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N-Methyl-2-pyrrolidone is expected to be removed from air by wet deposition or by reaction with hydroxyl radicals. The substance is not transformed by chemical hydrolysis but is rapidly biodegraded under aerobic conditions. The substance is not expected to bioconcentrate. Very few reliable ecotoxicological data were found. However, the available results from short-term tests on aquatic species (fish, crustaceans, algae, and bacteria) and terrestrial species (birds) indicate that NMP has low acute toxicity. Also, very few data on measured concentrations in the environment were identified. The available ecotoxicological data should not be used for a quantitative risk assessment until fully evaluated. As a tentative conclusion, however, based on the biodegradability of the substance, the absence of bioconcentration tendency, and the indicated low acute aquatic toxicity, NMP is not expected to present a significant risk to the environment. ">A 23-year-old laboratory technician was occupationally exposed to N-Methyl-2-pyrrolidone( NMP) during her first 20 weeks of pregnancy. The uptake via the lungs was probably of minor importance, as the NMP was handled at room temperature. Hand rinsing of glassware with NMP and cleaning up of an NMP spill in week 16 of pregnancy may have brought about a much larger uptake through the skin. During the 4 days following the spill, malaise, headache, and nausea were experienced. Examination of the pregnancy at week 14 showed no signs of delayed development; however, at week 25, signs of delayed fetal development were observed, and at week 31, a stillborn fetus was delivered. Stillbirth in this period of pregnancy is unusual. However, as the level of exposure is unknown, it is impossible to establish if exposure to N-Methyl-2-pyrrolidone is the causative factor . 1.Study on human A total of 15 24-h exposures in a repeated-insult patch test in human subjects (n = 50) caused minor to moderate transient irritations. No signs of contact sensitization were observed. Direct contact of skin with NMP caused redness, swelling, thickening, and painful vesicles when NMP was used as a cleaner or as a paint stripper . Workers exposed to NMP in working areas with air concentrations up to 280 mg/m3 reported severe eye irritation and headache. With the methods of assessing the exposure level and the response , it is impossible to develop a concentration– response relationship . Six volunteers exposed to 10, 25, or 50 mg/m3 during 8 h in a chamber study registered their symptoms, before the start of exposure and then every 2 h for 16 h, in a questionnaire on a scale from 0 to 10 (0 = no symptoms and 10 = not tolerated). The volunteers displayed none of the following symptoms: eye or respiratory tract irritation; hacking cough, nose secretion, or blockage, sneezing, itching, or dryness in the mouth and throat, or other symptoms in upper airways; itching, secretion, smarting pain, visual disturbances, or other symptoms such as headache, dizziness, and nausea; and other symptoms. Two volunteers reported detecting an odour at 50 mg/m3. There were no significant differences in the spirometric data displayed by the forced expiratory volume in 1 s, vital capacity, and the highest forced expiratory capacity measured before or after any level of exposure. There were no acute changes in the nasal cavity assessed by continuous acoustic rhinometry. Even though the effects observed in this study were not very pronounced, the possibility of undetected effects still remains 2.Evaluation of environmental effects Water and air are considered to be the most relevant compartments for NMP, since the substance may be released both as volatile emissions to the atmosphere and as a component of wastewater, municipal as well as industrial. Since the substance shows high mobility in soil, leaching from landfills is a possible route of contamination of groundwaters. N-Methyl-2-pyrrolidone is expected to be removed from air by wet deposition or by reaction with hydroxyl radicals. The substance is not transformed by chemical hydrolysis but is rapidly biodegraded under aerobic conditions. The substance is not expected to bioconcentrate. Very few reliable ecotoxicological data were found. However, the available results from short-term tests on aquatic species (fish, crustaceans, algae, and bacteria) and terrestrial species (birds) indicate that NMP has low acute toxicity. Also, very few data on measured concentrations in the environment were identified. The available ecotoxicological data should not be used for a quantitative risk assessment until fully evaluated. As a tentative conclusion, however, based on the biodegradability of the substance, the absence of bioconcentration tendency, and the indicated low acute aquatic toxicity, NMP is not expected to present a significant risk to the environment.
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