Hood Cleaning and Fire Safety: An Interval, a Record, and a Next Date

Fire safety in a commercial kitchen is not a campaign. It is not a month on the calendar, and it is not a feeling you get after a hood cleaning. It is an interval, a record, and a next date — and if any one of those three things is missing, the other two do not protect you.

We see this every week. We go into kitchens where the work was done once, the report is somewhere in a folder, and nobody set the next date. The interval elapsed. The fuel load built. And the kitchen leaders running that operation had no idea, because nothing alarmed, nothing broke, and nothing looked wrong from the floor.

That is exactly how a grease fire starts.

The Fuel Load Is the Problem. The Interval Is the Response.

Grease accumulates in the exhaust system every service, every shift, every day. It coats the interior of the duct, the plenum, the fan housing, and the sections of the system that nobody sees from the kitchen floor. It does not announce itself. It does not slow down. It accumulates at a rate determined by what the kitchen cooks, how long the equipment runs, and how hard the exhaust system is working to move that volume of air.

NFPA 96, the standard that governs commercial kitchen ventilation control and fire protection, sets inspection intervals based on cooking type and volume. A high-volume kitchen running solid fuel or doing continuous wok cooking is inspected on a shorter interval than a kitchen doing light-volume cooking. The standard sets that inspection interval — and what the inspection finds is what determines whether cleaning is needed and when.

The inspection interval and the cleaning trigger are two different things. The inspection tells you the condition of the system. The condition of the system tells you whether cleaning is required. Cooking type sets how often you must look. What you find when you look sets whether you must clean.

If your kitchen has not been inspected on the interval the standard requires, you do not actually know the condition of your system. You know the condition it was in on the date of the last report.

What We Find When We Get There

When we arrive at a kitchen, we access the duct system, inspect it, and do the work. What we find is specific and measurable.

We find grease accumulation at depths that tell us how far the system has drifted from clean. The standard references thresholds — 50 microns for a system that is in acceptable condition after cleaning, 2,000 microns as the point at which a system requires cleaning, and 3,175 microns as the point at which a fan housing requires cleaning. Those numbers are not estimates. They are physical measurements of fuel load in a duct system.

We find fan housings packed with grease that has migrated past the duct because the duct was not cleaned on interval. We find access panels that were never installed, which means sections of the duct that have never been reached by any previous crew. We find systems where the last report shows a clean date but the physical condition of the system does not match that date — because the work was not completed to the full extent of the duct.

We document what we find before we clean, and we document the condition after. That is what goes on the report.

The Five Systems the Standard Addresses

NFPA 96 covers more than the duct and the fan. A compliant commercial kitchen exhaust system has five components the standard addresses together: the hood assembly, the grease removal devices, the exhaust duct, the exhaust fan, and the fire-suppression system. Each of those has its own inspection requirement and its own service interval.

Kitchen leaders who think of “the hood” as a single thing often do not realize that the suppression system inside it is inspected and serviced separately from the Kitchen Exhaust Cleaning work we perform. A clean duct with an uninspected suppression system is not a compliant system. A serviced suppression system connected to a grease-laden duct is also not a compliant system. The standard addresses all five together for a reason.

When we complete a service, our report identifies the scope of what we performed and what we observed. If we find conditions outside our scope — a suppression system showing signs of a lapse in service, a fan with mechanical failure — we note it. We do not perform suppression system service, but we do not leave without documenting what we saw.

The Record Is the Third Leg

An interval without a record is just a habit. A record without a next date is a closed file. The standard requires documentation, and it requires that documentation to be available to the authority having jurisdiction when they ask for it.

What that documentation should contain is specific: the date of service, the name and credentials of the company and technicians, the condition found, the work performed, and the areas of the system that were accessed. A report that only says “hood cleaned” and lists a date is not sufficient documentation.

Cleaning Pros Plus, LLC is an IKECA member, #76716495. Our founder is a Certified Exhaust System Inspector (CESI) #200771 and a Certified Exhaust Cleaning Specialist (CECS) #200452. Our crew are PECT Designated Technicians. Credentials matter because the people performing Kitchen Exhaust Cleaning have to know what they are doing and document it properly. A credential is only as useful as the report it produces.

When we complete a service, we produce a written report. That report is yours. It is the record that demonstrates the work was done, by whom, on what date, and to what condition. It is also the starting point for the next interval. You can see what one looks like in our sample Report of Service.

After a Fire: What the Record Does

If a fire occurs in a commercial kitchen, the authority having jurisdiction will want to know the service history of the exhaust system. Insurance carriers will ask the same question. The record of your last Kitchen Exhaust Cleaning service, the credentials of the company that performed it, and the documented condition of the system on that date become material facts in whatever review follows.

A kitchen that has its records in order — correct interval, credentialed crew, documented condition, next date already set — is in a fundamentally different position than a kitchen where the work was done but nobody can find the paperwork, or where the interval lapsed, or where the report covers only part of the system.

We have seen both situations. The difference between them is not about whether the kitchen leaders intended to stay current. It is about whether the system was in place to make sure they did.

The founder of Cleaning Pros Plus, LLC was retained as an NFPA 96 expert witness in a case involving a commercial kitchen fire. The questions asked in that context are the same questions every kitchen should be able to answer before a fire, not after: When was the system last inspected? Who performed the service? What condition was the system in? When was the next service due?

Set the Next Date Before the Month Ends

Fire safety in a commercial kitchen comes down to three things: the interval, the record, and the next date. The interval is set by the standard based on your cooking type and volume. The record is produced by the crew that performs the work. The next date is set before we leave.

If you do not know your current interval, do not know where your last report is, or do not have a next date on the calendar, those are the three things to resolve this month — not because of any campaign, but because the fuel load in your duct system does not wait for a convenient time.

We perform Kitchen Exhaust Cleaning, we document what we find, and we set the next date with you before we go.

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About the Author

Arthur Haggerty is the founder of Cleaning Pros Plus, LLC and the family of companies — EvidLY, HoodOps and Stovio Advisors. He is a Certified Exhaust System Inspector (CESI) #200771 and a Certified Exhaust Cleaning Specialist (CECS) #200452. Cleaning Pros Plus, LLC is an IKECA member (#76716495). He has been retained as an NFPA 96 expert witness.