IGEM/UP/19 Edition 2, Design And Application Of Interlock Devices

IGEM/UP/19 Edition 2 – Design & application of interlock devices/associated systems in gas appliance installations in catering.

UP/19 was introduced in 2014 and written to supersede TB140 with the latest update to Edition 2 released in 2022.

This standard has been designed to give guidance to engineers involved in the design and maintenance of commercial kitchens and provides support and clarification to BS6173.

It is important that the interlock and ventilation scheme has been designed to ensure adequate ventilation levels are met and that Gas Safety (Installation and Use) Regulations 1998 (GSIUR) are being followed.

This statutory document states:

“Regulation 27(4) No person shall install a power-operated flue system for a gas appliance unless it safely prevents the operation of the appliance if the draught fails.”

As a mandatory document, this takes precedent over UP19.

The specification and guidance for kitchen ventilation can be found within BESA DW/172 with the latest 2018 version having been updated to reflect the latest cooking techniques, catering appliances and allowable CO2 levels.

UP19 supports BS6173 in that ventilation interlock should be provided to prove safe working conditions and need to monitor the mechanical ventilation by at least one of the following:

• Air flow
• Air pressure
• Fan current/power absorption

It also provides further support for the monitoring of CO2 levels to determine adequate ventilation levels are met and the potential for controlling the mechanical ventilation above the set minimum.

For newly designed kitchens the CO2 level within the staff working areas of the kitchen should be below 2,800 ppm and the gas should be isolated if the CO2 level rises above this limit. For existing installations where a 5,000 ppm limit is reached the kitchen gas supply will be isolated until the CO2 reduces.

Only CO2 detectors that have been designed for the arduous conditions of a commercial kitchen should be used, with features such as a PTFE filter that can be easily changed periodically being considered. Although commercial and industrial CO2 detector heads will make some allowance for unclean air they could eventually become blind in the air of a commercial kitchen.

Please don’t hesitate to contact us to discuss the location and mounting of CO2 detectors in a commercial kitchen.

Maintenance and Inspection

In Great Britain, the (GS(I&U)R) Reg 35 is the primary legislation concerning the maintenance of gas systems and appliances, together with duties under the Health and Safety at Work Act. And Provision and Use of Work Equipment Regulations (PUWER), etc. require employers/self-employed persons ensure that safety devices are maintained in a safe condition to prevent the risk of injury to any person,

5.2 Where practicable, users need to be advised that the frequency of servicing and testing of ventilation systems and associated interlocks is to be based upon the manufacturer’s instructions and the use of the catering equipment, but otherwise at least yearly will be a reasonable minimum frequency (this also applies to the gas installation).

Note 1: It is the responsibility of the employers/self-employed persons to ensure that all safety interlocks and environmental detectors (CO2 detector heads) and safety controls are maintained and checked for calibration as specified by the manufacturer. Failure to perform such tests may result in undetected failure and thus unsafe conditions (see IGEM/UP/19).

If you require any additional information on our systems to help meet these design standards or wish to discuss the standards further, please don’t hesitate to contact us.