High Consequence Dangerous Goods (HCDG): Safety basics

High consequence dangerous goods

HCDG are:

• ammonium nitrate
• calcium ammonium nitrate containing more than 45% ammonium nitrate
• ammonium nitrate emulsions and mixtures containing more than 45% ammonium nitrate.

HCDG are also known as security sensitive ammonium nitrate (SSAN) in some jurisdictions such as Queensland, Western Australia and South Australia.

What HCDG are used for

Ammonium nitrate is used to make products like fertilizers and is a key ingredient in some explosives.

Industries like agriculture and mining rely on the use of HCDG. Its misuse can have catastrophic results.

If not used appropriately HCDG poses significant security and safety risks, therefore its use is tightly controlled through a licensing and permit system, with security and police checks.

What are not considered HCDG

Solutions and ammonium nitrate products that are class 1 explosives are not HCDG.

Solutions refer to water based mixtures where all the HCDG are dissolved in water and there are no visible solid particles in the mixture.

United Nations numbers for HCDG

The following United Nations (UN) numbers may be used for HCDG. UN numbers are a globally recognised way of labelling dangerous goods.

HCDG licences and permits

You must have an appropriate licence or permit if you do any of the following with HCDG:

• import
• export
• manufacture
• store
• sell
• supply
• use
• handle
• transfer
• transport
• dispose of

This applies to many industries, particularly the mining, agricultural, transport, retail and manufacturing industries.

Licence and permit applicants must also undergo a security and police check.

Licenses and permits are valid for 5 years, but may be renewed for a further term.

Licences

Licences are only given to people or businesses that demonstrate legitimate need.

WorkSafe requires applicants to submit a security plan with their application form outlining how they will deal with the many risks associated with HCDG.

Permits

Employees will be required to get a permit if they access HCDG unsupervised.

Permits are only issued if the employer holds a HCDG licence.

Main hazards of ammonium nitrate

There are 3 main hazards when working with ammonium nitrate:

• Decomposition: ammonium nitrate melts at 170 degrees celsius and above 210 degrees celsius it decomposes releasing toxic gas
• Fire: ammonium nitrate in solid or liquid state is an oxidising agent which supplies oxygen to the fuel in a fire and supports burning even where air is excluded
• Explosion: in a fire, hot pools of ammonium nitrate liquid may form and if confined, for example in a drain, may explode.

Risk management

If you occupy premises where dangerous goods are stored and handled, you must make sure any associated risks are eliminated or reduced, so far as is reasonably practicable. To do this, you must consider whether the quantity of dangerous goods can be reduced, and whether other goods, or dangerous goods, with lower risks can be substituted.

Occupiers must make sure any risk control measures are reviewed and if necessary revised:

• before any change is made to a process or system that is likely to change the risks associated with storing and handling dangerous goods
• if required following an investigation due to an incident at the premises
• if they do not adequately control the risks.

The Dangerous Goods (Storage and Handling) Regulations 2012 list what you must consider when identifying hazards at premises where dangerous goods are stored and handled.

Safe storage and handling

• Use an appropriate building. If ammonium nitrate is stored in a building it should be a well-ventilated, single-storey building made of a material that will not burn.
• Keep ammonium nitrate dry. The risk of explosion increases if the product gets wet and the surface forms a crust on the outside. The crust confines the decomposing gases making explosions more likely.
• Store away from drains, channels and pits where molten ammonium nitrate from a fire could become confined.
• Store away from ignition or heat sources.
• Store ammonium nitrate at least 1.2 m away from walls. Regularly clean walls and framing or structures, depending on where it is stored.
• Don't store ammonium nitrate in stacks higher than 3 m.
• Provide appropriate fire protection as per the safety data sheet.
• Provide information and training to relevant employees about safe storage and handling.

Storing away from incompatible materials

Do not store ammonium nitrate with incompatible materials as the risk of fire and explosion is increased. This includes:

• flammable or combustible liquids such as petrol, diesel, oil, grease, solvents, oil-based pesticides, gas cylinders
• combustible materials including organic matter, hay, straw, animal feed, wooden pallets (ammonium nitrate should be stored away from such materials by a distance of at least 8m)
• finely powdered metal zinc

Separate ammonium nitrate from:

• class 8 corrosive liquids, acids and alkalis
• chlorites, chlorates, bromides
• cement, lime, sulphur, hexamine
• galvanised iron, copper, zinc

A list of incompatible materials can be found in the Australian Standard 4326, 'Storage and handling of oxidizing agents'.

For more information please contact us at [email protected]

Related legislation

The Dangerous Goods (HCDG) Regulations 2016 regulates the following activities for HCDG:

• purchase
• sale
• use
• storage
• transport
• import
• export
• supply