What makes something hazardous in nature?
Something is hazardous in nature when harm can follow from what it is, not from a mistake in how it is used. Petrol is flammable whether it sits in a sealed tank or an open bucket; the container changes the risk, not the hazard. Safety work starts by naming that property, because the control has to match it.
Types of hazardous nature
| Type | What causes the harm | Workplace examples |
|---|---|---|
| Physical | Energy or force | Moving machinery, noise, heat, electricity, work at height |
| Chemical | Properties of a substance or mixture | Flammable solvents, corrosive acids, toxic fumes, silica dust |
| Biological | Living organisms or their products | Bacteria, viruses, mould, Q fever from livestock |
| Ergonomic | Load and posture on the body | Repetitive lifting, awkward reaching, vibration |
| Psychosocial | How work is designed and managed | High job demands, bullying, fatigue, poor support |
How is the hazardous nature of a chemical shown?
Under the Globally Harmonized System (GHS), which Australian WHS laws apply through GHS Revision 7, chemicals are classified into physical, health and environmental hazard classes. The classification shows up in three places:
- Label – pictograms, a signal word (Danger or Warning) and hazard statements such as H225 "Highly flammable liquid and vapour".
- Safety data sheet (SDS) – section 2, Hazard identification, lists each hazard class and category.
- Hazardous chemicals register – the site list of every hazardous chemical held, with its current SDS.
Under the model WHS Regulations a substance is a hazardous chemical if it meets the criteria for a GHS hazard class. Dangerous goods are classified separately for transport under the ADG Code, and many products are both.
Hazardous nature vs risk
The hazardous nature stays the same; the risk does not. Risk combines how likely harm is with how severe it would be, and it changes with quantity, exposure, controls and who is nearby. That is why a risk assessment first identifies each hazard and its nature, then works down the hierarchy of control: eliminate it, substitute something less hazardous, isolate or engineer it out, and only then rely on procedures and PPE.