The NFPA 96 Frequency Tiers
NFPA 96 (the Standard for Ventilation Control and Fire Protection of Commercial Cooking Operations) sets inspection-and-cleaning intervals based on the type and volume of cooking. The greasier and busier the operation, the more often the whole exhaust system has to be cleaned. The widely used tiers are:
| Frequency | Type of Cooking Operation | Typical Examples |
|---|---|---|
| Monthly | High-volume, solid-fuel, or 24-hour cooking | Charbroiling, wok lines, wood/charcoal grills, 24-hour diners, high-volume quick-service |
| Quarterly | Moderate-volume cooking | Most full-service restaurants, busy family restaurants, pubs and bistros |
| Semi-Annually | Light-volume cooking | Cafés, low-volume kitchens, steam-table and limited-menu operations |
| Annually | Low-volume cooking | Seasonal businesses, places of worship, senior centres, day camps |
These are guideposts, not a substitute for judgment. NFPA 96 also requires the system to be inspected for grease accumulation at intervals tied to the same volume bands, and if grease is building up faster than expected — a common surprise for kitchens that have added a fryer or a char-grill since their last review — the cleaning frequency must increase to match. The safest approach is to have a qualified technician confirm your interval based on what they actually find in your ducts.
What "Cleaning the Hood" Really Means
The most common and most dangerous misconception is that cleaning the hood means wiping the shiny stainless canopy over the cooking line. Under NFPA 96 a compliant cleaning covers the entire exhaust system, to bare metal where accessible:
- Baffle filters — removed and degreased (these also get frequent in-house cleaning, see below).
- Hood canopy and plenum — the interior chamber behind the filters where grease collects.
- Horizontal and vertical ductwork — the grease-conveying ducts running from the hood to the roof.
- Exhaust fan — the rooftop or in-line fan, including the housing and blades.
When the service is complete, the technician affixes a cleaning label or certificate recording the date, the cleaning company and technician, and any sections found inaccessible or not cleaned. The operator keeps that record on file. That documentation is what a fire inspector or insurance adjuster asks to see — and a hood that looks clean but has no record, or whose ducts have never been touched, will not satisfy either.
Baffle Filters and the Daily Line: the In-House Layer
Between certified exhaust cleanings, the kitchen still has daily and weekly grease work that keeps the system safe and slows accumulation:
- Baffle filters — soaked and degreased on a regular cycle (often nightly or every few nights in a busy kitchen); many operations run them through the dishwasher.
- Hood exterior and drip troughs — wiped and grease cups emptied daily.
- Cooking line, fryers, and surrounding walls/floors — degreased on a daily and deep-clean schedule.
This back-of-house degreasing is exactly the kind of work a commercial cleaning crew or kitchen staff handle. It does not replace the NFPA 96 interior cleaning — but a kitchen that keeps filters and surfaces degreased puts far less grease into the ducts between certified services.
Why this is the highest-stakes cleaning in your building
Grease-laden ductwork is the leading fuel for commercial kitchen fires. A flare-up on the line can ignite grease in the hood and ducts and travel through the building's exhaust system. An overdue or undocumented hood cleaning doesn't just risk a fire — it can void your fire-insurance coverage, draw a fire-code order at inspection, and show up as visible grease build-up on a health inspection. The cleaning record is as important as the cleaning.
Who Is Allowed to Clean It
The full exhaust system — ducts and fan — should be cleaned by a qualified, trained, certified kitchen-exhaust cleaning company. It involves the entire grease-conveying system, awareness of the fire-suppression system around the hood, and the certification record that fire inspectors and insurers require. The in-between work — baffles, hood exterior, line and floor degreasing — can be done by kitchen or cleaning staff.
Zusashi handles your back-of-house grease — and the certified hood cleaning through our partner
Our crews degrease the hood exterior and baffles, the cooking line, walls, and floors on a schedule that keeps grease out of your ducts — and the NFPA 96 interior duct and fan certification is managed through our certified hood-cleaning partner, who issues the fire-marshal cleaning certificate. One provider, one schedule, full documentation. Serving restaurants and commercial kitchens across the GTA, no long-term contracts.
See Commercial Kitchen CleaningKeep the Records
Whatever your frequency, retain the documentation: the dated cleaning certificate/label from each certified service, a note of any inaccessible duct sections, and your in-house log of baffle and line degreasing. If a fire inspector, your insurer, or a public-health inspector asks how your exhaust system is maintained, a tidy record of NFPA 96-interval cleanings answers the question in one folder — and demonstrates that grease management is a system, not a guess.
Frequently Asked Questions
How often does a commercial restaurant hood need to be cleaned in Ontario?
The standard recognized in Ontario is NFPA 96, which sets cleaning frequency by cooking volume, not a single calendar date. As a guide: monthly for high-volume, 24-hour, or solid-fuel and charbroiling operations; quarterly for moderate-volume cooking; semi-annually for light-volume cooking; and annually for low-volume operations such as seasonal businesses, places of worship, and senior centres. The Ontario Fire Code requires commercial cooking exhaust systems to be maintained, and NFPA 96 is the benchmark used to determine how often. When in doubt, a qualified technician should inspect and recommend a frequency based on measured grease accumulation.
What does a compliant hood cleaning actually include?
NFPA 96 requires the entire exhaust system to be cleaned where accessible — not just the hood canopy. That means the filters/baffles, the hood plenum, the horizontal and vertical duct runs, and the exhaust fan, cleaned to bare metal where reachable. After the service, the technician affixes a label or certificate showing the date, the company and technician, and any areas found inaccessible or not cleaned, and the operator keeps the record on file. Wiping only the visible stainless steel of the hood is not a compliant cleaning.
Who is allowed to clean a commercial kitchen exhaust system?
The full exhaust system — ducts and fan — should be cleaned by a qualified, trained, and certified kitchen-exhaust cleaning company, because it involves the entire grease-conveying system, fire-suppression awareness, and a certification record that satisfies fire inspectors and insurers. Day-to-day tasks such as cleaning or soaking the baffle filters, degreasing the hood exterior, and wiping the cooking line can be handled by kitchen or cleaning staff between certified services. Zusashi's crews handle the hood exterior, baffles, and back-of-house degreasing, and the NFPA 96 interior duct/fan certification is performed through our certified hood-cleaning partner.
What happens if you don't clean your kitchen hood often enough?
Grease accumulation in the hood, ducts, and fan is the leading fuel for commercial kitchen fires — a flare-up on the line can ignite grease-laden ductwork and spread through the building. Beyond the fire risk, an overdue or undocumented exhaust cleaning can void fire-insurance coverage, trigger fire-code orders during an inspection, and contribute to failed health inspections where grease build-up is visible. Keeping to the NFPA 96 frequency and retaining the cleaning records protects the building, the staff, the insurance, and the licence to operate.
Note: This post is for informational purposes only and does not constitute fire-safety, legal, or insurance advice. Frequencies are general guidance based on NFPA 96; your authority having jurisdiction (local fire department), insurer, and the actual grease accumulation in your system determine the requirement. Always refer to the current edition of NFPA 96, the Ontario Fire Code (O. Reg. 213/07), and your insurance policy, and confirm intervals with a qualified kitchen-exhaust cleaning professional.