ATF Federal Explosives Storage Magazine Requirements

ATF Federal Explosives regulations noted in 27 CFR Part 555 Subpart K specify detailed construction requirements for explosive magazines. All explosive material MUST be kept in locked magazines UNLESS:

  • In the process of manufacture
  • Physically handled by a licensee or user during the operating process
  • Currently in use
  • In transport to a place of storage or use by a licensee, permittee, or an individual who lawfully and legally acquired explosive materials under Section 106 Subpart F

Explosive materials MUST be kept in magazines that meet the construction, locking, and specified table of distance requirements noted in Subpart K. When none of the specified conditions and standards listed above apply:

  • All explosive materials must be stored in appropriate magazines
  • Magazines must meet construction and housekeeping fulfillments noted in Sections

555.211 & 215

  • Magazines must meet table of distance requirements presented in Section 218
  • Magazines must be inspected every 7 days
  • Permanent outdoor magazines must have a solid foundation or be metal skirted to prevent access from underneath
  • Explosive materials may not be left unattended in Type-3 magazines (including “day boxes”) and must be removed to Type-1 or -2 magazines for storage
  • Storage regulations DO NOT apply to binary explosives until mixed

Explosive Types and Storage

High Explosives

High explosives is a function by detonation that causes a rapid decomposition of the material caused by a shock wave moving through the product at a rate faster than the speed of sound. All high explosives (including blasting caps, detonating cord, dynamite, shaped charges, boosters, etc.) in accordance to Section 555.203 must be stored in:

Low Explosives

Low explosives detonate producing a large volume of heated gas. All low explosives in accordance to Section 555.203 (such as black powder, display fireworks, safety fuse, igniters, etc.) must be stored in:

  • Type-1, -2, or -4 Permanent, portable or mobile (indoor/outdoor) magazines

Blasting Agents

Blasting agents are a material or mixture that consists of fuel and oxidizer that is intended solely for blasting and that cannot be detonated by a No. 8 test blasting cap when unconfined. Blasting agents may be stored** in:

  • Type-5 Permanent, portable, or mobile (indoor/outdoor) magazines

**Blasting agents stored WITH high explosives must be stored in a Type-1 or -2 magazine


Storage Security

Hinges and Hasps

Hinges and hasps must be attached to storage doors by bolting, riveting, or welding so that the door bolts cannot be removed from the outside.


Having the appropriate locks will help hinder robberies and break-ins. The ATF recommends that any padlock securing an explosives magazine have an ASTM (American Society of Testing Materials) rating of at least 5.

More information can be found in ASTM’s F883-97 “Standard Performance Specifications for Padlocks”.

General requirements:

  • Two mortise locks
  • Two padlocks fastened in separate hasps and staples
  • Padlocks must have at least five tumblers and a casehardened shackle of at least ⅜-inch diameter
  • Padlocks must be protected with no less than ¼-inch steel hoods constructed so as to prevent sawing or lever actions on the locks, hasps, and staples
  • Three-point lock
  • Combination of mortise lock and padlock
  • Mortise lock requiring two keys to open

Indoor Magazines

The locking requirements for indoor magazines are similar to outdoor magazines requirements with a few exceptions. An indoor magazine located in a locked secured room with door hinges and lock hasp securely fastened to the magazine (noted in 27 CFR 555.208(b), 555.210(b) and 555.211(b)), may have each door locked with one steel padlock that meets the stated requirements above.

“Hockey Puck” Locks

“Hockey puck” locks have no visible shackle. The locking bolt and staple are completely covered and protected by the lock body. For the locks to be approved for use, the lock must have a casehardened shackle and a close-fitting shroud to prevent sawing or prying of the lock.

Prior to installation, the licensee/permittee must submit a request for a variance.

Flush Mounted Locks

Flush mounted locks (aka “flush-mount lever locks”) do not provide sufficient protection against pulling or prying the lid off the magazine. A flush mounted lock fails to provide an acceptable level of theft-resistance for indoor storage of low explosive materials and may not be used to secure Type-4 indoor magazines. Additional information can be found at ATF Ruling 2004-3.

Licensee and/or permittee who desires to use this type of lock in a secured room that is locked as noted in subparagraph (b) of 27 CFR 555.210 may submit a request for a variance.

Vehicular Magazines for Storage 

Type-2, -4, and -5 unattended vehicular magazines must have the wheels removed or otherwise immobilized by kingpin locking devices. Other methods must be approved by the Director.

Magazine Inspections

  • Magazines must be inspected at least once every 7 days. Inspection must be sufficient to determine if there has been unauthorized or attempted entry
  • A full inventory of your explosive materials is required annually and entered into your Daily Summary of Magazine Transactions

Bullet Resistance

Federal regulations require that Type-1 and Type-2 explosive magazines be bullet-resistant. “Bullet-resistant” means resistant to penetration by a bullet of 150 grain M2 ball ammunition (nominal muzzle velocity of 2,700 feet per second). Construction requirements for Type-2 outdoor magazines (i.e. exterior and doors constructed of not less than ¼-inch thick steel and lines with at least 2 inches of hardwood) are fixed to guarantee bullet-resistance.

ATF Ruling 76-18 details alternate construction standards for explosive magazines.

Bullet Resistance for Type-2 Indoor Storage

Type-2 indoor magazines do not need to be bullet-resistant if the buildings in which they’re stored in provide protection from bullet penetration. Type-2 indoor magazines have less strict construction regulations due to the additional protection afforded by the associated building (see Part 555.208(b)). Please note that if the magazine, nor the building in which it is located, is bullet resistant, then the magazine and building must meet bullet-resistance requirements.

If there’s a concern that the combined construction doesn’t meet listed requirements and ATF Ruling 76-18 doesn’t address the situation, a licensee or permittee may submit a request for a variance to the requirements contained in 27 CFR 555.208. Variance requestions should be submitted to the Explosives Industry Programs Branch via your local ATF office. When submitting your request for a variance, please include specific construction information for both the magazine and building in which it is located.