What is a CP42 commercial catering gas certificate?

The CP42 is a form published by CORGIdirect and filled in by a Gas Safe registered engineer with catering qualifications after inspecting a commercial kitchen. It is not named in any regulation, and no law obliges a kitchen to hold one. What the law obliges is the employer keeping the gas installation safe, and this form is the trade's usual way of showing a competent person checked it.

What is a CP42?

CP42 is the code CORGIdirect gives its Gas Safety Inspection Form for commercial catering appliances. CORGIdirect describes the form as “originally conceived and produced in-house”, so it is an industry publisher's document rather than a Gas Safe Register or government one, and it says the current version was revised to reflect the procedures in IGEM/UP/19 and IGEM/IG/2 while still drawing on BS 6173. The pad holds 25 forms with a carbon copy each, A4 portrait, at £8.00 excluding VAT, and CORGIdirect will only sell it to a Gas Safe registered business. That is worth knowing when a kitchen operator asks to see “the CP42”: what they are really asking for is the inspection, and plenty of firms issue the same content on their own digital template instead of the printed pad.

The form comes in two parts. Part 1 is the catering environment: the gas installation and isolation, the electrics, the interlocks, and the extract and ventilation system. Part 2 is the appliances, taken one at a time. An earlier “Risk Assessment” element was dropped from the form after engineer feedback, which CORGIdirect describes as a source of debate and confusion. CORGIdirect publishes that structure but not the field list, so the table below is drawn from the reproduction of the form sold as a ServiceM8 template by Hazel Whicher, checked on 6 September 2026.

One absence on that list surprises people: there is no flue section of the kind a boiler report has. Most catering appliances are flueless, and the canopy does the work a flue would. Gas Safe Register puts it directly, saying the interlock requirement links back to the duty to maintain flues in a safe condition “where the extract canopy is acting as a flue”. That is why the extract system, not a chimney, occupies the front half of the form.

Who needs a CP42?

Any business running gas catering appliances at a place of work under its control: restaurants, pubs and hotels, cafes, takeaways and fish and chip shops, school, hospital and care home kitchens, staff canteens, and event catering. The duty behind it is regulation 35 of the Gas Safety (Installation and Use) Regulations 1998, which puts it on “every employer or self-employed person” to ensure any gas appliance, installation pipework or flue installed at a place of work under their control is maintained in a safe condition so as to prevent risk of injury to any person.

Regulation 35 asks for a safe installation, not for a piece of paper. Gas Safe Register bridges the gap plainly: you may be required to provide evidence that the duty is being met, and one way of achieving that is to retain records of the completed safety checks, produced by an appropriately qualified Gas Safe registered engineer. The CP42 is the trade's standard shape for that record.

• Environmental health officers: Gas Safe Register says that during an EHO inspection you will likely be asked for evidence of ongoing maintenance, and that where none is produced or there are safety concerns the officer may serve a formal notice setting out what must be done to comply.
• Insurers and landlords of commercial premises: neither is a legal requirement, but both routinely make an annual gas inspection a condition, and the record is the cheapest evidence that one happened.
• Workplaces outside GSIUR: HSE's catering guidance notes that in premises where GSIUR does not apply, such as canteens in factories, the employer still has to ensure whoever does the work is competent, and that Gas Safe registration is the clearest way of demonstrating it.
• Hotels, guest houses and staff accommodation: the residential parts carry the separate landlord duty under regulation 36, a 12-month check with the record given to the occupier within 28 days. That is a CP12 matter, not a CP42 one, and a hospitality site can easily need both.
• Mobile catering: vehicles and trailers sit outside IGEM/UP/19's scope and off the fixed-premises form. CORGIdirect publishes a separate CP44 for them.

How often is a CP42 required?

Every 12 months in practice, though no regulation sets that interval for a commercial kitchen. Gas Safe Register says the gas equipment and the extraction and ventilation system should be installed, commissioned and adequately maintained, including checks for safe operation, on an annual basis by an appropriately qualified Gas Safe registered engineer. HSE's catering guidance is worded more carefully: the frequency may vary with the equipment and its use and should follow the manufacturer's recommendations, but “as a general rule, annual inspections are a reasonable minimum frequency”. Gas Safe Register's catering factsheet adds the practical anchor, that the maximum period between services specified by equipment manufacturers is generally 12 months.

The 12-month figure that genuinely is in law belongs to a different form. Regulation 36(3)(a) requires a landlord to have relevant appliances and flues in domestic rented accommodation checked within 12 months of installation and at intervals of no more than 12 months after that, and regulation 36(3)(c) lists the particulars the resulting record must contain. Nothing equivalent exists for catering, which is why an honest answer to “when does my CP42 expire” is that the record does not expire, the installation moves on. A new appliance, a rebuilt canopy or a changed interlock arrangement is a reason to reinspect rather than to wait out the year.

Worth separating from all of that: Gas Safe Register defines a safety check as different from a service, in that cleaning of the appliance is not carried out, and describes it as a series of basic safety function and condition checks much like an MOT on a car. A CP42 records an inspection. It does not by itself show that every appliance was serviced to the manufacturer's instructions, and a kitchen relying on it as proof of servicing has half the evidence it thinks it has.

Does a commercial kitchen need a gas interlock?

Yes for anything new or updated. Gas Safe Register states that new and updated ventilation systems are required to be interlocked with the gas supply, with built-in safety devices preventing the cooking equipment from being used if the ventilation fails to operate. HSE puts the same requirement on the installer: the appropriate interlocking system between any mechanical ventilation system and the operation of gas appliances, so that failure of the ventilation causes the gas supply to the appliances to be shut off. On bypasses HSE leaves no room at all, saying installation of manual bypasses to such interlock systems is not permitted.

The standard behind it is IGEM/UP/19, “Design and application of interlock devices and associated systems in gas appliance installations in catering”. Edition 2 was published in July 2022, applies to new commercial catering establishments and to replacements or extensions of existing installations at up to 100 mbar, and excludes dwellings, mobile catering and temporary event catering. It superseded Edition 1 and replaced Gas Safe Register's Technical Bulletin 140, so a specification or a service sheet still citing TB 140 is working from withdrawn guidance. Supplement 1, published in August 2024, is the engineer-facing guidance and superseded IGEM/IG/2. BS 6173 remains the installation and maintenance specification for gas-fired catering appliances, and HSE is careful to say that although it is not a statement of the law, British Standards set out agreed good practice.

A kitchen with no interlock is not an automatic fail, because BS 6173 is not retrospective and older installations are common. HSE's instruction is to assess whether a risk is likely to arise and, if so, make sure it is prevented or controlled. The engineer applies the Gas Industry Unsafe Situations Procedure and the risk assessment protocol from the catering guidance, and where the risk factors are present may classify the installation At Risk or Immediately Dangerous. HSE lists what pushes it that way.

• Evidence that the ventilation system is not used or is unreliable.
• Small room volume, or poor general ventilation.
• Obviously poor design or maintenance of the ventilation system: long convoluted ducts, broken fans, leaking ductwork, visible escape of cooking fumes or steam.
• Lack of user awareness of the effect of using gas appliances without adequate ventilation.
• Extensive use of gas appliances for long periods without a correctly functioning ventilation system.
• An ageing system or installation, and no routine or planned maintenance.

This is where the air quality test on the form earns its place. The core catering assessment requires the engineer to confirm the interlock installation to UP/19 and to confirm the existing ventilation, make-up air and extract, is operating correctly by carrying out an air quality test, and it separately assesses dealing with interlocks fitted with overrides. The acceptance figures for that test live in IGEM/UP/19 and are not reproduced here. For context on the gas being measured, HSE's EH40/2005 workplace exposure limits give carbon dioxide a long-term limit of 5,000 ppm over eight hours and a short-term limit of 15,000 ppm over 15 minutes.

How does a CP42 differ from a CP12, a CP17 and a CP15?

By scope, and by whether the law prescribes what goes on the form. Only the CP12 has its contents set out in regulation. The rest are industry forms answering a duty that the regulations state as an outcome rather than as paperwork. Every pad in the table below sells for £8.00 excluding VAT.

A restaurant with a gas boiler and a gas kitchen usually needs a CP17 and a CP42 both, and often from two different engineers on two different visits, because the qualifications do not overlap. An owner who books one visit and files one certificate frequently has half the site covered without knowing it.

Who can issue a CP42?

A Gas Safe registered engineer whose ID card carries commercial catering, which means the core catering assessment plus a COMCAT for each kind of appliance in that kitchen. Gas Safe Register defines the commercial catering card category as competence in the install, commission, disconnect, service and repair of gas fired commercial flued or flueless catering appliances, and flags in the same line that various elements make up the full competency. Those elements are the ACS assessments below, quoted in the scheme's own wording from the January 2020 assessment criteria. CCCN1 is the core, sitting on top of the non-domestic core generic assessment, and every COMCAT specification names CCCN1 or CoDC1, the changeover route in from domestic work, as its prerequisite.

Gas type is a separate axis again. Gas Safe Register's own worked example is that in a fish and chip shop the engineer must be registered for commercial catering, natural gas and fish and chip range, while a mobile catering vehicle needs commercial mobile catering, LPG and the appliance type. A domestic CCN1 reaches none of it. Assessment centres put the reassessment cycle at five years, with reassessment allowed up to six months early without losing time, so a card can be current and an individual element close to running out. The onus sits with the person booking the work: the categories and expiry are printed on the card, and Gas Safe Register will confirm them on 0800 408 5500.

What happens if the kitchen fails?

The engineer classifies the defect under the Gas Industry Unsafe Situations Procedure and the appliance or installation comes out of use, which in a working kitchen means a conversation about that evening's service. HSE sets out the sequence for catering specifically.

The find that catches kitchens out is the defeated interlock. A busy kitchen decides the fan is noisy, somebody overrides it, and the safety case for the whole room quietly disappears. HSE's line that manual bypasses are not permitted is matched on the assessment side, where the core catering assessment tests the engineer on dealing with interlocks fitted with overrides. HSE also offers the reassuring half of the picture: an At Risk or Immediately Dangerous classification is unlikely if proper regular maintenance has been done.

What does a CP42 cost?

Around £150 to £200 for a small kitchen, rising with the number of appliances. No trade body publishes a survey of catering inspection prices, so there is no national average to quote. What does exist is individual firms' advertised list prices, and the three below were all published and checked on 6 September 2026. All three are London firms, so read the table as a starting point rather than a going rate: a fish and chip range with forced draught burners is a different afternoon from a cafe with one combi oven.

How do engineers keep catering records straight?

Catering sites are awkward to administer for the same reasons they are interesting to work on: several appliances on one record, more than one record per site, renewal dates that drift apart, and a client who wants last year's report emailed this afternoon. The failure mode is almost never the inspection, it is the filing. Manifold keeps every record against the site and its appliances, so this year's visit opens with last year's findings and renewals get chased before they lapse.