New Report: N-Methylaniline May Pose Cancer and Genetic Defect Risks

The evaluation, conducted in 2023 and documented in a recently released report, has confirmed significant concerns regarding the carcinogenicity and mutagenicity of N-methylaniline. The substance is widely used as an additive in gasoline and for other industrial applications.

Key Findings of the Report

The Bureau for Chemical Substances (MSCA), the competent authority in Poland responsible for the evaluation, identified several potential risks associated with N-methylaniline:

1. Carcinogenicity: The evaluation confirmed concerns about the carcinogenic potential of N-methylaniline. Based on the available data, including studies on structurally similar compounds such as aniline and N,N-dimethylaniline, the substance is suspected of causing cancer. The MSCA has proposed a harmonized classification for N-methylaniline as Carcinogenic Category 2 (H351: Suspected of causing cancer).
2. Mutagenicity: Concerns about the mutagenic potential of N-methylaniline have also been confirmed. Studies suggest that N-methylaniline, due to its structural similarity with known mutagens, could cause genetic defects. Consequently, the substance has been proposed for classification as Mutagenic Category 2 (H341: Suspected of causing genetic defects).
3. Worker and Consumer Exposure: The report raises alarms about potential exposure levels to workers and consumers. In particular, the MSCA noted that the current exposure assessments provided by registrants might significantly underestimate the risks, especially during prolonged exposure scenarios, such as gasoline refueling or equipment maintenance.
4. High Risk Characterization Ratio (RCR): The derived No Effect Levels (DNELs) for dermal and inhalation exposure routes suggested by the MSCA are lower than those previously calculated by the registrants. This discrepancy indicates a higher risk characterization ratio, which could lead to an unacceptable level of exposure for workers under certain conditions.

Regulatory Actions and Recommendations

Given these findings, the MSCA has recommended several regulatory actions and follow-up measures:

• Harmonized Classification and Labelling: The MSCA proposes that N-methylaniline be classified and labeled as both a suspected carcinogen and mutagen. This classification could trigger further regulatory obligations, such as those outlined in Directive 2004/37/EC, which aims to protect workers from risks related to exposure to carcinogens and mutagens.
• Revised Exposure Assessments: The report recommends that registrants reassess and update their exposure scenarios for both workers and consumers to reflect more accurate risk levels, especially considering the potential for higher exposure during full work shifts or frequent use scenarios.
• Risk Management Measures: If the carcinogenic potential of N-methylaniline is further substantiated, the MSCA suggests that additional risk management measures be implemented to protect workers and the general population. These measures may include stricter exposure controls, updated safety guidelines, and potentially limiting the use of N-methylaniline in certain applications.

Conclusion

The completion of this evaluation marks a critical step in ensuring the safe use of chemicals within the European Union. While no immediate regulatory measures have been imposed, the findings underscore the need for vigilance and potential action to mitigate the risks associated with N-methylaniline. Stakeholders, including manufacturers, regulatory bodies, and public health officials, are urged to take these findings seriously and to prepare for possible updates to regulatory requirements in the near future.