The Gold Standard of Commercial Kitchen Exhaust Cleaning Services begins with a distinction that can prevent a dangerous misunderstanding: wiping the visible hood is not the same as cleaning the whole kitchen exhaust system. Grease can accumulate in ducts, fans and sections no diner sees. A responsible specialist maps the actual system, manages the cleaning risks, removes deposits from the agreed and required components, and produces evidence that the restaurant owner and building manager can act on.
Imagine a fictional Singapore food-court operator who books an overnight ‘exhaust deep clean’. The crew polishes the stainless-steel hood and washes the removable filters. The following morning, the counter looks immaculate. But the shared duct route above the ceiling is not accessed, its cleaning history is unknown and the technician leaves only a generic invoice saying ‘hood cleaned’. The visible appearance cannot establish that the full fire-safety maintenance duty was met.
Singapore’s SCDF Fire Code 2023, Clause 7.1.13(d) requires the entire interior and exterior kitchen exhaust duct and hood to be degreased and cleaned at least once every 12 months by a specialist, with records kept by the owner or operator. Its Fire Safety Instruction Manual, section 4.12 specifies dated photographic evidence and a visible maintenance label containing cleaning dates, contractor details and cleaning method. These duties are a stronger starting point than a promise that the restaurant will ‘smell fresh’.
Quick answer: how often must kitchen exhaust ducts be cleaned in Singapore?
SCDF requires the entire kitchen exhaust duct, inside and outside, and the kitchen hood to be degreased and cleaned at least once every 12 months by a specialist. Relevant owners/operators must retain cleaning records, and the Fire Safety Instruction Manual specifies time-stamped photographs and an A5-or-larger maintenance label. A hood-only wipe does not fulfil the whole-system requirement.
The complete grease-exhaust cleaning journey
Follow the chapters from duct survey and responsible parties through access, specialist work, containment, documentation and proper return to cooking.
1. Identify whether this is a commercial grease-exhaust system
A restaurant hood, an ordinary bathroom vent and an air-conditioning supply duct do different work. Kitchen extraction may carry grease-laden vapours from cooking equipment and must be assessed under the applicable fire-safety arrangements. Do not sell the same domestic air-duct spray package for a commercial hood and its ductwork.
Ask which cooking activities, hoods, ducts, fans and shared routes are present. The inspection and service scope must match the installed system, not only the stainless-steel canopy the customer can see.
Back to chapters · Next chapter
2. Map the entire system before quoting
Identify the hood, grease-removal devices, extraction ducts, bends, vertical risers, outlets, fans, access openings and areas within common property. Existing drawings can help, but they may not reflect changes made after tenancy renovations. A competent site assessment identifies where access and cleaning are feasible and where a specialist plan is needed.
The food-court operator cannot be assured that the system has been cleaned if no one has established the length and route of its duct. A priced area for the hood’s visible face is not a complete exhaust-system scope.
Back to chapters · Next chapter
3. Recognise shared ducts and responsibility boundaries
SCDF allows certain commercial kitchen exhaust-sharing configurations under prescribed conditions. An operator may own its hood while the building owner or MCST controls a shared riser or another part of the route. Clarify who authorises access, who funds the service and who retains the final maintenance evidence.
A contract divided by tenancy boundaries can leave an unmaintained section if parties assume that it belongs to someone else. Draw the complete responsibility map and name one person to coordinate cross-boundary work.
Back to chapters · Next chapter
4. State the real minimum maintenance requirement
SCDF Clause 7.1.13(d) requires the complete interior and exterior exhaust duct and kitchen hood to be degreased and cleaned at least once every 12 months by a specialist. The period is a minimum prescribed interval, not proof that an unusually heavily used kitchen can safely ignore deposits for the full year regardless of conditions.
Plan inspection and cleaning frequency around actual grease loading and the applicable site requirements. A contractor should not casually claim that an annual sticker means every restaurant is automatically safe until the next calendar date.
Back to chapters · Next chapter
5. Check current grease condition without inventing a universal threshold
Visible deposits, cooking intensity, filter condition and known system history help establish the task. However, a photograph of one oily filter cannot establish the condition of every internal duct section. Use suitable professional inspection methods, record locations and distinguish known deposits from sections not yet assessed.
A good report states which components actually required work and what could not be accessed. If contamination is substantial or an access defect exists, management needs an honest response rather than a generic percentage-cleanliness claim.
Back to chapters · Next chapter
6. Use suitably qualified specialist cleaners
SCDF requires a specialist to carry out degreasing and cleaning. The vendor should be able to explain its experience with commercial grease-exhaust systems, safe access, equipment and documentation. A general office cleaning team should not automatically be treated as technically competent to dismantle or clean an overhead commercial duct system.
Where a job needs additional qualified access, rigging or electrical support, identify those roles in the contract. The word ‘specialist’ should correspond to practical competence and a safe method.
Back to chapters · Next chapter
7. Coordinate the building owner, operator and fire-safety team
Restaurant staff, landlord, MCST, exhaust specialist and the building’s relevant fire-safety personnel may each hold critical information. Establish who signs off access, isolation of cooking operations, repair of defects and system return. One absent owner can leave a cleaned duct disconnected or an important concern unaddressed.
Give all responsible parties a current communication route for exceptions. The food-court management should know whether shared sections were included rather than assume each stall’s invoice covers the building.
Back to chapters · Next chapter
8. Protect staff and premises before degreasing
Cleaning may involve chemicals, slippery surfaces, heights, sharp sheet metal, hot equipment and mechanical fans. Arrange safe access, appropriate shutdown or isolation by competent personnel, protective controls, ventilation and public separation. Kitchen business pressure cannot justify work around moving or energized machinery without the appropriate process.
Singapore MOM risk-management guidance
Back to chapters · Next chapter
9. Manage electrical and mechanical plant interfaces properly
Extract fans, motors, controllers, switches and fire-safety interfaces may be connected to the kitchen system. Degreasing crews should not improvise electrical repairs or change control settings to get faster access. Use competent electrical or mechanical specialists when technical work is needed.
After service, the installed system must be appropriately reassembled and returned to its intended operation. An exhaust fan that was left disconnected is a failure even when internal metal surfaces look clean.
Back to chapters · Next chapter
10. Plan access to concealed and high-level duct sections
Parts of the system may pass above ceilings, through shafts or near other building services. SCDF Fire Code prescribes design and access provisions for relevant kitchen exhaust arrangements. Use authorised access points and competent methods; do not cut through protected construction simply because a cleaning tool cannot reach.
If an inaccessible segment prevents a complete required clean, identify it as an exception requiring the responsible qualified person’s decision and necessary access works. An undisclosed gap cannot be reported as the entire duct cleaned.
Back to chapters · Next chapter
11. Keep filters, hood and ductwork separate in the work record
Filters collect some grease, but deposits can also occur inside the hood, plenum, horizontal runs, risers and near fans. List each part separately at inspection, cleaning and verification. Removing a filter and washing it in a sink is not evidence of complete downstream work.
The food-court invoice should state the actual system components covered. The owner needs evidence to verify the duty in SCDF Clause 7.1.13, not a decorative description of a gleaming canopy.
Back to chapters · Next chapter
12. Select methods to suit deposits and construction
Professional methods may involve appropriate manual scraping, mechanical brushing, approved chemical washing or specialist equipment according to the installed system. SCDF’s Fire Safety Instruction Manual acknowledges these as examples of cleaning methods that must be declared on the maintenance label. The correct choice depends on materials, access and contamination.
Do not use uncontrolled high-pressure water or aggressive chemicals on an electrical assembly, fire-rated construction or unsuitable finish. Method selection must include containment, worker protection and protection of adjacent areas.
Back to chapters · Next chapter
13. Prevent grease and wash water from contaminating other spaces
Degreasing can dislodge large amounts of oily residue. Protect food-preparation surfaces, stored ingredients, floor drains and neighbouring premises with an appropriate containment and removal plan. The cleanup method must not create new slip hazards or dispose of oily waste through an inappropriate route.
A restaurant should not reopen food preparation next to leaked cleaning chemicals or unmanaged residues. Coordinate final sanitation with the operator before the kitchen resumes normal use.
Back to chapters · Next chapter
14. Distinguish exhaust cleaning from fire suppression servicing
A kitchen hood may interact with a wet-chemical fire-extinguishing system or other approved controls. Cleaning the hood does not certify the fire-suppression equipment, and cleaners should not disconnect, alter or discharge it without appropriate competent authorisation. Each system needs its own relevant inspection and maintenance evidence.
SCDF Fire Code describes conditions for wet-chemical systems in relevant kitchen exhaust designs. Coordinate access and reinstatement with the authorised fire-safety professionals so the cleaning process does not leave protection impaired.
Back to chapters · Next chapter
15. Check fan housings and the discharge route
Cleaning only an accessible duct opening may leave heavy deposits at the fan, discharge or a high point in the system. Assess the entire agreed and applicable exhaust route and identify where specific equipment or specialist access is required. Maintain a location-based record rather than a generic ‘100% serviced’ statement.
The work outcome must distinguish a completed section from one awaiting separate technical attention. If a fan is unsafe or defective, refer it through the correct maintenance process instead of concealing the finding.
Back to chapters · Next chapter
16. Inspect reassembly, access panels and duct integrity
After cleaning, verify that relevant filters, access closures, seals and panels are restored as designed. Protect the fire-rated construction and other approved features. A system left with an open access panel or displaced component may operate differently and expose people to hazards.
Where the work involved changes requiring specialist technical review, the responsible qualified person should inspect and accept them. A cleaning supervisor’s signature is not a universal engineering certification.
Back to chapters · Next chapter
17. Keep time-stamped photographic evidence usable
SCDF’s Fire Safety Instruction Manual requires dated photographic evidence of the cleaning in the report. Photographs should identify meaningful system sections and stages sufficiently for the owner to understand what they show. A glossy image of the outside hood cannot substitute for evidence of internal duct cleaning.
Store the report in an accessible building or business maintenance record. It should permit a later reviewer to distinguish systems, dates, personnel, methods and any inaccessible areas without calling the former restaurant manager.
Back to chapters · Next chapter
18. Provide the correct visible maintenance label
SCDF’s Fire Safety Instruction Manual section 4.12 requires a prominently displayed maintenance label, at least A5 size, showing the last cleaning date, the cleaning contractor’s name and UEN, the method of cleaning, and the date the next cleaning is due. These details must reflect actual work performed, not an automatically generated future date.
Place it where the relevant operator can see it, consistent with the required arrangement. A label helps staff identify maintenance status; it does not excuse failure to keep the detailed records.
Back to chapters · Next chapter
19. Keep owner records distinct from a contractor’s marketing certificate
An invoice, promotional certificate and meaningful inspection record do different things. The owner or operator must be able to produce the required maintenance evidence, including identity of the specialist and methods. Retain it in the building’s fire-safety management arrangement where applicable.
A provider should not claim SCDF has formally endorsed its particular chemical or commercial package merely because it cites the SCDF Fire Code. Demonstrating conformity is a matter of actual work and records.
Back to chapters · Next chapter
20. Review frequency when cooking operations change
A new wok station, longer operating hours or different cooking fuel may change grease loading and maintenance demand. Assess the effect with relevant specialists and building management before continuing an unchanged cleaning programme. A minimum legal interval does not replace judgment about actual risk.
Document when an operating change prompts a new assessment. Do not wait for a visible smoke or odour problem before investigating a significantly altered system.
Back to chapters · Next chapter
21. Quote access and completeness rather than a cheap hood price
Costs can include survey, equipment isolation, specialist access, entire duct length, fan treatment, residue containment, overnight attendance, records, label and follow-up of defects. Itemise the actual scope and conditions. An inexpensive ‘hood clean’ quote cannot be compared fairly with a complete system degreasing service.
Singapore’s CCS price-transparency guidelines
Back to chapters · Next chapter
22. Plan cleaning around safe kitchen shutdown and reopening
Restaurant operations may be affected by overnight work and drying or reassembly. Coordinate cooking shutdown, securing of food, ventilation isolation, worker access, final sanitation and any competent technical verification. Do not promise an exact reopening time while significant defects or safety concerns remain unresolved.
An open restaurant should not operate with an exhaust system that the responsible technical or fire-safety personnel consider impaired. The plan should include a practical alternative if the cleaning reveals a condition that prevents safe reopening.
Back to chapters · Next chapter
23. Use a room-by-room and section-by-section acceptance check
Before signing off, reconcile the original duct map, actual cleaned sections, photographic evidence, reassembled components, visible label and any exceptions. The owner should know precisely which part of the system remains unverified and who will decide the next action.
For the food court, successful acceptance includes the hidden duct route where required, not only the hood above the cooking line. Management should be able to demonstrate the work to the relevant authority from the records.
Back to chapters · Next chapter
24. Handle recurring grease and defects as diagnostic feedback
If grease returns unusually quickly, a fan malfunctions or inspection reveals persistent inaccessible deposits, review cooking practice, equipment condition and servicing methods with appropriate specialists. Do not repeatedly apply stronger chemicals while ignoring the underlying issue.
Track repeat callouts, blocked access, incomplete records, cleaning-related damage and incidents. A credible supplier changes its plan when evidence shows the previous work was not adequate.
Back to chapters · Next chapter
25. Measure fire-safety maintenance, not stainless-steel shine
Useful measures include completed required system coverage, independent review of exceptions, safe worker practices, absence of new damage, proper records, functioning exhaust equipment and prompt fault correction. The number of polished filters or social-media before-and-after images says very little about concealed grease ducts.
The gold standard is a complete, specialist, traceable degreasing service that leaves the commercial kitchen and building managers with a defensible understanding of their exhaust system. Safety and continuity emerge from verified work behind the ceiling as much as from the visible hood.
A polished hood with an uncleaned riser: a worked example
The food-court operator buys an overnight deep clean, believing the full system is covered. At inspection, the specialist maps hood, duct runs, riser, access points and fan, then agrees the actual complete system scope with the owner and MCST. The crew follows a controlled cleaning method with appropriate plant isolation, grease containment and documentation of the identified sections.
The receiving team checks the dated photographs, cleaning method, completed duct map, any technical exceptions and the required visible maintenance label. If a shared duct section remains inaccessible, the responsible manager receives an explicit unresolved action rather than a false ‘fully clean’ claim. The kitchen returns to use only under the appropriate safe technical conditions.
The exhaust-cleaning acceptance matrix
| Requirement | Professional control | Evidence on handover |
|---|---|---|
| Whole system covered | Hood, interior/exterior duct and relevant components mapped | Actual cleaned sections verified |
| Specialist work | Competent team and safe access and isolation | True contractor details and methods |
| Grease handled safely | Containment and waste management | No new slip, chemical or fire-safety defect |
| SCDF records provided | Dated photos and maintenance details | Usable report and required A5 label |
| Safe reopening | Access panels, fans and relevant interfaces reinstated | Qualified technical exceptions resolved or owned |
Frequently asked questions
Does SCDF require the entire kitchen exhaust system to be cleaned annually? Yes. Clause 7.1.13(d) states the entire interior and exterior duct and hood must be degreased and cleaned at least once every 12 months by a specialist.
Is a photograph of a polished hood adequate evidence? No. SCDF’s Fire Safety Instruction Manual calls for time-stamped photographic evidence and records that identify actual cleaning and degreasing. Hidden duct coverage needs truthful documentation.
What must appear on the maintenance label? At minimum the last cleaning date, contractor name and UEN, cleaning method and next due date on a prominently displayed label of at least A5 size.
SCDF official requirements and related eduKate guides
Singapore primary sources: SCDF Fire Code 2023 Clause 7.1.13: Kitchen Exhaust Systems; SCDF Fire Safety Instruction Manual section 4.12: Kitchen Exhaust Duct Records and Label; MOM Workplace Risk Management; CCS Price Transparency.
Connected eduKate articles: Air Duct Cleaning Services (ordinary HVAC distinctions), Fire Alarm Maintenance Services, Cleaning Services and Catering Services.