What is a ul300?

Are ansul system required in a hood over a pizza oven with no open flame?

Under current Ansul design specifications, UL300 and NFPA 17A standards, there is no requirement if the pizza oven is fitted with a door. If the oven is open, even with no open flame, due to a build up of oils and greases from cheese and meats within the appliance, there is still the potential for these to ignite from the heat (as these natural oils could reach flashpoint) and therefore, would be considered as a high risk appliance and should be covered along with the hood and extract duct. This is the same for grills (Salamander Broilers).