Grease: The Fire Problem
Over the last 30 years there has been a huge rise in the numbers and types of food outlet in the United Kingdom. Where there were banks, churches and shops are Restaurants, Café’s, Pubs, Clubs, wine Bars, Fish & Chip Shops, Fast Food and Take – Away outlets – all selling hot food. Indeed, the huge number of outlets and choices available to the public across many ethnic and specialist food outlets suggests the tradition of home cooking must almost be a hobby.
The Trouble With Grease
A build up of grease in kitchen extract ventilation systems is a major fire risk – it is easily ignited and is quickly uncontrollable. Both the food outlet and neighbouring property are at risk as the ducting of the extraction system will inevitably lead to other occupier’s property, giving the potential for a major loss.
Types of Grease
Different cooking styles will inevitably create different grease residues.
- Deep frying produces grease similar to translucent creosote.
- Frozen foods containing large quantities of water create a hard shiny layer of grease.
- Oriental style cooking creates a very sticky, syrup-like grease that can become very adhesive to metal surfaces.
- Meats cooked on solid fuel ranges or charbroiled produce large quantities of grease. An average burger loses 9g of fat when cooked. A first layer of grease will bond to metal surfaces, and then subsequent layers of black carbon will build-up created by ash and grease from the cooking process.
At temperatures above 200 degrees C flammable vapours are given off from cooking oils and spontaneous ignition can occur at temperatures between 310 and 360 degrees. It’s a short time from ‘safe’ to ‘dangerous’ if thermostats are not working correctly.
The flashpoint of cooking oil is lowered by progressive oxidation as a result of repeated use. Deposits of some mixtures, such as chicken fat and vegetable oil are particularly easy to ignite.
Fire Risks in a Kitchen
Any fire will require ignition, fuel and air. There are several primary risks of fire in the kitchen:
- Flames, sparks or hot gases can ignite combustible deposits trapped in extract ducts and filters
- Superheated oils causing spontaneous ignition
- Fan-motor failure or overheating due to hardened grease
- Faulty thermostats and or the absence of a second high level safety thermostat
- Metal extract ducts are good conductors of heat and can ignite nearby building materials or litter
- Catalytic converters decompose grease, but operating at 1000 degrees C are a potential source of ignition
- Tandoori ovens without igniters/pilot lights lit by burning pieces of paper/absence of flame failure or safety shut off device
- Non tested and non maintained electrical and cooking equipment
- Design of the extract ventilation, such as long duct runs, horizontal ducts, type of fan, number of access doors, inaccessible extract ducts etc
- Contractors may only clean hoods and easily accessible and visible areas
- Poor positioning or failure of fire suppression system
The above are the main fire risks however there are many others associated with kitchens:
Unattended cooking equipment during operation and not switched off at end of day, gas torches, Incompetent cleaning contractors.
We have a true passion for reducing risk and ensuring the success of every business we work with, we pride our self on it, so please, pick up the phone today.