In an organic chemical industry, at about 8.20 pm, there are a release of ethyl chloride solution from a recirculating pump near the base of reactor vessel. A toxic, corrosive chloride cloud enveloped the plant. The on-site and external emergency services is activated.

During 1h30, the fire brigade tried to control the leakage to suppress the further release and prevented the cloud spreading. In spite of these attempts, at 22.08pm, the pool of ethyl chloride was ignited resulting in a fire. By about 1 am, the fire is being contained and control is being achieved at about 8 pm. 3 firemen and 1 employer are detained in hospital overnight and twelve firemen received treatment. A nearby road is closed and two neighboring premises are alerted in case evacuation became necessary.

The leak occurred at a point between the discharge port of a reactor recirculating pump and associated fixed pipework. HSE investigators foresee two hypothesis:

• a corroded securing flange on the pump working loose,
• the failure of flexible connection (bellows) to pump discharge to the pipe.

The HSE believes the first of these possible causes was the more probable. The most likely source of ignition was an electrical box. HSE served a Prohibition Notice prohibiting company from restarting production of ethyl chloride until it had demonstrated that “the major accident hazards had been identified and that appropriate precautions had been taken to limit the consequences to persons and the environment.