Final Risk Evaluation for n-Methylpyrrolidone (NMP)

Additional Supporting Documents

View the final revised risk determination for NMP.

Read the 2020 NMP risk evaluation.

Final Risk Evaluation for n-Methylpyrrolidone Supplemental Information File on Occupational Risk Calculations (xlsx)

Final Risk Evaluation for n-Methylpyrrolidone Supplemental Information File on Consumer Exposure Assessment, Consumer Exposure Model and Multi-Chamber Concentration and Exposure Model (xlsx)

Final Risk Evaluation for n-Methylpyrrolidone Supplemental Information File on Consumer Exposure Assessment, Consumer Exposure Model and Multi-Chamber Concentration and Exposure Model (xlsx)

Final Risk Evaluation for n-Methylpyrrolidone Supplemental Information File on Consumer Exposure Assessment PBPK Model Inputs and Outputs, and Consumer Risk Calculations (xlsx)

In December 2022, EPA released a final revised risk determination for n-methylpyrrolidone (NMP) as a whole chemical substance. This revision supersedes the previous condition of use-specific risk determinations in the 2020 NMP risk evaluation (and withdraws the associated order under TSCA section 6(i)(1)). These chemical-specific changes are in accordance with the path forward for the first 10 risk evaluations under TSCA laid out by EPA in June 2021. 

The final revised risk determination does not assume that all workers exposed to NMP are protected by personal protective equipment (PPE). The consideration of this information will be part of the risk management process.  

EPA determined that 29 out of the 37 conditions of use evaluated drive the determination that NMP presents an unreasonable risk of injury to human health under its conditions of use.

Read the Federal Register notice. 

Read the revised NMP risk determination.

Read the Response to Public Comments to the draft revised Unreasonable Risk Determination for NMP.

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Risk Evaluation Findings

In December 2022, EPA released a final revised risk determination for NMP. The final revised risk determination finds that NMP presents an unreasonable risk of injury to human health when evaluated under its conditions of use. 

In the December 2020 risk evaluation, EPA reviewed the exposures and hazards of NMP uses and made risk findings on this chemical. This risk evaluation includes input from the public and peer reviewers as required by TSCA and associated regulations. EPA considered the hazards and exposure, magnitude of risk, exposed population, severity of the hazard, uncertainties, and other factors as part of its unreasonable risk determination. 

EPA determined that NMP, as a whole chemical substance, presents unreasonable risk to human health.

EPA assessed the impact of NMP on workers, occupational non-users, consumers and bystanders. The primary health risks identified in the risk evaluation are developmental post-implantation fetal loss from short-term exposure and reduced fertility and fecundity from long-term exposure to the chemical. After reviewing these data, EPA determined that risk to workers for all occupational uses and to consumers from one consumer use of NMP drive the whole chemical determination of unreasonable risk of injury to health. Risk from 29 out of 37 conditions of use, including import, processing, commercial use, consumer use, and disposal, of NMP drive the whole chemical determination of unreasonable risk to health. 

The revised risk determination for NMP does not reflect an assumption that workers always and appropriately wear personal protective equipment (PPE), even though some facilities might be using PPE as one means to reduce worker exposure, or that there is widespread non-compliance with applicable federal standards. EPA understands there could be occupational safety protections in place at some workplace locations; however, not assuming use of PPE in its baseline exposure scenarios reflects EPA’s recognition that certain subpopulations of workers exist that may be highly exposed because they are not covered by OSHA standards, because their employers are out of compliance with OSHA standards, because OSHA’s chemical-specific Permissible Exposure Limits (largely adopted in the 1970’s) are described by OSHA as being “outdated and inadequate for ensuring protection of worker health,” or because OSHA has not set a chemical-specific PEL, as is the case for NMP. The consideration of information on use of PPE, engineering controls, and other ways industry protects its workers, as potential ways to address unreasonable risk will be part of the risk management rule development process. 

Next Steps and Public Participation

In June 2024, EPA proposed a risk management rule to address the unreasonable risk posed by n-methylpyrrolidone NMP to human health. Learn more and submit a comment.

EPA hosted a webinar on June 20, 2024, about the proposed risk management rule. View materials from the webinar.

Stay up to date on additional opportunities for public participation. Just like the risk evaluation process, there will be opportunities for public comment as EPA works to propose and finalize risk management actions for NMP. You can stay informed by signing up for our email alerts or checking the public docket at EPA-HQ-OPPT-2020-0744 at www.regulations.gov. 

2020 Risk Evaluation and Supporting Files

Below are the final revised risk determination, 2020 risk evaluation for NMP, non-technical summary, response to comments, and other supporting documents.

The discussion of the issues in the final revision to the risk determination supersedes any conflicting statements in the 2020 NMP risk evaluation and the response to comments document.

Read the Federal Register notice.

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Last updated on August 29, 2024