A chemical company has been fined over safety failures that led to a potentially deadly explosion.

The firm was prosecuted after there was a 3am blaze involving loud explosions. The police declared it “a major incident”.

The court heard heated ovens or “hot boxes” had been used to heat up sealed drums containing dangerous substances. They burst open causing a large “fireball”.

The Health & Safety Executive (HSE) claimed a large fire in one of the ovens was a “significant risk to life”.

It said: “There were a number of members of staff on site at the time when the explosion took place. Had any of them been in the vicinity of the hot box they would almost certainly have suffered serious or fatal injuries.”

Poor risk assessment

Senior management had been told the hot box had been overheating that day but did not stop the operation.

The HSE said the company’s risk assessment was “inadequate and flawed” and that this led to a mistaken belief the operation was “low risk”.

The company failed to make sure its equipment was suitable to:

• control temperature and pressure
• prevent ignition to an uncontrolled release

Safety failings included:

• unreliable equipment
• an incorrectly set alarm
• not identifying potential problems
• inadequate maintenance and testing of the hot boxes

The company had “very limited understanding” of its own equipment. Staff wrongly believed there was an automatic trip if temperatures rose too high.

The HSE said the company should have found a safer way to operate.

Sentence

Vertellus Specialties UK Limited failed to take sufficient steps to prevent a major accident and limit its effects.

It admitted breaking the Control of Major Accident Hazards Regulations 1999.

The judge said: “It is accepted the fire was the responsibility of the company as a consequence of their breach of duty. The company didn’t carry out a sufficiently rigorous examination of risk.”

He fined the company £135,000 with £37,650 costs.

The HSE said: “Luckily no one was injured as a result of this uncontrolled fire. Duty holders, particularly those who could be subject to a major incident, need to carry out robust planning to prevent and control major accidents. All engineering disciplines should be used, using outside assistance if needed. Here there was a failure to recognise how a leak could develop into a larger problem.”