The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated dimethylformamide, considering all toxicity endpoints. Available publications are described in detail.
The critical target organ after exposure to dimethylformamide (DMF) has been shown in humans and rats to be the liver. After chronic exposure via inhalation, DMF induces significant increases of hepatocellular carcinomas in rats after exposure to 800 ml/m3 and in mice in response to 200 ml/m3 and higher. Several in vitro and in vivo studies have indicated that DMF is not genotoxic. The results of the long‐term studies reveal that the tumors develop in the liver only after chronic toxic inflammatory and degenerative changes have developed in this organ. The tumors are a result of chronic damage. Therefore it can be assumed that exposure to DMF at concentrations which do not induce necrotic changes is not associated with an increased cancer risk. DMF was classified in Carcinogen Category 4 with a MAK value of 5 ml/m3. The MAK value was established in 2006 on the basis of data from a 2‐year study in mice and a BMD and BMLD calculation. The assignment of DMF to Peak Limitation Category II with an excursion factor of 8, also in 2006, is retained. The assignment to Pregnancy Risk Group B in 1989 is confirmed.