The importance of genotoxic acrolein congeners and allylic and benzyl compounds as industrial compounds, ubiquitous environmental pollutants, and naturally occurring substances necessitates the availability of adequate biomonitoring techniques. Endogenously formed acrolein congeners are considered to play an important role in carcinogenesis. Our studies have demonstrated that acrolein congeners react with DNA components and form adducts with the guanine moiety. We have identified and characterized cyclic 1,N2-deoxyguanosine adducts, cyclic 7,8-guanine adducts, linear 7-guanine adducts, 1,N2,7,8-bis-cyclic adducts, and 1,N2-cyclic, 7-linear bis adducts. Both the reactivity of the acroleins toward nucleosides and their mutagenicity in S. typhimurium TA100 decrease with increasing degree of alkyl substitution. Adducts are now available as reference substances for developing sensitive detection methods. Of the biomonitoring methods investigated for allylic and benzyl compounds, the detection of cysteine and histidine adducts isolated from hemoglobin seems to be the most sensitive. Gas chromatography with electron capture detection of heptafluorobutyric acid derivatives allows a detection limit in the femtomole range, HPLC-fluorescence detection of O-phthalic dialdehyde derivatives allows a limit in the picomole range, and detection of 9-fluorenylmethyl-chlorofomiate derivatives allows a limit in the femtomole range.