Control gas, ventilation and legionella risks in a commercial kitchen

Commercial kitchens rely on gas-fired ovens, hobs, fryers and grills, and on ventilation to remove the heat, fumes and combustion products they produce. Poorly maintained gas equipment can cause explosions, and incomplete combustion produces carbon monoxide. Employers and the self-employed have duties under the Gas Safety (Installation and Use) Regulations 1998 and the Health and Safety at Work etc. Act 1974 to keep gas appliances and installations safe.

Gas safety

Train everyone who uses gas equipment to use it properly and to make visual checks for obvious faults, such as damaged pipework or connections, inoperative flame supervision devices, missing restraints on equipment and smells of escaping gas. All staff should know what to do if they find one. New equipment has flame supervision devices, and second-hand equipment with burners should be fitted with them before installation.

Use only blowtorches of an approved proprietary design, and never place a gas blowtorch on or near a hot surface. A gas engineer who finds an unsafe installation will classify it as at risk or immediately dangerous and advise you not to use it.

Ventilation and extraction

The Workplace (Health, Safety and Welfare) Regulations 1992 require effective and suitable ventilation in every enclosed workplace, and a kitchen needs mechanical extraction through a canopy over the cooking appliances. HSE guidance says a good system:

• has a canopy hood for every appliance or other source of fumes and heat, as close to the source as the work allows;
• replaces the air it extracts with fresh make-up air that does not impair the flues serving gas appliances;
• uses filters and ductwork that are easy to clean and made of non-combustible material;
• is designed for your cooking load, the equipment you use, the layout and the number of staff.

Clean grease filters and ductwork regularly, because a build-up of grease and fat is a fire risk, particularly above open-flame appliances. Industry guidance from the Building Engineering Services Association, TR19, covers cleaning of ventilation systems. Maintain the system according to the installer's instructions and keep records of its design criteria, commissioning performance and maintenance.

Where the extraction system acts as the flue for an appliance that needs one, the Gas Safety (Installation and Use) Regulations 1998 mean it must be interlocked with the gas supply. Where an older kitchen has no interlock, assess whether a risk is likely to arise and, if so, prevent or control it. Charcoal ovens cannot be switched off, so they need ventilation even when covered and cooling overnight, to stop carbon monoxide building up.

Legionella

Hotels, spas and leisure venues carry more legionella risk because of large storage tanks, long pipe runs, showers that create spray, rooms used rarely, and cooling towers.

Appoint a competent person, who can be you, a member of staff or an outside contractor, to carry out the risk assessment of your water systems. If you have 5 or more employees you must record the significant findings; with fewer than 5, writing them down is still sensible. Keep records for as long as they stay current and at least 2 years afterwards, and keep monitoring results for at least 5 years.

Sentinel outlets are the nearest and furthest from the cylinders and tanks. Cold water should read below 20°C at them after running for two minutes. Routine microbiological testing is not usually needed for hot and cold water systems, but it may be if you doubt your controls or the target temperatures are not being met. Open systems such as cooling towers and spa pools need testing at least quarterly.

Enforcement

Health and safety inspectors can serve improvement and prohibition notices and prosecute breaches of these duties. Following HSE guidance is not compulsory, but if you follow it you will normally be doing enough to comply with the law.