BS 6173:2020 is the current British Standard for the installation and maintenance of gas-fired catering appliances used in catering establishments with second- and third-family gases—principally natural gas and LPG. It addresses safe installation, commissioning, servicing and maintenance. It is not a replacement for gas-safety law, manufacturer instructions or appliance-specific competence.
What BS 6173 covers
The British Standards Institution lists BS 6173:2020 as current and published on 31 March 2020.
Its scope includes new and previously used gas-fired commercial catering appliances such as:
- ranges and cookers;
- ovens;
- fryers and fish-and-chip ranges;
- café boilers and urns;
- bain-marie units;
- tandoori ovens;
- kebab grills;
- barbecues;
- other gas catering equipment within the standard's scope.
It also covers typical domestic-style cooking appliances when they are installed in commercial catering establishments. That does not mean a domestic installer is automatically qualified to work on them in a commercial catering setting.
Is BS 6173 a legal requirement?
BS 6173 is a British Standard rather than an Act or statutory instrument. Legal duties arise through legislation including the Gas Safety (Installation and Use) Regulations 1998 and wider health-and-safety law.
Regulation 35 requires employers and self-employed people to ensure gas appliances, installation pipework and flues at a workplace are maintained in a safe condition: Gas Safety Regulations, regulation 35.
BS 6173 provides the recognised technical specification used by competent professionals when installing and maintaining catering appliances. It may also be required by the project specification, contract, insurer or other stakeholder.
The practical mistake is arguing about whether the letters “BS 6173” appear in legislation while ignoring the underlying legal duty to keep the installation safe.
Ventilation is connected to gas safety
Gas appliances require enough air for combustion and a safe means of dealing with combustion products and cooking emissions. The room and extraction system therefore form part of the gas-safety picture.
The HSE's gas safety in catering guidance should be read alongside its kitchen ventilation guidance. A canopy may act as part of the means by which combustion products are removed, and changes to fans or replacement air can affect safe operation.
This is why a ventilation contractor and gas engineer need coordinated information rather than arriving independently at the end of the job.
How IGEM/UP/19 fits in
IGEM/UP/19 Edition 2 covers the design and application of interlock devices and associated systems used with gas appliance installations in commercial catering establishments.
An interlock can prevent or isolate gas operation when required ventilation or air-quality conditions are not established. The final arrangement depends on the installation and current standard. It is not enough to fit a generic panel and assume the requirement has been met; proving, controls, valve arrangement, commissioning and interaction with the appliances all matter.
What BS 6173 does not prove
The phrase “installed to BS 6173” does not, on its own, prove that:
- the kitchen ventilation system is correctly designed to DW/172;
- the extraction duct route meets fire-strategy requirements;
- planning permission has been obtained;
- odour and noise are acceptable to the local authority;
- the engineer is qualified for every appliance category on site;
- the incoming gas supply and pipework have adequate capacity;
- the equipment is being maintained at a suitable frequency;
- electrical, water and drainage services are correct.
Those issues require their own evidence and responsible parties.
Check the engineer's actual work categories
Gas Safe registration is essential, but the engineer's current ID card should also show categories appropriate to the work and appliance.
Commercial catering appliances are divided into COMCAT categories. Examples include atmospheric-burner appliances, steam equipment, fryers/grills, fish-and-chip ranges and forced-draught burner appliances. The exact scope shown on the card matters.
Gas Safe Register explains that commercial categories relate to property, appliance type, pipework and gas consumption. Ask to see both sides of the card and verify the engineer where necessary.
Information the project team should provide
Before installation, the gas engineer should have access to:
- the exact appliance schedule and manufacturer instructions;
- fuel type;
- appliance heat input and connection information;
- proposed positions and restraints;
- ventilation design and commissioning information;
- interlock/control strategy;
- gas meter and pipework information;
- fire and emergency-shutdown requirements;
- any existing records relevant to reused appliances.
Late appliance substitutions should be reviewed rather than treated as an equal swap.
What owners should retain at handover
Ask the responsible contractors for a coordinated handover pack containing, as relevant:
- appliance details and manuals;
- commissioning and test records;
- gas-safety documentation describing the work performed;
- interlock test and operating information;
- ventilation commissioning results;
- as-installed drawings;
- isolation and emergency procedures;
- maintenance schedule;
- records of defects, limitations or recommendations;
- responsible company and engineer details.
There is no benefit in a certificate that cannot be matched to the appliances and work actually completed.
Maintenance after opening
Regulation 35 is an ongoing duty. Maintenance frequency should be based on manufacturer instructions, operating conditions, risk and competent advice—not an assumption that every appliance only needs attention at one universal interval.
Operators should also ensure:
- staff know emergency isolation arrangements;
- faults and flame problems are reported promptly;
- ventilation and interlocks are not bypassed;
- equipment is kept clean without damaging safety components;
- appliance or menu changes are reviewed;
- only competent people carry out gas work.
For appliance servicing and repair, a specialist such as Catering RS illustrates the type of commercial catering engineer operators may need; always verify the individual engineer's current Gas Safe categories for the work.
Connect gas safety to the wider installation
The KIG 317 Commercial Kitchen Installation Guide helps teams plan the connections between gas appliances, ventilation, layout, utilities, contractors and handover information.
Sources and further reading
- BSI: BS 6173:2020
- Gas Safety Regulations 1998, regulation 35
- HSE: Gas safety in catering and hospitality
- IGEM: UP/19 Edition 2
- Gas Safe Register: ID card categories
This is a practical overview, not the text of BS 6173 or a gas-safety assessment. Gas work must be completed by a suitably qualified Gas Safe registered engineer using current documents and manufacturer instructions. Last reviewed: 13 August 2026.