Fire risks associated with working with acetylene

The dangers of acetylene

Review the use of acetylene in your premises

What you can do to avoid an acetylene incident

Ask yourself the following questions:

  • Have I carried out a fire risk assessment
  • Do I really need to keep acetylene?
  • Have I got more than I actually need?
  • Is there a safer alternative
  • Is my storage area safe and secure?
  • At night safe storage is vital. If possible, store acetylene cylinders in a secure container outside the building away from other hazards.
  • Am I and/or my staff suitably trained and competent to use the equipment?
  • Is my equipment safe and regularly tested?
  • Have I provided any warning signs?
  • If cylinders are stored inside are they on a trolley close to an exit?
  • Are staff trained in what to do in the event of a fire? 
  • Do I have plans of the location of the cylinders? 
  • The cylinders can be treated as a person and, if safe to do so, be evacuated in the event of a fire - very gently. 

Warning signs (signage)

In order to comply with the requirements of Health and Safety (Signs and Signals) Regulations, suitable sized hazard warning signs should be provided in accordance with BS ISO 3864-1: 2011 and displayed prominently outside the building.

See below for examples of suitable signs:

What to do in the event of a fire

  • if you have a fire alarm, activate it   
  • dial 999 to call the fire and rescue service and tell them cylinders are on the premises  
  • never try to put out a fire involving cylinders, leave it to the fire and rescue service 
  • take plans of the building with you 
  • tell everybody to leave the premises and go to a safe place well away from the installation  
  • it is safer to evacuate everyone from the area - an overheated cylinder can explode violently

If you have acetylene cylinders

  • make sure they are included in your fire risk assessment
  • you should consider providing a fire service information pack that would include details and location of acetylene and any other hazardous materials on your premises, location of electrical mains switch, gas cut off and water stop cock
  • inform your insurance provider
  • tell us: by telephone on 023 8064 4000, alternatively fill in the acetylene reporting form  

Disposing of unwanted cylinders

Unwanted cylinders should be disposed of safely by contacting the gas supply company, the details can usually be found on the printed label on the shoulders of the cylinder.

Advice concerning safe disposal can also be obtained by contacting BOC Industrial and following the advice provided. They have a 24-hour helpline and can be reached by telephone on 0800 111 333.

About acetylene

All gas cylinders are potentially dangerous when exposed to fire and may explode. 

Acetylene cylinders may react differently to other gas cylinders after exposure due to a chemical reaction called decomposition. 

This reaction gives out a great deal of heat which, if unchecked, can cause the reaction to accelerate and the cylinder to rupture, even after the fire has been put out. 

Oxy-acetylene welding, commonly referred to as gas welding, is a process that relies on combustion of oxygen and acetylene. Acetylene has been used in steel welding and other heat treatment processes for more than a century. 

The mixture of oxygen and acetylene is used because it has been the only gas combination with enough heat to weld steel. Despite the fact that in most industrial applications oxy-acetylene welding has given place to other methods such as: 


Acetylene is an extremely flammable gas and differs from other fuel gases due to its very unstable nature. Cylinders must be handled with extreme care. Acetylene is also a very serious atmospheric pollutant.