Peroxyacetic Acid; Exemption From the Requirement of a Tolerance

Note: EPA no longer updates this information, but it may be useful as a reference or resource.
 [Federal Register: May 6, 1998 (Volume 63, Number 87)]
[Rules and Regulations]               
[Page 24949-24955]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr06my98-13]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[OPP-300654; FRL-5789-3]
RIN 2070-AB78

 
Peroxyacetic Acid; Exemption From the Requirement of a Tolerance

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: This document establishes an exemption from the requirement of 
a tolerance for residues of the antimicrobial pesticide peroxyacetic 
acid up to 100 ppm, in or on raw agricultural commodities, in processed 
commodities, when such residues result from the use of peroxyacetic 
acid as an antimicrobial agent on fruits, tree nuts, cereal grains, 
herbs, and spices. Ecolab, Inc. requested this exemption under the 
Federal Food, Drug, and Cosmetic Act, as amended by the Food Quality 
Protection Act of 1996 (Pub. L. 104-170).

DATES: This regulation is effective May 6, 1998. Objections and 
requests for hearings must be received by EPA on or before July 6, 
1998.
ADDRESSES: Written objections and hearing requests, identified by the 
docket control number, [OPP-300654], must be submitted to: Hearing 
Clerk (1900), Environmental Protection Agency, Rm. M3708, 401 M St., 
SW., Washington, DC 20460. Fees accompanying objections and hearing 
requests shall be labeled ``Tolerance Petition Fees'' and forwarded to: 
EPA Headquarters Accounting Operations Branch, OPP (Tolerance Fees), 
P.O. Box 360277M, Pittsburgh, PA 15251. A copy of any objections and 
hearing requests filed with the Hearing Clerk identified by the docket 
control number, [OPP-300654], must also be submitted 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, 
bring a copy of objections and hearing requests to Rm. 119, CM #2, 1921 
Jefferson Davis Hwy., Arlington, VA.
    A copy of objections and hearing requests filed with the Hearing 
Clerk may also be submitted electronically by sending electronic mail 
(e-mail) to: opp-docket@epamail.epa.gov. Copies of objections and 
hearing requests must be submitted as an ASCII file avoiding the use of 
special characters and any form of encryption. Copies of objections and 
hearing requests will also be accepted on disks in WordPerfect 5.1/6.1 
file format or ASCII file format. All copies of objections and hearing 
requests in electronic form must be identified by the docket control 
number [OPP-300654]. No Confidential Business Information (CBI) should 
be submitted through e-mail. Electronic copies of objections and 
hearing requests on this rule may be filed online at many Federal 
Depository Libraries.

FOR FURTHER INFORMATION CONTACT: By mail: Marshall Swindell, Product 
Manager 33, Antimicrobials Division (7510W), Office of Pesticide 
Programs, Environmental Protection Agency, 401 M St., SW., Washington, 
DC 20460. Office location, telephone number, and e-mail address: 2800 
Crystal Drive, 6th Floor, Arlington, VA, 22202, 703-308-6341, e-mail: 
swindell.marshall@epamail.epa.gov.

SUPPLEMENTARY INFORMATION: In the Federal Register of January 14, 1998 
(63 FR 2232) (FRL-5759-6), EPA, issued a notice pursuant to section 408 
of the Federal Food, Drug, and Cosmetic Act (FFDCA), 21 U.S.C. 346a(e) 
announcing the filing of a pesticide petition (PP) 7F4808 for tolerance 
by Ecolab, Inc., 370 Wabasha Street, St. Paul, MN 55102. This notice 
included a summary of the petition prepared by Ecolab, Inc., the 
registrant. There were no comments received in response to the notice 
of filing.
    Subsequently, the proposed tolerance exemption was amended to 
delete meat, meat by-products, poultry, milk, and eggs. This was done 
because at the low proposed use concentrations, no residues of 
toxicological concern are expected on any animal feeds that may be 
exposed to peroxyacetic acid. Therefore, no residues of toxicological 
concern are anticipated either in animals that may consume these feeds, 
or in associated animal by-products.
    In addition, the proposed tolerance exemption was amended to 
include a maximum residue limit of 100 ppm for peroxyacetic acid. This 
limitation was added because of Agency concerns that a high use 
concentration could result in measurable residues of peroxyacetic acid. 
Residue data will be needed to increase or remove this limitation.

I. Risk Assessment and Statutory Findings

    New section 408(b)(2)(A)(i) of the FFDCA allows EPA to establish a 
tolerance or an exemption from the requirement of a tolerance (the 
legal limit for a pesticide chemical residue in or on a food) only if 
EPA determines that the tolerance or exemption from the requirement of 
a tolerance is ``safe.'' Section 408(b)(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.'' This includes exposure through 
drinking water and in residential settings, but does not include 
occupational exposure.
    Section 408(b)(2)(C) requires EPA to give special consideration to 
exposure of infants and children to the pesticide

[[Page 24950]]

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. . . 
.''
    EPA performs a number of analyses to determine the risks from 
aggregate exposure to pesticide residues. First, EPA determines the 
toxicity of pesticides based primarily on toxicological studies using 
laboratory animals. These studies address many adverse health effects, 
including (but not limited to) reproductive effects, developmental 
toxicity, toxicity to the nervous system, and carcinogenicity. Second, 
EPA examines exposure to the pesticide through the diet (e.g., food and 
drinking water) and through exposures that occur as a result of 
pesticide use in residential settings.

A. Toxicity

    1. Threshold and non-threshold effects. For many animal studies, a 
dose response relationship can be determined, which provides a dose 
that causes adverse effects (threshold effects) and doses causing no 
observed effects (the ``no-observed effect level'' or ``NOEL'').
    Once a study has been evaluated and the observed effects have been 
determined to be threshold effects, EPA generally divides the NOEL from 
the study with the lowest NOEL by an uncertainty factor (usually 100 or 
more) to determine the Reference Dose (RfD). The RfD is a level at or 
below which daily aggregate exposure over a lifetime will not pose 
appreciable risks to human health.
    An uncertainty factor (sometimes called a ``safety factor'') of 100 
is commonly used since it is assumed that people may be up to 10 times 
more sensitive to pesticides than the test animals, and that one person 
or subgroup of the population (such as infants and children) could be 
up to 10 times more sensitive to a pesticide than another. In addition, 
EPA assesses the potential risks to infants and children based on the 
weight of the evidence of the toxicology studies and determines whether 
an additional uncertainty factor is warranted. Thus, an aggregate daily 
exposure to a pesticide residue at or below the RfD (expressed as 100% 
or less of the RfD) is generally considered acceptable by EPA.
    EPA generally uses the RfD to evaluate the chronic risks posed by 
pesticide exposure. For shorter term risks, EPA calculates a margin of 
exposure (MOE) by dividing the estimated human exposure into the NOEL 
from the appropriate animal study. Commonly, EPA finds MOEs lower than 
100 to be unacceptable. This 100-fold MOE is based on the same 
rationale as the 100-fold uncertainty factor.
    Lifetime feeding studies in two species of laboratory animals are 
conducted to screen pesticides for cancer effects. When evidence of 
increased cancer is noted in these studies, the Agency conducts a 
weight of the evidence review of all relevant toxicological data 
including short-term and mutagenicity studies and structure activity 
relationship. Once a pesticide has been classified as a potential human 
carcinogen, different types of risk assessments (e.g., linear low dose 
extrapolations or MOE calculation based on the appropriate NOEL) will 
be carried out based on the nature of the carcinogenic response and the 
Agency's knowledge of its mode of action.
    2. Differences in toxic effect due to exposure duration. The 
toxicological effects of a pesticide can vary with different exposure 
durations. EPA considers the entire toxicity data base, and based on 
the effects seen for different durations and routes of exposure, 
determines which risk assessments should be done to assure that the 
public is adequately protected from any pesticide exposure scenario. 
Both short and long durations of exposure are always considered. 
Typically, risk assessments include ``acute,'' ``short-term,'' 
``intermediate term,'' and ``chronic'' risks. These assessments are 
defined by the Agency as follows.
    Acute risk, by the Agency's definition, results from 1-day 
consumption of food and water, and reflects toxicity which could be 
expressed following a single oral exposure to the pesticide residues. 
High end exposure to food and water residues are typically assumed.
    Short-term risk results from exposure to the pesticide for a period 
of 1-7 days, and therefore overlaps with the acute risk assessment. 
Historically, this risk assessment was intended to address primarily 
dermal and inhalation exposure which could result, for example, from 
residential pesticide applications. However, since enaction of the Food 
Quality Protection Act of 1996 (FQPA), this assessment has been 
expanded to include both dietary and non-dietary sources of exposure, 
and will typically consider exposure from food, water, and residential 
uses when reliable data are available.
    In this assessment, risks from average food and water exposure, and 
high-end residential exposure, are aggregated. High-end exposures from 
all three sources are not typically added because of the very low 
probability of this occurring in most cases, and because the other 
conservative assumptions built into the assessment assure adequate 
protection of public health. However, for cases in which high-end 
exposure can reasonably be expected from multiple sources (e.g. 
frequent and widespread homeowner use in a specific geographical area), 
multiple high-end risks will be aggregated and presented as part of the 
comprehensive risk assessment/characterization.
    Since the toxicological endpoint considered in this assessment 
reflects exposure over a period of at least 7 days, an additional 
degree of conservatism is built into the assessment; i.e., the risk 
assessment nominally covers 1-7 days exposure, and the toxicological 
endpoint/NOEL is selected to be adequate for at least 7 days of 
exposure. (Toxicity results at lower levels when the dosing duration is 
increased.)
    Intermediate-term risk results from exposure for 7 days to several 
months. This assessment is handled in a manner similar to the short-
term risk assessment.
    Chronic risk assessment describes risk which could result from 
several months to a lifetime of exposure. For this assessment, risks 
are aggregated considering average exposure from all sources for 
representative population subgroups including infants and children.

B. Aggregate Exposure

    In examining aggregate exposure, FFDCA section 408 requires that 
EPA take into account available and reliable information concerning 
exposure from the pesticide residue in the food in question, residues 
in other foods for which there are tolerances, residues in groundwater 
or surface water that is consumed as drinking water, and other non-
occupational exposures through pesticide use in gardens, lawns, or 
buildings (residential and other indoor uses).
    Dietary exposure to residues of a pesticide in a food commodity are 
estimated by multiplying the average daily consumption of the food 
forms of that commodity by the tolerance level or the anticipated 
pesticide residue level. The Theoretical Maximum Residue Contribution 
(TMRC) is an estimate of the level of residues consumed daily if each 
food item contained pesticide residues equal to the tolerance.
    In evaluating food exposures, EPA takes into account varying 
consumption patterns of major identifiable subgroups of consumers, 
including infants and children. The TMRC is a ``worst case'' estimate 
since it is based on the

[[Page 24951]]

assumptions that food contains pesticide residues at the tolerance 
level and that 100% of the crop is treated by pesticides that have 
established tolerances.
    If the TMRC exceeds the RfD or poses a lifetime cancer risk that is 
greater than approximately one in a million, EPA attempts to derive a 
more accurate exposure estimate for the pesticide by evaluating 
additional types of information (anticipated residue data and/or 
percent of crop treated data) which show, generally, that pesticide 
residues in most foods when they are eaten are well below established 
tolerances.
    Percent of crop treated estimates are derived from federal and 
private market survey data. Typically, a range of estimates are 
supplied and the upper end of this range is assumed for the exposure 
assessment. By using this upper end estimate of percent of crop 
treated, the Agency is reasonably certain that exposure is not 
understated for any significant sub-population group.
    Further, regional consumption information is taken into account 
through EPA's computer-based model for evaluating the exposure of 
significant sub-populations including several regional groups, to 
pesticide residues. For peroxyacetic acid, based on the lack of any 
residues of toxicological concern, it is unlikely that significant 
exposure through the proposed use would occur to any sub-population 
although sensitive sub-populations may exist (eg.,catalase deficient 
individuals).

II. Aggregate Risk Assessment and Determination of Safety

    Consistent with section 408(b)(2)(D), EPA has reviewed the 
available scientific data and other relevant information in support of 
this action, EPA has sufficient data to assess the hazards of 
peroxyacetic acid and to make a determination on aggregate exposure, 
consistent with section 408(b)(2), for an exemption of a requirement 
for a tolerance for residues of peroxyacetic acid up to 100 pm, in or 
on raw agricultural commodities, in processed commodities, when such 
residues result from the use of peroxyacetic acid as an antimicrobial 
agent on fruits, tree nuts, cereal grains, herbs, and spices. EPA's 
assessment of the dietary exposures and risks associated with 
establishing the tolerance follows.

A. Toxicological Profile

    EPA has evaluated the available toxicity data and considered its 
validity, completeness, and reliability as well as the relationship of 
the results of the studies 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. The nature of the toxic effects caused by peroxyacetic acid 
(C<INF>2</INF>H<INF>4</INF>O<INF>3</INF>) are discussed below.
    Ecolab, Inc. has requested a waiver of all toxicology testing 
requirements for peroxyacetic acid. This includes waivers for all 
acute, 90-day sub-chronic, chronic, carcinogenicity, developmental, 
reproductive, mutagenicity, neurotoxicity and metabolism requirements. 
Ecolab's rationale for waivers in each of these areas is similar, and 
are summarized by the following four arguments:
    1. Available data at the Agency are sufficient to estimate the 
potential human health hazard of the end use product.
    2. Peroxyacetic acid reacts rapidly on contact with material such 
as food and is degraded to moieties which present no toxicological 
concern. The primary degradation products of peroxyacetic acid are 
acetic acid, which is generally regarded as safe (GRAS) according to 
the Food and Drug Administration (21 CFR 184.1005), water, and oxygen.
    Based on the chemical reactivity of this compound and the unstable 
nature of the peroxide bond, conduct of long term residue or metabolism 
studies would be extremely difficult and unreliable. This peroxyacetic 
acid petition is also the companion to a similar tolerance petition 
being ruled on for hydrogen peroxide. Peroxyacetic acid and hydrogen 
peroxide are classified as peroxy compounds and have similar 
characteristics for degradation, residue chemistry, dose-relationship 
toxicology, and risk of exposure with the proposed food contact uses.
    The published Reregistration Eligibility Document for Peroxy 
Compounds (Case 4072, December, 1993), has waived all further 
toxicology testing requirements for peroxyacetic acid.
    The Agency has reviewed the data waivers requested and concurs that 
no additional acute short term or long term toxicology or mutagenicity 
testing will be needed for peroxyacetic acid for the following reasons.
    1. Peroxyacetic acid is highly reactive and short lived because of 
the inherent instability of the peroxide bond (i.e., the O-O bond). 
Agitation or contact with rough surfaces, sunlight, organics, and 
metals can accelerate decomposition. The instability of peroxyacetic 
acid to exist as itself, along with detoxifying enzymes found in cells 
(eg., catalase, glutathione peroxidase), makes it very difficult to 
find any residues of peroxyacetic acid in or on foods (at the proposed 
use levels), by conventional analytical methods.
    The proposed food contact applications utilize very low 
concentrations of peroxyacetic acid. Therefore, food residues produced 
by the proposed uses are expected to be short-lived, based on half-
lives for peroxyacetic acid which can be as short as a few minutes. The 
primary degradates are acetic acid, oxygen, and water, and these 
degradates are not of toxicological concern.
    2. There are acceptable acute generic data referenced in the 
Reregistration Eligibility Document for Peroxy Compounds (December 
1993, Case 4072). Peroxyacetic acid was found to be corrosive and 
severely irritating to the eyes, skin, and mucous membranes but only 
when high concentrations were used. The proposed food contact use 
patterns are not expected to result in any residue levels of 
toxicological concern. The RED document waived all additional non-acute 
toxicology data requirements for peroxyacetic acid.
    3. No data exists for the subchronic, chronic, carcinogenicity, 
mutagenicity, developmental and reproductive toxicity of peroxyacetic 
acid. However, peroxyacetic acid shares similar chemical 
characteristics with hydrogen peroxide which has a more extensive 
toxicology data base. For example, peroxyacetic acid and hydrogen 
peroxide both decompose into two identical degradates that do not pose 
any toxicological concern. These two degradates are oxygen and water. 
Acetic acid is the third additional residue degradate of peroxyacetic 
acid which also does not pose any toxicological concern.
    Peroxyacetic acid and hydrogen peroxide also show similar chemical 
characteristics for corrosivity, pH, rapid peroxide bond dissociation, 
and production of oxygen molecules. Because of these similar chemical 
characteristics, and low expected exposures with the proposed uses, the 
dose-response toxicology relationships (i.e., adverse effects 
experienced only at very high doses) shown by the data for hydrogen 
peroxide, can also be expected with peroxyacetic acid. The remaining 
toxicology testing requirements for peroxyacetic acid were waived 
because of the similar chemical characteristics, similar expected dose-
response relationships with hydrogen peroxide, low exposure levels 
under the proposed uses, and for the reasons given above.

[[Page 24952]]

    The following generic acute toxicology data for peroxyacetic acid 
were cited in the 1993 RED document.
    Acute studies for peroxyacetic acid-- i. A study on rats showed an 
acute oral LD<INF>50</INF> of 1,540 milligrams/kilogram (mg/kg).
    ii. A study on rabbits showed an acute dermal LD<INF>50</INF> of 
1,410 mg/kg.
    iii. A study on rats showed an acute inhalation LC<INF>50</INF> of 
0.450 mg/L.
    iv. An eye irritation study on rabbits produced severe irritation.
    v. A dermal irritation study on rabbits showed hydrogen peroxide 
was corrosive.

B. Toxicological Endpoints

    1. Acute toxicity. The Agency has concluded that with the proposed 
food contact uses of peroxyacetic acid, no apparent toxicity endpoint 
exists to suggest any evidence of significant toxicity from a one-day 
or single-event exposure.
    2. Short - and intermediate - term toxicity. The Agency has 
concluded that for the proposed food contact uses of peroxyacetic acid, 
based on the similarity and commonality in the peroxide bond chemistry, 
residues, degradates, and also with the dose-response relationships 
with hydrogen peroxide, no apparent toxicity endpoint would be expected 
from short and intermediate term exposure.
    3. Chronic toxicity. A RfD for peroxyacetic acid has not been 
established because of its short half life and lack of any residues and 
degradates of toxicological concern. As discussed in the December 1993 
Reregistration Eligibility Document for Peroxy Compounds, and in this 
final rule, under the proposed and existing dietary related use 
patterns (i.e., raw and processed agricultural commodities, food 
processing equipment in breweries, wineries, and beverage plants), 
there is also expected to be a lack of any residues and degradates of 
toxicological concern.
    4. Carcinogenicity. The Agency believes that based on the known 
chemistry of peroxy compounds, toxic effects occur as a result of 
species formed either during spontaneous decomposition or enzymatic 
conversion of the peroxy bond (i.e., O-O bond). These effects occur 
only after long term administration of high dose levels, where the 
parent compound is continually present. Available data show that 
peroxyacetic acid rapidly breaks down into oxygen, water, and acetic 
acid. Because of this rapid decomposition, the Agency does not expect 
residues of the parent compound on the treated comodities.
    Based on the proposed use concentrations for peroxyacetic acid, and 
data indicating a lack of residues of concern on food, exposure to 
peroxyacetic acid under the proposed food contact use concentrations is 
not likely to result in any adverse clinical effects, including 
promotion of carcinogenisis. This conclusion is supported by the rapid 
decomposition of peroxyacetic acid into oxygen, water, and acetic acid, 
which are not of toxicological concern, and the existence of specific 
enzymes in the human body (i.e., catalase and glutathione peroxidase) 
which also can break down peroxyacetic acid.

C. Exposures and Risks

    1. From food and feed uses. An exemption from the requirement of a 
tolerance is being established (40 CFR 180.1196) for the residues of 
peroxyacetic acid) up to 100 ppm, in or on a variety of (raw 
agricultural commodities, in processed commodities, when such residues 
result from the use of peroxyacetic acid as an antimicrobial agent on 
fruits, tree nuts, cereal grains, herbs, and spices.
    There are no existing tolerances or exemptions from tolerances in 
title 40 of the CFR for peroxyacetic acid for direct food and feed 
contact uses. The following 21 CFR tolerances and/or exemptions from 
tolerances are noted:
    Under 21 CFR 184.1005, the acetic acid degradate of peroxyacetic 
acid is GRAS as a direct food additive substance when used in baked 
goods, cheeses, dairy product analogs, chewing gum, condiments, 
relishes, fats, oils, gravies, sauces, and meat products. Under 21 CFR 
178.1010, peroxyacetic acid is approved for use as a sanitizing 
solution for use on food processing equipment and utensils, and on 
dairy processing equipment. It is also approved for use in sterilizing 
polymeric food-contact surfaces. Under 21 CFR 173.315, peroxyacetic 
acid is approved for use in washing or to assist in the lye peeling of 
fruits and vegetables.
    Risk assessments were conducted by EPA to assess dietary exposures 
and risks from peroxyacetic acid as follows:
    i. Acute exposure and risk. Acute dietary risk assessments are 
performed for a food-use pesticide if a toxicological study has 
indicated the possibility of an effect of concern occurring as a result 
of a one day or single exposure. No acute exposure and risk assessment 
is applicable for peroxyacetic acid because no acute toxicological 
effects of concern are anticipated with the proposed food contact uses 
for peroxyacetic acid. This is due to the lack of any residues of 
toxicological concern as a result of the rapid decomposition of 
peroxyacetic acid into acetic acid, oxygen, and water.
    ii. Chronic exposure and risk. Residues of peroxyacetic acid are 
not expected to remain on the surface of materials which it contacts. 
Therefore, the risk from dietary exposure is expected to be negligible. 
No chronic exposure and risk assessment is applicable because no 
chronic toxicological effects are anticipated with the proposed food 
contact uses for peroxyacetic acid. This is due to the lack of any 
residues of toxicological concern as a result of the rapid 
decomposition of peroxyacetic acid into acetic acid, oxygen, and water.
    2. From drinking water. Although the proposed food contact uses for 
peroxyacetic acid may result in transfer of peroxyacetic acid to 
potential drinking water sources, no risk assessment is applicable 
because of: (a) the rapid degradation of peroxyacetic acid into acetic 
acid, oxygen, and water, and (b) there are not expected to be any 
residues of toxicological concern. Information from the EPA Office of 
Water also indicates that when used for potable water disinfection, no 
measurable residues of peroxyacetic acid were present by the time the 
water is pumped through the distribution system and arrived at the tap.
    3. From non-dietary exposure. Peroxyacetic acid is currently 
registered by EPA for a wide variety of uses including: agricultural 
premises and equipment; food handling/storage establishments premises 
and equipment; commercial, institutional and industrial premises and 
equipment; residential and public access premises; medical premises and 
equipment; materials preservation; and industrial processes and water 
systems. The Agency does not know of all approved or actual uses for 
peroxyacetic acid. However, non-dietary exposures are not expected to 
pose any quantifiable added risk because of the lack of any expected 
residues and degradates of toxicological concern. Minimal residues and 
degradates are expected due to previously discussed unique chemistry 
associated with peroxide bond chemistry.
    4. Cumulative exposure to substances with common mechanism of 
toxicity. Section 408(b)(2)(D)(v) requires that, when considering 
whether to establish, modify, or revoke a tolerance, 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.''

[[Page 24953]]

    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 toxicity and 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 mechanism 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 
that 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 and evaluating the 
cumulative effects of such chemicals. The Agency anticipates, however, 
that even as its understanding of the science of common mechanisms 
increases, decisions on specific classes of chemicals will be heavily 
dependent on chemical specific data, much of which may not be presently 
available.
    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 
issues can be resolved. These pesticides include pesticides that are 
toxicologically 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).
    The Agency does not at this time have data specifically either to 
support, or to refute a common mechanism of toxicity for peroxy 
compounds (i.e., hydrogen peroxide, peroxyacetic acid). The Agency 
believes that based on the known common chemistry of peroxy compounds, 
toxic effects occur as a result of species formed either during 
spontaneous decomposition or enzymatic conversion of the peroxy bond 
(i.e., O-O bond). These effects occur only after long term 
administration of high dose levels, where the parent compound is 
continually present. Although a common mechanism of toxicity may or may 
not be inferred, the Agency's concerns for cumulative risk is mitigated 
by the lack of any measurable residues of the parent compound 
(peroxyacetic acid) at proposed use levels, and by the rapid 
decomposition of the parent compound into products which are not of 
toxicological concern (i.e., oxygen and water). As data become 
available, the Agency may require further studies on the peroxy 
compounds to determine whether a cumulative risk assessment is 
warranted.
    The Agency does not have, at this time, available data to determine 
whether peroxyacetic acid shares a common mechanism of toxicity with 
other substances or how to include this pesticide in a cumulative risk 
assessment. For the purposes of this tolerance action, EPA has not 
assumed that peroxyacetic acid has a common mechanism of toxicity with 
other substances.

D. Aggregate Risks and Determination of Safety for U.S. Population

    1. Acute, short term and intermediate risk. The Agency has 
concluded that no toxicological endpoint exists for peroxyacetic acid 
with the proposed food contact uses to suggest any evidence of 
significant toxicity from acute, short term or intermediate term 
exposures. Short- and intermediate-term aggregate exposure takes into 
account chronic dietary food and water (considered to be a background 
exposure level) plus indoor and outdoor residential exposure.
    The Agency concludes that there is a reasonable certainty of no 
harm for acute, short term, and intermediate risk from aggregate 
exposure to peroxyacetic acid under the proposed use concentrations.
    2. Chronic risk. Low residues of peroxyacetic acid are expected 
from the proposed food contact uses and these residues are expected to 
convert rapidly into the harmless degradates of acetic acid, oxygen, 
and water. Therefore, the chronic risk from dietary exposure is 
expected to be negligible. No chronic exposure and risk assessment is 
applicable because no chronic toxicological effects are anticipated 
with the proposed food contact uses for peroxyacetic acid.
    The Agency concludes that there is a reasonable certainty of no 
harm for chronic risk from aggregate exposure to peroxyacetic acid 
under the proposed use concentrations.

E. Aggregate Cancer Risk for U.S. Population

    The Agency believes that based on the known chemistry of peroxy 
compounds, toxic effects occur as a result of species formed either 
during spontaneous decomposition or enzymatic conversion of the peroxy 
bond (i.e., O-O bond). These effects occur only after long term 
administration of high dose levels, where the parent compound is 
continually present. Available data show that peroxyacetic acid rapidly 
breaks down into oxygen, water, and acetic acid. Because of this rapid 
decomposition, the Agency does not expect residues of the parent 
compound on the treated commodities.
    Based on the proposed use concentrations for peroxyacetic acid, and 
data indicating a lack of residues of concern on food, exposure to 
peroxyacetic acid under the proposed food contact use concentrations is 
not likely to result in any adverse clinical effects, including 
promotion of carcinogenisis. This conclusion is supported by the rapid 
decomposition of peroxyacetic acid into oxygen, water, and acetic acid, 
which are not of toxicological concern, and the existence of specific 
enzymes in the human body (i.e., catalase and glutathione peroxidase) 
which also can break down peroxyacetic acid.
    The Agency concludes that cancer cancer risk for the U.S. 
population from aggregate exposure to peroxyacetic acid is negligible 
under the proposed food contact use concentrations.

F. Aggregate Risks and Determination of Safety for Infants and Children

    Safety factor for infants and children. In assessing the potential 
for additional sensitivity of infants and children to residues of 
peroxyacetic acid, EPA considered data from developmental and 
reproductive toxicity studies available on hydrogen peroxide from the 
scientific literature and summarized by the Office of Water. The 
developmental toxicity studies are designed to evaluate adverse effects 
on the developing organism resulting from maternal pesticide exposure 
during gestation. Reproduction studies provide information relating to 
effects from exposure to the pesticide on the reproductive capability 
of mating animals and data on systemic toxicity.
    FFDCA section 408 provides that EPA shall apply an additional 
tenfold margin of 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

[[Page 24954]]

of safety will be safe for infants and children.
    Margins of safety are incorporated into EPA risk assessments either 
directly through use of a MOE analysis or through using uncertainty 
(safety) factors in calculating a dose level that poses no appreciable 
risk to humans. In either case, EPA generally defines the level of 
appreciable risk as exposure that is greater than 1/100 of the NOEL in 
the animal study appropriate to the particular risk assessment. This 
100-fold uncertainty factor/margin of exposure is designed to account 
for inter-species extrapolation and intra-species variability.
    In the case of the proposed food contact uses for peroxyacetic 
acid, because of the lack of any significant residues of toxicological 
concern, a NOEL was not identified for risk assessment purposes, and 
the uncertainty (safety) factor approach was not used for assessing any 
risk level by peroxyacetic acid. For the same reason, an additional 
safety factor to protect infants and children is unnecessary. 
Additionally, based on the following information, no increased 
susceptibility to infants or children is expected to occur.
    1. Three studies on the developmental and reproductive effects of 
hydrogen peroxide (and by similarity, peroxyacetic acid) are available. 
The data from these studies indicates that no apparent developmental or 
reproductive effects were observed from administration of hydrogen 
peroxide at concentrations up to 1% (1,000 mg/kg).
    2. Peroxyacetic acid is a highly reactive and short lived molecule 
because of the inherent instability of the peroxide bond (i.e., the O-O 
bond). Agitation or contact with rough surfaces, sunlight, organics, 
and metals accelerates dissociation. The instability of peroxyacetic 
acid to exist as itself, along with natural detoxifying enzymes found 
in plant and animal cells (eg., catalase, glutathione peroxidase), 
makes it very difficult to find any residues of peroxyacetic acid in or 
on foods (at proposed use levels), by conventional analytical methods. 
The proposed food contact applications utilize very low concentrations 
of peroxyacetic acid ( ppm). Food residues are expected to be short-
lived and are not expected to accumulate. This is because peroxyacetic 
acid dissociates rapidly into acetic acid, oxygen, and water. The 
Agency has no toxicological concern with acetic acid, oxygen, and 
water.
    3. A waiver was granted for all the remaining toxicology testing 
requirements because of the reasons given in items a and b above.
    Therefore, because of the rapid decomposition of peroxyacetic acid 
residues into degradates that are of no toxicological concern (i.e., 
oxygen, water, acetic acid), the Agency concludes that there is a 
reasonable certainty of no harm for infants and children from exposure 
to peroxyacetic acid under the proposed food contact use 
concentrations.

III. Other Considerations

A. Endocrine Disruption

    EPA is required to develop a screening program to determine whether 
certain substances (including all pesticides and inerts) ``may have an 
effect in humans that is similar to an effect produced by a naturally 
occurring estrogen, or such other endocrine effect...'' The Agency is 
currently working with interested stakeholders, including other 
government agencies, public interest groups, industry and research 
scientists in developing a screening and testing program and a priority 
setting scheme to implement this program. Congress has allowed three 
years from the passage of the FQPA (August, 1999) to implement this 
program. At that time, the EPA may require further testing of this 
active ingredient and end use products for endocrine disrupter effects. 
There is no current evidence to suggest that peroxyacetic acid acts in 
a manner similar to any known hormone or that it acts as an endocrine 
disrupter.

B. Analytical Enforcement Methodology

    Because an exemption from the requirement of a tolerance is being 
granted for peroxyacetic acid, an enforcement analytical method is not 
needed. However, an adequate analytical method (called QATM 202 by 
Ecolab, Inc., a redox titration procedure), is available in the 
interim. Because of the long lead time from establishing a tolerance or 
exemption of the requirement of a tolerance to publication of the 
enforcement methodology in the Pesticide Analytical Manual., Volume II, 
the analytical method is being made available to anyone interested in 
pesticide enforcement when requested from Norm Cook, Antimicrobials 
Division (7510W), Office of Pesticide Programs, U.S. Environmental 
Protection Agency, 401 M Street, SW., Washington, DC 20460. Office 
location and telephone number: 2800 Crystal Drive, 6th Floor, 
Arlington, VA 22202, 703-308-6411.

C. Magnitude of Residues

    Residues of peroxyacetic acid are short lived on treated crops and 
are not expected to bioaccumulate in livestock and/or poultry that 
consume treated feedstuffs. Because of the lack of any residues of 
toxicological concern, the Agency has waived this data requirement.

D. International Residue Limits

    There are no Codex Alimentarius Commission (Codex) Maximum Residue 
Levels (MRLs) for peroxyacetic acid.

IV. Conclusion

    Therefore, the exemption from the requirement of a tolerance is 
established for residues of peroxyacetic acid up to 100 ppm in or on 
raw agricultural commodities, in processed commodities, when such 
residues result from the use of peroxyacetic acid as an antimicrobial 
agent on fruits, tree nuts, cereal grains, herbs, and spices.
    It should be understood that the Agency may take appropriate 
regulatory action, and/or require the submission of additional data to 
support the exemption from the requirement of a tolerance for 
peroxyacetic acid, if new relevant adverse effects information comes to 
the Agency's attention.

V. Objections and Hearing Requests

    The new FFDCA section 408(g) provides essentially the same process 
for persons to ``object'' to a tolerance regulation issued by EPA under 
new section 408(e) and (l)(6) as was provided in the old section 408 
and in section 409. However, the period for filing objections is 60 
days, rather than 30 days. EPA currently has procedural regulations 
which govern the submission of objections and hearing requests. These 
regulations will require some modification to reflect the new law. 
However, until those modifications can be made, EPA will continue to 
use those procedural regulations with appropriate adjustments to 
reflect the new law.
    Any person may, by July 6, 1998, file written objections to any 
aspect of this regulation and may also request a hearing on those 
objections. Objections and hearing requests must be filed with the 
Hearing Clerk, at the address given above (40 CFR 178.20). A copy of 
the objections and/or hearing requests filed with the Hearing Clerk 
should be submitted to the OPP docket for this rulemaking. The 
objections submitted must specify the provisions of the regulation 
deemed objectionable and the grounds for the objections (40 CFR 
178.25).
    Each objection must be accompanied by the fee prescribed by 40 CFR 
180.33(i). If a hearing is requested, the objections must include a 
statement of

[[Page 24955]]

the factual issues on which a hearing is requested, the requestor's 
contentions on such issues, and a summary of any evidence relied upon 
by the requestor (40 CFR 178.27).
    A request for a hearing will be granted if the Administrator 
determines that the material submitted shows the following: There is 
genuine and substantial issue of fact; there is a reasonable 
possibility that available evidence identified by the requestor would, 
if established, resolve one or more of such issues in favor of the 
requestor, taking into account uncontested claims or facts to the 
contrary; and resolution of the factual issues in the manner sought by 
the requestor would be adequate to justify the action requested (40 CFR 
178.32).
    Information submitted in connection with an objection or hearing 
request 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 
information that does not contain CBI must be submitted for inclusion 
in the public record. Information not marked confidential may be 
disclosed publicly by EPA without prior notice.

VI. Public Docket

    EPA has established a record for this rulemaking under docket 
control number [OPP-300654] (including any comments and data submitted 
electronically). 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 public record is located in Room 119 of the Public Information 
and Records Integrity Branch, Information Resources and Services 
Division (7502C), Office of Pesticide Programs, Environmental 
Protection Agency, Crystal Mall #2, 1921 Jefferson Davis Hwy., 
Arlington, VA.
    Electronic comment may be sent directly to EPA at:
    opp-docket@epamail.epa.gov.


    Electronic comments must be submitted as an ASCII file avoiding the 
use of special characters and any form of encryption.
    The official record for this rulemaking, as well as the public 
version, as described above will be kept in paper form. Accordingly, 
EPA will transfer any copies of objections and hearing requests 
received electronically into printed, paper form as they are received 
and will place the paper copies in the official rulemaking record which 
will also include all comments submitted directly in writing. The 
official rulemaking record is the paper record maintained at the 
Virginia address in ``ADDRESSES'' at the beginning of this document.

VII. Regulatory Assessment Requirements

    This final rule establishes an exemption from the tolerance 
requirement under FFDCA section 408(d) 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). 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 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 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, since these tolerances and exemptions that are 
established on the basis of a petition under FFDCA section 408(d), 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. Nevertheless, the Agency has 
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 published on May 
4, 1981 (46 FR 24950) and was provided to the Chief Counsel for 
Advocacy of the Small Business Administration.

VIII. 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 
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: April 30, 1998.

Frank Sanders,
Director, Antimicrobials Division, Office of Pesticide Programs.
    Therefore, 40 CFR chapter I is amended as follows:

PART 180-- [AMENDED]

    1. The authority citation for part 180 continues to read as 
follows:

    Authority: 21 U.S.C. 346a and 371.

    2. Section 180.1196 is added to read as follows:


Sec. 180.1196  Peroxyacetic acid; exemption from the requirement of a 
tolerance.

    An exemption from the requirement of a tolerance is established for 
residues of peroxyacetic acid up to 100 ppm in or on raw agricultural 
commodities, in processed commodities, when such residues result from 
the use of peroxyacetic acid as an antimicrobial agent on fruits, tree 
nuts, cereal grains, herbs, and spices.

[FR Doc. 98-12036 Filed 5-5-98; 8:45 am]
BILLING CODE 6560-50-F
Peroxyacetic Acid; Exemption From the Requirement of a Tolerance

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