IGEM/UP/19 “Design and application of interlock devices and associated systems used with gas appliance installations in commercial catering establishments” was published in October 2014 and supports the requirements for interlocking mechanical ventilation systems required by BS 6173. 
 
Note: BS 6173, as currently written, is not intended to apply to dwellings or primarily domestic premises, such as those in Bed & Breakfast installations. For these latter installations reference has in the past been made to standards such as BS 5440‐2 and BS 6172.  
 
The aim of this Guide is to clarify some of the options and requirements for new and existing installations in catering establishments, both large and small. 
 
Catering establishments are generally defined as those preparing meals for the public other than in domestic situations. However, the Standard IGEM/UP/19 and this guide covers all catering establishments that fall within The Food Safety (General Food Hygiene) Regulations. 
 
Note:     This guidance does not apply to mobile catering installations or transportable temporary event catering installations (see Nationwide 
Caterers Association (NACSS) guidance). 
 
This guide has been prepared in consultation with the commercial catering industry bodies CEDA and CESA. 
 

This Guide may be used to clarify some of the options and requirements for ventilation systems for new and existing gas installations in catering establishments that are required by IGEM/UP/19. 
 
This Guide is not intended for use in isolation, it is to provide support to the competent gas engineer working in catering establishments, and includes extracts from the IGEM publication IGEM/UP/19. 
 
This Guide includes the risk assessment protocols for new and existing catering installations along with the air quality testing procedure, acceptance criteria and sign posting to the Gas Industry Unsafe Situations Procedure (GIUSP) for commercial catering establishments. 
 
This Guide is applicable to those installing, servicing or maintaining catering equipment. 
 
This Guide includes supporting questions and advice for sample testing and it also covers maintenance, inspection, records and user instructions. 
 
Note: Notes have been added either directly from IGEM/UP/19 or by the Catering Equipment Industry Technical Representatives in each section and sub‐section where applicable.