Quoting from BS6173:2009 Section 11.2 Interlocking
“An interlock shall be provided which will cut off the gas supply or prevent the operation of appliances if the mechanical ventilation system provides an inadequate airflow rate for the safe operation of appliances and the safety of personnel.
If an installation pre-dating September 2001 does not have an interlock fitted, the installation shall be assessed to establish whether an unacceptable risk is likely to arise.”
Tower Commercial Catering come across such installations (pre Sept. 2001) periodically and undertake the required assessment. To date, only seven kitchens have been classed as unsafe i.e. the level of risk associated with the installation has been deemed unacceptable. In each case the absence of the interlock system hasn’t been the only problem – merely one more indicator of an unsafe kitchen environment.
For kitchens which have yet to assess their operational safety relating to ventilation issues or any other aspect of operation we recommend doing so as soon as practicable. Much better to be safe than sorry!