An overview of the AS 1940-2017 capacity and separation rules for storing flammable and combustible liquids.
Flammable vs combustible
The Australian Dangerous Goods Code distinguishes between flammable and combustible liquids based on their flash point and boiling point:
- Flammable: liquids with a flash point below 60°C.
- Combustible: liquids with a flash point between 60°C and 93°C.
Rules on handling, storage, and transport vary by class.
The basics
600mm between horizontal tanks
Horizontal tanks must have at least 600mm between each other when installed together.
AS 1940-2017 5.7.5 and 5.7.6
1 metre between vertical tanks
Vertical tanks must have at least 1 metre between each other when installed together.
AS 1940-2017 5.7.5 and 5.7.6
Tanks inside buildings: 1,000 L maximum
Tanks for combustible C1 liquids can be installed inside a building provided they are not more than 1,000 L, are not interconnected, and there is provision to contain small leaks and spills.
AS 1940-2017 5.6.3.1
No polyethylene tanks on construction sites
Polyethylene and composite storage tanks are not allowed on construction sites. Tanks on such sites must be 1 metre away from any boundary, protected place, or environmentally sensitive area.
AS 1940-2017 2.2.6
3 metres from ignition sources
A minimum of 3 metres is required between a flammable self-bunded tank and any ignition source, including the vehicle being refilled.
AS 1940-2017 5.9.2 (g)
Minor storage exemptions
Storage of flammable or combustible liquids in quantities not exceeding the amounts below may be classified as minor storage and is exempt from the other sections of AS 1940. Multiple minor storages in an allowable area must be separated by at least 20 metres indoors or 15 metres outdoors.
AS 1940-2017 2.1 and 2.2.3
Class 3 PG II (Petrol)
| Location | Limit |
|---|---|
| Indoors: factories / warehouses / workshops | 1 L per 2 m², not exceeding 250 L in 500 m² |
| Indoors: commercial buildings | 10 L per 50 m² |
| Outdoors: commercial buildings with 1 m separation | 250 L |
| Construction sites | 2,500 L |
| Open land | 5,000 L |
AS 1940-2017 2.2.4 and 2.2.5, Table 2.1
Class 3 PG III (Jet Fuel / Kerosene)
| Location | Limit |
|---|---|
| Indoors: factories / warehouses / workshops | 1 L per 2 m², not exceeding 500 L in 500 m² |
| Indoors: commercial buildings | 25 L per 50 m² |
| Outdoors: commercial buildings with 1 m separation | 1,400 L in tanks not over 700 L each |
| Construction sites | 5,000 L |
| Open land | 5,000 L |
AS 1940-2017 2.2.4 and 2.2.5, Table 2.1
Class C1 & C2 (Diesel / Lube Oil)
| Location | Limit |
|---|---|
| Indoors: factories / warehouses / workshops | 4 L per m², not exceeding 2,000 L in 500 m² |
| Indoors: commercial buildings | 500 L per 500 m² |
| Outdoors: commercial buildings with 1 m separation | 5,000 L |
| Construction sites | 10,000 L |
| Open land | 10,000 L |
AS 1940-2017 2.2.4 and 2.2.5, Table 2.1
Separation distances
Distance to a boundary or security fence
- Flammable Class 3 (Petrol / Kerosene): width or diameter of the tank, or 15 m (whichever is less), but not less than 6 m or the distance based on capacity below.
- Combustible Class C1 (Diesel): width or diameter of the tank, or 7.5 m, but at least 3 m, whichever is lesser.
- Combustible Class C2 (Lube Oil): unrestricted, determined by the compound.
AS 1940-2017 5.7.2, Table 5.3
Distance from off-site protected places: Class 3 PG I & II (Petrol)
| Max capacity | Minimum distance | Tank options |
|---|---|---|
| 250 L | Unrestricted | BOX-0.25 |
| 1,000 L | 3 m | BOX-1.1 |
| 2,000 L | 4 m | BOX-2.25 |
| 4,000 L | 5 m | BOX-4.5 |
| 7,000 L | 6 m | BOX-6.6 |
| 10,000 L | 7 m | BOX-11 / STORE-11 |
| 14,000 L | 8 m | CON-12 |
| 20,000 L | 9 m | CON-18 / STORE-16 |
| 26,000 L | 10 m | CON-30 |
| 34,000 L | 11 m | CON-38 |
| 42,000 L | 12 m | CON-38 |
| 64,000 L | 14 m | CON-69 |
| 77,000 L | 15 m | CON-75 |
AS 1940-2017 5.7.2, Table 5.4
Distance from off-site protected places: Class 3 PG III (Jet Fuel)
| Max capacity | Minimum distance | Tank options |
|---|---|---|
| 500 L | Unrestricted | BOX-0.25 |
| 4,000 L | 3 m | BOX-4.5 |
| 8,000 L | 4 m | BOX-8.8 |
| 16,000 L | 5 m | STORE-16 |
| 28,000 L | 6 m | CON-30 / STORE-22 |
| 40,000 L | 7 m | CON-38 |
| 56,000 L | 8 m | CON-38 |
| 80,000 L | 9 m | CON-69 / 75 / 80 |
| 104,000 L | 10 m | CON-110 |
| 136,000 L | 11 m | CON-110 |
AS 1940-2017 5.7.2, Table 5.4
Distance from off-site protected places: Class C1 (Diesel)
| Max capacity | Minimum distance | Tank options |
|---|---|---|
| 2,500 L | Unrestricted | BOX-2.25 / STORE-2.5 |
| 10,000 L | 3 m | BOX-11 / STORE-11 |
| 20,000 L | 4 m | CON-18 / STORE-22 |
| 40,000 L | 5 m | CON-30 / 38 |
| 70,000 L | 6 m | CON-69 / 75 |
| 100,000 L | 7 m | CON-80 / 90 / 110 |
AS 1940-2017 5.7.2, Table 5.4
Distance from off-site protected places: Class C2 (Lube Oil)
| Max capacity | Minimum distance | Tank options |
|---|---|---|
| 5,000 L | Unrestricted | BOX-5.5 / STORE-5.5 |
| 20,000 L | 3 m | CON-18 / STORE-22 |
| 40,000 L | 4 m | CON-30 / 38 |
| 80,000 L | 5 m | CON-69 / 75 / 80 |
| 140,000 L | 6 m | CON-90 / 110 |
AS 1940-2017 5.7.2, Table 5.4
Distance to on-site protected places
On-site protected places include office buildings, warehouses, manufacturing and processing areas, workshops, or amenities blocks within the same premises or boundary as the storage tank.
- Flammable Class 3 (Petrol / Kerosene): required distance based on capacity above, but need not exceed 15 m.
- Combustible Class C1 (Diesel): required distance based on capacity above, but need not exceed 7.5 m.
- Combustible Class C2 (Lube Oil): unrestricted, determined by the compound.
AS 1940-2017 5.7.2, Table 5.3
Clustering of tanks
Vertical tanks
- Width or diameter: tanks with width or diameter greater than 3 m but not more than 10 m can be clustered with reduced tank-to-tank spacing.
- Reduced distance: at least 1 metre between two tanks.
- Cluster area: total cross-sectional area of all tanks must not exceed 320 m².
AS 1940-2017 5.7.5
Horizontal tanks
- Compliance: horizontal tanks must comply with AS 1692 and AS 1940.
- Reduced distance: at least 600 mm between two horizontal tanks.
- Clustering with vertical tanks: distance from an adjacent vertical tank must be at least 1 metre.
- Placement: tanks may be arranged parallel but not end-to-end unless the potential end-failure and exposure hazard has been considered.
AS 1940-2017 5.7.6
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This guide summarises selected requirements from AS 1940-2017. Always consult the current Standard and your local regulator before installing fuel storage.