potassium dihydrogen phosphate Proposed Tolerance Requirement Exemption 2/98
[Federal Register: March 3, 1998 (Volume 63, Number 41)]
>From the Federal Register Online via GPO Access [wais.access.gpo.gov]
ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 180
Potassium Dihydrogen Phosphate; Proposed Exemption from the
Requirement of a Tolerance
AGENCY: Environmental Protection Agency (EPA).
ACTION: Proposed rule.
SUMMARY: EPA proposes to establish an exemption from the requirement of
a tolerance for residues of potassium dihydrogen phosphate
(KH<INF>2</INF>PO<INF>4</INF>) in or on all food commodities, when
applied as a fungicide in accordance with good agricultural practices
to control powdery mildew in fruits and vegetables. EPA is proposing
this regulation on its own initiative.
DATES: Comments, identified by the docket control number [OPP-300618]
must be received on or before May 4, 1998.
ADDRESSES: By mail, submit written comments to: Public Information and
Records Integrity Branch, Information Resources and Services Division
(7502C), Office of Pesticide Programs, Environmental Protection Agency,
401 M St., SW., Washington, DC 20460. In person, deliver comments to:
Rm. 119, CM #2, 1921 Jefferson Davis Highway, Arlington, VA.
Comments and data may also be submitted electronically to: opp-
firstname.lastname@example.org. Follow the instructions under Unit IV of this
document. No Confidential Business Information (CBI) should be
submitted through e-mail.
Information submitted as a comment concerning this document may be
claimed confidential by marking any part or all of that information as
CBI. Information so marked will not be disclosed except in accordance
with procedures set forth in 40 CFR part 2. A copy of the comment that
does not contain CBI must be submitted for inclusion in the public
record. Information not marked confidential will be included in the
public docket by EPA without prior notice. The public docket is
available for public inspection in Rm. 119 at the Virginia address
given above, from 8:30 a.m. to 4 p.m., Monday through Friday, excluding
FOR FURTHER INFORMATION CONTACT: By mail: Suku Oonnithan, c/o Product
Manager (PM) 91, Biopesticides and Pollution Prevention Division
(7511W), Office of Pesticide Programs, Environmental Protection Agency,
401 M St., SW., Washington, DC 20460. Office location; telephone
number; and e-mail address: Crystal Station #1, 5th Floor, 2800 Crystal
Drive, Arlington, VA 22202; 703-308-9524;
SUPPLEMENTARY INFORMATION: Pursuant to section 408(e) of the Federal
Food, Drug, and Cosmetic Act (FFDCA), 21 U.S.C. section 346a(d), EPA
proposes to amend 40 CFR part 180 by establishing an exemption from the
requirement of a tolerance for residues of potassium dihydrogen
phosphate in or on all food commodities.
I. Risk Assessment and Statutory Authority
New section 408(c)(2)(A)(i) of FFDCA allows EPA to establish an
exemption from the requirement of a tolerance (the legal limit for a
pesticide chemical residue in or on a food commodity) only if EPA
determines that the tolerance is ``safe.'' Section 408(c)(2)(A)(ii)
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.'' These include
exposure through drinking water and in residential settings, but does
not include occupational exposure. Section 408(b)(2)(B) requires EPA to
give special consideration to exposure of infants and children to the
pesticide chemical residue in establishing an exemption 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.'' 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.
II. Risk Assessment and Statutory Findings
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, reliability, and
relationship 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.
A. Toxicological Profile
Potassium dihydrogen phosphate is a naturally occurring mineral
and is widely used as a fertilizer with no reported adverse effects.
The acute toxicological data available on potassium dihydrogen
phosphate include: acute oral toxicity in rats (LD<INF>50</INF> > 500
mg/kg and Toxicity Category III), acute dermal toxicity in rabbits
(LD<INF>50</INF> > 2,000 mg/kg and Toxicity Category III), primary eye
irritation in rabbits (Toxicity Category III), and primary skin
irritation in rabbits (Toxicity Category IV).
Phosphate is ubiquitous and abundant in biological materials. Most
of the phosphate ingested by humans and animals is converted to
orthophosphate, both as H<INF>2</INF>PO<INF>4</INF> and HPO<INF>4</INF>
in the digestive tract, prior to absorption in the small intestine.
Phosphate is found in blood, cytoplasm, bone, teeth, urine, and feces.
It is essential in the tightly regulated physiological and metabolic
processes of energy production, carbohydrate metabolism, iron
absorption, plasma buffering, maintenance of certain hormone levels,
and muscular contraction. Phosphates are molecular components of
phospholipids, nucleic acids, energy generating compounds, certain
sugars, and some proteins. Dietary phosphate, that is not absorbed is
passed through the body via the feces and the absorbed excess phosphate
is excreted renally via the urine.
Potassium also is ubiquitous in nature and in biological systems.
It is an essential cationic component of body fluids and cytoplasm. It
is essential for amino acid and sugar transport, cell permeability,
muscle contraction, and is required as a cofactor for certain enzymes.
Excess potassium is excreted in the urine. Potassium also is found in
saliva, sweat, tears, and in gastric secretions and fluids.
Potassium phosphate is widely used as a fertilizer. Therefore it's
use as a pesticide is not likely to significantly increase exposure
that already occurs in the diet from natural sources, including
drinking water. While deficiencies of potassium and phosphate may
adversely impact human health, excessive intake via natural exposures
B. Aggregate Exposure
In examining aggregate exposure, FQPA directs EPA to consider
available information concerning exposures from the pesticide residue
in food and all other non-occupational exposures, including drinking
water from groundwater or surface water and exposure through pesticide
use in gardens, lawns, or buildings (residential and other indoor
1. Dietary exposure--i. Food. It is anticipated that no significant
residues of potassium dihydrogen phosphate will occur in treated foods
other than that present as a mineral and as mineral complexes
manufactured by the plant through photosynthesis and enzymatic
ii. Drinking water exposure. Potassium dihydrogen phosphate is used
as an agricultural fertilizer. Exposure to its residues in drinking
water from pesticidal use is not expected to be significant or harmful
to human health.
2. Other non-occupational exposure--i. Dermal exposure. No undue
risk is expected as a result of the use of potassium dihydrogen
phosphate as a fungicide.
ii. Inhalation exposure: None expected as a result of the use of
potassium dihydrogen phosphate as a fungicide.
C. Cumulative Exposure to Substances with Common Mechanism of Toxicity
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 Agency believes that ``available
information'' in this context might include not only toxicity,
chemistry, and exposure data, but also scientific policies and
methodologies for understanding common mechanisms of the toxicity for
conducting cumulative risk assessments. For most pesticides, although
the Agency has some information in its files that may turn out to be
helpful in eventually determining whether a pesticide shares a common
mechanism of toxicity with any other substances, EPA does not at this
time have the methodologies to resolve the complex scientific issues
concerning common mechanisms of toxicity in a meaningful way. EPA has
begun a pilot process to study this issue further through the
examination of particular classes of pesticides. The Agency hopes the
results of this pilot process will increase the Agency's scientific
understanding of this question such that EPA will be able to develop
and apply scientific principles for better determining which chemicals
have a common mechanism of toxicity for evaluating the cumulative
effects of such chemicals. The Agency anticipates, however, that even
as its understanding of the science of common mechanism of toxicity
increases, decisions on specific classes of chemicals will be heavily
dependent on chemical specific data, much of which may not be presently
Although at present the Agency does not know how to apply the
information in its files concerning common mechanism issues to most
risk assessments, there are pesticides as to which the common mechanism
can be resolved. These include pesticides that are toxicologically and
structurally dissimilar to existing chemical substances (in which case
the Agency can conclude that it is unlikely that a pesticide shares a
common mechanism of activity with other substances) and pesticides that
produce a common toxic metabolite (in which case common mechanism of
activity will be assumed).
Potassium dihydrogen phosphate does not share any common
mechanisms of toxicity with other pesticide chemicals. Its use as a
fungicide should not significantly increase exposure to other uses as
an agricultural fertilizer. Therefore, no impact on the potential for
toxic effects from the pesticidal use of potassium dihydrogen phosphate
D. Safety Determinations
1. U.S. population. Potassium dihydrogen phosphate has low
mammalian toxicity and EPA has exempted it from tolerance when used as
an inert ingredient as a buffering agent in pesticide formulations (40
CFR 180.1001(d)). The subject chemical occurs in nature and has been
used as a fertilizer for many years with no reported adverse effects.
Based on available information, the Agency believes that exposure to
this chemical will not pose any appreciable risks to human health.
2. Infants and children. Section 408 of FFDCA provides that EPA
shall apply an additional tenfold margin of exposure (safety) for
infants and children in the case of threshold effects to account for
pre- and post-natal toxicity and the completeness of the database,
unless EPA determines that a different margin of exposure (safety) will
be safe for infants and children. Margins of exposure (safety) are
often referred to as uncertainty (safety) factors. In this instance,
the Agency believes that there is reliable data to support that
potassium dihydrogen phosphate is practically non-toxic to mammals,
including infants and children, and, thus, there are no threshold
effects, and EPA has not used a margin of exposure (safety) approach to
assess the safety of potassium dihydrogen phosphate. As a result, the
provision requiring an additional margin of exposure (safety) does not
E. Other Considerations
1. Endocrine disruptors. There are no reports of any estrogenic and
other adverse effects to human population as a result of the use of
potassium dihydrogen phosphate as an agricultural fertilizer. Based on
this information combined with its low mammalian toxicity, EPA
concludes that there is a reasonable certainty that no adverse
endocrine effects will result from the use of potassium dihydrogen
phosphate as a fungicide.
2. Analytical method(s). Since the Agency proposes to establish an
exemption from the requirement of a tolerance without any numerical
limitation, the Agency has concluded that an analytical method is not
required for enforcement purposes for the residues of potassium
F. Existing Tolerances
No existing tolerances or exemptions from the requirement of a
tolerance have been issued for potassium dihydrogen phosphate as an
active ingrdient in the United States.
G. International Tolerances
There are no CODEX tolerances or international tolerance
exemptions for potassium dihydrogen phosphate.
Based on the information and data considered, EPA is proposing
that an exemption from the requirement of a tolerance be established as
set forth below.
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. Based on the information and data considered, the Agency
has determined that, in amending 40 CFR part 180 as proposed, there is
reasonable certainty that no harm to the general population including
infants and children will result from aggregate exposure to the
pesticide chemical residue.
Under FFDCA section 408(e)(2), EPA must provide for a public
comment period before issuing a final tolerance or tolerance exemption
under section 408(e)(1). The public comment period is to be for 60 days
unless the Administrator for good cause finds that it is in the public
interest to reduce that comment period.
IV. Public Docket and Electronic Submissions
The official record for this rulemaking, as well as the public
version, has been established for this rulemaking under docket control
number [OPP-300618] (including comments and data submitted
electronically as described below). A public version of this record,
including printed, paper versions of electronic comments, which does
not include any information claimed as CBI, is available for inspection
from 8:30 a.m. to 4 p.m., Monday through Friday, excluding legal
holidays. The official rulemaking record is located at the Virginia
address in ``ADDRESSES'' at the beginning of this document.
Electronic comments can be sent directly to EPA at:
Electronic comments must be submitted as an ASCII file avoiding the
use of special characters and any form of encryption. Comment and data
will also be accepted on disks in Wordperfect 5.1/6.1 or ASCII file
format. All comments and data in electronic form must be identified by
the docket control number [OPP-300618]. Electronic comments on this
proposed rule may be filed online at many Federal Depository Libraries.
V. Regulatory Assessment Requirements
This action proposes an exemption from the tolerance requirement
under FFDCA section 408(e). 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). In addition, this proposed 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 under Title II of the
Unfunded Mandates Reform Act of 1995 (UMRA) (Pub. L. 104-4). Nor does
it require any prior consultation as specified by Executive Order
12875, entitled Enhancing the Intergovernmental Partnership (58 FR
58093, October 28, 1993), or special considerations as required by
Executive Order 12898, entitled Federal Actions to Address
Environmental Justice in Minority Populations and Low-Income
Populations (59 FR 7629, February 16, 1994), or require special OMB
review in accordance with Executive Order 13045, entitled Protection of
Children from Environmental Health Risks and Safety Risks (62 FR 19885,
April 23, 1997).
In addition, under the Regulatory Flexibility Act (RFA) (5 U.S.C.
601 et seq.), the Agency previously assessed whether establishing
tolerances, exemptions from tolerances, raising tolerance levels or
expanding exemptions might adversely impact small entities and
concluded, as a generic matter, that there is no adverse economic
impact. The factual basis for the Agency's generic certification for
tolerance actions was published on May 4, 1981 (46 FR 24950), and was
provided to the Chief Counsel for Advocacy of the Small Business
VI. Submission to Congress and the General Accounting Office
Under 5 U.S.C. 801(a)(1)(A), as added by the Small Business
Regulatory Enforcement Fairness Act of 1996, the Agency has submitted 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 General Accounting Office prior to publication of this rule in
today's Federal Register. This is not a ``major rule'' as defined by 5
List of Subjects in 40 CFR Part 180
Environmental protection, Administrative practice and procedure,
Agricultural commodities, Pesticides and pests, Reporting and record
Dated: February 18, 1998.
Janet L. Andersen,
Director, Biopesticides and Pollution Prevention Division, Office of
Therefore, it is proposed that 40 CFR chapter I be amended as
1. The authority citation for part 180 continues to read as
Authority: 21 U.S.C. 346a and 371.
2. Section 180.1193 is added to subpart D to read as follows:
Sec. 180.1193 Potassium dihydrogen phosphate; exemption from the
requirement of a tolerance.
Potassium dihydrogen phosphate is exempted from the requirement of
a tolerance in or on all food commodities when applied as a fungicide
in accordance with good agricultural practices.
[FR Doc. 98-5418 Filed 3-2-98; 8:45 am]
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