Explosives Questions and Answers

When storing high explosives (HE) near blasting agents (BA)

• Calculate distance using table 555.220, with HE as the donor.
• Calculate the distance using 555.218, with BA as the donor.
• The more restrictive of the two distances is the minimum required distance between magazines of HE and BA.
• Use table at 555.218 to determine required distance to inhabited buildings, highways and passenger railways.
• When determining minimum required distance from detonator storage to BA storage, the detonator magazine is always the donor. (Only the table at 555.220 may be used for this calculation.)

When storing blasting agents (BA) near other BA

• Use only the table at 555.220.
• The weight (row) to be used is based upon the donor material (the greater amount).
• The column to be used (BA) is based upon the acceptor material.
• Multiply the distance by 6 when unbarricaded.

When storing high explosives (HE) or blasting agents (BA) near ammonium nitrate (AN)

• HE or BA to AN storage: use 555.220 with AN as the receptor—AN alone is never the donor.
• Combine ½ the weight of the AN (with the donor) if the distance from the HE or BA to AN does not meet minimum separation distance.
• Multiply minimum distances in table 220 by 6 when the AN or BA are not barricaded.

ATF has issued an open letter to addresses issues such as BA storage near HE, BA or AN and how to determine which storage magazine is the “donor” and which is the “acceptor” when applying the tables of distances at 27 CFR 555.218 and 27 CFR 555.220. Industry members who store blasting agents or ammonium nitrate should read the complete open letter at https://www.atf.gov/rules-and-regulations/explosives-open-letters.

Except for those items and activities given exempt status under 18 U.S.C. 845 (also see 27 CFR 555.141), or exempted under 27 CFR 555.32, Special Explosives Devices, all persons who store explosive materials must store them in conformity with the provisions of sub part K of the regulations.

[18 U.S.C. 842(j); 27 CFR 555.29, 555.141, 555.201(a)]

There are 3 classes of explosive materials:

(a) High explosives (for example, dynamite, flash powders, and bulk salutes);

(b) Low explosives (for example, black powder, safety fuses, igniters, igniter cords, fuse lighters, and “display fireworks”, except for bulk salutes); and

(c) Blasting agents (for example, ammonium nitrate-fuel oil and certain water gels).

[27 CFR 555.202]

No. Storage of explosive materials in a residence or dwelling is prohibited. (See also ATF Ruling 2002-3.)

[27 CFR 555.208(b), 555.210(b), 555.211(b)]

The more restrictive distance, generally the table of distances for high explosives at 27 CFR 555.218 would be applied using the total weight of explosive materials in the magazine.

[27 CFR 555.218]

Yes. Any person storing explosives must inspect the magazines at least once every 7 days to determine whether there has been unauthorized entry or attempted entry into the magazines or unauthorized removal of the contents of the magazines.

[27 CFR 555.204]

You must notify ATF of any changes or additions to your approved explosives magazines. Mobile or portable Type 5 magazines and magazines used to temporarily store explosives (under 24 hours) are exempt from this ATF notice requirement. If you begin storing at a new location, you must also notify the local fire authority. That location then becomes part of your annual notice, and you must also notify the fire authority when you stop storing there. 

[27 CFR 555.63, 555.201(f)]

Smokeless powders designed for use in small arms ammunition are exempt from regulation under 18 U.S.C. Chapter 40 and the regulations in 27 CFR Part 555. Packaging that readily identifies the smokeless powder as being designed for use in small arms ammunition may help in determining whether it is entitled to the exemption. Smokeless powder designed for use other than in small arms ammunition, and explosive products such as squibs, fireworks, theatrical special effects, or other articles that may contain smokeless powders, are regulated and must be stored pursuant to the regulations at 27 CFR 555, Subpart K – Storage.

It should be noted that persons engaged in the business of importing or manufacturing smokeless powder designed for any use must have a Federal explosives license. Further, importers of smokeless powder designed for use in small arms ammunition must also possess an ATF firearms importers license (Type 08 or 11); must register with ATF under the provisions of the Arms Export Control Act; and must submit (to ATF) and receive an approved ATF Form 6 – part I (5330.3A), Application and Permit for Importation of Firearms Ammunition and Implements of War.

Yes. Anyone who stores regulated explosive materials must notify the authority having jurisdiction for fire safety in the locality where they are storing the explosives. Notice is required at three points:

When you begin storing: give oral notice before the end of the day you begin storing, then written notice within 48 hours. The written notice must list the type of explosive materials, magazine capacity, and the location of each storage site in that local authority’s jurisdiction.

Every 12 months after that: give written notice to the same local authority, listing the type of explosive materials, magazine capacity, and the location of each storage site within their jurisdiction the.

When you stop storing at a location: give written notice within 48 hours after you discontinue storing explosives at that location.

[27 CFR 555.11, 555.201(f)]

No. However, products which are manufactured with a detonator attached to the detonating cord as an integral part need not be disassembled and stored separately.

[27 CFR 555.213]

Yes. There is no exemption in the law or regulations for the storage of explosive materials by any state or political subdivision thereof.

[18 U.S.C. 842(j), 845(a)(6); 27 CFR 555.141(a)(3), (a)(5)]

You must give written notice when you begin storing, and every 12 months after that for as long as you store explosive materials at that location. You must also give written notice when you stop storing at a location. 

[27 CFR 555.201(f)]

The annual written notice must identify type of explosive materials, magazine capacity, and the location of each explosives magazine you maintain in that jurisdiction. 

[27 CFR 555.201(f)]

Your annual notice is due every 12 months after your initial written notice.

[27 CFR 555.201(f)]

Yes. When you stop storing explosive materials at a location, you must notify the local fire authority in writing within 48 hours after you discontinue storing explosive materials at that location. 

[27 CFR 555.201(f)]

Yes. You must retain a copy of each written notice for five years from the notice date.

Data is entered as soon as the U.S. Bomb Data Center has received the information. Each incident's case information is updated throughout the case history of the file.

All activities conducted outside the scope of a U.S. Government contract are subject to the requirements of Part 555, even if the activities are conducted on property owned by the military.

[18 U.S.C. 845(a)(3), (a)(6); 27 CFR 555.26, 555.29, 555.41, 555.141(a)(3), (a)(5)]

Yes, provided that all the explosive materials in question are manufactured under a government contract. Any explosive materials manufactured in anticipation of receiving a government contract would not qualify for this exemption. If the contractor manufactures any explosive materials not pursuant to a U.S. military contract, the manufacture and the explosive materials are subject to all requirements of the law and regulations.

Some contracts may allow the contractor to retain excess or extracted explosive materials for their own use, for use in further manufacture, or for sale in commerce. In such a case, ownership of the explosive materials typically passes from military to the private company. ATF generally considers this acquisition and any further activities involving the explosive materials to be regulated by 27 CFR Part 555.