4-Hydroxybutyl-(2-propenyl)nitrosamine , its CAS NO. is 61424-17-7, the synonyms are 1-Butanol, 4-(nitroso-2-propenylamino)- ; 4-(Allylnitrosamino)-1-butanol ; BRN 2716345 ; 1-Butanol, 4-(allylnitrosamino)- .