On 6th September, a hazardous waste treatment centre received pyrotechnic waste from an arms and munitions factory; the delivery included 6 drums of methyl ethyl ketone (MEK). On 20th September, the waste was treated: the solvent was pumped to be distilled, the drums were then drilled, compressed and placed in an intermediate container. While transferring the drums on 24th September in a skip to a scrap metal yard, a drum burst into flames causing the residual solvent to ignite. Employees extinguished the fire with a 50-kg extinguisher and a fire hose. No one was hurt. The 200-litre drum that caused the fire was partially redeployed and the bottom broke off; the lid of the skip was damaged. The pyrotechnical amount involved was estimated at several tens of grams.

The drum was different from those normally used, especially its markings; moreover, it contained the remains of a brush and needles for bonding parts. According to the operator, the incident was due to the following sequence of events: the drum contained an unusually high amount of product used for pyrotechnic compositions in the form of a sludge at the bottom; compression did not initiate the product present, as the residual solvent passivated the rest of the composition. The solvent partly evaporated during the 4 days of storage and the dry nitrocellulose and/or pyrotechnic composition may have formed on the drum walls. A shock during transfer of the product caused the drum to explode and fire to break out on residual solvent in the skip.

To prevent recurrence of this incident, the solvent used for cleaning tools in contact with pyrotechnic compositions was to be destroyed directly on the arms and munitions factory site. To accomplish this, special attention would be paid to the drum markings; the volume required to collect MEK, which may be contaminated, was to be reduced to avoid excessive residence time in the drum before destruction.