PHMSA has the primary responsibility for the issuance of DOT special permits and approvals to the Hazardous Materials Regulations (HMR). A special permit is a document which authorizes a person to perform a function that is not currently authorized under the authority of the HMR. An approval is a similar document that is issued under specific authority granted in the HMR (for example this authority covers the approval of explosives, organic peroxides, and chemical oxygen generators). Follow the links below for further information regarding the functions of each Office and the similarities and differences between special permits and approvals.
If you have any questions, please contact the Office of Hazardous Materials Special Permits and Approvals from the link below.