NFPA 96 (Commercial Kitchen Exhaust)

NFPA 96 is the National Fire Protection Association's standard for ventilation control and fire protection of commercial cooking operations. In practice it governs how restaurant and commercial-kitchen grease-exhaust systems must be cleaned and maintained.

It's what makes commercial duct work different from residential. Grease building up in a kitchen exhaust is a serious fire hazard, so NFPA 96 sets cleaning frequency tied to cooking volume — from monthly for high-volume operations to annually for light use — and requires documentation of the work.

If you run a restaurant or any facility with commercial cooking, your provider should clean to NFPA 96 and leave you a service record (many insurers and health inspectors ask for it). A company that only does residential air-duct cleaning is not equipped for this scope.