What Your Fire Marshal Actually Looks For During a Hood Inspection
A walkthrough of the seven things a California fire marshal checks when they inspect your kitchen exhaust system — and how to pass on the first visit.
Fire marshal inspections feel mysterious from the operator's side of the counter. They are not. Every inspector in California works from the same NFPA 96 checklist, and most of them follow the same order. Here is what they look at, in roughly the sequence they look at it, with the specific failure modes that trigger a citation in Contra Costa, Alameda, San Francisco, Napa, and Santa Clara counties.
1. The most recent service report
Before they ever climb a ladder, the inspector asks for your last cleaning report. They want a date, a company name, the technician's certification number, photos, and a signature. A handwritten invoice is not a service report. An emailed line item that says 'hood cleaning — $450' is not a service report.
If you cannot produce a current report on the spot, expect the inspector to assume the system has not been serviced and to grade everything else more harshly. The single highest-leverage thing you can do before any inspection is have the last two reports queued up on your phone.
2. Access panels
NFPA 96 requires access panels at every change of direction in horizontal duct and at every 12 feet of straight run. Missing panels are the single most common citation we see in the Bay Area, because most older buildings were built when the requirement was looser.
If your duct cannot be fully cleaned because there are no access panels, that fact must appear on every service report. The fix is access-panel installation — usually a one-time project that takes a half day and removes the citation permanently.
3. Grease thickness in the duct
Inspectors carry a depth gauge — a small comb-like tool that measures buildup at the bottom of the duct. NFPA 96 considers a system in need of cleaning when grease reaches 0.078 inches (2 mm) of buildup at any measured point. Anything over 0.125 inches (3.2 mm) is an immediate citation and possible red-tag of the cooking equipment.
This is the most objective test the inspector runs. There is no negotiating with a depth gauge.
4. Filter condition and fit
Filters must be UL-listed grease baffles, in place, undamaged, and tight against the frame. The failure modes are familiar:
- Mesh filters (cheaper, but not UL-listed for grease) — fail
- Cardboard or foil 'plugging' a missing filter — fail and possible suppression-system failure
- Bent or warped baffles with visible gaps to the plenum — fail
- Filters resting on the cook line because no one put them back after the night clean — fail
The fix is cheap: keep a spare set of UL-listed baffles in the back of house and rotate them in whenever one is bent or damaged.
5. The fan
The exhaust fan must hinge open for service, must have a working hinge-kit and grease cup, and must show no signs of grease pooling on the roof around the curb. A fan welded shut, or a fan with the hinge bolts rusted solid, is a citation.
Inspectors in San Francisco and Oakland increasingly check the roof condition around the fan as part of the same inspection. If they see staining radiating out from the curb, expect questions about your containment device and your roof-membrane history.
6. The suppression system
Your Ansul or equivalent wet-chemical system must show a current semi-annual tag from a licensed suppression contractor. The tag is dated and signed; if it is more than six months old, the system is out of compliance regardless of whether it would actually work in a fire.
Inspectors also check that nozzles are capped (uncapped nozzles get clogged with grease vapor and will not spray properly) and aimed at the correct appliances. A new fryer dropped in where the old grill used to be, with no nozzle realignment, is a common Bay Area failure mode after kitchen renovations.
7. Clearances to combustibles
The inspector will check that no wood, cardboard, or plastic is stored within 18 inches of any duct, and that nothing on the roof obstructs the fan discharge. Pallets stacked against the duct chase, dry storage shelves built up to the ceiling under the duct run, and HVAC techs leaving a tarp on the roof next to the fan are all common citations.
How to pass on the first visit
There is no trick to it. Have your last service report on your phone before the inspector arrives. Walk them to the access panels first — it signals you know what they are about to check. Make sure the suppression tag is current. Confirm filters are seated. Look up at the duct chase and clear anything within arm's reach.
The inspections that go badly are the ones where the operator looks surprised by every question. The inspections that go well are the ones where the operator hands over a binder before being asked.
What happens if you fail
A typical first-time failure produces a 30-day correction notice. Major failures (grease over 3 mm, expired suppression tag, missing access panels combined with heavy buildup) can produce an immediate red-tag of the cooking equipment, which means you stop cooking until corrections are verified by a reinspection.
Reinspections in most Bay Area jurisdictions are billable and scheduled at the inspector's convenience — meaning you may be closed for several days. The cost of one failed inspection almost always exceeds the cost of an extra cleaning.