Commercial Kitchen Exhaust Cleaning Standards Australia — AS 1851 Compliance Guide
Commercial kitchen exhaust systems in Australia must be cleaned according to AS 1851-2012 (Routine Service of Fire Protection Systems and Equipment). The standard requires cleaning at intervals determined by cooking type: heavy cooking (chargrills, woks, deep fryers) every 3 months; moderate cooking (standard commercial kitchens) every 6 months; light cooking (cafes, low-volume operations) every 12 months. Non-compliance with AS 1851 voids the building's fire insurance and breaches fire safety legislation. In Victoria, the Metropolitan Fire Brigade (MFB) and Country Fire Authority (CFA) enforce fire safety compliance. A compliance certificate must be issued after every AS 1851 cleaning service by the qualified contractor.
- What Is AS 1851?
- Why AS 1851 Matters — Fire Risk and Insurance
- Cooking Type Classification and Cleaning Frequency
- What a Compliant AS 1851 Clean Covers
- The Compliance Certificate — What It Must Show
- Enforcement — MFB, CFA, and Insurers
- How to Choose a Qualified AS 1851 Contractor
- How to Set Up an AS 1851 Compliance Program
- FAQ — 8 Questions Answered
1. What Is AS 1851?
AS 1851-2012 is the Australian Standard for Routine Service of Fire Protection Systems and Equipment. It is published by Standards Australia and specifies the minimum service intervals and procedures for maintaining fire protection systems in buildings — including commercial cooking exhaust systems. Section 17 of AS 1851-2012 specifically addresses kitchen exhaust systems, defining cooking type categories, required cleaning frequencies, and the minimum scope of a compliant cleaning service.
AS 1851 is not a food safety standard — it is a fire safety standard. Its application to commercial kitchen exhaust systems is based on the established fire risk created by grease accumulation in exhaust ductwork. Grease deposited in a kitchen exhaust duct is a fuel source. A duct fire ignited by a flare-up or equipment malfunction travels through the grease-coated duct to the roof, ceiling cavity, or exterior — creating a potentially catastrophic structural fire in a building that may be occupied by hundreds of diners, staff, and neighbouring tenants.
The 2012 version of AS 1851 (AS 1851-2012) is the current version applicable to all commercial kitchen exhaust systems in Australia. It superseded the 2005 version and introduced the three-tier cooking classification system that now defines the cleaning frequency for all Australian commercial kitchen exhaust systems.
Kitchen exhaust system: The complete system comprising the rangehood or exhaust hood above cooking equipment, the exhaust filters (grease filters), the exhaust duct from the hood to the termination point (roof or wall discharge), the exhaust fan, and the external termination. AS 1851 requires the cleaning of the entire system — not just the filters, which require separate weekly maintenance.
2. Why AS 1851 Matters — Fire Risk and Insurance
Non-compliance with AS 1851 voids the building's fire insurance. An insurance policy for a commercial building with a commercial kitchen is written on the assumption that the kitchen exhaust system is being maintained in accordance with AS 1851. If a fire occurs and the insurer's investigation reveals the exhaust system was not serviced at the required AS 1851 frequency, the insurer can deny the claim — including for fire damage caused by an unrelated ignition source if the non-compliant exhaust system contributed to fire spread. This is not a theoretical risk: it has been the basis for insurance claim denials in Australian commercial kitchen fires.
How Grease Accumulation Creates Fire Risk
Commercial kitchen cooking — particularly charcoal grilling, wok cooking, and deep frying — generates grease-laden vapour that rises with the hot air column above the cooking equipment. The exhaust system captures this vapour and draws it through the filters, ductwork, and fan to the termination point. The grease in the vapour condenses on the interior surfaces of the duct and fan as it cools.
Over time, this condensed grease accumulates as a semi-solid layer on duct walls, fan blades, and exhaust hood interior surfaces. The rate of accumulation depends directly on cooking type and volume — a high-volume charcoal grill restaurant can deposit a 6–12mm grease layer in a duct within 3 months; a low-volume cafe with an electric cooktop may take 12 months to deposit the same accumulation.
When a cooking equipment malfunction, grease fire, or flare-up occurs, the radiant heat and flame can ignite the accumulated grease on the lower section of the duct. Once ignited, the burning grease provides fuel for the fire to travel upward through the duct — which functions as a chimney — carrying fire into the roof space and building structure. The temperature inside a duct fire can exceed 1,000°C, causing structural steel to fail and building materials to ignite well beyond the immediate vicinity of the kitchen.
AS 1851 cleaning removes the accumulated grease before it reaches the depth at which it constitutes a fire risk — preventing the duct fire scenario entirely rather than relying on suppression systems to control one after it has started.
3. Cooking Type Classification and Cleaning Frequency
AS 1851-2012 Section 17 classifies commercial kitchens into three categories based on cooking type and establishes the minimum exhaust cleaning frequency for each. The classification is determined by the primary cooking method — the cooking that generates the highest grease load in the exhaust system.
Classification rule: The cooking type is determined by the highest-grease-load equipment in the kitchen — not the average or most common cooking method. A restaurant that primarily uses gas ovens but also has a single chargrill must be classified as heavy cooking and cleaned quarterly. If the chargrill is removed, the classification can be reviewed and the frequency extended.
| Venue Type | Typical Classification | Required Frequency | Rationale |
|---|---|---|---|
| Charcoal chicken restaurant | Heavy | Every 3 months | Charcoal rotisserie generates extreme grease and carbon accumulation |
| Chinese restaurant (wok cooking) | Heavy | Every 3 months | High-temperature wok cooking with oil creates very high grease vapour load |
| Steakhouse / chargrill restaurant | Heavy | Every 3 months | Direct-flame chargrill generates grease and particulate accumulation |
| Indian restaurant (tandoor) | Heavy | Every 3 months | Tandoor oven generates intense heat and grease accumulation |
| Standard full-service restaurant | Moderate | Every 6 months | Gas range, ovens, and fryers without charcoal or wok equipment |
| Pizza restaurant (wood-fired oven) | Heavy to Moderate | Every 3–6 months | Wood-fired ovens generate significant particulate; assess individually |
| Pub / bistro kitchen | Moderate | Every 6 months | Standard commercial kitchen without high-grease-load primary cooking |
| Cafe with full kitchen (gas) | Moderate to Light | Every 6–12 months | Lower volume and standard cooking methods; assess by actual equipment |
| Cafe / espresso bar (minimal cooking) | Light | Every 12 months | Minimal cooking; grease accumulation very low |
| Food court tenancy (standard cooking) | Moderate | Every 6 months | Standard commercial cooking at food court volume |
4. What a Compliant AS 1851 Clean Covers
A compliant AS 1851 exhaust clean is significantly more involved than a rangehood filter clean or a standard kitchen clean. AS 1851 requires cleaning of the entire exhaust system — from the exhaust hood interior to the termination point at the roof or wall. Filter replacement or cleaning alone does not satisfy AS 1851 requirements.
| Component | What Is Done | AS 1851 Requirement |
|---|---|---|
| Exhaust hood interior | Full degreasing of all interior surfaces, baffles, and plenum chamber. Commercial alkaline degreaser applied; dwell time observed; mechanical scrub; rinse. | Required — hood interior accumulates primary grease condensation |
| Grease filters | Removed; immersed in commercial degreaser bath; scrubbed; rinsed; reinstalled. Damaged filters replaced. | Required — filters are inspected for damage and condition at each AS 1851 service |
| Grease collection trays and cups | Removed; fully cleaned; emptied of collected grease; reinstalled. | Required — grease collection points cleaned and confirmed functional |
| Exhaust duct interior — accessible sections | Access panels opened; interior surfaces degreased with commercial alkaline product; mechanical scrub of accessible duct sections; inspection of inaccessible sections via camera where required. | Required — duct interior cleaning is the core purpose of AS 1851 |
| Exhaust duct — full length | Chemical application to full duct length where direct access is not possible; fogging degreaser applied through access points; grease allowed to flow to collection point. | Required — full duct length must be addressed, not just accessible sections |
| Exhaust fan and fan housing | Fan blades degreased (fan interior); fan housing cleaned; fan belt and bearings inspected; impeller balance confirmed. | Required — fan grease accumulation reduces airflow and creates fire risk at the fan motor |
| Duct exterior (where accessible) | Exterior surfaces degreased where grease seepage has occurred through joints or access panel seals. | Required where external grease staining indicates duct joint or seal failure |
| Before and after photos | Photographic record of duct interior condition before and after cleaning. | Required — compliance certificate must be supported by photographic evidence of before/after condition |
The following do not satisfy AS 1851 requirements: Weekly rangehood filter cleaning alone; standard kitchen deep clean that includes rangehood filter service; "exhaust cleaning" that covers only the exhaust hood without the duct interior; any service that does not include the full duct length from hood to termination; and any service that does not produce a written compliance certificate from a qualified contractor. A certificate of service from an unqualified contractor does not constitute AS 1851 compliance.
5. The Compliance Certificate — What It Must Show
After every AS 1851 exhaust cleaning service, the contractor must issue a written compliance certificate. This certificate is the legal evidence that the exhaust system has been serviced in accordance with AS 1851-2012. The certificate must be retained on site and produced on request during a fire safety inspection by the MFB or during an insurance assessment.
| Certificate Element | What It Must Show |
|---|---|
| Contractor details | Name of the company; ABN; relevant certifications (contractor must hold appropriate fire safety qualifications); contact details |
| Premises details | Business name; address of the food premises; description of the exhaust system serviced (location, size, number of hoods) |
| Service date | Date the cleaning was performed; must correspond with the required AS 1851 interval from the previous certificate |
| Cooking type classification | The AS 1851 classification applied (Heavy / Moderate / Light) and the equipment that determined the classification |
| Scope of work completed | List of components cleaned — hood interior, filters, grease trays, duct sections, fan, termination — confirming all AS 1851 required components were addressed |
| Condition assessment | Duct grease depth reading before and after cleaning; condition of filters, seals, and access panels; any deficiencies identified that require rectification |
| Photographic evidence | Before and after photographs of duct interior condition confirming cleaning was completed to AS 1851 standard |
| Next service due date | The date by which the next AS 1851 service must be completed based on the cooking type classification |
| Contractor declaration | Signed declaration by the qualified contractor that the service was completed in accordance with AS 1851-2012 |
6. Enforcement — MFB, CFA, and Insurers in Victoria
AS 1851 exhaust cleaning compliance in Victoria is enforced through two pathways: fire authority inspection and insurance assessment.
Metropolitan Fire Brigade (MFB) and Country Fire Authority (CFA)
The MFB (Metropolitan Fire Brigade) enforces fire safety compliance in Melbourne's urban area; the CFA (Country Fire Authority) enforces compliance in regional and outer metropolitan Victoria. Both authorities have the power to inspect food premises for fire safety compliance under the Building Act 1993 (VIC) and the Building Regulations 2018 (VIC), which adopt AS 1851 as the maintenance standard for fire protection systems.
An MFB or CFA inspection that finds an overdue AS 1851 exhaust service results in a fire safety notice requiring immediate rectification. Continued non-compliance can result in the premises being prohibited from operating until the AS 1851 service is completed and a valid certificate is obtained. Fire safety notices are also associated with the premises' building permit record, which can affect the operator's ability to transfer or renew the food premises registration.
Insurance Assessment
Building and contents insurers for commercial premises with kitchen operations require AS 1851 compliance as a condition of the policy. This condition is typically specified in the policy schedule or product disclosure statement — often under fire protection maintenance obligations. In the event of a fire, the insurer's assessor will review the AS 1851 service records for the kitchen exhaust system. If the records demonstrate non-compliance (service overdue, certificate missing, or certificate not from a qualified contractor), the insurer can deny or substantially reduce the claim on the basis that the operator failed to maintain the premises in accordance with the policy conditions.
Critically, an insurer can deny a claim for fire damage caused by an unrelated source if the non-compliant exhaust system contributed to the fire's spread — even if the exhaust system itself was not the ignition source. The argument is that a compliant, clean exhaust system would not have allowed the fire to spread via the duct, making the operator's non-compliance a contributing cause of the extent of the damage.
7. How to Choose a Qualified AS 1851 Contractor
Not every kitchen cleaning company can perform a compliant AS 1851 exhaust service. The contractor must have specific qualifications, equipment, and documentation capability. Use these criteria when evaluating AS 1851 contractors for your Melbourne food premises.
| Evaluation Criterion | What to Confirm | Why It Matters |
|---|---|---|
| Relevant fire safety qualifications | Contractor holds current fire safety servicing qualifications appropriate for AS 1851 work; confirm their specific qualification category covers kitchen exhaust systems | An unqualified contractor's certificate does not constitute AS 1851 compliance — the insurer will verify contractor qualification in the event of a claim |
| Duct access and full-length cleaning capability | Contractor can access and clean the full duct length — not just the accessible hood sections. Confirm they have access panel installation capability if the duct lacks access panels. | AS 1851 requires the full duct interior to be cleaned; partial cleaning (hood only) does not satisfy the standard |
| Camera inspection capability | Contractor uses camera inspection for duct sections that cannot be reached by direct manual access | Compliance with the full-duct requirement requires verification of inaccessible sections |
| Certificate format and content | Contractor produces a written certificate that includes all required elements (see Section 5) including before/after photographs | An incomplete certificate is not acceptable evidence of AS 1851 compliance in an insurance or MFB assessment |
| Public liability insurance | Contractor holds current public liability insurance appropriate for the work scope — minimum $10M for standard commercial kitchen work | AS 1851 work involves entry into ductwork and roof spaces; adequate insurance is required |
| Melbourne references | Contractor can provide references from comparable Melbourne restaurant clients with similar cooking classification | Cooking classification experience matters — a contractor experienced in light-cooking cafe exhaust may not have the equipment or methodology for a heavy-cooking wok restaurant |
8. How to Set Up an AS 1851 Compliance Program for Your Melbourne Restaurant
Classify your cooking type
Identify the primary cooking equipment generating the highest grease load in your exhaust system. If you have a chargrill, charcoal oven, or wok range — even as secondary equipment — your classification is Heavy and your frequency is every 3 months. Gas range and standard commercial kitchen without high-grease-load equipment is Moderate (every 6 months). Electric cooktop and minimal cooking is Light (every 12 months).
Locate your previous AS 1851 certificate
If you have taken over an existing food premises, the previous operator should have AS 1851 service records. The certificate will show the last service date and the next due date. If no records exist, engage a qualified contractor for an initial assessment — they will inspect the duct condition, advise on accumulated grease depth, and provide a compliant initial clean and certificate.
Engage a qualified AS 1851 contractor
Select a contractor meeting the criteria in Section 7. Confirm their qualification category covers kitchen exhaust systems, confirm they can access and clean your full duct length, and confirm their certificate format meets AS 1851 documentation requirements before engagement.
Schedule the service program
Book the AS 1851 service in advance — 4 weeks before the due date is recommended to allow scheduling flexibility. Heavy-cooking restaurants (quarterly) should have all four annual service dates booked at the start of each year. Moderate (bi-annual) restaurants book two dates; Light (annual) restaurants book one.
Maintain rangehood filters weekly between AS 1851 services
Weekly rangehood filter removal, soaking in commercial degreaser, rinsing, and reinstallation is required between AS 1851 services. This does not substitute for AS 1851 but reduces the grease accumulation rate in the duct, keeping the system operating at full airflow efficiency and reducing the volume of grease the AS 1851 contractor needs to remove at each quarterly or bi-annual service. Golden Star's weekly kitchen deep clean includes rangehood filter service as standard.
File and retain all certificates on site
File every AS 1851 compliance certificate on-site immediately after receipt. Retain certificates for a minimum of 3 years (insurers may request historical records). Store digitally as well as physically — a digital backup ensures the certificate is available even if the physical copy is lost in a fire or renovation. Present certificates to the MFB or insurer immediately if requested.
Need AS 1851 exhaust cleaning coordinated for your Melbourne restaurant?
Golden Star coordinates AS 1851 qualified contractors for all Melbourne food business clients — scheduling, compliance certificates, and integration with your regular kitchen cleaning program.
9. FAQ — AS 1851 Exhaust Cleaning for Melbourne Restaurants
AS 1851-2012 is the Australian Standard for Routine Service of Fire Protection Systems and Equipment. Section 17 specifically applies to commercial kitchen exhaust systems and requires cleaning at intervals determined by cooking type. AS 1851 applies to any Melbourne food premises with a commercial exhaust system over a cooking appliance — restaurants, cafes, food courts, commercial kitchens, canteens, and any venue with a rangehood over a commercial cooking appliance. Light-cooking cafes with electric cooktops and minimal cooking volume are classified Light (annual cleaning). Full-service restaurants with gas ranges are Moderate (every 6 months). Charcoal, wok, or deep-fry dominant kitchens are Heavy (every 3 months).
No. Weekly rangehood filter cleaning is an important maintenance task that reduces duct grease accumulation rate, but it does not satisfy AS 1851 in any way. AS 1851 requires cleaning of the full exhaust system — hood interior, grease filters, grease collection trays, duct interior from hood to termination, exhaust fan, and fan housing — by a qualified contractor who issues a written compliance certificate. A filter-only service, however frequent, does not constitute an AS 1851 service and does not produce a compliance certificate.
Non-compliance with AS 1851 creates three categories of risk: fire safety enforcement (MFB or CFA fire safety notice requiring immediate rectification; potential prohibition from operating until resolved); insurance exposure (fire insurance policy conditions typically require AS 1851 compliance — non-compliance can void or reduce coverage and allow the insurer to deny a fire claim); and personal liability (if a fire occurs in a non-compliant premises, the operator may face personal liability for the resulting damage, injuries, and losses where negligence is established). The combination of these risks makes AS 1851 non-compliance one of the most serious compliance failures a Melbourne restaurant operator can have.
AS 1851 exhaust cleaning in Melbourne typically costs $400–$900 per service for a standard single-kitchen restaurant, depending on duct length, cooking classification, and access difficulty. Heavy-cooking restaurants with long or complex duct runs (charcoal chicken shops, multi-floor venues) can cost $800–$2,000 per service. The cost should be viewed in context: a quarterly AS 1851 service at $600 costs $2,400 per year — which is a fraction of the cost of a single fire insurance claim denial or a fit-out replacement after a duct fire.
Classification is determined by the highest-grease-load cooking equipment in your kitchen. If you have a chargrill, charcoal oven, wok range, tandoor, or solid-fuel cooker — even as a single piece of equipment among others — your classification is Heavy (quarterly). If your kitchen runs on gas ranges, commercial ovens, flat-top grills, and standard fryers without charcoal or wok equipment, you are likely Moderate (every 6 months). If you run electric cooktops with minimal cooking volume, you may be Light (annual). When in doubt, a qualified AS 1851 contractor will assess your specific equipment and confirm the classification in writing as part of the initial service.
No. AS 1851 requires the cleaning to be performed by a qualified contractor and documented with a compliance certificate. A self-performed clean — regardless of how thorough — does not satisfy AS 1851 because it cannot produce a valid compliance certificate from a qualified contractor. The certificate is the legal evidence of compliance that insurers and the MFB require. An undocumented or self-documented clean produces no legally acceptable evidence of compliance and provides no insurance protection.
Engage a qualified AS 1851 contractor immediately for an initial assessment and service. The contractor will inspect the duct interior condition, assess grease accumulation depth, perform the initial compliant clean, and issue a certificate that starts your compliance record from that point. Do not operate the commercial kitchen for an extended period without AS 1851 records — every day of operation without records is a day of uninsured fire risk. The initial service establishes your compliance baseline and confirms the correct classification and frequency for your cooking equipment.
Golden Star Retail Cleaning coordinates AS 1851 qualified exhaust cleaning contractors for all Melbourne food business clients — scheduling the service, ensuring the contractor meets the qualification and certificate requirements, and integrating the AS 1851 program with the regular kitchen cleaning schedule. The weekly rangehood filter service (removal, degreaser soak, rinse, reinstall) is included as standard in all Golden Star restaurant kitchen deep clean programs — this reduces duct accumulation rate between AS 1851 services. Call 0484 042 336 to discuss your AS 1851 program requirements.
Related guides: Complete Restaurant Cleaning Guide · Food Safety Cleaning Standards Australia · How Often Should a Restaurant Be Cleaned? · Kitchen Equipment Cleaning Services · All Cleaning Guides