atf.gov
Bureau of Alcohol, Tobacco, Firearms and Explosives
Federal explosives regulations generally exempt the importation, distribution, and storage of items classified as UN0431 or UN0432 explosives―by the U.S. Department of Transportation (DOT) at 49 CFR 172.101―and generally known as “articles pyrotechnic.” However, not all items classified by DOT as articles pyrotechnic are exempt from ATF regulations.