EPA Issues Final Risk Evaluation for n-Methylpyrrolidone

In December 2020, a final risk evaluation for n-methylpyrrolidone (NMP) was released by the U.S. Environmental Protection Agency (EPA). The issuance of this evaluation is part of the Agency’s continued efforts to protect human health and the environment. In this blog post, we review NMP and discuss some of the findings from the recent evaluation.

About n-Methylpyrrolidone

NMP is a clear, liquid, organic solvent that has seen wide use in the electronics, petrochemical, chemical manufacturing, and pharmaceutical industries, as well as others. Use in the production of lubricants, adhesives, and paints has been common on the consumer side.


IUPAC Name1-Methylpyrrolidin-2-one
Chemical FormulaC5H9NO
CAS Registry Number872-50-4

Several exposure routes exist for NMP, including exposure via the skin (dermal), inhalation, and ingestion (oral). A connection between exposure to NMP and a diversity of harmful neurological, hepatic, renal, immune, developmental, and reproductive health effects has been found in animal and human studies. Among other factors, duration and amount of exposure may impact the extent of these effects.

Unreasonable Risks

An assessment of 37 conditions of use was conducted for the EPA's final risk evaluation of NMP. This assessment concluded that:

  • For any condition of use, no unreasonable risks to the environment were found
  • For many conditions of use (26 of the 37), unreasonable risks to human health were found
    • Unreasonable risks were found for 25 commercial uses of NMP
    • Unreasonable risks were found for 1 consumer use of NMP

For both workers and consumers, vapor inhalation, skin exposure, and vapor penetration through the skin may yield such risks.

Moving Forward

NMP is among the first group of ten chemical substances for which risk evaluation was required under the amended Toxic Substances Control Act (TSCA). Following the issuance of the final risk evaluation for NMP, the EPA will review public feedback on it and must implement actions considered necessary for managing the chemical’s determined unreasonable risks. It has two years in which to do so. The Agency will keep the public up to date on its risk management progress via its website.

Accessing the Information You Need

Efforts to help protect human and environmental health frequently rely on data obtained from the risk evaluation of chemicals. For accessing detailed information on the risks associated with a multitude of chemical substances, ToxPlanet offers an invaluable resource. ToxPlanet is the world’s largest and most comprehensive content-as-a-service provider focused on supporting the toxicology and chemical hazard information needs of professionals. Our authoritative solutions deliver access to an abundance of vital chemical hazard content. Contact us to learn more about all of the valuable data that our solutions can provide, and to register for a Free Trial.