Periodic cleaning of kitchen exhaust ducts_008615019189367

Periodic cleaning of kitchen exhaust ducts_008615019189367

Ouyong

    The general control standard for the periodic cleaning, fire-safety construction, and industry inspection/acceptance of kitchen exhaust ducts stipulates that the thickness of residual grease on the interior walls after cleaning must be ≤0.5 mm; if this threshold is exceeded, immediate cleaning and corrective action are required.

    Exhaust ducts in factories, commercial kitchens, and food processing facilities—particularly those associated with heat treatment or deep-frying processes that generate grease—must undergo a comprehensive inspection and cleaning at least once every quarter. For areas with high grease accumulation or high-temperature operating conditions, the cleaning frequency should be increased (e.g., monthly or bimonthly); allowing grease to accumulate over long periods without removal is strictly prohibited. Where ducts pass through fire compartments or where branch ducts connect to vertical main ducts, fire dampers—calibrated to actuate at 150°C—must be installed to prevent the rapid spread of fire through the ductwork in the event that accumulated grease ignites. Furthermore, a safe, insulated clearance must be maintained between the outer surface of the ducts and any combustible materials.

    Cleaning tasks should preferably be entrusted to qualified professional service providers. The scope must comprehensively cover areas prone to grease accumulation—such as range hoods, the interior walls of ducts, exhaust fans, air purification units, elbows, and duct transitions—rather than being limited to visible surfaces. Records, including photographs taken before and after cleaning, formal cleaning logs, and inspection sign-off documents, must be retained. A fire safety ledger should also be established to facilitate periodic fire safety oversight and audits.

    Grease deposits are flammable or combustible materials; once they exceed a certain thickness, they can easily ignite upon contact with sparks or high-temperature flue gases. Fires originating in ducts are often difficult to detect initially and tend to spread rapidly. Regular internal inspections should be implemented, with a grease thickness of ≤0.5 mm established as the threshold for compliance; if localized thickening of grease is detected, operations must be halted immediately for cleaning. Failure to clean as required—leading to significant grease accumulation—creates a severe fire hazard; timely cleaning is essential to prevent avoidable losses. Safety is about taking proactive measures to prevent incidents before they occur.