OHS Risk Assessment South Africa: Severity + Probability + Exposure Matrix [2026]
Section 8 of the Occupational Health and Safety Act 85 of 1993 requires employers to identify hazards and take reasonable steps to control them. An OHS risk assessment is how you record that process. This guide explains the scoring method used in our demo and how to generate the document.
The scoring method: Severity + Probability + Exposure
For every hazard you score three factors from 1 to 50:
- Severity (S): how bad would the harm be?
- Probability (P): how likely is it to happen?
- Exposure (E): how often, or for how long, are people exposed?
Risk score = S + P + E, giving a total between 3 and 150.
| Score | Level | What to do |
|---|---|---|
| 1 to 50 | Low | Monitor and review periodically |
| 51 to 100 | Medium | Control measures required, monitor their effectiveness |
| 101 to 130 | High | Immediate action required before work proceeds |
| 131 to 150 | Extreme | Stop work and escalate to management |
Raw risk vs residual risk
Each hazard is scored twice:
- Raw risk: before controls
- Residual risk: after controls
In the demo, working at height on a roof structure scores S 40, P 35, E 35, a raw risk of 110 (High). With safety harnesses, guardrails and edge protection it drops to S 10, P 15, E 12, a residual risk of 37 (Low). The document makes that reduction visible.
How the document is organised
- Areas of the site, for example administration or construction site
- Hazard categories within each area, for example fall hazards
- Activities under each category, with the hazards identified and the health effects
- Existing controls, recommendations, a risk owner and a due date
Generate it
- Open Generate Documents and choose OHS Risk Assessment (Industry Standard)
- Enter the project name, contact person and location
- Add an area, a hazard category and an activity, with the hazards and health effect
- Enter the Severity, Probability and Exposure scores before and after controls
- Add the controls, recommendations and the person responsible
- Click Generate Document to receive the colour-coded, landscape PDF
Use it with your other documents
- Trade-specific version: Risk assessment template for electricians and trades
- The written safe work procedure: Method statement template
- The legal background: Construction Regulations 2014 summary
Important
SiteReady documents are templates based on common industry requirements, not legal advice. Scores are only as good as the judgement behind them: have a competent person review every risk assessment against the real site.
Frequently asked questions
What is raw risk and residual risk?
Raw risk is the level of risk before any controls are applied. Residual risk is what remains after your control measures are in place. A good risk assessment shows both, so you can see how much each control reduces the risk.
How is the risk score calculated?
In this template each of Severity, Probability and Exposure is scored from 1 to 50 and the three are added, giving a total from 3 to 150. 1 to 50 is Low, 51 to 100 is Medium, 101 to 130 is High and 131 to 150 is Extreme (stop work and escalate).
Is this the only legally accepted risk matrix?
No single matrix is prescribed for every workplace. What matters is that you use a consistent, documented method, that it is applied by a competent person and that you act on the results. Your OHS practitioner may prefer a different matrix, and that is fine.
Why is the document in landscape?
Risk assessments have many columns: hazards, effects, raw and residual scores, controls, owners and due dates. Landscape keeps every column readable without cutting anything off.