N-Ethyl-2-pyrrolidone [MAK Value Documentation, 2014]

The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has evaluated the maximum concentration at the work place (MAK value) of N‐ethyl‐2‐pyrrolidone to derive a maximum concentration at the workplace (MAK value), considering all toxicological endpoints. The main effect observed in a 28‐day inhalation study in rats is mild degeneration/regeneration of the olfactory epithelium at 17 ml/m3. As a NOAEC was not achieved and the effects were mild, a NAEC (no adverse effect concentration) of about 8 ml/m3 is assumed. It cannot be excluded that the NAEC may be lower after long‐term exposure, therefore, a MAK value of 2 ml/m3 has been established for N‐ethyl‐2‐pyrrolidone. As local effects are critical, N‐ethyl‐2‐pyrrolidone is assigned to Peak Limitation Category I and because only minimal irritation occurred at the LOAEC, an excursion factor of 2 is set. The NOAEL for developmental toxicity is 50 mg/kg body weight and day in rats and 60 mg/kg body weight and day in rabbits, which after toxicokinetic scaling correspond to concentrations of 87.5 and 175 mg/m3, respectively, at the work place. Damage to the embryo or foetus is unlikely when the MAK value is observed and thus, N‐ethyl‐2‐pyrrolidone is classified in Pregnancy Risk Group C. Skin contact may contribute significantly to systemic toxicity and N‐ethyl‐2‐pyrrolidone is designated with an “H” notation. N‐Ethyl‐2‐pyrrolidone is not genotoxic and there are no carcinogenicity studies available. Sensitization is not expected from the limited data