The U.S. Environmental Protection Agency (EPA) has issued new Significant New Use Rules (SNURs) by the end of 2024, including two specifically addressing multi-walled carbon nanotubes (MWCNTs). These rules require reporting unless the substances meet certain criteria, such as being fully reacted (cured), entrained in a polymer, or incorporated into an article.
Key Provisions in SNURs for MWCNTs
1. Exposure Control Measures
- Engineering controls (e.g., operation enclosures, ventilation) or administrative controls (e.g., workplace policies) must be implemented to minimize exposure.
- If respirators are necessary:
- A National Institute for Occupational Safety and Health (NIOSH) assigned protection factor (APF) of at least 1,000 is required for capture and reduction rates ≥99.5% but <99.975%.
- An APF of at least 50 is required for capture and reduction rates ≥99.975%.
2. Hazard Communication
- MWCNTs may cause the following:
- Eye and skin irritation
- Respiratory and skin sensitization
- Genetic and reproductive toxicity
- Carcinogenicity
- Specific target organ toxicity
- Toxicity to aquatic life
- Employers and manufacturers must communicate these hazards in accordance with the Globally Harmonized System (GHS) or OSHA standards. Alternative statements meeting these criteria may be used.
3. Industrial, Commercial, and Consumer Activities
- Significant new uses include:
- Manufacturing substances containing the confidential impurity listed in the order above 1% by weight.
- Processing or using the substance outside the confidential use allowed in the order.
- Processing or using the substance in methods that generate vapor, mist, dust, or aerosol, unless these occur in enclosed processes.
For full details, visit the EPA’s SNURs for MWCNTs page.
Industry Implications
These SNURs emphasize the importance of strict controls in the handling and processing of MWCNTs to minimize environmental and human health risks. Stakeholders are encouraged to review the new rules and assess their compliance measures accordingly.
