The preferred quaternary ammonium disinfectant has the formula ##STR2## wherein R1 is a substituted or unsubstituted alkyl or alkylene group containing from about 8 to about 20 carbon atoms, preferably from about 12 to about 18 carbon atoms; R2, R3 and R4 are each selected from the group of substituted or unsubstituted alkyl or alkylene groups containing from 1 to 4 carbon atoms and benzyl groups,