United States Prevention, Pesticides EPA 738-F-05-XX
Environmental Protection and Toxic Substances September 2005
Agency (7508C)
Mancozeb Facts
Pesticide Reregistration
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 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 the pesticide mancozeb, case number 0643.
Regulatory History
Mancozeb was first registered in the United States in 1948 as a broad spectrum fungicide
used in agriculture, professional turf management, and horticulture. Mancozeb is a member of the
ethylene bisdithiocarbamate (EBDC) group of fungicides, which includes the related active
ingredients maneb and metiram. The EBDCs share the common degradate ethylenethiourea (ETU),
which has been considered in the Agency's assessments. The EBDCs have been the subject of two
Special Reviews. In 1977, the Agency initiated a Special Review for products containing EBDCs
based on evidence suggesting that the EBDCs and ETU, a contaminant, metabolite and degradation
product of these pesticides, posed potential risks to human health and the environment. In 1982, the
Agency concluded this Special Review by issuing a Final Determination (PD 4) which required risk
reduction measures to prevent unreasonable adverse effects, pending development and submission of
additional data needed for improved risk assessment.
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In 1987, EPA issued a second Notice of Initiation of Special Review of the EBDC pesticides
because of health concerns caused by ETU, including potential carcinogenic, developmental and
thyroid effects. The Special Review's Preliminary Determination (PD 2/3) was published on
December 20, 1989 (54 FR 52158) and the Final Determination (PD 4) on March 2, 1992 (57 FR
7484). The Agency concluded that the dietary risks of EBDCs exceeded the benefits for the
following food/feed uses for which one or more of the EBDC pesticides were registered: apricots,
carrots, celery, collards, mustard greens, nectarines, peaches, rhubarb, spinach, succulent beans, and
turnips. Accordingly, EPA canceled all mancozeb and other EBDC products registered on the above-
listed food/feed crops.
EPA issued the registration standard for mancozeb, "Guidance for the Reregistration of
Pesticide Products Containing Mancozeb as the Active Ingredient, " in April 1987. The Agency also
issued a Generic Data Call In (DCI) requiring data needed to complete the reregistration of mancozeb
in April 1987. EPA completed an update to the registration standard for product and residue
chemistry data requirements in August 1992. Additional DCIs for mancozeb were issued in March
and October 1995 to require data to evaluate exposure to pesticide handlers and re-entry workers.
Uses
Mancozeb is used in agriculture, professional turf management, and horticulture. Mancozeb
is used on a wide variety of food/feed crops, including tree fruits, vegetable crops, field crops,
and grapes, ornamental plants, and sod farms. Other uses include greenhouse grown flowers
and ornamentals, and seed and seed piece treatment.
Approximately 5.6 million pounds of mancozeb are used annually, with the greatest use on
potatoes and apples. Mancozeb is also used extensively on grapes, onions, pears, tomatoes,
squash, and melons.
• Mancozeb is not a Restricted Use Pesticide.
Health Effects
Similar to other EBDCs and ETU, the thyroid is the target organ for mancozeb. Thyroid
effects were observed in multiple studies across species. Thyroid toxicity was manifested as
alterations in thyroid hormones, increased thyroid weight, and microscopic thyroid lesions
(mainly thyroid follicular cell hyperplasia), and thyroid tumors.
Risks
Acute, chronic, and cancer dietary (food only) risk from mancozeb, mancozeb-derived ETU,
and ETU from all sources are low and below the Agency's level of concern.
The drinking water exposure assessment for mancozeb addresses concentrations of ETU only,
since mancozeb is not expected to remain in drinking water long enough to reach a location
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that would supply water for human consumption, whether from surface or groundwater
sources. Estimated concentrations of ETU, for both surface and ground water sources of
drinking water, are low and not of concern.
Mancozeb is registered for use in home vegetable gardens and on residential turf. However, a
use restriction prohibiting homeowner use on sweet corn will effectively eliminate any risk
concerns associated with the home garden use. In addition, registrants have agreed to
voluntarily cancel all mancozeb use on residential lawns and turf and delete these uses from
all product labels.
• Potential residential exposure to mancozeb may also occur from residues remaining on
transplanted turf from sod farms. However, the reduced application rate and/or extended PHI,
combined with the logistics of transplanting turf and installation restrictions, effectively
reduced the potential contribution from this use pattern to a level not of concern to the
Agency.
• Acute, short-term, and chronic (non-cancer) aggregate risks are low and not of concern.
Aggregate cancer risk estimates are within a negligible risk range.
EPA has risk concerns for some workers who mix, load, and/or apply maneb to agricultural
sites and for workers who re-enter treated areas.
The Agency's screening level ecological assessment showed potential acute and chronic risk
concerns for some terrestrial and aquatic species. These risk concerns have been mitigated to
the extent practical and feasible by use restrictions. EPA has a potential concern for chronic
effects on listed species of birds and mammals, acute and chronic effects on listed species of
freshwater fish and freshwater invertebrates, and acute effects on listed species of
estuarine/marine fish, should exposure actually occur. The risk mitigation measures
described below will reduce the likelihood that endangeered and threatened species may be
exposed to mancozeb at levels of concern.
Risk Mitigation
The following use restrictions and personal protective equipment (PPE) must be implemented
for mancozeb to be eligible for reregistration. These mitigation measures are to be incorporated into
all mancozeb labels.
Use Restrictions
Turf - All Formulations
• Establish a 3 day preharvest interval (PHI) on turf grown on sod farms
• For sod, restrict the amount that can be used to a maximum of 4 applications per year and
reduce the maximum rate from 19 Ibs ai/A to 17.4 Ibs ai/A (69.6 Ibs ai/A/season)
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• Extend application interval from 7 to 10 days to 10 to 14 days
Turf - Wettable Powder (WP) Formulation
• Delete sod farm use from WP labels
Use engineering controls (water soluble packs) for WP used on turf (golf courses & industrial
parks)
Turf- Liquid Formulations
• Prohibit the application of liquids aerially to golf courses or sod farms, and prohibit the
application of liquids in chemigation systems to golf courses
Papaya
Reduce application rate from 4 to 2 Ib ai/A
Cut Flowers/Greenhouse Grown Ornamentals
• Limit number of applications to 20 per year
Sweet Corn
• Prohibit homeowner use (remove from homeowner label)
Human Flaggers
• Prohibit human flaggers or require mechanical flaggers with aerial application
Personal Protective Equipment
WP Formulation. All Crops Except Turf
Require single layer PPE, with PF 5 respirator and gloves (except pilots, groundboom
applicators, and airblast applicators)
Require single layer PPE for pilots, groundboom applicators, and airblast applicators
WP Formulation. Turf
• Delete sod farm use from WP labels
Require use of engineering controls (water soluble packs) for WP used on turf (golf courses &
industrial parks)
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WP Formulation. Seed Treatment
Require single layer PPE, with PF 5 respirator and gloves (all handlers except sewers and
baggers)
Require single layer PPE for sewers and baggers
Require application as a liquid slurry or mist
Dry Flowable Formulation (All Crops) and Liquid Formulations (All Crops Except Turf)
• Require single layer PPE with gloves for all handlers except aerial, airblast, & groundboom
applicators
Require single layer, no gloves, for aerial, airblast, & groundboom applicators (to avoid
contaminating cab)
Liquid Formulations (Turf)
• Require single layer PPE with gloves and a PF 5 respirator for handlers mixing and loading to
support chemigation application to sod
Prohibit the application of liquids aerially to golf courses or sod farms, and prohibit the
application of liquids in chemigation systems to golf courses
Seed Treatment Liquids
• Require single layer PPE, with gloves (all handlers except sewers and baggers)
• Require single layer PPE for sewers and baggers
Potato Seed-Piece Treatment Dust Formulation
Require engineering controls, i.e., dust collection equipment, for commercial loaders and
applicators
• Require single layer PPE with gloves and a PF5 respirator for all on-farm handlers
Regulatory Conclusion
The Agency has determined that products containing the active ingredient mancozeb are
eligible for reregistration provided that the risk mitigation measures are adopted and labels are
amended to reflect these measures. The following uses of mancozeb are not eligible for reregistration
and are being voluntarily canceled by registrants and deleted from all mancozeb labels: foliar use on
cotton, use on pineapple seed pieces (for propagation), use on residential lawns/turf, use on athletic
fields/turf, and use on pachysandra.
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For More Information
Electronic copies of the Mancozeb RED and all supporting documents are available in Docket
# EPA-HQ-OPP-2005-0176 at http://www.regulations.gov.
For more information about EPA's pesticide reregistration program, the Mancozeb RED, or
reregistration of individual products containing mancozeb, please contact the Special Review and
Reregistration Division (7508C), Office of Pesticide Programs, 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 Pesticide Information Center
(NPIC). Call toll-free 1-800-858-7378, from 6:30 am to 4:30 am Pacific Time, or 9:30 am to 7:30 pm
Eastern Standard Time, seven days a week. The NPIC internet address is http://npic.orst.edu.
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