Greasy kitchen extraction systems can pose a serious fire hazard - filters simply cannot eliminate all the vaporised grease that today's commercial kitchens generate. These greasy residues then condense and build up on the canopy plenum, duct and fan surfaces.

You don't even need a spark to trigger a fire, with the heat from cooking, the grease can spontaneously combust. The grease then acts as a fuse, carrying the fire throughout the building at an alarming rate.

Not surprisingly, insurance companies insist that extract systems are professionally cleaned on a regular basis and that you have valid certificate (to HVCA TR/19 guidelines) to prove this.

As you are aware, insurance companies now insist that extract systems are professionally cleaned on a regular basis and that you have valid certificate to prove this.  Therefore buildings insurance may be invalid if your kitchen systems are not regularly cleaned to the industry standard. The number of claims arising from a fire within the canopy or ducting is increasing & insurance companies are not paying the claims because extraction system cleaning work has not been done as stated in the policy.