Commercial kitchen operators are mandated by law (NFPA-96 Standard) to have their kitchen hoods regularly inspected for compliance and so there is the need for their kitchen hoods to be cleaned at regular intervals. Other establishments like schools, hotels, hospitals, malls, and airports also need this service.

If you are a restaurant owner, you need to abide by the existing rules and regulation in regards to cleaning your kitchen hoods. The actual commercial kitchen exhaust system cleaning guidelines are stated in the National Fire Protection Association Standard 96 otherwise known as the Standard for Ventilation Control and Fire Protection of Commercial Cooking Operations. This regulation provides the minimum fire safety standards related to the design, installation, operation, inspection, and maintenance of all public and private cooking operations. All commercial kitchen operators and kitchen exhaust hood cleaners must observe strict compliance with this regulation.

How often the cleaning lies on NFPA-96 Standard section 11.4, “the entire exhaust system shall be inspected for grease build up by a properly trained, qualified and certified person(s) acceptable to the authority having jurisdiction and in accordance with Table 11.4”


Type or Volume of Cooking Frequency Frequency
Systems serving solid fuel cooking operations Monthly
Systems serving high-volume cooking operations such as 24-hour cooking, charbroiling or work cooking Quarterly
Systems serving moderate-volume cooking operations Semi-annually
Systems serving low-volume cooking operations, such as churches, day camps, seasonal business or senior centers Annually

What is considered clean according to NFPA-96 Standard?

The industry standard is to clean to “bare metal.” If a system has not been properly cleaned for a long period of time, sometimes it may require multiple cleaning sessions before getting to bare metal. According to NFPA-96 Standard section 11.6.2, “Hoods, grease removal devices, fans, ducts, and other appurtenances shall be cleaned to remove combustible contaminants prior to surfaces becoming heavily contaminated with grease or oily sludge.”

The best way to determine if a surface is clean is to inspect it. If it looks like there is an accumulation of grease on a surface, then it probably needs cleaning. You can ask your kitchen hood cleaning contractor for the procedures they can perform to have your whole kitchen exhaust systems cleaned to bare metal.

Duct Access Doors

Duct access doors will allow professional hood cleaners to perform a thorough “top to bottom” cleaning of the exhaust system. They help facilitate the cleaning, maintenance, and inspection of the exhaust system.

NFPA-96 sections 7.4.1 and 7.4.2 recommend the installation of openings large enough to permit thorough cleaning at a minimum of every 12 feet of horizontal ductworks and on every floor of vertical ductwork. It is also necessary to have access doors at every change of direction.

What are the advantages of a clean kitchen hood?