Are you working with any spontaneously combustible chemicals, such as white phosphorus or aluminium alkyls? These dangerous substances require specific storage conditions in order to keep your people and property safe. In this post, we’ll explore spontaneously combustible substances and offer some tips on how you can protect your organisation from the risk of combustion.
As the name suggests, spontaneously combustible chemicals are those which can spontaneously combust when they are exposed to oxygen (ie. air).
Spontaneously combustible substances are recognised as Class 4.2 substances that fall within the Class 4 Dangerous Goods category. The chemical property of the substance that determine this dangerous goods classification is that the product can ignite when in contact with air within just 5 minutes.
The Australian Dangerous Goods Code – commonly referred to as the ADG Code – explains the classification of these goods:
Class 4 Dangerous Goods are divided into 3 divisions:
REMEMBER: All dangerous goods have unique physical and chemical properties that must be controlled to reduce the risks associated with the substance. Always refer to the safety data sheet (SDS) of your chemicals, as well as the relevant Australian Standard, to develop safe handling and storage procedures for your dangerous goods.
In Section 2.4.3.1.1 of the ADG Code, we find the definition of Division 4.2 substances.
Substances liable to spontaneous combustion are defined as:
Substances, including White Phosphorus, are spontaneously combustible chemicals.
Spontaneous Combustible substances require strict controls to mitigate the devastating effects that combustion can pose to your organisation.
From human harm and fatalities to the destruction of property and environmental damage, spontaneous combustion of Division 4.2 substances is a risk that requires dedicated handling and storage practices.
Risks include:
The degree of risk that the substances can pose is largely determined by the packing group of the chemical product.
One of three packing groups into which dangerous goods are designated in the ADG Code, in decreasing order of hazard.
Packing groups are designated by the Roman numerals:
Some examples of packing groups for spontaneously combustible substances include:
Class 4 dangerous goods pose a risk to staff, property and the environment if they are not handled and stored in a careful and compliant manner.
When considering Class 4 Dangerous Goods for your workplace, you will have to factor in a range of risks.
REMEMBER: Your safety data sheet will provide you with the details of your chemicals, including the dangerous goods class or division and the packing group assigned to your substances.
When storing any type of Class 4 dangerous goods, there are a limited number of chemical stores that are applicable under the requirements of the Australian Standards.
AS NZS 5026 – The storage and handling of Class 4 dangerous goods outlines the various store types that are suitable for spontaneously combustible substances or other Class 4 chemicals.
Package store options may include:
REMEMBER: Storemasta manufactures compliant chemical storage cabinets that meet the requirements of the relevant Australian Standard. Spontaneously combustible substances can be safely kept in a Class 4.2 chemical storage cabinet.
There are a range of requirements that apply when choosing cabinet storage for your spontaneously combustible substances.
You must ensure your chemical storage cabinets are suitable for the dangerous goods that you’re storing.
These requirements include, but are not limited to:
Class 4 cabinets must also be marked with a variety of signs to maintain compliance and safety.
These chemical storage cabinets must feature:
Cabinet markings alert staff and visitors to chemical hazards in the work area.
If a toxic or flammable gas could be emitted from the packages, compliant mechanical ventilation should be installed.
The ventilation ducting must be designed to prevent back-pressure, with the ducting directed away from:
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Any potential ignition source — whether it’s a hot surface, equipment that produces a spark, static electricity from workwear, or a lit cigarette — must be identified and excluded from any storage or handling areas for spontaneously combustible substances.
You’re required to exclude ignition sources from the cabinet and surrounding area by a distance of at least 3 metres.
REMEMBER: Make sure you educate your staff on how to spot an ignition source, so they don’t unknowingly bring an ignition source into the work area. It’s also essential that you provide up-to-date dangerous goods training so they can understand all the hazards associated with Class 4 dangerous goods.
As we’ve highlighted in this post, there are many factors to consider when working with spontaneously combustible substances. As these dangerous goods pose a great risk to your organisation and community, the first step in safety is properly identifying any hazards that may be present. By studying your safety data sheets and the Australian Standards, you can access highly detailed information that will help you maintain chemical safety in your operations. However, as we have touched on here, there are many requirements that apply to both the storing and handling of dangerous goods.
That’s why it’s so important that you start with an accurate risk assessment of your workplace. The risk assessment process will allow you to have an overall view of your workplace hazards, so you can work on identifying and controlling chemical hazards, to provide a safe environment for your team.
Access your free risk assessment template today — and take the next steps towards achieving chemical compliance.