What are the risks associated with dangerous goods?
Jun 6, 2018

What are the risks associated with dangerous goods?

Rachel Chesterfield Rachel Chesterfield

No doubt you’ve heard of the term dangerous goods before, and the same goes for hazardous substances, hazmat, hazchem, flammable liquids and corrosive substances.  You probably know that they’re all related somehow.  But what really are dangerous goods? 

Dangerous goods can be defined as an object, substance or material that presents a particular degree of risk to people, property and the environment due to its physical and chemical properties.

The Classification of Dangerous Goods

Dangerous goods are classified into nine core divisions as follows:

  • Class 1: Explosives
  • Class 2: Gases
  • Class 3: Flammable liquids
  • Class 4: Flammable solids; substances liable to spontaneous combustion; substances which, on contact with water, emit flammable gases
  • Class 5: Oxidizing substances and organic peroxides
  • Class 6: Toxic substances and infectious substances
  • Class 7: Radioactive material
  • Class 8: Corrosive substances
  • Class 9: Miscellaneous dangerous substances

Potential Risks associated with different classes of dangerous goods

The level of risk and type of reaction associated with dangerous and hazardous substances varies according to the class division and unique properties of the substance.  Naturally, the quantity, location and properties of other materials within the vicinity also play an important role in determining the level of risk associated with the substance in question.

Risks associated with Class 1: Explosives

The risk and outcome associated with explosives is reasonably obvious.  Should an explosive contact with an ignition source, or a detonator with a booster, it will explode.  Whether the key danger arises from the heat or the shock wave, the risk is very significant.  If any personnel are within the vicinity of the explosion, the likely consequences can include death, eruptions of ear drums and blood vessels, fire, inhalation of toxic gasses and severe burns. Explosive substances also pose various risks upon property and the environment.

Risks associated with Class 2: Gasses

Gasses are classed into 3 divisions.  Division 2.1 gases are capable of ignition when a mixture of 13% or less by volume with air at standard lab conditions (20°C and 101.3kPa).  Division 2.2 are non-flammable and non-toxic, but can act as an oxidizing agent.  Division 2.3 have a toxic or corrosive nature.  Gas is often difficult to visibly see, and can disperse easily and spread over large distances quickly.  Dependent on the division, gasses are also likely to irritate eyes and the respiratory system.

Risks associated with Class 3: Flammable Liquids

Flammable and combustible liquids emit vapours capable of ignition when above their flash point temperatures.  For flammable liquids, this is generally at or below standard working temperatures.  Should the vapour come into contact with an ignition source, the substance is likely to ignite, creating a very hot and fast burning fire.  Again, the risks are obvious, with inhalation of toxic fumes and burns.

Risks associated with Class 4: Flammable Solids

Flammable solids are thermally unstable and further classified into three divisions. Each division has different properties that vary the risks associated with the substances.  Division 4.1 flammable solids are likely to self-react particularly through friction, generally in the form of a strong exothermic reaction.  Division 4.2 substances spontaneously heat in normal conditions and likely to catch fire.  Division 4.3 substances will ignite in the presence of water.  Similarly to class 3 dangerous goods, substances classified as flammable solids are likely to combust in certain conditions, releasing a toxic gas and creating a fast-moving fire.

Don’t forget to have emergency spill kits, working first aid kits and safety showers and eye wash stations in easy access in case an incident should occur.

Risks associated with Class 5:  Oxidizing Substances

Chemically, oxidizing substances oxidize other materials, causing them to lose a number of electrons. At a more obvious outlook, oxidising agents react with other substances causing them to spontaneously combust.  An organic peroxide is any organic compound. Organic compounds are compound that contains carbon. Organic peroxides are very unstable and susceptible to dangerous reactions such as combustion. The biggest risk that organic peroxides pose upon people is suffocation. Organic peroxides are also toxic and they will cause a lot of irritation when brought into contact with eyes or skin. 

Risks associated with Class 6: Toxic Substances

The risk of toxic and infectious substances are described by the Australian standard AS NZS 4452-1997. This standard states:  “Toxic substances are liable either to cause death or serious injury or to harm human health if swallowed or inhaled by skin contact. AS/NZS also define infections substances as: "substances that are known or reasonably expected to contain pathogens, which can cause disease in humans or animals.”

Risks associated with Class 7: Radioactive Material

On a daily basis we come into contact with class 7 dangerous goods a lot more than most of us would realise.  A certain amount of radiation in our bodies is considered ‘normal’. However, should radioactive material be emitted in large quantities and escape into an uncontrolled environment, they can be very dangerous. As a result of the development of the atom bomb, the risks associated with radioactive materials are probably one of the most feared today.

Radiation is generally invisible, and emits waves of varying frequencies.  Without going into too much detail, radiation ionizes parts of our cells and damages our DNA.  Medically, one common result is cancer.

Risks associated with Class 8: Corrosive Substances

Have you seen the black and white warning diamond sign with a test tube with a hand underneath and a substance burning a hole in the hand? Corrosive materials eat away at a substance and gradually destroy them.  As skin is a living tissue, the same principle applies.  Corrosives can destroy most materials by erosion, but are also capable of burning the skin, respiratory tract, and eyes even to the point of blindness.

Corrosives are also likely to share properties of other classes of dangerous goods, such as flammable liquids or toxic substances.

Risks associated with Class 9 – Miscellaneous Substances

Class 9 dangerous goods are substances that present a risk to people or property not covered by the other 8 classes.

Next Steps

If your organisation uses dangerous goods on a regular basis, it is very important that you store and manage them in a way that minimises the risks that they pose upon the people, property and environment of your organisation. This can be done by firstly identifying the dangerous goods classification of the substance. Once the DG classification has been identify, you can then start to implement controls to reduce the specific hazardous associated with the substance. If you would like more information on how to reduce the risks associated with flammable liquids, download our FREE eBook by clicking on the image below.

How to reduce the risk of flammable liquids in the workplace

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