N‐Vinyl‐2‐pyrrolidon
MAK-Begründung, Nachtrag
Andrea Hartwig1 (Vorsitz der Ständigen Senatskommission zur Prüfung gesundheitsschädlicher Arbeitsstoffe, Deutsche Forschungsgemeinschaft)MAK Commission2
1 Institut für Angewandte Biowissenschaften, Abteilung Lebensmittelchemie und Toxikologie, Karlsruher Institut für Technologie (KIT), Adenauerring 20a, Geb. 50.41, 76131 Karlsruhe, Deutschland
2 Ständige Senatskommission zur Prüfung gesundheitsschädlicher Arbeitsstoffe, Deutsche Forschungsgemeinschaft, Kennedyallee 40, 53175 Bonn, Deutschland
Abstract
The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated the maximum concentration at the workplace (MAK value) and the Pregnancy Risk Group of N‐vinyl‐2‐pyrrolidone [88‐12‐0].
N‐Vinyl‐2‐pyrrolidone is a non‐genotoxic carcinogen in liver, nose and larynx of rats. In 28‐day inhalation studies it was shown that cell proliferation in liver and hyperplasia in the nasal epithelia of rats is increased at 0.5 ml/m3 with a NOAEC of 0.2 ml/m3. The former MAK value of 0.02 ml/m3 was derived from this concentration, the MAK value is now lowered to 0.01 ml/m3. This takes into account the increased respiratory volume at the workplace, because the blood:air partition coefficient of N‐vinyl‐2‐pyrrolidone is > 5 (see List of MAK‐ and BAT values chapters I b and I c). Since a systemic effect is critical, Peak Limitation Category II is retained. As the critical metabolite is not known, the default excursion factor of 2 for systemically acting compounds is confirmed.
For rats, the NOAEC for developmental toxicity after inhalation is 5 ml N‐vinyl‐2‐pyrrolidone/m3, where reduced maternal body weight gain occurred. At 20 ml/m3 reduced foetal bodyweight and an increase of variations were observed. Taking into account the increased respiratory volume at the work place the NOAEC for developmental toxicity is 250 times higher than the MAK‐value. Therefore, N‐vinyl‐2‐pyrrolidone remains assigned to Pregnancy Risk Group C.
