A member of the class of N-nitrosoureas that is 1,3-bis(2-chloroethyl)urea in which one of the nitrogens is substituted by a nitroso group. ChEBI: Carmustine is a member of the class of N-nitrosoureas that is 1,3-bis(2-chloroethyl)urea in which one of the nitrogens is substituted by a nitroso group. It has a role as an alkylating agent and an antineoplastic agent. It is a member of N-nitrosoureas and an organochlorine compound.