US EPA

2178525 

Technical Report 

Chloracne--an up to date assessment 

Crow, KD 

1978 

Yes 

Annals of Occupational Hygiene
ISSN: 0003-4878
EISSN: 1475-3162 

NIOSH/00166746 

21 

297-298 

English 

155998 

10.1093/annhyg/21.3.297 

Current knowledge on chloracne was assessed. With the exception of chlorobiphenyls (PCBs) and chloronaphthalenes (CNs), the remaining chloracneigens (chlorodibenzodioxins (PCDDs), chlorodibenzofurans (PCDFs), chloroazo-benzenes (TCAB) and chloroazoxy-benzenes (TCAOB)), are contaminants formed accidentally during manufacture. Rhesus-monkeys and hairless-mice may be used to detect chloracne like changes, but rabbit ear is most sensitive and particularly valuable for assessment of toxicity. The problem of long term, low dose effects such as carcinogenicity and mutagenicity is currently under investigation, particularly with respect of additive effects. Dose related carcinogenicity of 2,3,7,8-tetrachlorodibenzodioxin (1746016) (TCDD) has been demonstrated in rats, with signs of poisoning. In man, severe chloracnes and general toxicity are so far confined to industrial workers poisoned with TCDD as well as the 1200 victims of a Japanese accident in 1968. Isomerism is much more important that the degree of chlorination in determining chloracneigenicity and general toxicity. Enzyme induction (aryl-hydrocarbon-hydroxylase) is the most important technique for investigating toxicity. This technique has recently revealed the apparent chemical basis for the toxicity of chloracneigens. The authors suggest that the rabbit ear test should become standard procedure in the evaluation of any new halogenated aromatic compounds.