NFPA 96 requirements 4

https://myexhaustductcleaningshop.clarionvale.com/posts/why-exhaust-duct-cleaning-matters-for-fire-safety-in-commercial-kitchens

NFPA 96 requirements set the standard for commercial kitchen exhaust systems, covering everything from hood design to ductwork and fan operations to prevent grease fires. Regular cleaning intervals are mandatory, with schedules varying by cooking volume. Fire suppression systems must be inspected semi-annually, and all components need to meet specific clearance distances from combustibles. Compliance isn't optional—it's critical for safety and insurance.