Dangers associated with storing aged ammunition reloading propellant powders

Previously issued as Mines Safety Bulletin 7 on 18 July 2002.

Purpose

To present information on recent accidents which resulted in injury, that were caused by the accidental initiation of propellant powders.

To outline the dangers associated with long term storage of ammunition reloading propellant powders.

To provide details on the correct methods for disposal of unwanted powders.

Scope

All shooters, ammunition reloaders, gun shops and members of the general public.

Issues

Two incidents involving the accidental initiation of quantities of propellant powders have been reported to the Explosives Inspectorate in the past 14 months:

1. In February 2001, a young boy received third degree burns to 60% of his body when the muzzle flash from his rifle ignited a poorly sealed drum containing approximately 2kg of 25 year old shotgun powder. The boy received third degree burns to his arms including fingers, his back and legs. Second degree burns were received to the ears, and first degree burns were sustained on the boy's face, groin, buttocks, chest and head area.
2. In May 2002, a man received serious burns to his arm and upper chest area when a bag of gunpowder exploded as a result of sparks from an angle grinder he was using. The man was unaware that the powder, which was in an unmarked calico bag, was on the bench near where he was working. The powder was reported to be at least 50 years old.

A Mackay man who stored propellant powders in an old bank safe in his gunroom woke to discover that the deflagration of propellant powders stored within the safe had bulged the safe door outward, allowing the gases to escape. The gases escaped with sufficient force to blow out a brick wall immediately beside the safe.

It is well known that ammunition can deteriorate with age to a stage where it will not reliably fire. It is not widely known that propellant powder deteriorates and decomposes with age. A retardant is added to powder to stop or delay decomposition. However, in time, the retardant loses its effectiveness, decomposition sets in a spontaneous combustion can occur. It appears that this was the case in this incident.

Contributing factors

In all cases the powders were old. In the cases resulting in injury, the powders were not stored in an appropriately secure container. The calico bag carried no marking to the effect that the contents
were explosives.

Recommendations

It is important that people who possess reloading propellant powders use their older stocks first and consider buying their powders in smaller quantities unless their usage rate demands larger stock. Further, it is essential they comply with the shelf life recommended by the manufacturer of the powder.

Note: In the absence of a recommended shelf life any powders older than 10 years should be destroyed.

Conclusion

Propellant powders may be destroyed in small quantities by spreading the powder in a thin long trail on the ground, away from combustible matter, in an open and clear area remote from habitation. The person disposing of the powder should light the powder trail from one end and then stand clear. No other persons or animals should be allowed in the immediate vicinity while this procedure is being conducted.

Precautions must also be taken to ensure that such disposal does not cause a bushfire. Things to consider may include wind strength, amount of combustible material in the immediate vicinity and soil moisture.

Alternatively, powder may be disposed of by contacting your local Inspector of Explosives or nearest police station to arrange for collection by an Explosives Inspector. Unwanted powders will then be safely destroyed at no charge.

Authorised by Chief Inspector of Explosives

Contact: Manager, Explosives Licensing , +61 7 3199 8057 explosives@dnrm.qld.gov.au

Issued by Queensland Department of Mines and Energy