Two horrific accidental deaths involving Autoclaves and Industrial Ovens have shown how dangerous this equipment can be and why it is vital to have safety procedures in place. Our article tells you what you need to know to ensure the safety of your staff.

A large international tyre manufacturer has been hit with a fine of £150,000 after the death of an employee who was trapped inside an industrial autoclave for over two hours.

The employee was found dead at the factory in September 2012. The machine was used by the company to heat parts of tyres to temperatures that could reach 145 degrees Celsius.

Following an investigation, it was found that the company did not have a system in place to ensure checks were made on the autoclave before switching it on. The HSE subsequently began a prosecution of the company.

The court heard that about an hour after the employee was last seen alive on CCTV footage, a colleague shut the door on the autoclave and started its operating cycle.

The pressure door on the autoclave could not be opened from the inside and there was no facility for somebody inside the machine to stop its cycle once it had begun.

During the autoclave’s operation, pressurised steam was piped into the vessel, meaning that the atmosphere inside the chamber would contain virtually no oxygen.

During the investigation, the HSE discovered that on occasions between cycles, when the pressure door was open, employees would enter the autoclave to recover fallen materials.

Even though this practice was taking place, the company had failed to identify the autoclave as a confined space that posed a serious risk to the safety of employees. No measure had been put in place to prevent access to the autoclave, such as instructions or signs.

It was also discovered that there was no system in place to check that there was anybody in the autoclave before the door was shut and the operating cycle started.

The company pleaded guilty to a breach of the Health and Safety at Work Act. It was fined £150,000 and ordered to pay £46,706 in prosecution costs.

This case has unfortunate echoes of the death of an employee who was trapped inside an industrial oven at a moulding company in 2010 (the company was found guilty of corporate manslaughter in January 2015) and the case of an employee who died in an industrial oven in a food processing plant in California in 2012.

What should employers do?

Employers should always be involved with the risk assessment process and the following points should be included:

  • Involve ALL who are involved in the process

  • Actively seek employees’ views

  • Ask the employees what they perceive as hazards

  • Know your limits – if you do not know, ASK for assistance (specialist knowledge may be required)

  • Implement effective control measures

  • Monitor and review regularly

In this case, a robust risk assessment as required under section 3 of The Management of Health and Safety at Work Regulations 1999 should have identified the hazards.

Once the hazards have been identified, the appropriate control measures can be implemented.

The Health and Safety Executive’s Safety Requirements for Autoclaves (Guidance Note PM73 (rev3)) 2012 contains guidance on what steps could be taken to increase the safety of autoclaves.

Inadvertent pressurisation with a person inside the autoclave

18 If the autoclave is large enough for an operator to enter, fit the autoclave door with a device to prevent the door from closing and the cycle from starting with the operator inside.19 Where full-body access inside the autoclave is possible, it is also advisable, depending on the process, to reduce the risk further by providing a safety alarm or pull cord inside the vessel to automatically engage the emergency stop circuit.

They also issued a safety bulletin following the moulding company accident: