Risk assessment (WHS)

A risk assessment in WHS is a written exercise that identifies hazards, evaluates the likelihood and consequence of harm, and specifies controls to eliminate or reduce the risk to as low as reasonably practicable (ALARP). It is mandated under the Model WHS Regulations 2011 (Part 3.1) for any high-risk construction work (HRCW), manual handling task, asbestos removal, confined space entry, or any other named hazardous activity. The risk assessment is the direct precursor and information source for any Safe Work Method Statement (SWMS), entry permit, or control measure.

The four-step process (AS/NZS ISO 31000:2018 framework):

Step	Activity	Output
1. Identify hazards	Walk the site; review past incidents; consult workers	Hazard register: each named hazard
2. Evaluate the risk	Score likelihood (1-5) and consequence (1-5); product is the risk score	Risk matrix entry per hazard
3. Apply controls	Use the hierarchy (see below) to reduce the risk	Control list, residual risk score
4. Review	Re-assess after changes, after incidents, periodically	Updated risk assessment

The hierarchy of controls (most-effective to least-effective):

Level	Control type	Example
1. Eliminate	Remove the hazard entirely	Use prefab structures so no working at height; pre-coat steel offsite to remove paint hazard at height
2. Substitute	Replace with a less-hazardous alternative	Water-based instead of solvent-based coating
3. Isolate	Physical barrier between worker and hazard	Hoarding around demolition; perimeter fencing
4. Engineering	Engineered control reducing exposure	Local exhaust ventilation for silica dust; guards on machinery
5. Administrative	Procedure, training, supervision, rotation	Hot work permit, lockout/tagout, work-rest cycles
6. PPE	Personal protective equipment	Hard hat, safety boots, respirator, harness

PPE is the last resort, not the first. A risk assessment that jumps straight to “PPE: respirator” without considering elimination, substitution, isolation, or engineering controls is non-compliant with WHS principles.

Risk scoring (typical 5x5 matrix):

	Insignificant (1)	Minor (2)	Moderate (3)	Major (4)	Catastrophic (5)
Almost certain (5)	5	10	15	20	25
Likely (4)	4	8	12	16	20
Possible (3)	3	6	9	12	15
Unlikely (2)	2	4	6	8	10
Rare (1)	1	2	3	4	5

Score	Risk level	Action
1-4	Low	Monitor; standard controls
5-9	Moderate	Specific controls required
10-14	High	Immediate action plan
15-25	Extreme	Cease activity until controlled

When a risk assessment is mandatory:

All high-risk construction work (HRCW) under WHS Reg s.291 (falling from height, plant, asbestos, refractory ceramic fibre, asbestos, demolition, structural alterations affecting stability, etc.).
Hazardous chemicals above thresholds.
Manual handling with specific risk factors.
Confined space entry (precursor to the entry permit).
Plant and equipment before commissioning.
Any new task or changed task introducing new hazards.

Relationship to the SWMS:

The risk assessment is internal to the workplace (the PCBU’s safety system). The SWMS is task-specific and worker-facing (the document that tells the worker how to do the job safely). The SWMS is built from the risk assessment, but the two are distinct documents. A SWMS without a risk assessment behind it is a checklist; a risk assessment without a SWMS isn’t actionable on-site.

Common defects:

Generic risk assessment lifted from a template without site-specific adaptation. The template is a starting point, not the finished assessment.
Skipping the hierarchy of controls and going straight to PPE.
Failing to consult workers during identification of hazards. Frontline workers spot hazards office-based assessors miss.
Static document filed in a binder, never reviewed after incidents or changes.
Risk score manipulated to fit a desired outcome (the “we always score this as Moderate” trap).

Also known as: WHS risk assessment; safety risk assessment; HRCW risk assessment; pre-task risk assessment.

Category: WHS.

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