Zineb

Описание

Zineb is a light-coloured powder/crystal and insoluble in water. Zineb is one of the nonsystemic (surface-acting) fungicides of the group ethylenebisdithiocarbamates (EBDCs). Zineb is a polymer of ethylene (bis)thiocarbamate units linked with zinc and used for the control and prevention of crop damage in the field and also to protect harvested crops from deterioration during storage or transport. Zineb was used to protect fruit and vegetable crops from a wide range of foliar and other diseases. It was available in the United States as wettable powder and dust formulations. Zineb can be formed by combining nabam and zinc sulphate in the spray tank.

Химические свойства

Pure product is white crystal, industrial product is white to light yellow powder. Soluble in carbon disulfide and pyridine, insoluble in most organic solvents, insoluble in water (10mg/L). It is unstable to light, heat and humidity, and decomposes easily when it meets alkaline substances or copper. The decomposition products of zineb include ethylene thiourea, which is more toxic.

Использование

Zineb is a contact fungicide that provides protection against a wide variety of fungal diseases (including leaf spots, blights, rust, downy mildew, scab, etc.) in field crops, fruits, vines, vegetables, ornamentals, citrus and bananas.

Определение

ChEBI: Zineb is a polymeric complex of zinc with the ethylene bis(dithiocarbamate) anionic ligand. Formerly used as an agricultural fungicide for the control of downy mildews and rusts, its use is no longer permitted in the US or the EU. It has a role as an antifungal agrochemical. It is a macromolecule, a zinc coordination entity and a dithiocarbamate salt. It contains an ethylenebis(dithiocarbamate).

Общее описание

An off-white powder. Used as a fungicide.

Реакции воздуха и воды

Decomposes gradually, accelerated by exposure to air, moisture, and heat. Insoluble in water. Thio and dithiocarbamates slowly decompose in aqueous solution to form carbon disulfide and methylamine or other amines. Such decompositions are accelerated by acids.

Профиль реактивности

Zineb is a zinc salt of a dithiocarbamic acid. May generate flammable gases with aldehydes, nitrides, and hydrides. Incompatible with acids, peroxides, and acid halides.

Опасность

Toxic by inhalation and ingestion; irritant to eyes and mucous membranes. Questionable carcinogen.

Пожароопасность

Flash point data for Zineb are not available, but Zineb is probably combustible.

Контактные аллергены

Zineb is a pesticide of the dithiocarbamate group. Sensitization can occur in gardeners and florists.

Метаболический путь

Zineb and other alkylenebis( dithiocarbamate) fungicides are degraded and metabolised via a common pathway. The primary degradation reaction of zineb in water, soil, plants and animals involves the initial dissociation of the metal complex and decomposition to numerous degradation products including ethylenethiourea (ETU) and ethyleneurea (EU) as major products (Scheme 1).

Методы очистки

Crystallise this herbicide several times from hot toluene or from hot CHCl3 by addition of EtOH. It is a skin irritant. [Beilstein 4 III 149, 4 IV 234.]

Оценка токсичности

Zineb has a low mammalian toxicity however, it may cause adverse reproduction/developement effects if ingested. It is moderately toxic to most fauna and flora.