 Carbamic acid is an intermediate in the industrial production of urea, which involves the reaction of carbon dioxide and ammonia.Some carbamate esters have use as muscle relaxants which bind to the barbiturate site of the GABAA receptor, while others are used as insecticides, for example aldicarb.An amine functional group –NH2 can be protected from unwanted reactions by being formed as carbamate ester residue –NHC(=O)–OR.