The chlorination by-products chloral hydrate and chloropicrine were as
sayed for genotoxicity in three short-term tests. Chloropicrine was 10
0-fold more potent than chloral in inducing mutations in strain TA100
of S. typhimurium (fluctuation test) and, at variance with chloral, wa
s positive in the SOS chromotest using strain PQ37 of E. coli. On the
other hand, only chloral caused a significant increase in the frequenc
y of micronucleated erythrocytes following in vivo exposure of the amp
hibian Pleurodeles waltl newt larvae.