NFPA 96 explained: how often does your kitchen need hood cleaning?
July 17, 2026
NFPA 96 governs cleaning of your kitchen's exhaust hood, canopy, ducts, and rooftop fan. It was adopted into the Ontario Fire Code in 2025, which means it isn't optional guidance: it's the legal minimum a fire inspector checks against. The part most kitchen owners get wrong isn't whether they need this service. It's how often.
Frequency is set by volume, not a sales calendar.
NFPA 96 doesn't set one flat schedule for every kitchen. It scales the required frequency to how much grease your exhaust system actually accumulates, which depends on your cooking volume and method. A 24-hour diner running solid-fuel cooking builds up grease at a completely different rate than a seasonal church kitchen, and the standard reflects that.
| Kitchen volume | Examples | Required frequency |
|---|---|---|
| Critical (24-hr / heavy frying) | Ghost kitchens, 24-hr diners, solid-fuel cooking | Monthly |
| High volume | Korean BBQ, wok/wings/Indian kitchens, busy hotels | Quarterly |
| Moderate volume | Nursing home & corporate kitchens | Semi-annually |
| Low volume (no frying / seasonal) | Church kitchens, event spaces | Annually |
Why the frequency isn't negotiable.
Grease buildup inside an exhaust system is a documented ignition source, not a housekeeping issue. That's the entire reason NFPA 96 exists as a fire-prevention standard rather than a cleaning recommendation. A kitchen running quarterly-tier volume but cleaning semi-annually isn't saving money: it's carrying fire risk between visits that the standard was written to prevent.
Structural issues can block sign-off entirely.
A cleaning visit sometimes surfaces something bigger than grease: a missing duct access panel, or a rooftop fan with no hinge kit. Both are structural fire-code blockers, not something a cleaning crew should quietly patch and bill for. They belong in writing, as part of your service report, with full NFPA 96 sign-off following once they're corrected, not before.
Northfire's hood & exhaust cleaning is priced and scheduled against this exact table, not a generic maintenance calendar. See what's included in every visit →