Carbamates

Compounds in this group are high-boiling liquids or solids. They are generally nonflammable, but are combustible. Combustion products include noxious NOx and carbon monoxide.

Materials in this group are chemically similar to, but more reactive than amides. Like amides they form polymers such as polyurethane resins. Carbamates are incompatible with strong acids and bases, and especially incompatible with strong reducing agents such as hydrides. Flammable gaseous hydrogen is produced by the combination of active metals or nitrides with carbamates. Strongly oxidizing acids, peroxides, and hydroperoxides are incompatible with carbamates.

Many carbamates are used as pesticides. These materials can be extremely toxic. They act by blocking the function of cholinesterase, an enzyme that is essential to the transmission of nerve impulses. Oral exposure is the principal concern. Absorption through the skin is slow, but dermal exposure must still be avoided because of the high toxicity.

Compounds in this group are derivatives of carbamic acid (NH2COOH). The urethanes are alkyl carbamates, that is, esters of carbamic acid.

Carbamic acid, ammonium carbamate, bendiocarb, carbaryl, oxamyl, propoxur, urethane.