N,N-Dimethylformamide. MAK Value Documentation, supplement – Translation of the German version from 2019

Abstract

The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re-evaluated N,N -dimethylformamide [68-12‐2] taking into account the increased respiratory volume at the workplace (see List of MAK and BAT Values, Sections I b and I c). N,N -Dimethylformamide is a liver toxin and the maximum concentration at the workplace (MAK value) of 5 ml/m3 was set using data from a two-year study in mice showing liver cell hypertrophy and single cell necrosis at the lowest concentration tested of 25 ml/m3. In this study, rats were less susceptible as regards the liver toxicity of N,N -dimethylformamide. Species differences in toxicokinetics are a plausible explanation for the higher toxicity in mice. As human metabolism of N,N -dimethylformamide is quantitatively similar to that of rats, their susceptibility is expected to be similar to that of rats. On the basis of the NOAEC (no observed adverse effect concentration) of 25 ml/m3 for rats, the MAK value of 5 ml/m3 is retained even taking into account the increased respiratory volume at the workplace. Peak Limitation Category II and the excursion factor of 2 are confirmed. The assignment of N,N -dimethylformamide to Pregnancy Risk Group B is retained. In an earlier assessment, it was concluded that exposure to a concentration of up to 1 ml/m3 is not expected to lead to developmental toxicity. This prerequisite for an assignment of N,N -dimethylformamide to Pregnancy Risk Group C is confirmed, also taking into account the increased respiratory volume at the workplace. The MAK Collection for Occupational Health and Safety 2020, Vol 5, No 1 1 MAK Value Documentations — N,N-Dimethylformamide MAK value (2005) 5 ml/m3 (ppm) ≙ 15 mg/m3 Peak limitation (2011) Category II, excursion factor 2 Absorption through the skin (1969) H