Restaurant fires not only claim lives and injure people each year, but millions of dollars in property loss are attributed to those fires. The National Fire Protection Association (NFPA) reported that between 2010 and 2014, there were an average of 7,410 restaurant fires each year.¹ Annual losses contributed to those fires were three deaths, 110 injuries, and $165M in property damage. The good news is that two-thirds of those fires did not spread beyond the area of origin. That means the hood systems and extinguishers probably controlled or extinguished these fires before the fire department’s arrival. These fires were the ones that fire departments responded to. The number of restaurant fires where the installed fire equipment performed well is much higher.

Failure to Clean Leads to Fire Losses

However, the troubling statistic in the NFPA study is that “failure to clean was a factor in 22% of the fires in these properties.” A takeaway from the NFPA statistics is that if we do a better job inspecting and cleaning kitchen exhaust ducts, we can reduce the losses from future restaurant fires. Here is information you can use and share with your customers to help them save lives and minimize restaurant property losses.

Thorough Inspections are Key to Safety

The first step in maintaining hoods and ducts to keep grease levels reasonable is to follow a strict inspection protocol. Although it would be ideal always to have bare metal hoods and ducts, this is impossible, since grease-laden vapors deposit grease on these surfaces as soon as cooking commences after cleaning. Therefore, the objective is to inspect them on a schedule based on cooking operations and clean them when the grease depth reaches a specific limit.

Special Tool Used During Inspections

The inspection frequencies established in NFPA 962 are in the table to the right. But to use the table, you’ll need a special tool called a depth gauge comb, more commonly known as a grease comb. According to NFPA 96, a grease comb measures the grease depth of hoods, ducts, fans, and other surfaces exposed to grease-laden vapors to measure the grease buildup. There are three levels of grease measured with this depth gauge. Two of the measurements trigger the need for cleaning (i.e., grease depth of hood and duct surfaces must not exceed 0.078 in., and grease on fan housings must not exceed 0.125 in.). The third measurement is the maximum allowable depth of grease permitted to remain on surfaces after cleaning (0.002 in.).

Create a Cleaning Schedule

A cleaning schedule can be developed based on the inspections performed per the frequencies outlined in NFPA 96. The important thing to remember is that the NFPA requirement is for inspections (monthly, quarterly, semiannually, and annually). There is no cleaning frequency table in NFPA 96. The need to clean is triggered by the measurement of grease depth as determined using the grease comb.

FireTech™ Grease Comb

This plastic FireTech™ GREASE COMB accurately measures the amount of grease buildup on hoods, fans, ducts, and other surfaces using depth-gauge teeth (clearly printed in microns and inches).

Grease Buildup Inspection Frequencies

Grease Buildup Inspection and Cleaning Reports

Two reports are now required based on the 2024 edition of NFPA 96. Upon completion of an inspection for grease buildup, a written report must be submitted within 2 weeks to the owner or the owner’s agent [96, 12.6.14]. Similarly, a written report is required within 2 weeks after completion of cleaning [96, 12. 6.15]. NFPA 96² provides details in the updated 2024 edition on what is required for each report.

Documentation Must Include the Following Information:

After an exhaust system is inspected, an adhesive label is required to be attached to the hood with the following information:^*

• Date service was performed, indicated by a perforation
• Name of person performing the work
• Name, address, and phone number of service provider

^*The label must remain affixed until the next inspection or cleaning event.

After an inspection for grease buildup is complete, a written report is required to be provided to the system owner or owner’s agent within 2 weeks. The report is required to provide a record of the following information:^*

• Areas in need of cleaning where grease is found to exceed the limits outlined in NFPA 96
• Areas that are inaccessible and were not inspected
• Areas that are accessible but were not inspected
• Location(s) of duct access panel(s)
• Location(s) of visible leakage(s) from ductwork
• Location(s) of leaking access panel(s)

^* Where required, the inspection report is submitted to the authority having jurisdiction.

The need to clean kitchen exhaust systems is not only for the safety of restaurant workers and patrons. On August 29, 2007, two career firefighters died fighting a fire at a restaurant in Massachusetts, where exhaust cleaning was identified as an issue.³

We can all do our part to help reduce fire loss statistics from restaurant fires. An important activity to help improve those numbers is to inspect and clean kitchen exhaust systems diligently. Following the kitchen exhaust inspection and cleaning criteria outlined in NFPA 96 improves safety.