Can You Store Flammable Liquids in a Shipping Container? What AS 1940 Actually Requires

A shipping container can carry flammable liquids around the world. Parked at your site, that same container is probably not a compliant store. Here is why, and what AS 1940 actually asks for.

Paints, thinners, adhesives, solvents, fuels and aerosols turn up in almost every workshop, warehouse and trade business. Most of them are Class 3 flammable liquids. They get bought a carton at a time, stored wherever there is room, and nobody totals up how much is on site until something goes wrong.

Start with the Hazard, Not the Product

The hazard is not the drum. It is the vapour. A flammable liquid gives off enough vapour to ignite at 60°C or below, and many common products do it well below room temperature. Most solvent vapours are heavier than air. They collect in low and enclosed spaces, and can travel a long way to an ignition source and flash back.

What It Looks Like on Real Sites

These patterns are common across Australian workplaces. None of them are unusual, and all of them are fixable.

• A "paint store" holding thinners and adhesives, placarded for Class 3, but with a broken lock, no bunding and no chemical register.
• A tin of toluene kept in a kitchenette that doubles as the first aid room.
• Flammable liquids and aerosols on open retail shelving, with a stained floor from an earlier spill and no containment underneath.
• A Class 3 placard at the warehouse entrance, but no current inventory, so nobody can say whether placarding, manifest or notification thresholds have actually been triggered.
• Flammable liquids spread across several pallet racking locations, some at height, on the assumption that each spot counts as "minor storage".

And a good one: limited quantity cartons stored at ground level inside lockable metal cages. Simple, secure, no falling objects.

Step 1: Work Out How Much You Actually Have

AS 1940:2017 is the Australian Standard for storing and handling flammable and combustible liquids. Section 2 sets out minor storage quantities. Stay under them, follow the basic precautions in that section, and most of the heavier requirements in the rest of the standard do not apply.

For factories, workshops and warehouses, the indoor limits are worked out per square metre of floor space with a cap per 500 m² area, and they differ by packing group. As a guide, the most hazardous liquids (PG I and II) are capped at 250 L in any 500 m² area, and PG III liquids at 500 L. Check Table 2.1 for your building type, because retail, offices and outdoor storage all have different numbers.

Two traps catch people out:

• Spreading it around does not reset the count. If you rely on more than one minor storage area on the same premises, AS 1940 requires them to be well apart (20 m indoors, 15 m outdoors), unless they are in separate buildings divided by open space or a fire-resisting wall as the standard describes. The intent of minor storage is dispersal, not clustering just under the limit.
• Minor storage still has rules. Secure access, ventilation, spill clean-up, no ignition sources where vapour can collect, keep packages closed, and keep incompatible goods apart. Above certain volumes you also need an extinguisher and signage.

You cannot do any of this without a current chemical register and current Safety Data Sheets. That is the first fix on most sites, and it costs nothing but time.

Step 2: Indoors, the Answer Is Usually a Cabinet

Once you are over minor storage, or simply want the stock controlled in one place, a flammable liquids storage cabinet is the most practical indoor control. AS 1940 Clause 4.9 sets out what a compliant cabinet looks like, including:

• Double-walled sheet steel with at least a 40 mm gap between the walls.
• A liquid-tight sump in the base at least 150 mm deep, which cannot be used as a shelf.
• Perforated shelves, so vapour and air can move and leaks drain into the sump.
• A maximum capacity of 850 L per cabinet, with extra requirements above 250 L.

When buying, ask what standard the cabinet was built and tested to. Overseas approvals are not the same thing as AS 1940 construction.

Step 3: Outdoors, a Container Can Work, Once It Is Modified

This is where the shipping container comes in, and where most of the confusion sits.

Why a container that is fine at sea is not fine at your site

A shipping container carrying dangerous goods is covered by transport rules: the IMDG Code at sea, the ADG Code on road and rail. Its CSC plate confirms the box is structurally safe to lift, stack and ship. During transport the packages stay sealed, nobody works inside, and the goods are in transit.

AS 1940 does not cover transport, and its definition of a "container" leaves freight containers out. Once the box is parked on your premises, it stops being a transport unit and becomes a store. The doors get opened every day. Forklifts go in and out. Packages get punctured. Vapour builds up in a sealed steel box with no airflow. People walk inside to find stock. A CSC plate says nothing about any of that.

There is one in-between case: transit storage. AS 1940 Clause 3.10 covers goods held for at least 12 hours and less than five days on their way somewhere else, with its own rules on stacking, separation and spill catchment. Once the goods are there to stay, the container is a store and Clause 4.8 applies.

Clause 4.8 is direct about it: apart from loading and unloading, a freight container must not be used to store flammable or combustible liquids in packages unless it has been modified to meet the standard's requirements for separation, segregation, ventilation and spill containment. On top of that, a container store must:

• Not double as a workshop.
• Have its floor checked for contamination from previous cargo before first use.
• Have a clearly marked internal walkway at least 800 mm wide.
• Have a hazardous area assessment done, with only suitably rated electrical equipment in the hazardous zone.
• Have no point more than 6 m from an exit door. A 40 ft unit typically needs doors at both ends.
• Have doors that open from the inside, with any external lock deactivated.

Then the site questions follow: how far it sits from buildings, boundaries and other stores, how spills are kept out of drains, and who has access.

Can the container go inside the warehouse instead?

Which Option Fits?

A Note on Bunded Pallets

Portable spill pallets and flexible bunds are useful, but AS 1940 notes they are not suitable for permanent storage. There are no uniform performance criteria for their chemical or fire resistance, and they are easy to move to the wrong spot. They suit short-term holding of damaged packages, goods in transit, and work and handling areas. Two other failures are common: bunds full of rainwater, and incompatible chemicals sharing the same bund.

Questions to Ask Any Storage Supplier (Including Us)

1. Which clauses of AS 1940 is this built to? Can you show me the drawing or specification?
2. What is the sump or bund capacity, and how was it worked out?
3. How is the unit ventilated, and where does the vapour go?
4. Is the electrical fit-out included? If so, who certifies it for the hazardous area?
5. What fire rating is claimed, and to which test standard?
6. What is left for me to do on site: placement, separation distances, drainage, signage?

Be wary of "approved" on its own. Regulators set duties for the business holding the goods. They do not approve storage products. What matters is a documented build specification, test evidence, and a site set-up that fits your quantities.

Your Obligations Do Not Stop at the Store

In Victoria, storage and handling of dangerous goods sits under the Dangerous Goods (Storage and Handling) Regulations 2022, alongside the OHS Act and Regulations for hazardous substances. Most other states and territories apply the hazardous chemicals provisions of their WHS Regulations, and Western Australia has its own dangerous goods safety regulations. Depending on quantity, that can mean placarding, a manifest, notifying the regulator and an emergency plan. All of it starts with knowing what is on site.

And PPE stays in the picture. It is the last line of control, not the first, but anyone decanting, cleaning up a spill or handling damaged packages still needs the right gear for the product. Section 8 of the SDS tells you what.

Related reading: A Complete Guide to Workplace PPE in Australia and Work Gloves Explained: Matching Hand Protection to the Hazard.

Sources

• AS 1940:2017 The storage and handling of flammable and combustible liquids, Standards Australia. Clauses 1.2.2, 1.4.14, 2.2, 2.3, 3.10, 4.2, 4.3.3, 4.4.2, 4.4.3, 4.8 and 4.9, and Table 2.1.
• Dangerous Goods (Storage and Handling) Regulations 2022 (Vic).
• Safe Work Australia, Model Code of Practice: Managing risks of hazardous chemicals in the workplace.