Fat may be off the menu, but that doesn't stop airborne fats, oils and grease collecting in your kitchen extract ductwork. Summer is the best time to tackle this, says Gary Nicholls, MD of Swiftclean Building Services.
16 June 2014
During the summer months many buildings have a shutdown period, while others will have many of their usual occupants away on holiday.
This alone would make it a good time to carry out some essential specialist cleaning. But there is also another seasonal reason to tackle the removal of airborne fats, oils and grease (FOGs) from the ductwork that runs from extractor fan to canopy in a commercial kitchen.
At this time of year the ambient temperature outside causes a rise in the duct temperature and a change in the consistency of accumulated grease deposits in the kitchen extract ductwork. These deposits, which are flammable even in the colder temperatures of winter, become even more combustible in the summer, simply because of higher temperatures within the ductwork. This represents a significant fire risk, but one that us fairly easily diminished by some timely kitchen extract fire safety cleaning.
Look at the ductwork to determine the extent of the FOG build-up and then test the thickness of any grease accumulations using the wet film thickness test, as recommended within TR/19, the leading industry guide to good practice for the internal cleanliness of ventilation systems, issued by the Building and Engineering Services Association (B&ES).
This may be easier said than done. In the past, ductwork systems were sometimes installed without inspection hatches being placed at regular intervals. If this is the case, not only will you need an expert to inspect the ductwork for you, it will also require them to retrofit the necessary quick release inspection hatches so that future inspections and cleaning can be conducted more easily.
If there is a significant grease layer close to or above 200 microns, the next step is to clean it off. If your ductwork has not been cleaned in the past year it is likely that it will have significant FOG deposits, which are a natural result of cooking; no matter how healthy the menu. If the kitchen is heavily used, you may need to clean as frequently as once a quarter; an expert will be able to advise you on this.
FOG removal is a specialist fire safety task that must be carried out in accordance with TR/19, Every part of the grease extract system must be completely cleaned to remove the fire risk created by the grease layer. It is essential that you have sufficient access to achieve this, so it may be necessary to install inspection/cleaning hatches if they are not already installed.
The third step is to ensure that you have certification to demonstrate that you have complied with the TR/19 guidelines. A specialist should provide you with post-fire safety clean documentation, with clear photographic evidence of cleaned surfaces that indicates that TR/19 and fire safety control measures have been complied with. You must, of course, keep this up to date and an expert can advise you on a planned preventative maintenance programme to keep control of the fire risk. Such a programme would depend on how many hours a day your kitchen is used or what the rate of grease accumulation is, in order to meet TR/19 guidelines.
It is important that your building is compliant with TR/19 for buildings' insurance purposes too. There have been a few incidents in recent years of insurance companies refusing to pay out following devastating fires in cases where cleaning to TR/19 had not been carried out at the recommended intervals.
This is perhaps not surprising, as forensic fire investigators tell us that in 25 per cent of fires investigated that have involved commercial kitchens the fire has been made worse by the presence of grease deposits in kitchen extract ductwork. The ductwork itself can help to spread the fire farther through the building, sometimes to residential areas -posing a threat to life and limb. Despite this finding, fire statistics don't yet record how many fires were exacerbated by FOGs in the kitchen extract ductwork.
Swiftclean is campaigning to have this recorded in the statistics so that targets to reduce incidences of fires can be set.
If a fire does occur, being able to provide documentation showing that cleaning was carried out to TR/19 standards will be important as it helps to demonstrate clear compliance and that you have not been negligent. Because the appointed responsible person can be prosecuted for negligence and face severe legal consequences, this documentation can offer essential protection to that individual. The penalties for negligence can include imprisonment, especially if there has been a fatality.
Kitchen extract ductwork is largely out of sight, but it can still be kept front of mind. Hidden grease deposits - or their removal - should be a high priority, appearing on every FM's to do' list at this time of year.
Inspect, clean and comply proactively now, and you can relax and enjoy a grease-free summer.
Gary Nicholls, MD of Swiftclean Building Services