CP1: The Commercial Gas Safety Record
The CP1 is the commercial equivalent of a domestic gas safety check — for catering appliances, plant and larger installations — and it works to a different standard and competence set entirely.
Commercial gas work — restaurant kitchens, pubs, plant rooms, larger boilers and catering appliances — is a separate world from domestic, with its own regulations, competences and paperwork. The CP1 (Commercial Gas Safety Record) is the record of a commercial installation's safety inspection, the commercial counterpart to a domestic gas safety record but broader in scope and worked to commercial standards.
This guide explains what a CP1 covers, how it differs from a domestic check, the TR/CP1 basis it's completed to, and what an engineer inspects and records. It's guidance for engineers and duty holders; commercial gas work requires the relevant commercial Gas Safe categories and must be carried out by a suitably registered engineer.
Key takeaways
- The CP1 is the Commercial Gas Safety Record — the inspection record for commercial gas installations (catering, plant, larger appliances), completed to TR/CP1.
- It differs from a domestic gas safety record in scope, competence and standards: commercial installations, commercial appliance categories, and industry standards for commercial pipework and plant.
- Commercial work requires specific commercial Gas Safe categories (e.g. catering, commercial heating/plant) — domestic categories don't authorise it.
- The engineer checks installation soundness, ventilation, flueing/products of combustion, appliance operation and safety devices to the commercial standards, and classifies defects under the industry unsafe-situations procedure.
- As with domestic records, defects are classified (ID/AR/NCS) and unsafe appliances are dealt with, not simply noted — but under the commercial framework.
What a CP1 is
The CP1 is the standard record used to document the inspection and safety check of a commercial gas installation and its appliances. It covers the sorts of installations you don't meet in a house: commercial catering appliances (ranges, ovens, fryers), commercial heating and hot water plant, larger boilers, and the associated commercial pipework, meters and ventilation.
Like a domestic gas safety record it evidences that appliances and the installation were checked and their condition recorded, but it sits within the commercial gas framework — different appliances, different standards, and a different competence to complete it. It's the document a duty holder relies on to show their commercial gas installation was inspected.
How it differs from a domestic check
The differences run deeper than the form. Scope is broader — commercial catering and plant rather than domestic boilers, fires and cookers — and the standards are the commercial ones (for commercial catering appliances, commercial pipework and installations, ventilation and flueing of commercial plant) rather than the domestic BS standards and manufacturer data alone.
Competence is the big one: commercial gas work needs specific commercial Gas Safe categories. An engineer carded only for domestic appliances is not qualified to inspect a commercial kitchen or plant room, and completing a CP1 without the right commercial categories is working outside registration. The pipework, meters and pressures are also frequently larger and higher than domestic, needing the corresponding commercial procedures for sizing and tightness testing.
Not a domestic ticket's job
A CP1 is not a bigger domestic check. It needs commercial Gas Safe categories (catering, commercial heating/plant and so on). A domestic-only engineer completing a CP1 is working outside their registration — check the categories match the installation.
The TR/CP1 basis and what's inspected
The CP1 is completed to its supporting guidance, TR/CP1, which sets out how the commercial inspection is carried out and recorded. Broadly, for each appliance and the installation the engineer confirms the installation is sound (tightness tested to the appropriate commercial procedure), that ventilation is adequate for the appliances present, that flueing and the removal of products of combustion are satisfactory, that appliances operate correctly at the right pressure and rate, and that safety devices function.
Commercial catering brings its own specifics — interlocks between mechanical ventilation and the gas supply in commercial kitchens, for example, so that the gas can't be used without adequate extract. The engineer records the condition of each appliance and any defects, exactly as on a domestic record but against the commercial standards and with the commercial appliances in scope.
Ventilation, flueing and interlocks in commercial settings
Commercial appliances often present far larger inputs and more demanding ventilation and flueing than domestic ones, and getting the air and products of combustion right is central to the CP1. Commercial kitchens in particular rely on a gas interlock system tied to the extract ventilation: the interlock proves adequate airflow before allowing gas to the appliances, and shuts the gas if ventilation fails.
The inspection therefore checks not just that vents and flues exist and are clear, but that these commercial safety systems — interlocks, extract, and any associated CO/atmosphere monitoring — function. These are systems you simply don't meet on a domestic check, and they're a core reason commercial work is a separate competence.
Classifying defects and the duty holder
Defects found during a commercial inspection are classified under the industry unsafe-situations framework — Immediately Dangerous, At Risk or Not to Current Standards — and the appropriate action taken (making safe, turning off with permission, issuing a warning notice) just as in domestic work, but within the commercial context. The CP1 records the classification and the action.
The duty holder — the business operating the premises — carries responsibilities for the safety of the gas installation under the health and safety legislation for workplaces, so a CP1 with unsafe findings isn't a document to file and ignore. Remedial work must follow, and unsafe appliances mustn't be returned to use until made safe and re-checked. The record is both the evidence of inspection and the trigger for putting things right.
Frequently asked questions
What is a CP1?
The CP1 is the Commercial Gas Safety Record — the record of the inspection and safety check of a commercial gas installation and its appliances (catering, plant and larger appliances), completed to its supporting guidance TR/CP1. It's the commercial counterpart to a domestic gas safety record.
How is a CP1 different from a domestic gas safety check?
It's broader in scope (commercial catering and plant rather than domestic boilers and cookers), worked to commercial standards, and requires specific commercial Gas Safe categories to complete. Commercial pipework, pressures, ventilation and safety systems (like kitchen gas interlocks) all differ from domestic.
Can a domestic gas engineer complete a CP1?
Not without the relevant commercial Gas Safe categories. Commercial work (commercial catering, commercial heating/plant and so on) is a separate competence — a domestic-only engineer completing a CP1 would be working outside their registration.
What's a commercial kitchen gas interlock?
It's a safety system linking the gas supply to the extract ventilation: it proves adequate airflow before allowing gas to the catering appliances and shuts the gas off if ventilation fails. Checking it functions is part of the commercial inspection recorded on the CP1.
From guidance to action
Related guides
CP12: The Landlord Gas Safety Record
What a CP12 checks, the landlord’s legal duties, and how to complete one correctly.
At Risk and Immediately Dangerous: GIUSP
Classifying unsafe gas situations under the GIUSP — ID, AR and NCS — and the action each needs.
Gas Safe Registration Explained
How Gas Safe registration works, the ACS route, and keeping your categories current.
