Grease ducts accumulate grease with every cooking session. This is inevitable and dangerous. Grease build-up creates fire hazards, NEA compliance issues, and progressive performance degradation. Most operators neglect maintenance until problems surface: a kitchen filling with smoke during service, an NEA inspection flagging non-compliance, or in the worst case, a fire travelling the full length of the exhaust duct. This post is for food production operators with grease-laden exhaust systems, central kitchen and cloud kitchen operators, and any operator with commercial cooking equipment exhaust who wants to stay compliant and avoid costly emergency clean-ups.
Consequences of Neglect
Grease fires in ducts spread rapidly and are difficult to extinguish. A duct fire can travel the full length of the exhaust system before reaching any suppression point. The fire risk from grease accumulation is not theoretical. It is a documented cause of serious fires in commercial kitchens.
Grease accumulation narrows the effective duct diameter, reducing exhaust airflow and clogging filters. A kitchen filling with smoke during service is a common symptom of neglected ducts.
Dirty ducts emit stronger discharge odours, which trigger neighbour complaints and NEA enforcement.
Grease deposits attract cockroaches and rodents, creating hygiene issues that can compromise food licensing.
SCDF or NEA inspectors check duct condition during routine inspections. Non-compliance results in enforcement notices.
Maintenance Schedule
Grease filters require cleaning weekly or more frequently for heavy cooking operations. Professional duct interior cleaning is required every 3–6 months for active cooking installations. The exact interval depends on cooking volume and the types of food being prepared.
Fan and motor inspection should be conducted monthly. Check for grease accumulation on fan blades and housing, unusual vibration, and bearing condition.
Fire damper testing should be performed quarterly to confirm they open and close freely and close properly in the event of a fire.
Roof-level discharge inspection should be done quarterly to check for grease accumulation at the discharge point and verify the terminal is clear and unobstructed.
Professional Cleaning
Licensed contractors disassemble access panels, apply chemical degreasing or pressure washing, and photograph before and after for record-keeping. Costs range from $500 to $3,000 or more depending on system size and complexity. The cost is modest relative to the fire risk or the cost of an NEA enforcement notice.
Maintaining cleaning records is essential for licence renewals and SCDF inspections. Contractors should provide documentation (photographs, service report, next service due) after each service. Keep these records accessible.
Summary
Grease duct maintenance is a recurring compliance obligation for food production operators. Neglect creates fire risk, operational problems, pest attraction, and inspection failures. Maintenance involves weekly filter cleaning, professional duct cleaning every 3–6 months, and regular inspection of fans, dampers, and discharge points. Records should be kept for licensing and inspection purposes.
For the full exhaust and ventilation overview, see Exhaust / Ventilation / Odour Control Basics.
For SCDF fire safety obligations, see SCDF Fire Safety Basics.
For make-up air requirements, see Make-Up Air Explained.
For rooftop duct routing, see Rooftop Duct Routing.
For the exhaust system viewing checklist, see Viewing Checklist: Exhaust System Condition.
For noise control basics, see Noise Control Basics.
References
[1] SCDF: Acts, Codes & Regulations (Fire Safety). https://www.scdf.gov.sg/fire-safety-services-listing/downloads/acts-codes-and-regulations [2] SCDF: Fire Safety (Buildings) Regulations. https://www.scdf.gov.sg/fire-safety-services-listing/downloads/acts-codes-and-regulations [3] NEA: Air Pollution Control — Commercial Kitchen Exhaust. https://www.nea.gov.sg/our-services/pollution-control [4] NEA: Odour Management. https://www.nea.gov.sg/our-services/pollution-control/ [5] SFA: Food Factory Licensing Requirements. https://www.sfa.gov.sg/food-manufacturing-storage [6] MOM: Workplace Safety & Health. https://www.mom.gov.sg/workplace-safety-and-health [7] PUB: Trade Effluent Regulations. https://www.pub.gov.sg [8] JTC: Industrial Space. https://www.jtc.gov.sg/find-space/