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Kitchen extraction - gas safety
In a commercial kitchen, gas and ventilation are not two separate systems - the law ties them together. A gas appliance is only allowed to run when the ventilation proving it is safe is running too, which is why gas safety and your extraction are the same conversation.
The short answer
A commercial kitchen using gas cooking appliances is required to have a gas interlock system, which links the gas supply to the ventilation so gas only flows when the extract and supply fans are proven to be running. This sits under the Gas Safety (Installation and Use) Regulations 1998 and the catering standard BS 6173, with an annual gas safety check by a Gas Safe registered engineer competent in commercial catering. Because the interlock depends on the ventilation, extraction is part of the gas-safety picture, not separate from it.
Why it is regulated so tightly
A commercial kitchen burns a lot of gas in an enclosed, busy space, and that carries two linked dangers: the products of combustion, including carbon monoxide, building up if they are not carried away, and gas escaping if something goes wrong. Both are managed by the same thing - ventilation that removes the combustion products and dilutes any escape, keeping the air in the kitchen safe to work in. Without effective ventilation running, a gas kitchen is not a safe place to have the burners lit.
That is why the law does not treat the ventilation as an optional comfort measure but as a safety-critical partner to the gas appliances. The whole regulatory approach to commercial catering gas rests on the principle that the burners should not be running unless the ventilation that makes them safe is running too. Everything else - the interlock, the checks - follows from that single idea, which is what makes gas safety and extraction inseparable in a commercial kitchen.
The interlock
The mechanism that enforces this is the gas interlock system. A commercial kitchen using gas cooking appliances is required to have one, to comply with BS 6173 and the related IGEM/UP/19 guidance. It works by linking the gas supply, through a solenoid valve, to the kitchen's ventilation: the gas is only released to the appliances when the extract and supply fans are proven to be running at the required rate. If the ventilation fails or is switched off, the interlock closes the gas valve and the burners cannot run.
So the interlock is a physical guarantee that the two systems stay coupled - it makes it impossible, in a properly working kitchen, to cook on gas without the ventilation that keeps the air safe. It removes reliance on staff remembering to switch the fans on, because the gas simply will not flow without them. This is the heart of the legal position: not just that a gas kitchen should be ventilated, but that it must be engineered so gas cannot flow when it is not.
The checks
Legal compliance is not just having the interlock but keeping it and the appliances verified. Commercial catering gas appliances require an annual gas safety check by a Gas Safe registered engineer who is competent in commercial catering - a domestic gas qualification does not cover it. That check confirms the appliances and the interlock are safe and working. Alongside the annual check, the interlock should be functionally tested regularly to confirm it actually cuts the gas when the ventilation stops.
This regime of annual competent checks plus regular functional testing is what keeps the safety real over time, because an interlock, like any safety system, can develop faults. A kitchen that installed an interlock but never has it checked cannot be confident it would actually close the gas in a ventilation failure - which is the one moment it exists for. The legal duty is ongoing verification by the right competent person, not a one-off installation.
Where cleaning connects
Because the interlock depends on proven ventilation, the condition of that ventilation matters to the whole safety case. The extract system is what carries away the combustion products and the heat, and it only works if it is not choked. A kitchen extract heavily loaded with grease has restricted airflow, which undermines the ventilation performance the gas system is relying on - so keeping the extract clean is part of keeping the gas-safety system genuinely effective, not just a fire-risk measure.
The two duties reinforce each other. Cleaning the kitchen extract to control grease fire risk also keeps the airflow that the gas interlock proves and depends on. A neglected, grease-clogged extract is a problem on both fronts at once - a fire risk in itself, and a drag on the ventilation that makes gas cooking safe. Looking after the extract is therefore not a separate task from gas safety but a support to it, keeping the ventilation half of the interlock working as it should.
The takeaway
The legal position on gas safety in a commercial kitchen comes down to a single principle: gas cooking is only safe with the ventilation running, so the law requires the two to be interlocked, checked annually by a competent Gas Safe engineer, and the interlock tested to confirm it works. Gas and extraction are not separate concerns - they are one safety system, coupled by design.
For an operator, that means gas safety and looking after the extract ventilation belong together. The interlock, the annual check and the interlock testing are the compliance backbone; keeping the extract clean and flowing is what keeps the ventilation half of that system genuinely effective. Treating gas and ventilation as one - which is what the law does - is the way to keep a gas commercial kitchen both compliant and actually safe to work in.
Questions
A commercial kitchen using gas cooking appliances is required to have a gas interlock system to comply with BS 6173 and IGEM/UP/19. It links the gas supply to the ventilation so gas only flows when the extract and supply fans are proven to be running.
It links the gas supply, through a solenoid valve, to the ventilation. Gas is only released to the appliances when the fans are proven to be running at the required rate; if the ventilation fails or is off, the interlock closes the gas valve.
Commercial catering gas appliances require an annual gas safety check by a Gas Safe registered engineer competent in commercial catering - a domestic qualification does not cover it. The interlock should also be functionally tested regularly.
The Gas Safety (Installation and Use) Regulations 1998, with the catering standard BS 6173 and the IGEM/UP/19 guidance on interlock devices setting out how gas appliances and ventilation should be coupled and maintained in commercial catering.
The interlock depends on proven ventilation, and a grease-clogged extract has restricted airflow that undermines that ventilation. Keeping the extract clean maintains the airflow the gas system relies on, as well as controlling fire risk.
Because commercial catering gas is a distinct discipline from domestic gas, covering the appliances, the ventilation and the interlock together. Only a Gas Safe registered engineer with commercial catering competence is qualified to verify it is safe.
We clean kitchen extract systems to control fire risk and maintain the airflow your gas interlock proves and depends on - supporting the safety system, not just the fire duty.
