Classification Of Flammable And Combustible Liquids

The globally harmonised system of classification and labelling of chemicals (GHS) defines a flammable liquid as a liquid having a flash point of not more than 93oC. A flammable liquid is classified in one of four categories for this class according to the following table:

GHS category Criteria
1 Flash point < 23°C and initial boiling point < 35°C
2 Flash point < 23°C and initial boiling point >35°C
3 Flash point > 23°C and < 60°C
4 Flash point > 60°C and < 93°C

For flammable liquid classifications, GHS categories 1-3 are equivalent to the ADG code packing group I-III. A change is that GHS has introduced category 4 which overlaps with the C1 combustible liquids as defined in AS1940.

An example of flammable liquid category 4 is diesel. Thus, the use, storage and handling of diesel is subject to the requirements of the Work Health and Safety Regulation 2011 (WHS Regulation) as a hazardous chemical (Part 7.1). While combustible liquids having a flash point >93°C are not classified as hazardous chemicals and therefore not subject to Part 7.1, they are addressed by the general provisions in terms of hazard identification and management of associated risks, storage of combustible substances (r53), and contribution to fire loads (r359).

The GHS classifications are now included in Schedule 11 where the prescribed quantities are listed for placarding and manifest thresholds. However, the manifest and placards must reflect the ADG code information as described in Schedule 12 and 13, respectively.


Hazardous chemical GHS flammable liquid category Equivalent ADG/AS1940 classification
Carbon disulphide 1 Class 3 PG I
Diethyl ether 1 Class 3 PG I
Isopropylamine 1 Class 3 PG I
Acetone 2 Class 3 PG II
Acetonitrile 2 Class 3 PG II
Ethanol 2 Class 3 PG II
Isopropyl alcohol 2 Class 3 PG II
Methanol 2 Class 3 PG II
Petrol 2 Class 3 PG II
Vinyl acetate 2 Class 3 PG II
Jet Fuel/Jet A1 3 Class 3 PG III
Kerosene 3 Class 3 PG III
Xylene 3 Class 3 PG III
Diesel fuel 4 C1
Fuel oil (Flash point <93°C) 4 C1
Lube oil (Flash point exceeds 150°C) - C2

Safety Duties

Persons conducting a business or undertaking (PCBUs) have specific duties to store and handle their hazardous chemicals (including flammable liquids and certain combustible liquids) as follows:

  • prepare, maintain and implement emergency planning (sections 43 and 361)
  • provide personal protective equipment such as organic vapour respirators (section 44)
  • manage risks from airborne contaminants such as vapours from flammable solvents (section 49-50)
  • manage risks from hazardous atmospheres for example, where concentration of flammable vapour exceeds five per cent of the lower explosive limit (section 51)
  • manage fire and explosion risks (sections 52 and 355)
  • keep the amount of flammable and combustible substances at the lowest practicable quantity (section 53)
  • label pipework (section 343)
  • if manifest threshold quantities of hazardous chemicals are involved, provide a manifest and site plan (PDF, 689 kB) (section 347) and notify WHSQ of this circumstance (section 348)
  • ensure storage areas are appropriately placarded (PDF, 423 kB) (sections 349-350) and safety signage erected (PDF, 103 kB) (section 353)
  • contain and manage leaks and spills (section 357)
  • protect containers (e.g., tanks and vessels), associated pipework and attachments from damage (section 358)
  • provide appropriately designed and built fire protection systems (section 359)
  • control risks associated with storage and handling systems such as drums, intermediate bulk containers (IBCs), tanks, vessels, processing equipment and associated equipment (section 363).

Abolition Of Licensing

The repeal of the Dangerous Goods Safety Management Act 2001 has resulted in the abolition of the flammable and combustible liquids (FCL) licences administered by local governments. A licence to store flammable and combustible liquids is no longer required under the WHS Regulation.


Various notifications for hazardous chemicals are required under the WHS Regulation which are relevant to the use, storage and handling of flammable and combustible liquids including for:

  • exceeding the prescribed manifest quantity
  • exceeding 10 per cent of the schedule 15 (MHF) prescribed quantity
  • abandoned underground tanks
  • pipelines used to convey schedule 11 hazardous chemicals
  • authorisation to use, handle or store prohibited or restricted hazardous chemicals or carcinogens.

Service Stations

Service stations are a likely place that a member of the public comes into contact with flammable and combustible liquids on a regular basis. Further information on service stations shows how operators can manage their hazardous chemical risks.

Further information

Further information on controlling risks associated with flammable and combustible liquids under the Work Health and Safety Act 2011 is available in the Managing risks of hazardous chemicals in the workplace published by Safe Work Australia.

The fire and explosion risks page provides an overview of relevant risk controls including managing hazardous areas and hot work activities and controlling ignition sources.

Specific guidance on the safe storage and handling of flammable and combustible liquids is available in the Australian Standard, AS1940: The storage and handling of flammable and combustible liquids. This standard covers the following topics:

  • precautions for minor storage (e.g. typically less than 250 litres)
  • general design and construction requirements for storage areas
  • package storage and handling areas
  • storage in tanks
  • systems for piping, valves, pumps and tank heating
  • fuel dispensing
  • tank vehicle loading facilities
  • operational and personnel safety
  • emergency management
  • fire protection
  • recommendations for design and construction of blending plants and batch-blending
  • use of non-flameproof forklifts and vehicles
  • issues to be considered in a risk assessment
  • gas-freeing precautions.

Other Australian standards are also available covering a range of related topics including:

  • AS/NZS 60079.10.1: Explosive atmospheres - Classification of areas - Explosive gas atmospheres
  • AS/NZS 60079: Electrical apparatus for explosive gas atmospheres (all parts)
  • AS4897: The design, installation and operation of underground petroleum storage systems
  • AS1020: The control of undesirable static electricity
  • AS1692: Steel tanks for flammable and combustible liquids
  • AS2507: The storage and handling of agricultural and veterinary chemicals
  • AS4745: Code of practice for handling combustible dusts
  • AS4979: Flammable and combustible liquids - Precautions against electrostatic ignition during tank vehicle loading
  • AS1674.1: Safety in welding and allied processes - Fire precautions in relation to welding.
  • Specific information on specialised topics such as design and construction of large welded storage tanks or process plant may be available from industry associations.