How Often Should You Clean Your Kitchen Exhaust Hood? (NFPA 96 Explained)

If you’ve ever asked how often your commercial kitchen exhaust hood actually needs cleaning, the honest answer is: it depends on what and how much you cook. NFPA 96, the national standard for commercial kitchen ventilation, doesn’t set one flat schedule for every kitchen — it ties cleaning frequency directly to cooking volume and fuel type.

The four frequency tiers

NFPA 96 breaks cleaning schedules into four tiers:

• Monthly — solid-fuel cooking operations (wood or charcoal-fired equipment)
• Quarterly — high-volume cooking, including 24-hour operations and high-turnover restaurants
• Semi-annually — moderate-volume kitchens, which covers most standard full-service restaurants
• Annually — low-volume operations, such as seasonal kitchens, churches, or day camps

Why this matters beyond just compliance

Grease buildup inside an exhaust system — on the hood, in the ductwork, around the rooftop fan — is one of the leading causes of restaurant fires. It’s also the single most common reason kitchens fail fire inspections. A cleaning that only addresses the visible hood surface and skips the ductwork and rooftop fan doesn’t actually bring a kitchen back into compliance, even if it looks clean from the kitchen floor.

How to know which tier applies to you

Most owners aren’t sure where their kitchen actually falls, and defaulting to “the schedule the last company used” isn’t always right — a kitchen that changed its cooking volume, added equipment, or shifted hours may need a different frequency now than it did a year ago. A real walkthrough, not a guess, is the only way to know for sure. A fire safety compliance consultation can also help if you’re unsure where your kitchen stands ahead of an inspection.

If it’s been a while since your last cleaning — or you’re not sure when your last one even was — that’s usually the first sign it’s time for one. See our full list of services or request a free quote to get started.