United States
Environmental Protection
Agency
Prevention, Pesticides
And Toxic Substances
(7508C)
EPA-738-F-03-002
September 2003
v-xEPA R.E.D. FACTS
Pesticide
Reregistration
Propanil
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 humans or the environment. Because of advances in
scientific knowledge, the law requires that pesticides which were first registered
before November 1, 1984, be reregistered to ensure that they meet today's more
stringent standards.
In evaluating pesticides for reregistration, EPA obtains and reviews a
complete set of studies from pesticide producers, describing the human health
and environmental effects of each pesticide. To implement provisions of the
Food Quality Protection Act of 1996, EPA considers the special sensitivity of
infants and children to pesticides, as well as aggregate exposure of the public to
pesticide residues from all sources, and the cumulative effects of pesticides and
other compounds with common mechanisms of toxicity. The Agency develops
any mitigation measures or regulatory controls needed to effectively reduce each
pesticide's risks. EPA then reregisters pesticides that meet the safety standard of
the FQPA and can be used without posing unreasonable risks to human health or
the environment.
When a pesticide is eligible for reregistration, EPA explains the basis for its
decision in a Reregistration Eligibility Decision (RED) document. This fact sheet
summarizes the information in the RED document for propanil (Chemical Code
No. 028201; Case No. 0226).
Use Profile
Propanil is a selective post-emergent use herbicide registered to control
broadleaf and grass weeds on rice. It is also registered (but not currently marketed)
for turf use at commercial sod farms. The small grain use was voluntarily
cancelled. There are no residential uses of propanil. EPA estimates that
approximately seven million pounds of active ingredient are used annually on rice.
Regulatory
History
Propanil was the subject of a Reregistration Standard Guidance Document
that was issued on December 23, 1987. In addition to the data requirements
imposed in the 1987 Guidance Document, a Data Call-in (DCI) notice dated June 9,
1989, required the registrant to analyze their propanil products for halogenated
dibenzo-p-dioxin and dibenzofuran contaminants. Based on the submitted data, the
Agency does not expect any potential for the formation of halogenated dibenzo-p-
dioxin and dibenzofuran contaminants in measurable quantities during the
manufacture of propanil. The Agency issued subsequent DCIs for propanil on July
1, 1994 and October 13, 1995. These data received in response to the DCIs were
used to reach the reregistration eligibility conclusions for propanil that are presented
in this RED.
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On June 5, 2002, EPA published its tolerance reassessment decision on
propanil in the Federal Register and released the human health and ecological risk
assessments for public comment [OPP-2002-0033; FRL-7179-4]. Subsequent to
the tolerance reassessment, the use of propanil on the small grains was voluntarily
cancelled by the technical registrants.
Human Health
Assessment
Toxicity
Propanil has low acute toxicity, with toxicity categories of HI (oral) and IV
(dermal, inhalation and primary skin irritation). No dermal sensitization was
observed; however, primary eye irritation was observed in rabbits. Propanil is
considered neither carcinogenic nor mutagenic.
Dietary Risks
The tolerance reassessment decision on propanil concluded that acute and
chronic dietary risk for food and drinking water did not exceed the Agency's level
of concern for all population subgroups.
Worker Risks
The risk to occupational handlers of propanil is potentially of concern for
several of the aerial exposure scenarios, even with maximum personal protective
equipment (PPE) and engineering controls. To reduce these risks initially, the
following mitigation measures are needed: (1) Spray drift management practices
consistent with best management practices for rice; (2) Require engineering controls
including closed cabs and closed mixing/loading systems; and (3) Maintain a
reentry interval of 24 hours for rice. In addition, propanil/rice-specific worker
exposure (bio-monitoring) data for the liquid formulation were developed by the
Propanil Task Force U.
The following mitigation will be needed unless EPA determines, based on the
bio-monitoring data currently under review, that lesser or no mitigation is
warranted: (1) Reduce maximum seasonal application rate to 6 Ibs. a.i./acre on rice;
and (2) Reduce maximum number of acres treated to 500 per day for aerial
applications of propanil on rice.
Long-term handler exposure is not expected for propanil. All post-
application worker risks associated with the rice use of propanil met or exceeded the
target MOE of 300, and thus, are not of concern at the current restricted entry
interval (REI) of 24 hours.
To address sod farm worker risk, the registrant has agreed to reduce the
maximum application rate to 5 Ibs. a.i./acre. In order to further mitigate the
Agency's remaining concerns, a REI of 34 days at the reduced maximum
application rate is required for transplanting sod. Further, a REI of 1 day following
application at the reduced maximum application rate is required for activities such
as aerating, fertilizing, irrigating, scouting and mechanical harvesting and weeding.
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Residential and Other Nonoccupational Risks
There are no residential or other nonoccupational risk concerns because
propanil does not have any residential uses.
FQPA Considerations
FQPA requires that the Agency consider the "available information"
concerning the cumulative effects of a particular pesticide's residues and "other
substances that have a common mechanism of toxicity." The Agency does not have
sufficient information at this time concerning common mechanism issues to
determine whether or not propanil shares a common mechanism of toxicity with
other substances, including other acetanilides. Therefore, for the purposes of this
risk assessment, the Agency has assumed that propanil does not share a common
mechanism of toxicity with any other chemicals.
Available data indicates that 3,4-DCA is a major metabolic degradate of
propanil. 3,4-DCA is also a metabolite of two other pesticides, linuron and diuron,
but to a much lesser extent. The Agency's MARC does not recommend
aggregating residues of 3,4-DCA for the propanil, linuron and diuron risk
assessments. 3,4-DCA is a degradate of these three pesticides; however, it is only a
significant residue of concern for propanil. 3,4-DCA is assumed to be of equal
toxicity to the parent.
More detailed information can be found in the technical supporting
documents for propanil referenced in the RED document.
Environmental
Assessment
Ecological Risks
Propanil use on rice may cause adverse ecological effects at the current
maximum seasonal application rate of 8 Ibs. a.i./acre/yr (from two 4 Ibs. a.i./acre
applications) in areas where rice is produced. Acute risks are estimated for birds,
small mammals, freshwater invertebrates and nontarget aquatic plants although RQs
are relatively low. Chronic risks are potentially a concern for small mammals and
freshwater fish and invertebrates.
The potential use of propanil on turf at the current maximum application
rate of 10 Ibs. a.i./acre may pose a risk to aquatic vascular/nonvascular plants and
terrestrial plants in semi-aquatic areas, and acute risk to birds, small mammals,
freshwater fish and invertebrates and estuarine/marine fish and invertebrates.
Chronic risks are a concern for small mammals at the current label rate. To reduce
the above risks, the following mitigation measures are needed:
• Reduce the maximum application rate for propanil use on turf from 10 Ibs.
a.i./acre to 5 Ibs. a.i./acre and eliminate aerial applications to mitigate
concerns for avian and mammalian species, and nontarget terrestrial, semi-
aquatic and aquatic plants.
• Establish a 7-day water holding (discharge) interval for rice in the Mississippi
Delta (Arkansas, Mssissippi, Mssouri & Northern Louisiana) and California;
a 10-day discharge interval along the Gulf Coast (Texas); and a 15-day
discharge interval in Southern Louisiana to address aquatic species concerns,
including those for endangered species.
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• Reduce the maximum application rate for propanil use on turf; eliminate
aerial applications to turf; and label language specifying best management
practices for spray drift to address concerns for nontarget terrestrial and semi-
aquatic plants, including those for endangered species.
Currently, the Agency does not have data to determine the risk from propanil
use on rice to terrestrial nontarget plants. In addition, no acceptable chronic avian
data were available, so chronic risks for avian species could not be assessed. Data
are required to address these gaps in the ecological assessment.
Summary This Fact Sheet explains the Agency's decision regarding the reregistration
eligibility of the registered uses of propanil. This document also presents the
Agency's tolerance reassessment decision for propanil, which includes the
consideration of risk to infants and children for any potential dietary, drinking
water, dermal, inhalation or oral exposures. The Agency's 2002 tolerance
reassessment decision for propanil was based on the data required for reregistration,
the current guidelines for conducting acceptable studies to generate such data, and
published scientific literature. The Agency has found that the current uses of
propanil on rice and turf are eligible for reregistration, provided the changes
specified in the RED are made to the labels. The small grain use has been
voluntary cancelled.
Additional Data EPA is requiring the following confirmatory data requirements for propanil to
Red UJ red confirm its regulatory assessments and conclusions and to further characterize the
toxicity of propanil and 3,4-DCA:
83 5.1240: Sediment and Soil Adsorption/Desorption on 3,4-DCA
835.2120: Hydrolysis on 3,4-DCA
835.2240: Photodegradation (Water) on 3,4-DCA
• 850.1010: Freshwater Invertebrate Acute Toxicity on 3,4-DCA
850.1035: Mysid Acute Toxicity on 3,4-DCA
• 850.1075: Freshwater and Estuarine/Marine Fish Acute Toxicity on 3,4-DCA
• 850.1300: Early-Life Stage in Freshwater and Estuarine/Marine Fish on 3,4-DCA
• 850.1350: Life Cycle in Freshwater and Estuarine/Marine Invertebrates on 3,4-DCA
850.2200: Avian Subacute Dietary Toxicity - Bobwhite Quail on 3,4-DCA
850.2300: Avian Reproduction - Bobwhite Quail for Parent Propanil and 3,4-DCA
850.2300: Avian Reproduction - Mallard Duck for Parent Propanil and 3,4-DCA
850.4100: Seedling Emergence (Tier 1) on 3,4-DCA
850.4150: Vegetative Vigor (Tier 1) on 3,4-DCA
850.4250: Vegetative Vigor (Tier 2) on Propanil - TEP
870.3465: 90-Day Inhalation - Rat
• 870.6200: Acute Neurotoxicity Screening Battery - Rat
870.7800: Immunotoxicity Study - Rat
• 875.1100: Estimation of Dermal Exposure at Outdoor Sites
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Product Labeling
Changes Required
All propanil end-use products must comply with EPA's current pesticide
product labeling requirements and with the following. For a comprehensive list of
labeling requirements, please see Section V of the propanil RED document.
Regulatory
Conclusion
EPA has determined that all products containing propanil as the active
ingredient for use on rice and turf are eligible for reregistration, provided changes
specified in the propanil RED are incorporated into the label and additional data
identified in Section V of the RED confirm this conclusion.
For More
Information
EPA is requesting public comments on the Reregistration Eligibility
Decision (RED) document for propanil during a 60-day time period, as
announced in a Notice of Availability published in the Federal Register. To obtain
a copy of the propanil RED document, please contact the OPP Public Docket
(7502C), US EPA, Ariel Rios Building, 1200 Pennsylvania Avenue, NW,
Washington, DC 20460-0001, telephone: (703)305-5805. Electronic copies of the
propanil RED and all supporting documents are also available on the Agency's
website at tog/ZH:J£Milpg^
Printed copies of the propanil RED and fact sheet can be obtained from EPA's
National Service Center for Environmental Publications (EPA/NSCEP), P.O. Box
42419, Cincinnati, OH 45242-2419, telephone: (800) 490-9198; fax: (513) 489-8695.
The propanil RED document also will be available from the National
Technical Information Service (NTIS), 5285 Port Royal Road, Springfield, VA
22161-0001, telephone: (800) 553-6847; fax: (703) 605-6000.
For more information about EPA's pesticide reregistration program or the
propanil RED, please contact the U.S. EPA, OPP, Special Review and Reregistration
Division (7508C), Washington, DC 20460-0001, telephone: (703) 308-8000.
For more information about the health effects of pesticides, or for assistance in
recognizing and managing pesticide poisoning symptoms, please contact the National
Pesticide Information Center (NPIC). Call toll-free (800) 858-7378, from 6:30 am to
4:30 pm Pacific Time, or 9:30 am to 7:30 pm Eastern Standard Time, seven days a
week. Their internet address is hffp:,//www. npic. orst. edit.
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