Burger King has had a difficult record with kitchen extract duct fires across Europe. The fire which brought Heathrow Terminal One to a standstill back in 1997 gave a huge boost to UK kitchen extract duct cleaning.
These images (thanks to Stuttgarter Nachrichten) from Pforzheim, Germany in 2015 bring it home what a disaster a dirty duct fire can be.
We know that Burger King EMEA now has a strict franchise policy on keeping kitchen exhaust ductwork clean. We hope that they will be able to contribute to the forthcoming revision to EN15780 which will deal with kitchen extract cleanliness and dirtiness levels.