Which United States department oversees the Hazardous Materials Regulations?

The U.S. Department of Transportation (DOT) is responsible for overseeing the Hazardous Materials Regulations (HMR) in the United States. This department sets forth regulations that ensure the safe and secure transportation of hazardous materials, thereby aiming to protect public safety, property, and the environment. The regulations governed by the DOT cover various elements including packaging, labeling, and documentation related to hazardous materials transport.

The other departments listed, while they may have roles in environmental protection and health concerns, do not specifically oversee the transportation of hazardous materials. For example, the Environmental Protection Agency primarily focuses on environmental protection regulations and enforcing laws regarding hazardous waste, while the Department of the Interior deals with conservation of federal land and resources. The Department of Health and Human Services is primarily involved in public health policies and welfare programs. Thus, the DOT's focus on transportation makes it the correct choice for overseeing Hazardous Materials Regulations.