Explosives Storage Requirements - Classification of Explosive Materials

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Classification of Explosive Materials

ATF defines “explosives” as “any chemical compound mixture, or device, the primary or common purpose of which is to function by explosion”.  18 U.S.C. 841(d).

For the purposes of subsections (d), (e), (f), (g), (h), and (i) of 18 U.S.C. 844, the term “explosive” means gunpowders, powders used for blasting, all forms of high explosives, blasting materials, fuzes (other than electric circuit breakers), detonators, and other detonating agents, smokeless powders, other explosive or incendiary devices within the meaning of paragraph (5) of section 232 of this title, and any chemical compounds, mechanical mixture, or device that contains any oxidizing and combustible units, or other ingredients, in such proportions, quantities, or packing that ignition by fire, by friction, by concussion, by percussion, or by detonation of the compound, mixture, or device or any part thereof may cause an explosion.  18 U.S.C. 844(j).

For purposes of 27 CFR, Part 555, ATF classifies explosive materials into the following classes:

High Explosives

Explosive materials which can be caused to detonate by means of a blasting cap when unconfined.  27 CFR § 555.202.

Low Explosives

Explosive materials which can be caused to deflagrate when confined.  27 CFR § 555.202.  

Blasting Agent

Any material or mixture, consisting of fuel and oxidizer, that is intended for blasting and not otherwise defined as an explosive; if the finished product, as mixed for use or shipment, cannot be detonated by means of a number 8 test blasting cap when unconfined.  27 CFR § 555.11.

As required in 18 U.S.C. 841(d) and 27 CFR § 555.23, ATF annually publishes a List of Explosive Materials in the Federal Register.  While the list is comprehensive, it is not all-inclusive.  The fact that an explosive material may not be on the list does not mean that it does not meet the definition of “explosive materials” in 18 U.S.C. 841.  Explosive materials are listed alphabetically by their common names, followed by chemical names and synonyms in brackets. Click here for the current List of Explosive Materials. 

Last Reviewed May 19, 2023