(DithaneTM, ForeTM, KaramateTM) is an
ethylene bisdithiocarbamate fungicide. Mancozeb is a General Use
Pesticide, meaning a pesticide applicators license is not required to
purchase or use this pesticide.
has a relatively low acute toxicity (oral rat LD50 > 5000 mg/kg, dermal
rabbit LD50 > 5000 mg/kg) and receives an U.S. Environmental Protection
Agency (EPA) toxicity class IV (I =
most toxic, IV = least toxic) rating, with the word CAUTION appearing on
all product labels. Despite its low acute toxicity, mancozeb is a skin and
eye irritant. Workers exposed to the pesticide have developed rashes.
is also a suspected endocrine disruptor, is mutagenic, and EPA classifies
it as a class B2 probable carcinogen (PANNA, 2000). In chronic exposure
studies, impaired thyroid function was observed as exposure to mancozeb
lowered iodine uptake after 24 months in dogs fed doses of 2.5 and 25
mg/kg/day (ETN, 1996). In rat studies, pregnant females exposed to the
pesticide had offspring affected by the exposure.
major toxicological concern in situations of chronic exposure is the
generation of ETU, a metabolite of mancozeb. In addition to having the
potential to cause goiter, a condition in which the thyroid gland is
enlarged, this metabolite has produced birth defects and cancer in
experimental animals (ETN, 1996).
is highly toxic to fish and other aquatic organisms, and slightly toxic to
the field, mancozeb has a half-life in the soil of 1 to 7 days. However,
ethylenethiourea (ETU), a toxicologically significant metabobilte
(breakdown product) of mancozeb, may persist up to 10 weeks (ETN, 1996).
Toxicology Network (ETN). 1996. “Mancozeb.” Pesticide
Action Network North America (PANNA). 2000. “Mancozeb.” Chemical