The fire marshal walks in at 12:40 on a Friday, right in the middle of the lunch rush, and asks to see the tag on your hood system. It was cleaned six weeks ago, and it looks great. But that isn’t what he asked for.
This is the misunderstanding we run into most often in kitchens across Memphis and DeSoto County. Hood cleaning and hood suppression inspection sound like the same thing. They get scheduled by the same manager, and sometimes they’re even sold together. But they’re two separate obligations, and doing one doesn’t cover the other.
Here’s what each one is, how often it’s due, and what gets kitchens written up.
Is hood cleaning the same as a hood suppression inspection?
No. Different services, usually different companies, different qualifications.
Hood cleaning is about grease. A crew degreases the hood, the filters, the duct run, and the fan, down to bare metal, so there’s less fuel sitting in your exhaust path. It’s housekeeping against the thing most likely to burn.
A hood suppression inspection is about the system that puts the fire out. A licensed technician checks the agent tank and confirms it hasn’t discharged, checks every nozzle for blockage and proper aim, replaces the fusible detection links, ensures the fuel shutoff actually cuts off the gas, tests the manual pull station, and tags it.
One lowers your odds of a fire. The other decides what happens when you have one anyway. You need both. A spotless hood with an expired suppression tag still fails.
How often does a hood suppression system have to be inspected?
Every six months, by a technician trained and authorized on your system. And again any time it goes off. That interval comes out of NFPA 96 and NFPA 17A, and your local fire code is what enforces it.
One detail that’s easy to miss: those fusible links get replaced at every semiannual service, not just inspected. They’re the little metal detection elements up in the hood that melt at a set temperature and trip the system, and they spend six months sitting in a hot, greasy airstream. A link with a coat of grease on it takes longer to hit its trip temperature. Sometimes it never gets there. If your last service ticket shows the links as inspected rather than replaced, that visit didn’t meet the requirement.
A real semiannual inspection catches something else, too. Your nozzles are aimed at specific appliances. Swap a fryer for a charbroiler, slide the range two feet down the line, add a piece of equipment, and the coverage the system was designed around isn’t the coverage you’ve got. That’s a design problem, not a maintenance one. It only gets caught if someone is checking for it.
How often does the hood and duct have to be cleaned?
This depends on what you cook and how much of it. NFPA 96 sorts kitchens into four tiers:
| Your operation | What that usually looks like | How often |
| Solid fuel | Wood-fired pizza, charcoal grills, barbecue smokehouses | Monthly |
| High volume | 24-hour kitchens, heavy charbroiling, wok cooking | Quarterly |
| Moderate volume | Most full-service restaurants | Semiannually |
| Low volume | Churches, day camps, senior centers, seasonal kitchens | Annually |
This part is commonly misunderstood. Those intervals set how often somebody has to inspect the system for grease. When deposits turn up, the cleaning happens then, not at the next scheduled visit. A busy kitchen can easily need cleaning ahead of its tier, and your AHJ can require more frequent service if an inspection finds buildup.
Classify yourself by your heaviest cooking, not your average week. And if anything under that hood burns wood or charcoal, the whole system drops to the monthly tier.
Do I still need a fire extinguisher if I have a hood suppression system?
Yes. A listed Class K extinguisher within 30 feet of the cooking appliances, on top of the fixed system. A kitchen with a flawless hood system still fails inspection without one.
The reason is practical. Your fixed system fires once. After it discharges it’s empty and offline until a technician recharges it, and that Class K unit on the wall is the only thing standing over your cook line until he gets there. It also covers you during service, when the fixed system is deliberately shut down, and it handles a small flare-up that doesn’t justify dumping the whole system.
Class K specifically. Those use a wet chemical agent built for vegetable oil and animal fat, which burn hotter and light back up faster than what an ABC unit is designed for. An ABC extinguisher is not a substitute over a fryer.
What happens after the system discharges?
The kitchen has to remain closed until the system is reset. There’s no shortcut here.
When the system activates, it dumps wet chemical across the appliances and kills the fuel. That shutoff has to be reset by hand. Then the tank gets recharged, the links replaced, the nozzles cleaned and re-capped, and the whole system re-tested and re-tagged by a licensed technician before you cook again. Everything the agent touched gets cleaned before food goes back on it.
The instinct in the moment is to wipe everything down and get the line back up for dinner. Don’t. Cooking under a discharged system means operating with no fire protection over the line, and your carrier will take that position if there’s a second incident.
Common Commercial Kitchen Code Violations
- An expired tag. The six-month clock ran out and nobody was watching it.
- Links inspected instead of replaced.
- Missing nozzle caps, which let grease vapor creep into the piping.
- New or rearranged equipment the nozzles no longer cover.
- No Class K extinguisher, or one hung too far off the line.
- An old dry chemical system. New and replacement systems must be UL 300-listed, and if yours predates that, your fire marshal or your carrier will eventually bring it up.
Enforcement varies more than people expect. Which edition of the code applies to you comes down to what your jurisdiction adopted, and Memphis, Shelby County, and DeSoto County don’t always line up. Some add their own reporting requirements on top. If you’re not sure what applies at your address, call your fire marshal or call us. It’s a five-minute conversation and it beats finding out mid-inspection.
How Mid-South Safety Services Can Help
Mid-South Safety Services has been doing this since 1976, and we’re locally owned right here in the Mid-South (Olive Branch, MS). We install, inspect, and repair kitchen hood suppression systems, and we handle the Class K and other portable extinguishers that go with them, plus emergency lighting, exit signs, and special-hazard suppression.
Our preventative maintenance programs put your semiannual service on a schedule that works around your hours rather than through them, with documentation that holds up when the marshal walks in during a mid-rush. You stop tracking dates. You’re just current.
Ready to hand off your fire safety compliance? Mid-South Safety Services has been keeping Mid-South facilities safe and code-compliant since 1976. Call 662-892-8723 or visit midsouthsafetyservices.com for a free estimate.