Residual Risk, Acceptable Risk & Tolerable Risk in H&S

Residual Risk

• Inherent risk represents the amount of risk that exists in the absence of controls.
• Residual risk (Remaining Risk)  is the amount of risk that remains after controls are accounted for.

An example of residual risk is given by the use of automotive seat-belts. Installation and use of seat-belts reduces the overall severity and probability of injury in an automotive accident; however, probability of injury remains when in use, that is, a remainder of residual risk.

Acceptable Risk & Tolerable Risk:

• If the residual risk is high, the decision to be made whether, the residual risk is Tolerable or  Acceptable level :
• If risk is acceptable, the risk is adequately controlled.
• If risk is unacceptable, it implied that still level of risk is too high and can’t allow the work to continue, more action is needed.
• If risk is lower and it may be tolerable for a short period of time  with interim control put in place.
• Un-tolerable Risk (Intolerable risk): The activity should not be started or continued until the risk has been reduced. If it is not possible to reduce risk even with unlimited resources, activity has to remain prohibited.

Priorities and Timescales for Control measures:

• Prioritization of Risk Control measure will depend upon the risk rating( High, Medium and low):

High-risk = high-priority actions. (Higher the risk higher the priority)

Low-risk = low priority.

• Timescale /  deadlines may vary as depend upon the control measure.
• E.g. –Installation of Hydrant system is required to prevent the Fire spread at High Hazard site and it may take 3-6 months timeframe. Fire Extinguisher may be provided immediately as interim control.
• Low-cost, easy actions should be taken, even if low priority.
• Medium priority still needs rapid action.