United States
Environmental Protection
Agency
Prevention, Pesticides
And Toxic Substances
(7508W)
EPA-738-F-94-013
September 1994
R.E.D. FACTS
Pesticide
Reregistration
Use Profile
Regulatory
History
Metalaxyl
All pesticides sold or distributed in the United States must be registered
by EPA, based on scientific studies showing that they can be used without
posing unreasonable risks to people or the environment. Because of advances
in scientific knowledge, the law requires that pesticides which were first
registered years ago be reregistered to ensure that they meet today's more
stringent standards.
In evaluating pesticides for reregi strati on, EPA obtains and reviews a
complete set of studies from pesticide producers, describing the human health
and environmental effects of each pesticide. The Agency imposes any
regulatory controls that are needed to effectively manage each pesticide's
risks. EPA then reregisters pesticides that can be used without posing
unreasonable risks to human health or the environment.
When a pesticide is eligible for reregi strati on, EPA announces this and
explains why in a Reregistration Eligibility Decision (RED) document. This
fact sheet summarizes the information in the RED for reregi strati on Case
0081, metalaxyl.
Metalaxyl is a systemic fungicide used to control plant diseases caused
by the Oomycetes or water-mold fungi. It is used on many food and feed
crops, and on non-food, residential and greenhouse crops such as tobacco,
ornamental plants, trees, shrubs and vines, and lawns and turf.
Formulations include a dust, granular, wettable powder, emulsifiable
concentrate, flowable concentrate, crystalline and ready-to-use liquid.
Metalaxyl may be applied by foliar application, soil incorporation, surface
spraying, drenching, sprinkler or drip irrigation, soil mix or seed treatment.
Use practice limitations on current product labeling prohibit use of treated
seed for feed, food or oil; feeding clippings, crop waste or vines to livestock;
or grazing treated areas. Preharvest interval restrictions also apply.
Metalaxyl was first registered as a pesticide in the U.S. in 1979. EPA
issued Registration Standards for metalaxyl in June 1981 (NTIS #PB82-
172297) and September 1988 (NTIS #PB89-128979). A June 1991 Data
Call-In (DCI) required additional aquatic plant growth and field rotational
crop studies.
Currently, 81 metalaxyl products are registered; 35 of these are full
Federal registrations and 46 are State special local need registrations. These
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Human Health
Assessment
products contain metalaxyl as the sole active ingredient or in combination
with other active ingredients.
Toxicity
Metalaxyl generally is of low acute toxicity but is a moderate eye
irritant and has been placed in Toxicity Category II (indicating the second-
highest degree of acute toxicity) for eye irritation effects.
In a subchronic feeding study using rats, reduced food consumption and
liver cell effects were noted at the highest dose tested. In a dermal study
using rabbits, no treatment-related effects were observed.
In a chronic toxicity study using beagle dogs, blood serum enzyme
effects and increased liver weights were noted in the highest dose group. A
study using rats resulted in liver effects.
Cancer studies using rats and mice raised concerns about the incidence
of thyroid, adrenal and liver tumors. EPA reviewed this issue in 1985 and
concluded that the studies demonstrated that metalaxyl did not have
carcinogenic potential in laboratory animals. In December 1985, EPA
classified metalaxyl as a Group E carcinogen; that is, a chemical that does not
show evidence of carcinogenicity for humans.
A developmental toxicity study using rats resulted in maternal toxicity
and fetotoxicity at the higher dose levels. However, no treatment-related
developmental effects were noted in a study using rabbits. Metalaxyl does not
cause reproductive toxicity or mutagenicity. A tobacco smoke inhalation
study using rats indicates that toxicological effects beyond those associated
with heavy cigarette smoking are unlikely.
Dietary Exposure
People may be exposed to residues of metalaxyl through the diet.
Tolerances or maximum residue limits have been established for well over
100 raw agricultural commodities, processed foods and feed (please see 40
CFR 180.408(a), (b) and (c); 40 CFR 185.4000(a), (b) and (d); and 40 CFR
186.4000(a), (b) and (d)). EPA has reassessed the metalaxyl tolerances and
found that numerous revisions are necessary. These revisions will be handled
administratively.
Numerous international Codex maximum residue limits (MRLs) have
been established for metalaxyl. Harmonization of Codex MRLs and U.S.
tolerances for metalaxyl is not possible at this time as Codex and U.S.
tolerance definitions are incompatible.
EPA has assessed the dietary risk posed by metalaxyl. For the overall
U.S. population and 22 population subgroups, exposure from all current
metalaxyl tolerances represents 16% of the Reference Dose (RfD), or amount
believed not to cause adverse effects if consumed daily over a 70-year
lifetime. The exposure level of the most highly exposed subgroup, children
ages 1 through 6, represents 31% of the RfD.
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Information on the percent of crop actually treated with metalaxyl was
included to more accurately estimate the dietary exposure of the same
population groups. The resulting Anticipated Residue Contribution (ARC)
for the overall U.S. population represents 8% of the RfD, and the ARC for
children is 15% of the RfD. When proposed metalaxyl tolerance changes are
considered, the exposure estimates for the overall U.S. population and all
subgroups are below the RfD. Therefore, it appears that chronic dietary risk
is minimal.
Occupational and Residential Exposure
Based on current use patterns, workers may be exposed to metalaxyl
both during and after applications in agricultural and other settings. However,
neither an application nor a post-application exposure assessment is required
because metalaxyl does not pose sufficient toxicity concerns.
Based on a reevaluation of eye irritation data (Toxicity Category II), the
12-hour Restricted Entry Interval (REI) imposed by the Worker Protection
Standard (WPS) is being increased to 24 hours to better protect workers. A
protective eyewear requirement also is being added to the Personal Protective
Equipment (PPE) previously required for early entry.
Human Risk Assessment
Metalaxyl generally is of low acute toxicity but is an eye irritant. It has
been classified as a Group E carcinogen; that is, a chemical showing evidence
of non-carcinogenicity for humans.
Although people may be exposed to residues of metalaxyl in many food
commodities, the chronic dietary risk from all uses is minimal. Application
and post-application risks to workers and others also are minimal because
metalaxyl has no toxicological endpoints of concern. Since metalaxyl can
irritate the eyes, a 24-hour restricted entry interval (REI) is being imposed and
use of personal protective equipment (PPE) including protective eyewear is
required.
Environmental
Assessment
Environmental Fate
Metalaxyl is moderately stable under normal environmental conditions.
It is photolytically stable in water when exposed to sunlight, with a half-life
of 400 days, and is stable to photodegradation in soil. In aquatic systems,
metalaxyl degrades moderately rapidly. Very little of the chemical is lost to
volatilization.
Metalaxyl is persistent and mobile, and both metalaxyl and its major
degradate readily leach in many soils. Monitoring data demonstrate that
metalaxyl and its primary degradate have the potential to reach groundwater.
Metalaxyl has been detected in ground water in five states at levels typically
reaching up to 3 parts per billion (ppb). Concentrations as high as 236 ppb
have been found, but are not likely the result of normal field use.
In order to reduce the possibility of groundwater contamination, EPA is
requiring a groundwater label advisory for metalaxyl end use products. The
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Additional Data
Required
Product Labeling
Changes Required
registrant also has agreed to conduct a user education program if levels of
metalaxyl are detected in groundwater at or above 400 ppb.
Ecological Effects
Metalaxyl is used in numerous sites, and exposure to non-target
organisms may result from direct application, spray drift and/or runoff from
treated areas.
Metalaxyl is practically non-toxic to birds on a dietary basis, and
slightly toxic on an acute, single dose basis. The risk to birds from granular
metalaxyl is minimal. Avian reproduction studies still are needed. Metalaxyl
is practically non-toxic to honeybees, and is not expected to present a risk to
small mammals. Minimal risks are posed to freshwater and estuarine
organisms. Metalaxyl is not expected to adversely affect aquatic plants.
Ecological Effects Risk Assessment
Metalaxyl poses minimal if any risks to birds, small mammals, fish and
estuarine species, honey bees and aquatic plants. The registered uses of
metalaxyl do not present an acute hazard to endangered terrestrial and aquatic
animals or plant species.
EPA is requiring the following additional generic data for metalaxyl to
confirm its regulatory assessments and conclusions: product chemistry,
animal metabolism, analytical method validation for additional metabolites,
storage stability, magnitude of the residue in plants for a newly registered
formulation, residue data for cotton gin byproducts, magnitude of the residue
in processed tomato products, and avian reproduction studies.
The Agency also is requiring product-specific data including product
chemistry and acute toxicity studies, revised Confidential Statements of
Formula (CSF) and revised labeling for reregi strati on.
All metalaxyl end-use products must comply with EPA's current
pesticide product labeling requirements, and with the following:
Worker Protection Standard - The following entry restrictions are required:
Non-WPS Occupational Uses
For liquid applications: "Do not enter or allow others to enter the
treated area until sprays have dried."
For dry applications: "Do not enter or allow others to enter the treated
area until dusts have settled."
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Homeowner Products
For liquid applications: "Do not allow people or pets to enter the
treated area until the sprays have dried."
For dry applications: "Do not allow people or pets to enter the treated
area until dusts have settled."
Other Occupational/Residential Requirements
Application Restrictions: "Do not apply this product in a way that will
contact workers or other persons, either directly or through drift. Only
protected handlers may be in the area during application."
Engineering Controls: "When handlers use closed systems, enclosed
cabs, or aircraft in a manner that meets the requirements listed in the
Worker Protection Standard (WPS) for agricultural pesticides (40 CFR
170.240 (d) (4-6), the handler PPE requirements may be reduced or
modified as specified in the WPS."
User Safety Requirements: "Follow manufacturer's instructions for
cleaning/maintaining PPE. If no such instructions exist for washables,
use detergent and hot water. Keep and wash PPE separately from other
laundry."
User Safety Recommendations: "Users should wash hands before
eating, drinking, chewing gum, using tobacco, or using the toilet."
"Users should remove clothing immediately if pesticide gets inside.
Then wash thoroughly and put on clean clothing."
"Users should remove PPE immediately after handling this product.
Wash the outside of gloves before removing. As soon as possible, wash
thoroughly and change into clean clothing."
Environmental Hazard Statement - The following language is required:
"For terrestrial uses, do not apply to water or to areas where surface
water is present, or to intertidal areas below the mean high water mark.
Do not apply when weather conditions favor drift from treated areas.
Do not contaminate water when disposing of equipment wash water or
rinsate."
Groundwater Advisory - The following language is required on all end-use
products:
"This chemical is known to leach through soil into groundwater under
certain conditions as a result of agricultural use. Use of this chemical in
areas where soils are permeable, particularly where the water table is
shallow, may result in ground water contamination."
RGQLllatory The use °f currently registered products containing metalaxyl in
Conclusion accordance with approved labeling will not pose unreasonable risks or adverse
effects to humans or the environment. Therefore, all uses of all products
containing the active ingredient metalaxyl are eligible for reregi strati on.
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For More
Information
These metalaxyl products will be reregistered once the confirmatory
generic data, product specific data, revised Confidential Statements of
Formula and revised labeling are received and accepted by EPA.
EPA is requesting public comments on the Reregi strati on Eligibility
Decision (RED) document for metalaxyl during a 60-day time period, as
announced in a Notice of Availability published in the Federal Register. To
obtain a copy of the RED document or to submit written comments, please
contact the Pesticide Docket, Public Response and Program Resources
Branch, Field Operations Division (7506C), Office of Pesticide Programs
(OPP), US EPA, Washington, DC 20460, telephone 703-305-5805.
Following the comment period, the metalaxyl RED document will be
available from the National Technical Information Service (NTIS), 5285 Port
Royal Road, Springfield, VA 22161, telephone 703-487-4650.
For more information about EPA's pesticide reregi strati on program, the
metalaxyl RED, or reregi strati on of individual products containing metalaxyl,
please contact the Special Review and Reregi strati on Division (7508W), OPP,
US EPA, Washington, DC 20460, telephone 703-308-8000.
For information about the health effects of pesticides, or for assistance
in recognizing and managing pesticide poisoning symptoms, please contact
the National Pesticides Telecommunications Network (NPTN). Call toll-free
1-800-858-7378, between 8:00 am and 6:00 pm Central Time, Monday
through Friday.
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