Chemical Incident with Peroxide Liquors
During a routine preparation of a phamaceutical intermediate, some waste liquors were stored in drums. This was normal practice with early batches, to ensure that the expected yield was obtained before disposing of the waste.
The process specified that the liquors were to be stored in plastic lined 200 litre drums, however several drums were needed, and the operator found he was one short. He therefore found a new steel drum and used that instead.
The waste liquors were mainly water with some excess hydrogen peroxide present.
The drum was filled at 5:30 in the evening, before the pilot plant staff went home.
At about 11pm, the night shift of the main plant were having lunch when they heard an explosion. On investigating they found the steel drum, half full and foaming, and no trace of the drum top, which had completely uncrimped itself.
Later on the drum top was found at some considerable distance - it had bent itself in half as it had been blown upward and hit a large steel gantry, and then shot off sideways and down the road.
- The cause of the explosion was the action of traces of rust on the peroxide which then generated enough pressure of liberated oxygen to blow off the drum lid
- On further checking, the other drums were also found to be slowly presurising, as the peroxide slowly and naturally decomposed - no-one had thought to use ventilated caps, as was normally supplied with fresh peroxide. These drums were quickly disposed of.