Flammable liquids are volatile substances that pose great risks to people, property and the environment. All flammable liquids identified in the Australian Dangerous Goods Code (ADG Code) have a very low flash point and they can easily ignite and cause a lot of destruction in the workplace.
What are flammable liquids, and why is safe storage important?
According to the ADG Code flammable liquids are defined as:
“Flammable liquids are liquids, or mixtures of liquids, or liquids containing solids in solution or suspension (for example, paints, varnishes, lacquers, etc., but not including substances otherwise classified on account of their dangerous characteristics) which give off a flammable vapour at temperatures of not more than 60 °C, closed-cup test, or not more than 65.6 °C, open-cup test, normally referred to as the flash point. This class also includes:
(a) liquids offered for transport at temperatures at or above their flash point; and
(b) substances that are transported or offered for transport at elevated temperatures in a liquid state and which give off a flammable vapour at a temperature at or below the maximum transport temperature.”
To protect the people, property, and environment, of your organisation from the risks associated with flammable liquids, it’s important to ensure that you store them in a safe and compliant manner. Flammable liquids can be safely stored indoors using a flammable storage cabinet. Flammable storage cabinets must be manufactured and used in accordance with strict specifications, to effectively protect your workplace from the risks associated with flammable liquids. These strict specifications are set out in AS1940-2017 - The storage and handling of flammable liquids. Section 4.9 of AS1940 specifies the requirements for the construction and use of flammable liquids storage cabinets. We will now discuss these requirements.
For the cabinet to adequately protect the surrounding from the risk of flammable liquids, the cabinet must have a safe and sturdy construction. Section 4.9.2 of AS1940 sets out the construction requirements for flammable liquids. These requirements include;
- The walls, floor, doors and roof of the flammable cabinet must be constructed from a double walled sheet steel construction. The gap between these walls must be no less than 40mm and can be left empty or filled with a fire-resistant insulation.
- The gaps around the doors and the walls of the flammable storage cabinet shall be sealed to prevent heat radiation and the spread of flames in the event of a fire.
- The base of the cabinet shall form a liquid-tight sump of at least 150mm deep. This sump must be designed in such a way that packages are prevented from being stored in the sump. This sump will contain any spills that may occur inside the cabinet.
- The shelves inside the cabinet must be perforated to allow for free air movement inside the cabinet. The shelves should also be sturdy and capable of carrying the maximum possible load.
- The inside of the cabinet including the shelves shall be designed in such a way that any spills are directed into the sump in the base of the cabinet.
- The doors of the cabinet shall be self-closing, close-fitting and held shut automatically by catches at two or more points.
- If the doors are equipped with a device to hold the doors permanently open when the cabinet is being loaded, the doors must automatically close when the temperature exceeds 80 degrees celsius.
- Materials that are critical to the structural integrity of the cabinet must not melt at temperatures below 850 degrees celsius. Seals and gaskets are an exemption to this requirement.
All these features are mandatory requirements for the construction of flammable storage cabinets. These features provide people, property, and the environment with protection from the risk associated with flammable liquids.
Construction requirements for cabinets exceeding 250L
For flammable storage cabinets with storage capacities exceeding 250L, extra features must be added to the construction of the cabinet to ensure that it adequately protects the workplace from the risk of storing greater quantities of flammable liquids. These requirements include:
- The height of the cabinet shall not exceed 2 meters
- The external surfaces of the cabinet shall be constructed from sheet steel of at least 1 mm thick.
- The spill containment sump in the base of the cabinet shall be capable of containing at least 25% of the aggregate capacity of the cabinet or the capacity of the largest container being stored in the cabinet, whichever is greater.
To ensure that everyone in the workplace is aware of the potential hazards associated with the flammable liquids being stored, clear safety signage must be displayed on all indoor flammable liquids storage cabinets. The signs that are required include;
- A class 3 dangerous goods label
- A sign stating “NO SMOKING NO IGNITION SOURCES WITHIN 3m”
The cabinets must also supply the name and address of the manufacturer in Australia and the cabinets' maximum storage capacity.
AS1940-2017 does not make ventilation of flammable storage cabinets a mandatory requirement, but it provides you with the option to do so if necessary. The main purpose of flammable liquids storage cabinets is to protect the flammable liquids inside the cabinet from a fire outside of the cabinet. If a ventilation system was installed on a cabinet, there’s a possibility that this protection will be reduced. However, if the flammable liquids that are stored inside the flammable storage cabinet are listed in the workplace exposure standards and the concentration of the vapor from this liquid is greater than the maximum concentration identified in the workplace exposure standard, a ventilation system will need to installed on the cabinet to extract the flammable vapours. This will keep the flammable vapours inside the cabinet at a safe concentration and reduce the risk of fire, explosion, asphyxiation or intoxication.
To ensure that the flammable liquids stored in the workplace pose the least risk to people, property and the environment, it is important to position your cabinet in a safe location. To do so, you must:
- Ensure flammable storage cabinets aren’t positioned in a location where they will impede escape in an emergency.
- Ensure cabinets with a greater capacity than 250L are not placed in residential or accommodation buildings, hospitals, commercial buildings, aged care buildings or schools.
- Only locate flammable storage cabinets with a capacity greater than 250L on floors that have direct access to the street or ground floor.
- Cabinets having a capacity greater than 250L shall not be placed any nearer than 3m to an internal wall that is common with another room, unless the wall is constructed of concrete or masonry to ceiling height or 3m above the cabinet (whichever is less) and 3m either side of the cabinet.
- The aggregate capacity of cabinets shall not be greater than:
- 850L per 250 m2 of floor space on a ground floor area;
- 250L per 250 m2 of floor space on floors other than the ground floor.
- Each aggregate quantity (850L on ground floors and 250L on other floors) shall be separated by at least 10m
- An indoor flammable storage cabinet can be used for outdoor storage as long as the cabinet provides adequate protection against the weather, corrosion and traffic damage.
Exclusion of ignition sources
Flammable liquids have the ability to easily ignite and cause intense fires and explosions. To prevent these dangerous events from occurring, it is important to ensure that flammable storage cabinets are always isolated from potential ignition sources.
- At all times no ignition sources shall be kept within the cabinet
- All flammable storage cabinets shall be isolated from all ignition sources within the workplace by at least 3m (measured laterally).
- Cabinets shall also be isolated from any ignition sources by at least 1m from the nearest opening on the cabinet (measured vertically)
To ensure the maximum safety in the workplace, it’s important to use flammable storage cabinets in such a way that it doesn’t impede greater risks to the people, property and the environment of your workplace. In all flammable storage cabinets:
- People shall be prevented from entering the cabinet
- Only one drum with a 60L capacity shall be keep in a horizontal decanting position at any one time.
- Only closed packages or those fitted with taps shall be stored within flammable storage cabinets
- Drums with a capacity greater than 60L shall not be stacked more than 2 high.
Flammable liquids pose great risks to our workplaces. To reduce these risks, it’s the responsibility of work health and safety managers to store their flammable liquids in a safe and compliant manner. The flammable liquids storage requirements outlined above are inline with the specifications stated in AS1940-2017. By following these requirements organisations will comply with the Australian Standards removing their risk of financial liability due to non-compliance. For more information on how to reduce the risks associated with flammable liquids, download our FREE eBook by clicking on the image below.