As anyone who's ever watched one of Gordon Ramsey's kitchen-themed TV programmes knows only too well; said environment can present many dangerous situations. Aside from being on the receiving end of the popular presenter/celebrity chef's vociferous tongue-lashings, lacerations from sharp implements (yes, more cutting than even Ramsey's barbs), slips, trips, burns, broken glass/exposed rough edges and getting hot peppers in sensitive areas (eyes, nose, etc) all figure prominently in any top 10 list of avoidable kitchen injuries.
In terms of the broader picture however, the danger isn't always lurking in plain sight. While this blog has made a recurrent habit of explaining the risk that unseen pathogens pose when going undetected (think legionella, salmonella, norovirus, Campylobacter spp., Toxoplasma gondii and E.coli to name-check but a few of the more usual suspects), here's we're addressing another inherent danger that a kitchen can play host to should the conditions be favourable to its instigation and rapid, potentially devastating progress thereafter.
We're referring to kitchen fires. And more specifically here and now as to how we can actively avoid them by paying particular attention to one of the most reported areas in terms of kitchen fires flaring up; ducts and extraction assemblages per se. These portals to indoor ventilation systems and the infrastructures which lie directly behind can prove deadly, if they're not properly monitored and subsequently maintained by those whose remit timely upkeep falls to.
Restaurant management amounts to considerably more than menu decisions, food ordering and quality of produce, general hygiene of an establishment and account management, as any practicing business or venue will quickly confirm. However kitchen duct cleaning isn't necessarily found as high up the weekly agenda, more's the pity.
Why Are Kitchen Ducts Seen as Potential Lethal?
For the simple reason that over a period of time, air ducts in commercial kitchens (significantly more so than in more domestic settings) provide a perfect final staging post for all manner of grease, bacteria, mould and any other particle-like deposits which are created in a hot, steamy kitchen, day after day after day. These seemingly innocuous-looking air ducts act as a magnet for grime and dust and a variety of unmentionables that congregate in the air space above chef's head, and are sucked into the ducts as is its job. Pretty much most of these substances comprise of a flammable element or core compound.
Picture another possible scene if it helps.
A flame is triggered in a commercial kitchen's stove. The flames are top high, perhaps, and cause the filter on top of the duct to catch fire. Such is the close proximity of the exhaust fan in situ, the flames are quickly attracted upwards, towards it. Meanwhile the grease deposits (located on the inner walls of the duct and flammable substances as already noted above) act as a natural accelerate once contact withe the flame is made, causing the duct itself to catch fire. We don't need to explain the next series of events, nor describe the huge damage and potential life-threatening nature of what might follow.
Faulty stoves, gas leaks and dirty fryers tend to be amongst the first things people think of when imagining the most obvious causes of fires starting in commercial kitchen environments, however as we're trying to instil in this blog, air ducts certainly aren't blameless and pose risks which should never have a blind eye turned to. Indeed, although kitchen ducts are primarily featured out of sight, they should never follow the latter part of that old adage. Not least because grease congealing in extraction systems statistically represents one of the most common causes of fire in catering establishments.
Facts of the Kitchen Duct Fire Matter
Facts don't lie. And according to recent ones, of some 24,000 accidental fires annually recorded as having started in commercial properties, around 6,000 of those are attributed to cooking/extraction systems. Then when you think of the way in which kitchen duct fires might proliferate - and the speed and ferocity of which - then you can understand the need to act. In many scenarios, extraction ducts are routed via other parts of a property, as they wind their way to the roof of the premises. Or alternatively channelled towards an external wall so as to extract the fumes away from the building.
Can You Put a Timeframe on Kitchen Duct Cleaning Regularity?
Not a hard and fast one, largely due to every business model being different. That being said, the following general rules of thumb apply. In the event that the kitchen is used between 12 - 16 hours per day (as illustrated by commercial kitchen practices) - and/or you're cooking a lot of grease-creating foodstuffs within that passage of time - then the ducts and associated ventilation infrastructure serving the ducts should realistically be cleaned every 3 months on average. Less heavy usage (anywhere in the region of 6 - 12 hours per day), then hygiene experts believe that 6-monthly cleaning of kitchen ducts is sufficient. Outside of these parameters, then anything less than once every 12 months simply isn't good enough.
It's worth noting that there are a number of tests that can be undertaken to determine the thickness of the build-up of grease or dust contaminants, which will shed further light on the cleaning frequency individual business would need to strictly adhere to. Again, experts in this field are more than willing to discuss the hygiene and safety needs of any aspect of their air quality (and related areas), with a view to establishing a plan of action which works best going forward.
Isn't Keeping a Commercial Clean and Hygienic Already a Thing Though? What Does This Protocol Focusing on Kitchen Ducts Highlight That Existing Practices Don't?
Admittedly it all might sound a bit like teaching your grandmother how to suck eggs, yet it's imperative that staff are acutely aware of the threat of grease and learn to recognise the presence of the substance for what it is. In as much as a potential fire-starter. While hygiene procedures already in place are one thing, as we've already touched on, grease collects in recesses that aren't always identified. Specifically in ducts. Canopies, hoods, filters and any other crucial component of kitchen ducts are normally readily accessible, so there are no valid excuses not to keep on top of monitoring.
The same can't be said when it comes to further along the ductwork, which tends to run into the ceiling and passes through floors in some cases as we've alluded to earlier. However at the human interface level, where grease first makes contact, then everyone has a fighting chance.
