Which authority enforces hazardous materials regulations?

The Federal Motor Carrier Safety Administration (FMCSA) is the authority responsible for enforcing hazardous materials regulations as they pertain to the transportation of hazardous materials by commercial motor vehicles. FMCSA primarily focuses on the safe operation of commercial vehicles, and thus oversees regulations that ensure these vehicles and their drivers comply with the standards set for transporting hazardous materials.

This includes adherence to guidelines regarding labeling, packaging, and documentation necessary for safely moving dangerous goods on the nation's highways. While other agencies like the Department of Transportation (DOT) and the Environmental Protection Agency (EPA) play critical roles in the overall regulation of hazardous materials, FMCSA is specifically tasked with the enforcement related to commercial vehicle operation, making it the correct authority in this context.