California Adds Fact Sheet on N-Methylpyrrolidone Exposure to Proposition 65 Website

A fact sheet released in March by the California Office of Environmental Health Hazard Assessment warns consumers about exposures to N-Methylpyrrolidone, or NMP, a chemical component of products that remove or strip away paint, graffiti, and coatings. NMP appears on California’s Proposition 65 list due to its potential to cause birth defects or other reproductive harm. Proposition 65 requires businesses to warn California residents about significant exposures to chemicals that cause cancer or have reproductive toxicity.

The most likely route of exposure to NMP for consumers is through skin contact with paint strippers and similar products, according to the fact sheet. But inhalation exposure is also a concern, particularly stemming from use of aerosol products that contain NMP. California OSHA’s permissible exposure limit for workplace exposure to NMP is 1 part per million as an 8-hour, time-weighted average. The California exposure limit also has a skin notation indicating that NMP can be easily absorbed into the bloodstream through the skin.

The fact sheet recommends that consumers use NMP-containing products outdoors if possible, to limit their use to no more than four hours per day, and to use NMP-resistant gloves. Indoor areas where NMP is to be used should be well ventilated.

NMP is a common alternative to the solvent methylene chloride, which is also present in paint and coatings strippers and removers. An investigative report in 2015 by the Center of Public Integrity linked methylene chloride to at least 56 accidental exposure deaths—both occupational and non-occupational—between 1980 and 2015. In 2019, EPA banned retail distribution of methylene chloride in paint and coating removal products for consumer use but did not ban commercial uses.