• 70 per cent of fires in commercial kitchens originate in faulty extract ventilation systems due to build up of fat and grease.
• Grease build up also causes an environmental health hazard by providing a breeding ground for bacteria.
• You can reduce these risks by carrying out regular cleaning of your kitchen extraction and ventilation systems.

Fire risks

Filters cannot remove all traces of grease and dirt from the air. Over time, a layer of grease and dirt builds up on the surfaces of ventilation ducts, canopies and extractor fans. This is a major fire risk.

Fires within ductwork are very difficult to stop. Ductwork is often inaccessible, and fire may break out of the ductwork into other buildings. Damage is often serious and businesses are forced to close.

Why carry out cleaning and maintenance?

• You will reduce the risk of fire.
• It prevents the build-up of grease deposits and bacteria within your kitchen extraction system.
• Under the Regulatory Reform (Fire Safety) Order 2005, your extract systems need to be included in your fire risk assessment with action taken to minimise any potential fire risk to buildings and occupants.
• Failure to carry out proper cleaning and maintenance could lead to a breach of Environmental Health regulations and could invalidate your fire insurance policy.

How often should I clean?

Ductwork

Ideally, you should measure the rate of build up of grease on the internal surfaces of ductwork. If this is not possible, your cleaning work should be planned around the level of use:

• Heavy use (12-16 hours per day) - clean every three months.
• Moderate use (6-12 hours per day) - clean every six months.
• Light use (2-6 hours per day) - clean every 12 months.

Where cooking processes involve fat frying or wood/charcoal burning, cleaning may need to be more frequent.

Extract hoods and filters

These should be cleaned and degreased daily, or in accordance with manufacturers recommendations. Cooking should never be carried out unless there is a filter in place.