Tolerable risk refers to a level of risk deemed acceptable by society or an organisation in a given context, even though it is not negligible and could potentially cause harm. It implies a willingness to live with a risk to secure certain benefits, with the understanding that the risk has been evaluated, is being adequately controlled, subjected to ongoing monitoring and reduced to “As Low As Reasonably Practicable” (ALARP).
Brief Explanation of the Term “Tolerable Risk”
Determining what constitutes a “tolerable risk” often involves a combination of legal requirements, industry standards, societal expectations, cost-benefit analysis, and expert judgment. It’s not a static concept and can evolve with new knowledge, technology, and societal values.
It does not mean the risk is desirable or negligible, but that it is tolerable under current conditions given the benefits, legal requirements, and controls in place.
The goal of occupational health and safety is to prevent harm to workers. However, some level of risk is often unavoidable due to the nature of certain tasks or environments. A tolerable risk is one that:
- Has been identified and assessed,
- It cannot be feasibly eliminated without excessive cost or effort.
- Has been reduced through appropriate control measures.
- And is considered acceptable for the task or situation, as long as it remains under control.
The concept of tolerable risk is closely linked to the ALARP principle. A risk becomes tolerable only after it has been reduced to ALARP levels and is being managed appropriately.
Example:
A manufacturing plant uses a machine that poses a risk of hand injury during operation.
- Hazard: Moving parts of the machine could cause injury.
- Risk Reduction Measures:
- Machine guarding is installed.
- Operators are trained in safe use.
- Emergency stop buttons are accessible.
- Routine inspections and maintenance are conducted.
- Necessary supervision is provided.
Despite these controls, a residual risk remains — for example, a minor chance of injury if a guard fails or if procedures are not followed. This remaining risk is not eliminated, but it is:
- Well understood,
- Controlled with effective safeguards,
- Reviewed periodically,
- Judged to be ALARP
- And Supervised
In this case, the remaining risk is considered tolerable, as the likelihood of harm is low, the consequences are not severe, and further reduction would require disproportionate time, effort, inconvenience or cost.