Q1. I have an Explosives Classification Approval (EX) with a seven-digit number and I understand that the U.S. Department of Transportation's Office of Approvals has changed the numbering system to a 10-digit number. Will my company have to apply for a new number? May I use packagings, labels and/or stamps with the old number?

A1. At the beginning of the Year 2000, it became necessary to revamp the CA numbering system, and the 10-digit numbering system was developed. The old seven-digit number (and in a few cases, the nine-digit number) and the new 10-digit number are interchangeable. It is NOT necessary to apply for a new number. For all CA's including renewals (which include EX Approval letters) the new 10-digit number will be used. If your company is using packagings, labels, and/or stamps with the old number, you may continue to use them until your supply has been exhausted. All new packagings, labels and/or stamps must have the new number on them.

Q2. I am with the Department of Defense and I need a copy of an existing Competent Authority Classification of Explosives (EX approval letter). How can I obtain a copy of an existing EX letter (for military purposes)?

A2. To obtain a copy of an existing EX approval letter issued to the U.S. Department of Defense, refer to the Joint Hazard Classification System (JHCS) at https://jhcs.deskes.dod-esb.army.mil/ or https://mhp.redstone.army.mil. Further questions should be referred to your specific Military Service point of contact as identified in the Defense Transportation Regulation (DTR), Cargo Movement (Part II) chapter 204 at https://www.ustranscom.mil/.

Q3. I submitted an application to obtain an EX classification approval and I have been checking my email for a copy of the EX approval letter. So far nothing has been sent. What is the time frame for obtaining a EX approval letter?

A3. The approval processing time is up to 120 days for EX classification approvals. You can view the status of your submission by entering the tracking number your application was assigned at the time of submittal into the search field at: https://www.phmsa.dot.gov/approvals-and-permits/hazmat/approvals-search

Q4. I need a copy of an explosives approval. How can I get a copy?

A4. Visit PHMSA's Hazardous Materials Approvals Search Page accessible via: https://www.phmsa.dot.gov/approvals-and-permits/hazmat/approvals-search, a link to a downloadable copy will appear.

If a downloadable copy is not available on the search page, send an email to explo@dot.gov.

Q5. How do I submit my application?

A5. Submit Firework and Explosive classification applications online through the Firework and Explosive portals accessible via https://portal.phmsa.dot.gov.

Q6. Can I email, mail, or fax my application?

A6. PHMSA published Final Rule HM-257A to streamline the EX approval process by requiring all explosive approval applications to be submitted online through the Fireworks and Explosive portals.

The rule takes effect on July 2, 2026. Beginning September 1, 2026, all firework and explosive classification applications must be submitted through the Fireworks and Explosive portals. Applications submitted by email, mail, or fax will not be accepted.

Q7. The name of our company has changed and I need to change the name listed on my EX approval. Can I submit a modification or do I need to submit a new application?

A7. EX approvals are non-transferable; however, they may be reissued to reflect the new company name when adequate documentation is provided. Please review PHMSA's guidance on Company Name Changes, Mergers, Acquisitions, and Changes in Legal Structure accessible via: https://www.phmsa.dot.gov/registration/faq-mergers-acquisitions-and-legal-status-changes-pdf.

Depending on the specifics of your company's situation, an EX approval may be eligible for reissuance, or you may have to apply for a new approval.