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Chemical Sampling Information (CSI)
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General Description

Synonyms: NMP; N-Methylpyrrolidinone; N-Methyl-2-Pyrrolidinone; 1-Methyl-5-Pyrrolidinone; Methylpyrrolidone; N-Methylpyrrolidone; N-Methyl-2-Pyrrolidone; Composite Constituent

OSHA IMIS Code Number: M139

IMIS Name History: 1-Methyl-2-Pyrrolidinone prior to 7/16/07

Chemical Abstracts Service (CAS) Registry Number: 872-50-4

NIOSH Registry of Toxic Effects of Chemical Substances (RTECS) Identification Number: UY5790000

Chemical Description and Physical Properties:

colorless liquid with a mild amine-like odor
molecular weight: 99.13
molecular formula: C5H9NO
boiling point: 202°C
flash point: 95°C
density: 1.027 @ 25°C

Health Factors

Potential Symptoms: Eye, skin irritation; headache; blurred vision; dermatitis (with redness, swelling, cracking, blisters) upon prolonged or repeated skin contact.

Health Effects: Irritation-Eye, Skin---Severe (with chronic exposure) (HE16); Reproductive hazards---possible fetal toxicity (HE5)

Affected Organs: Eyes, skin

Notes:

  1. OSHA does not have a PEL for 1-methyl-2-pyrrolidinone. Explosive vapor/air mixtures may be formed above 96°C.
  2. The disposition of 1-methyl-2-pyrrolidinone has been studied in humans by the oral, inhalational, and percutaneous routes. It is hydroxylated to 5-hydroxy-N-methyl-2-pyrrolidone, which is dehydrogenated to the diketone, N-methylsuccinimide, which in turn is hydroxylated to 2-hydroxy-N-methylsuccinimide.
  3. All of these metabolites, as well as a small amount of the parent compound, are excreted in the urine. Of these, 2-hydroxy-N-methylsuccinimide has been suggested as the biomarker of choice for monitoring occupational exposure, provided that sampling occurs after exposure for at least three consecutive workdays.
  4. Chronic dietary administration of 1-methyl-2-pyrrolidine to rats and mice for 2 or 1 1/2 years, respectively, was reported to have no observed effects at 5000 ppm (0.5%) for rats, at 600 ppm for male mice, and at 1200 ppm for female mice.

Literature Basis:

  • International Chemical Safety Cards (WHO/IPCS/ILO): N-Methyl-2-pyrrolidone.
  • Åkesson, B. and Jönsson, B.A.G.: Major metabolic pathway for N-methyl-2-pyrrolidone in humans. Drug Metab. Dispos. 25(2): 267-269, 1997.
  • Åkesson, B., Carnerup, M.A. and Jönsson, B.A.G.: Evaluation of exposure biomarkers from percutaneous absorption of N-methyl-2-pyrrolidone. Scan. J. Work Environ. Health 30(4): 306-312, 2004.
  • Jönsson, B.A.G. and Åkesson, B.: Human experimental exposure to N-methyl-2-pyrrolidone (NMP): toxicokinetics of NMP, 5-hydroxy-N-methyl-2-pyrrolidone, N-methylsuccinimide and 2-hydroxy-N-methylsuccinimide (2-HMSI), and biological monitoring using 2-HMSI as a biomarker. Int. Arch. Occup. Environ. Health 76(4): 267-274, 2003.
  • Leira, H.L., Tiltnes, A., Swendsen, K. and Vetlesen, L.: Irritant cutaneous reactions to N-methyl-2-pyrrolidone (NMP). Contact Dermatitis 27(3): 148-150, 1992.
  • Ligocka, D., Lison, D. and Haufroid, V.: Contribution of CYP2E1 to N-methyl-2-pyrrolidone metabolism. Arch. Toxicol. 77(5): 261-266, 2003.
  • Malley, L.A., et al.: Chronic toxicity and oncogenicity of N-methylpyrrolidone (NMP) in rats and mice by dietary administration. Drug Chem. Toxicol. 24(4): 315-338, 2001.
  • Solomon, G.M., Morse, E.P., Garbo, M.J. and Milton, D.K.: Stillbirth after occupational exposure to N-methyl-2-pyrrolidone. A case report and review of the literature. J. Occup. Environ. Med. 38(7): 705-713, 1996.

Date Last Revised: 07/06/2006

Monitoring Methods used by OSHA

Primary Laboratory Sampling/Analytical Method (SLC1):

  • sampling media: Charcoal Tube (100/50 mg sections; 20/40 mesh)
    analytical solvent: (95:5) Methylene Chloride:Methanol
    maximum volume: 10 Liters  
    maximum flow rate: 0.2 L/min
    current analytical method: Gas Chromatography; GC/FID
    method reference: OSHA Analytical Method (OSHA PV2043)
    method classification: Partially Validated

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