumbent wireless
service providers. The Commission
asked for comment on each of the
elements of this proposal, including
what types of material relationships
should trigger a restriction on the
availability of designated entity benefits
and what types of entities other than
large in-region incumbent wireless
service providers should be covered.
3. In the Designated Entity Second
Report and Order, the Commission
revised its Part 1 rules to include certain
material relationships as factors in
determining designated entity
eligibility. Specifically, the Commission
adopted rules to limit the award of
designated entity benefits to any
E:\FR\FM\14JNR1.SGM
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Agencies
[Federal Register Volume 71, Number 114 (Wednesday, June 14, 2006)]
[Rules and Regulations]
[Pages 34267-34272]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E6-8939]
-----------------------------------------------------------------------
ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 180
[EPA-HQ-OPP-2006-0299; FRL-8069-6]
Potassium Silicate; Exemption from the Requirement of a Tolerance
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.
-----------------------------------------------------------------------
SUMMARY: This regulation establishes an exemption from the requirement
of a tolerance for residues of potassium silicate in or on all food
commodities when applied/used as a fungicide, insecticide or miticide
so long as the potassium silicate is not applied at rates exceeding 1%
by weight in aqueous solution and when used in accordance with good
agricultural practices. PQ Corporation 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 potassium
silicate.
DATES: This regulation is effective June 14, 2006. Objections and
requests for hearings must be received on or before August 14, 2006,
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-2006-0299. 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 https://www.regulations.gov, or,
if only available in hard copy, at the OPP Regulatory Public Docket in
Rm. S-4400, One Potomac Yard (South Building), 2777 S. Crystal Drive,
Arlington, VA. The Docket Facility is open from 8:30 a.m. to 4 p.m.,
Monday through Friday, excluding legal holidays. The telephone number
for the Docket is (703) 305-5805.
FOR FURTHER INFORMATION CONTACT: Carol E. Frazer, Biopesticides and
Pollution Prevention Division (7511P), Environmental Protection Agency,
1200 Pennsylvania Ave., NW., Washington, DC 20460-0001; telephone
number: (703) 308-8810; e-mail address: frazer.carol@epa.gov.
SUPPLEMENTARY INFORMATION:
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 https://
www.regulations.gov, you may access this Federal Register document
electronically through the EPA Internet under the ``Federal Register''
listings at https://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 https://
www.gpoaccess.gov/ecfr.
C. Can I File an Objection or Hearing Request?
Under section 408(g) of 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
[[Page 34268]]
provided in 40 CFR part 178. To ensure proper receipt by EPA, you must
identify docket ID number EPA-HQ-OPP-2006-0299 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 August
14, 2006.
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-2006-0299, by one of the following methods:
Federal eRulemaking Portal: https://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
Building), 2777 S. Crystal Drive, 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
telephone number for the Docket is (703) 305-5805.
II. Background and Statutory Findings
In the Federal Register of July 27, 2005 (70 FR 43417) (FRL-7719-
5), EPA issued a notice pursuant to section 408(d)(3) of FFDCA, 21
U.S.C. 346a(d)(3), announcing the filing of a pesticide tolerance
petition (PP 5F6905) by PQ Corporation, P.O. Box 840 Valley Forge, PA
19482-0840. The petition requested that 40 CFR part 180 be amended by
establishing a temporary exemption from the requirement of a tolerance
for residues of potassium silicate. This notice included a summary of
the petition prepared by the petitioner PQ Corporation. There were no
comments received in response to the notice of filing.
Section 408(c)(2)(A)(I) of FFDCA allows EPA to establish an
exemption 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 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), 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), 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 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 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.
Potassium silicate is a synthetic compound that is chemically the
potassium salt of silicic acid. It is produced by combining pure silica
sand (SiO2) and potash (K2CO3 or
NaCO3). Silicic acid salts (i.e., silicates) are the most
common form of silicon. For the purposes of this tolerance exemption,
the Agency has relied on the extensive body of knowledge, data and/or
information from the public literature as submitted by PQ Corporation
and as researched by the Agency which document the similarity of silica
(also known as silicon dioxide) and potassium silicate and support the
conclusion that there is reasonable certainty of no harm that will
result from the use of potassium silicate as an agricultural pesticide.
Silicon dioxide (silica) has been assessed for its pesticidal uses
by the Agency and it was determined that the toxicity of this compound
is moderate to low and therefore, the human health risk is low and not
unreasonable. Further, silicon dioxide is recognized by the Food and
Drug Administration (FDA) to be a Generally-Recognized As Safe (GRAS)
substance, as a food additive (21 CFR 182.90 and 182.1711).
Comprehensive reviews and risk assessments have been conducted on
silicon dioxide (silica) and its related soluble silicates with regard
to its toxicity to human health and have concluded that silica and its
soluble silicates (potassium silicate) are low in toxicity and the
primary hazard of concern is the corrosive nature of the compound. The
corrosive nature of potassium silicate is not of a concern when used as
a very dilute solution (less than or equal to 1%). The soluble
silicates include: potassium silicate, sodium silicate and sodium
metasilicate, the latter of which the Agency has exempted in diluted
form from the requirement of a tolerance for use on all food
commodities. Additionally, the FDA has determined that sodium silicate
and potassium silicate can be used interchangeably which substantiates
information in the public literature that the compounds are very
similar.
The data submitted and reviewed on the end use pesticide product
containing 29.1% w/w potassium silicate caused moderate to low dermal
irritation and is classified as an eye irritant due to the high pH of
the product. When used as a pesticide (fungicide, insecticide and
miticide) the active ingredient is effective at very low concentrations
(less than or equal to 1%) and thus the dilution of the active
ingredient would reduce the risks to pesticide users. Labeling of such
products with the appropriate protective clothing, gloves and eyewear
would mitigate the risk of exposure to potassium silicate on pesticide
applicators. Potassium silicate residues which may result from its use
as an agricultural pesticide would be reduced by washing or processing
treated commodities before their consumption; this point is supported
by the water solubility of potassium silicate and the possibility of it
being washed off treated surfaces by rainfall in the field. Further,
potassium silicate is neutralized by stomach acid and primarily
excreted in the urine.
[[Page 34269]]
The components of potassium silicate are potassium and silicon.
Potassium is found in the environment and is an essential element in
human and plant nutrition. It is found in many fruits and vegetables
consumed by humans. A common soil plant nutrient and fertilizer (as
K2O), potassium comprises approximately 2.59% of the Earth's
crust by weight. The primary source of naturally-occurring soluble
potassium is from the weathering of potassium containing minerals.
Silicon is ubiquitous in the environment, the second most abundant
element in the lithosphere after oxygen. A nutritional element, silica
is required for proper and strong growth of mammalian bones. Silica is
present naturally in all plant stems and is present in larger amounts
in crops such as rice and sugar cane. It comprises approximately 31% of
the Earth's crust by weight and is present as dissolved silica,
amorphous silica in the solid phase (for example, silica and silica gel
(FDA GRAS chemicals), and silica bound to organic matter. In the normal
range of soil pH, silicic acid is the major silicate in soil water. In
natural waters most dissolved silica results from weathering of
silicate minerals. Research demonstrates that commercial soluble
silicates rapidly degrade to molecular forms that are indistinguishable
from natural dissolved silica (IUCLID, 1995). Beach sand, for example
is comprised of nearly 100% silica (Crop Protection handbook, 2003).
Additionally, silica is approved by the FDA for use as an anti-caking
agent in food.
Potassium silicate immediately breaks down in the presence of water
to the potassium and silicate ions which are indistinguishable from
natural components. As stated above, potassium silicate is produced by
direct fusion of precisely measured portions of pure silica sand
(SiO2) and potash (K2CO3) in a fired
furnace at temperatures above 1000[deg]C. Solutions of potassium
silicate are produced by dissolving alkali silica lumps in water at
elevated temperatures. Potassium silicate is classified as GRAS by FDA
(21 CFR 182.90 and 21 CFR 182.1711) for limited use in canned potable
water as a corrosion inhibiting agent and the EPA has exempted
potassium silicate from the requirement of a tolerance when used as an
inert ingredient, a surfactant, emulsifier, wetting agent, stabilizer,
or inhibitor (40 CFR 180.910). Data and/or information from the public
literature demonstrates a long history of safe use of fertilizers
containing potassium and silica. (HERA 2005, NOSB/TAP, 2003 and the
Silicon Dioxide and Silica Gel RED EPA, 1991, Kant, T., et al, 2003,
Savant N.K., et al., 1999). Fertilizers used in the agricultural
industry contain plant nutrients and micronutrients such as potassium
and silicon. Potassium silicate is approved by the USDA as a fertilizer
for conventional agriculture and is used on a variety of crops
including rice, wheat, barley, sugar cane, melons, grapes and cucurbits
(USDA/ERS, 2002, NOSB/TAP, 2003).
As mentioned above, silicon dioxide and its soluble silicates which
include potassium silicate have been fully characterized and assessed
by the Agency and other notable resources and it has been concluded
that silicon dioxide and its related soluble silicates exhibit moderate
to low toxicity, the Agency has therefore concluded there is a
reasonable certainty of no harm resulting from the use of potassium
silicate as an agricultural pesticide. This determination is based on
information from the literature which as stated above document the
similarity of silica (also known as silicon dioxide) and potassium
silicate. This information combined with the fact that the components
of potassium silicate (potassium and silica) are already naturally
present in the stems of all plants (silica) and naturally in foods
supports the Agency's conclusion that there is a reasonable certainty
of no harm resulting from the use of potassium silicate as an
agricultural pesticide and exposure from the use of potassium silicate
as a pesticide will not add to the exposure already present from its
natural occurrence, its presence in foods, in the human diet and in the
environment.
A. Acute Toxicity
The registrant did not submit any toxicity data testing the
technical grade of the active ingredient. Data waivers were requested
by the registrant and granted by the Agency based on the body of
extensive knowledge from the public literature and as researched by the
Agency. The toxicity of the soluble silicates via oral toxicity,
teratogenicity and genotoxicity were tested on the Technical Grade of
the Active Ingredient (TGAI) and reported and the Agency has relied
upon this information to support its decision to grant the waiver
requests for these studies. Acute toxicity data were submitted using
the end-use product as the test material which is approximately
a1/89/21/13/23/87/83/8 dilution of the technical grade of the
active ingredient. Requests for data waivers were granted for
additional toxicity studies described below. These data waiver requests
were granted based on the findings from comprehensive reviews and risk
assessments conducted on silicon dioxide (silica) and its related
soluble silicates (potassium silicate) with regard to its toxicity to
human health and the conclusion that silicon dioxide and its related
soluble silicates have moderate to low toxicity, and therefore, the
Agency concludes that there is a reasonable certainty of no harm
resulting from the use of potassium silicate. The data submitted and
waivers that were granted are as follows:
Acute oral rat OPPTS Harmonized Guideline 870.1100; Master Record
Identification (MRID) Number 46434903). LD50 = 5,000
milligrams/kilogram (mg/kg) (29.1% potassium silicate aqueous
solution). The test material is classified as a Toxicity Category IV
for acute oral toxicity and demonstrates that a dilution of the active
ingredient to a level that is comparable to the concentration of
potassium silicate in the proposed end-use product eliminates the
potential of the active ingredient to cause acute toxic effects. There
were no adverse effects reported at 5,000 mg/kg.
Technical grade of the active ingredient. A request to waive this
data requirement was submitted by the registrant. The Agency has
granted this data waiver based on: (1) Data from the public literature
which shows soluble silicates have a moderate to low acute toxicity by
the oral route (HERA 2005), (2) potassium silicate, a soluble silicate
that is both chemically and toxicologically similar to silicon dioxide
(silica) which has been fully characterized, assessed, and therefore
determined by the Agency that silicon dioxide and its related soluble
silicates pose no unreasonable adverse effects to human health when
used as an agricultural pesticide and (3) potassium and silica are
already present in the human diet as they are contained naturally in
various crops.
Acute dermal rat OPPTS 870.1200; (MRID 4643902). LD50 =
5,000 mg/kg (29.1% potassium silicate aqueous solution). The test
material is classified as a Toxicity Category IV for acute dermal
toxicity and demonstrates that a dilution of the active ingredient to a
level that is comparable to the concentration of potassium silicate in
the proposed end use product will be moderately irritating to the skin.
Technical grade of the active ingredient. Section 158.690(c)(2)(I)
states this test is not required if the test material is corrosive to
skin. Therefore, this test was not required. However, this active
ingredient is classified Toxicity Category I on the basis of potential
dermal irritation effects.
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Acute inhalation rat OPPTS 870.1300; (MRID 46434906).
LC50 >2.06 milligrams per liter (mg/L) (29.1% potassium
silicate aqueous solution). The test material is classified as a
Toxicity Category IV for acute inhalation toxicity and demonstrates
that a dilution of the active ingredient to a level that is comparable
to the concentration of potassium silicate in the proposed end use
product will not cause acute inhalation effects at greater than 2.06
mg/L.
Technical grade of the active ingredient. This test is only
required if the product consists of a respirable material. Since
potassium silicate does not consist of a respirable material under
normal conditions of use, this test is not required.
B. Genotoxicity, Immune Response, Mutagenicity, Developmental,
Oncogenicity, Subchronic and Chronic Toxicity
The applicant requested to waive the data requirements below and
submitted a summary of public literature to satisfy the data
requirements for 90-day oral toxicity (OPPTS 870.3100), genotoxicity
(OPPTS 870.5100; 870.5300; 870.5375), teratogenicity (OPPTS 870.3700)
and immunotoxicity (OPPTS 880.3550) for the active ingredient.
Potassium silicate waiver requests were submitted (MRID 46434701). As
mentioned above, the Agency has determined that the data requirements
were met by the submission of public literature. The public literature
demonstrates that potassium silicate has low toxicity by the oral route
when tested as the TGAI because potassium silicate is neutralized by
stomach acid and primarily excreted in the urine. The high pH of the
pesticide product may cause eye and skin irritation to humans. However,
risks to humans will be reduced by dilution of the pesticide product
and further mitigated by the use of protective personal equipment.
IV. Aggregate Exposures
In examining aggregate exposure, section 408 of 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. Potassium is found in the environment and is present in
the cells of humans and plants and is therefore an essential element in
human and plant nutrition. It is found in many fruits and vegetables
consumed by humans. Humans require an adequate supply of potassium from
consumption of foods for healthy growth and development. Humans consume
daily many sources of potassium, including a variety of fruits,
vegetables and beverages such as barley, bananas, plums, apricots,
strawberries, oranges, apples, grapes, spinach, potatoes, carrots,
celery, tomatoes, lettuce, cucumbers, milk, fruit juices, coffee, white
wine and light beers, etc. The average potassium content of the above
fruits and vegetables ranges from 2.4 K/kg (tomato) - 3.7 K/kg
(banana).
As mentioned above, potassium is a common soil plant nutrient and
fertilizer (as K2O), and comprises approximately 2.59% of
the Earth's crust by weight. Silicon is a ubiquitous mineral nutrient
in the environment (soil, water) and the second most abundant element
in the lithosphere after oxygen. A nutritional trace element, silicon
is required for proper and strong growth and development of mammalian
bones. In plants, silicic acid (Si(OH)4) is rapidly
absorbed. Once absorbed, silicic acid is readily circulated throughout
the plant and deposited as silicon dioxide. Consequently exposure to
soluble silica occurs on a daily basis and is a property of all plant
products in the human diet. The concentration of silicon in vegetable
plants varies greatly with cereals and grasses containing the highest
concentrations (0.2-2.0%).
Good agricultural practice when using potassium silicate means it
will most likely be used in aqueous solutions because application of
pure potassium silicate to crops is likely to be corrosive to crops
since the active ingredient is a known corrosive. When applied to food
crops at concentrations not to exceed 1% by weight of potassium
silicate in aqueous solution, it is highly unlikely there will be any
residues of significance in or on food.
Further dilution by tank mixing with water of a pesticide product
containing the active ingredient at 29% w/w of potassium silicate
before application of the pesticide reduces the amount of active
ingredient (to concentrations not to exceed 1% active ingredient) that
will be on the crop.
Furthermore, potassium silicate breaks down in the presence of
water to potassium and silicate ions, both of which occur naturally in
animals and plants. Concentrations of potassium silicate as a pesticide
in foliar sprays and nutrient solutions are dominated by silicic acid,
which as mentioned above, is readily absorbed by plants.
Therefore, given the use dilution of the pesticide product and
other good agricultural practices as required on product labels, the
likely dietary exposures to potassium silicate from the pesticidal uses
are not expected to add significantly to those levels of potassium
silicate already found in foods, beverages, and in drinking water as a
result of conventional agriculture and its natural occurrence in the
environment.
2. Drinking water exposure. Because potassium silicate breaks down
into potassium and silicate ions in the presence of water, there will
be no residues of potassium silicate in drinking water from its use as
a pesticide. The Agency does not expect the resulting potassium and
silicate ions resulting from this breakdown process will add
significantly to the level of potassium and silica presently in the
water.
Potassium and silicon dioxide are ubiquitous in the environment,
and the uses of soluble silicates are widespread in dishwashing soaps,
other soaps, and detergents. Potassium silicate is classified by the
FDA as a GRAS substance (21 CFR 182.90 and 21 CFR 182.1711) for limited
use in canned potable water as a corrosion inhibiting agent. Moreover,
both potassium and silicon are already present in natural waters. The
potassium (natural) content of drinking water varies greatly depending
on its source and may be larger in mineral and spa waters than ordinary
tap water. On average, the daily water consumption by adults supplies
less than 0.1% of their potassium intake (European Fertilizer
Manufacturers Association, 1997). In natural waters most dissolved
silica results from weathering of silicate minerals and it has been
demonstrated that commercial soluble silicates rapidly degrade to
molecular forms that are indistinguishable from natural dissolved
silica. Therefore, because of the levels at which potassium and silica
(silicon dioxide) are already present in the water supply, the Agency
does not expect that the use of potassium silicate as a pesticide will
result in detectable exposures aside from what is currently in the
environment.
B. Other Non-Occupational Exposure
1. Dermal exposure. Non-occupational dermal exposures to potassium
silicate when used as a pesticide are expected to be negligible because
it is limited to agricultural use.
2. Inhalation exposure. Non-occupational inhalation exposures to
[[Page 34271]]
potassium silicate when used as a pesticide are expected to be
negligible because it is limited to agricultural use and will be used
as a spray.
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
considers available information concerning the cumulative effects of a
particular pesticide's residues and other substances that have a common
mechanism of toxicity.
The information available at this time indicates that potassium
silicate when applied to food crops at a rate less than or equal to 1%
of potassium silicate by weight in aqueous solution does not have a
toxic effect. Therefore, cumulative effects from the residues of this
product are not anticipated.
VI. Determination of Safety for U.S. Population, Infants and Children
1. U.S. population. The Agency has determined that there is
reasonable certainty that no harm will result to the U.S. population
from aggregated exposure to residues of potassium silicate when used in
an aqueous solution in which the potassium silicate does not exceed
29.1% by weight. This includes all anticipated dietary exposures and
other exposures for which there is reliable information. The Agency
arrived at this conclusion based on the anticipated low acute exposure
estimates from its pesticidal use, the low mammalian toxicity in its
diluted form, the widespread exposure to potassium and silica, from
foods in the human diet, and the similarity both chemically and
toxicologically to silicon dioxide which has already been fully
characterized and assessed, and found that there is reasonable
certainty of no harm that will result from the use of silicon dioxide
and its related soluble silicates (potassium silicate) as an
agricultural pesticide.
2. Infants and children. FFDCA section 408 provides that EPA shall
apply an additional tenfold margin of exposure (MOE) for infants and
children in the case of threshold effects. Margins of exposure are
often referred to as uncertainty or safety factors, and are used to
account for potential prenatal and postnatal toxicity and any lack of
completeness of the data base. Based on available data and other
information, EPA may determine that a different MOE will define a level
of concern for infants and children or that a MOE approach is not
appropriate. Based on all the available information the Agency reviewed
on potassium silicate, including a lack of threshold effects, the
Agency concluded that potassium silicate, in its diluted form, is
practically non-toxic to mammals, including infants and children. Since
there are no effects of concern, the provision requiring an additional
margin of safety does not apply.
VII. Other Considerations
A. Endocrine Disruptors
Based on available data, no endocrine system-related effects have
been identified with consumption of potassium silicate. In addition,
there is no evidence to suggest that potassium silicate functions in a
manner similar to any known hormone.
B. Analytical Method(s)
The Agency proposes to establish an amendment to the exemption from
the requirement of a tolerance without any numerical limitation for
residues since it has determined that residues resulting from the
pesticidal uses of potassium silicate would be so low as to be
indistinguishable from the naturally occurring silicates that are
ubiquitous in the environment.
C. Codex Maximum Residue Level
There are no Codex Maximum Residue Levels for this chemical.
VIII. Conclusions
Based on the toxicology data submitted, there is reasonable
certainty no harm will result to the U.S. population including infants
and children from aggregate exposure of residues of potassium silicate
when the product is used in accordance with good agricultural
practices. This includes all anticipated dietary exposures and all
other exposures about which there is reliable information. As a result,
EPA establishes an exemption from tolerance requirements pursuant to
FFDCA 408(c) and (d) for residues of potassium silicate in or on all
food commodities so long as the potassium silicate is not applied to
food crops at rates that exceed 1% potassium silicate by weight in an
aqueous solution.
IX. Statutory and Executive Order Reviews
This final rule establishes an exemption from the tolerance
requirement under section 408(d) of FFDCA in response to a petition
submitted to the Agency. The Office of Management and Budget (OMB) has
exempted these types of actions from review under Executive Order
12866, entitled Regulatory Planning and Review (58 FR 51735, October 4,
1993). Because this rule has been exempted from review under Executive
Order 12866 due to its lack of significance, this rule is not subject
to Executive Order 13211, Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution, or Use (66 FR 28355,
May 22, 2001). This final rule does not contain any information
collections subject to OMB approval under the Paperwork Reduction Act
(PRA), 44 U.S.C. 3501 et seq., or impose any enforceable duty or
contain any unfunded mandate as described underTitle II of the Unfunded
Mandates Reform Act of 1995 (UMRA) (Public Law 104-4). Nor does it
require any special considerations under Executive Order 12898,
entitled Federal Actions to Address Environmental Justice in Minority
Populations and Low-Income Populations (59 FR 7629, February 16, 1994);
or OMB review or any Agency action under Executive Order 13045,
entitled Protection of Children from Environmental Health Risks and
Safety Risks (62 FR 19885, April 23, 1997). This action does not
involve any technical standards that would require Agency consideration
of voluntary consensus standards pursuant to section 12(d) of the
National Technology Transfer and Advancement Act of 1995 (NTTAA),
Public Law 104-113, section 12(d) (15 U.S.C. 272 note). Since
tolerances and exemptions that are established on the basis of a
petition under section 408(d) of FFDCA, such as the exemption in this
final rule, do not require the issuance of a proposed rule, the
requirements of the Regulatory Flexibility Act (RFA) (5 U.S.C. 601 et
seq.) do not apply. The Agency hereby certifies that this rule will not
have significant negative economic impact on a substantial number of
small entities. In addition, the Agency has determined that this action
will not have a substantial direct effect on States, on the
relationship between the national government and the States, or on the
distribution of power and responsibilities among the various levels of
government, as specified in Executive Order 13132, entitled Federalism
(64 FR 43255, August 10, 1999). Executive Order 13132 requires EPA to
develop an accountable process to ensure ``meaningful and timely input
by State and local officials in the development of regulatory policies
that have federalism implications.'' ``Policies that have federalism
implications'' is defined in the Executive order to include regulations
that have ``substantial direct effects on the States, on the
relationship between the national government and the States, or on the
distribution of power and
[[Page 34272]]
responsibilities among the various levels of government.'' This final
rule directly regulates growers, food processors, food handlers and
food retailers, not States. This action does not alter the
relationships or distribution of power and responsibilities established
by Congress in the preemption provisions of section 408(n)(4) of FFDCA.
For these same reasons, the Agency has determined that this rule does
not have any ``tribal implications'' as described in Executive Order
13175, entitled Consultation and Coordination with Indian Tribal
Governments (65 FR 67249, November 6, 2000). Executive Order 13175,
requires EPA to develop an accountable process to ensure ``meaningful
and timely input by tribal officials in the development of regulatory
policies that have tribal implications.'' Policies that have tribal
implications'' is defined in the Executive order to include regulations
that have ``substantial direct effects on one or more Indian tribes, on
the relationship between the Federal Government and the Indian tribes,
or on the distribution of power and responsibilities between the
Federal Government and Indian tribes.'' This rule will not have
substantial direct effects on tribal governments, on the relationship
between the Federal Government and Indian tribes, or on the
distribution of power and responsibilities between the Federal
Government and Indian tribes, as specified in Executive Order 13175.
Thus, Executive Order 13175 does not apply to this rule.
X. Congressional Review Act
The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the
Small Business Regulatory Enforcement Fairness Act of 1996, generally
provides that before a rule may take effect, the agency promulgating
the rule must submit a rule report, which includes a copy of the rule,
to each House of the Congress and to the Comptroller General of the
United States. EPA will submit a report containing this rule and other
required information to the U.S. Senate, the U.S. House of
Representatives, and the Comptroller General of the United States prior
to publication of this final rule in the Federal Register. This final
rule is not a ``major rule'' as defined by 5 U.S.C. 804(2).
List of Subjects in 40 CFR Part 180
Environmental protection, Administrative practice and procedure,
Agricultural commodities, Pesticides and pests, Reporting and
recordkeeping requirements.
Dated: May 31, 2006.
James Jones,
Director, Office of Pesticide Programs.
0
Therefore, 40 CFR chapter I is amended as follows:
PART 180--AMENDED
0
1. The authority citation for part 180 continues to read as follows:
Authority: 21 U.S.C. 321(q), 346a and 371.
0
2. Section 180.1268 is added to subpart D to read as follows:
Sec. 180.1268 Potassium silicate; exemption from the requirement of a
tolerance.
Potassium silicate is exempt from the requirement of a tolerance in
or on all food commodities so long as the potassium silicate is not
applied at rates exceeding 1% by weight in aqueous solution and when
used in accordance with good agricultural practices.
[FR Doc. E6-8939 Filed 6-13-06; 8:45 am]
BILLING CODE 6560-50-S