Methyl carbamate is formed by the reaction of ammonia with methyl chloroformate or methyl carbonate. According to US patent number 2834799 urea can be reacted with methanol to form it using boron trifluoride as a reagent. Unlike its close relative ethyl carbamate it is not mutagenic in salmonella (it tested negative in the Ames test), but it is mutagenic in Drosophila. Experimental evidence does show that it is a carcinogen in rat, and not carcinogenic in mice. The compound is "known to the state of California to cause cancer" per Proposition 65.