Implications for regulating nanomaterial-containing wastes: Hazardous waste or not?

Engineered nanomaterials have been incorporated into thousands of commercial products that are widely used by consumers and industry. Studies show that nanomaterials can be leached from such products, providing a route of entry into the environment. Toxic effects from nanomaterials may differ significantly based on their structure, functional groups, characteristics of the environmental matrix at the time of exposure, and the transformation of the nanomaterials once released into the environment. Consequently, traditional risk assessment models for conventional chemicals may not apply. Currently, engineered nanomaterials are not regulated as hazardous wastes, but the potential for significant negative human or environmental effects should not be ignored. The authors suggest that existing Resources Conservation and Recovery Act (RCRA) regulations could be modified to include categories for engineered nanomaterials. Given the ubiquitous nature of nanoenabled products, some regulatory action is required even before complete risk assessments can be determined.