What Is a Wet Chemical Fire Extinguisher Used For?
The wet chemical (AF type) extinguisher works by discharging a fine mist of potassium-based solution over the burning oil. This cools the oil rapidly and creates a soapy layer on the surface, smothering the fire and preventing re-ignition. It is rated for Class A fires (ordinary combustibles) and Class F fires (cooking oils and fats). Key applications include:
- Commercial kitchens and restaurant cooking lines
- Cafés and takeaway shops with deep fryers or woks
- Hotel and function venue kitchens
- School and aged care facility kitchens
- Food manufacturing and catering operations
WHAT IS WET CHEMICAL FIRE EXTINGUISHER?
Wet chemical fire extinguishers, identified by their oatmeal (light beige) band, contain a potassium-based solution specifically designed to combat cooking oil and fat fires. Under Australian Standards and the Building Code of Australia (BCA), wet chemical extinguishers are the recommended solution for commercial cooking environments where cooking oils and fats are used.
In addition to Class F fires, they can also be used on Class A fires involving ordinary combustible materials such as paper, wood, and textiles. Cafés and restaurants where large quantities of cooking oil are used should be protected by wet chemical fire extinguishers.
These extinguishers typically come in two sizes: 2-litre and 7-litre units. Our team can help determine the most suitable size and placement for your café or restaurant to ensure compliance and maximum safety.
Do Commercial Kitchens Need a Wet Chemical Extinguisher in NSW?
Yes. Under AS 2444 and the NSW fire safety framework, commercial cooking environments with oil or fat fire risks are required to have a Class F-rated extinguisher – which means a wet chemical type. A general-purpose ABE dry powder extinguisher does not satisfy this requirement. Failure to have the correct extinguisher type in a commercial kitchen can result in insurance implications, compliance notices, and significant fire risk to staff and property.
Wet Chemical vs Dry Powder Extinguisher
For kitchens with cooking oil risks, wet chemical is the mandatory and correct choice. Dry powder (ABE) extinguishers are not safe for use on Class F cooking oil fires – the fine powder can cause violent flame spread when applied to a burning oil surface. Always ensure your kitchen has a correctly rated and regularly serviced wet chemical extinguisher in addition to any general-purpose ABE units in adjacent areas.
Supply, Install & Service in Sydney & NSW
SPS supplies and installs wet chemical fire extinguishers for commercial kitchens and hospitality venues across Sydney and NSW. We assess your cooking equipment layout, determine the correct extinguisher size and placement, and provide full certification documentation to support your fire safety compliance obligations. Contact us for a commercial kitchen fire safety equipment quote in Sydney or NSW.
F CLASS APPLICABLE
COOKING OILS & FATS
- — Vegetable & animal oils
- — Commercial fryers
- — Woks & deep fat fryers
- — Overheated cooking oil
NEVER USE WATER OR CO2 ON COOKING OIL FIRES
Applying water to a burning oil fire causes an explosive steam reaction, dramatically escalating the fire. Only a wet chemical extinguisher should be used on Class F fires. This is a critical safety requirement in all commercial kitchen environments.
How It Works
When discharged, the wet chemical agent reacts with the hot oil in a process known as saponification. This creates a soapy foam layer that:
Forms a seal over the surface of the oil
Cools the burning fuel
Prevents oxygen from feeding the fire
Minimises the risk of re-ignition
NCC / BCA Requirements
Under the NCC, buildings that contain commercial cooking equipment involving deep frying or heating of oils must be provided with appropriate protection against Class F fire risks. This includes:
- Installation of suitable portable extinguishers
- Correct sizing and rating
- Appropriate placement within required travel distances
- Protection aligned with the specific kitchen hazard level
Typical Applications
Restaurants
Cafes
Commercial kitchens
Food courts
Catering facilities
Industrial food processing areas
Wet chemical extinguishers are considered the most effective portable solution for heated cooking oil fires and are essential wherever deep frying operations are present.
Fire Extinguisher Installation
Our installation is compliant to AS 2444. The extinguishers we supply are also compliant to Australian Standards.
The units itself must also comply with their own specific requirement. During installation, consideration should be made to ensure that the types, sizes, classification and distribution of extinguishers is made correctly so that the compliance for the particular occupancy is achieved.
Please refer to table below to get the complete understanding of difference classes of fire and fire extinguishers.
Types Of Fire Extinguisher We Supply
| Types | Class A Fire | Class B Fire | Class C Fire | Class E Fire | Class F Fire |
| Wood, Paper, Plastic | Flammable and combustible liquids | Flammable gases | Electrically energized equipment | Cooking oils & fats | |
| Water | Yes | No | No | No | No |
| Foam | Yes | Yes | No | No | No |
| Powder (ABE) | Yes | Yes | Yes | Yes | No |
| CO₂ | Limited | Limited | Limited | Yes | Limited |
| Wet Chemical | Yes | No | No | No | Yes |
Different types of extinguishers and how they put out fire
For a fire to occur, it will require the following three components, it is also called a fire triangle.
- FUEL: example wood, paper, textile, inflammable etc.
- HEAT: constant source of heat to keep the fire going.
- OXYGEN: constant source of oxygen to help fire keep going.
If any of the above three is discontinued, the fire will be extinguished. Fire extinguishers were designed based on this science.
- The CO2 fire extinguisher – or carbon dioxide fire extinguisher – is the go-to solution for protecting electrical equipment, server rooms, data centres, and any environment where residue-free suppression is critical. Available in 2kg, 3.5kg, and 5kg sizes, all approved to AS/NZS 1841.6, SPS supplies and installs CO2 extinguishers across Sydney and NSW with fast turnaround and full compliance documentation.
- The ABE dry powder fire extinguisher is Australia’s most versatile portable extinguisher, covering Class A, B, and E fires in a single unit. Whether you’re outfitting a warehouse, workshop, office, or industrial facility, the DCP fire extinguisher is the practical, multi-risk solution. SPS Fire & Safety supplies, installs, and services the full range of ABE dry chemical extinguishers – from compact 2kg units through to 9kg models – across Sydney and NSW to AS/NZS 1841.5.
- The wet chemical fire extinguisher – also known as the AF type fire extinguisher – is specifically engineered for Class F fires involving cooking oils and fats. It is a mandatory fire safety requirement in most commercial kitchens, restaurants, and food preparation environments across NSW. SPS Fire & Safety supplies, installs, and services wet chemical extinguishers for hospitality and food service businesses across Sydney and NSW, ensuring full compliance with Australian Standards and local fire safety regulations.
- The water fire extinguisher is the simplest and most cost-effective solution for Class A fires involving solid combustible materials such as wood, paper, fabric, and plastic. Suitable for offices, schools, warehouses, and low-risk commercial environments, the water extinguisher is a reliable first-response tool where flammable liquids and electrical equipment are not present. SPS Fire & Safety supplies and installs water fire extinguishers for businesses across Sydney and NSW to Australian Standards.
- Foam fire extinguishers are designed for Class A and Class B fires, making them ideal for environments where both solid combustibles and flammable liquids present a risk. The AFFF (aqueous film forming foam) extinguisher works by forming a blanket over the burning surface, cutting off oxygen and cooling the fuel. SPS Fire & Safety supplies and installs foam extinguishers – including PFAS-free and fluorine-free options – for industrial, commercial, and warehouse environments across Sydney and NSW.
- Evacuation diagrams are a legal requirement in Australian workplaces and buildings under AS 3745 (Planning for Emergencies in Facilities) and the Work Health and Safety Regulations. SPS Fire & Safety produces professional, site-specific evacuation diagrams for commercial buildings, offices, strata complexes, schools, and industrial facilities across Sydney and NSW. Our diagrams are compliant, easy to read, durable, and ready for display throughout your premises.
- A FIP zone block plan is a mandatory graphical document required at or adjacent to every Fire Indicator Panel (FIP), Sub-FIP, and Mimic Panel in a building’s fire alarm system. Under AS 1670.1, each zone block plan must clearly show the fire detection zones and their correspondence to the physical layout of the building, enabling fire brigade and facility personnel to rapidly locate the source of any alarm. SPS Fire & Safety produces compliant, professionally formatted FIP zone block plans for buildings across Sydney and NSW.
- The Fire Indicator Panel (FIP) is the central intelligence hub of a building’s fire detection and alarm system. It receives input from smoke detectors, heat detectors, manual call points, and other sensing devices, and activates audible and visual alarms, emergency warning systems, and brigade notification when a fire is detected. SPS Fire & Safety supplies, installs, tests, and maintains fire indicator panels and EWIS systems for commercial, residential, and industrial buildings across Sydney and NSW to AS 1670.