What ALARP means
ALARP means as low as reasonably practicable. It expresses the requirement to reduce risk to a level that is as low as reasonably practicable. It is particularly associated with the British safety framework. Its translation must not be used to replace specific obligations imposed by the applicable legislation in another country.
Related concept: Acceptable risk.
Not a decision based only on price
The comparison considers the sacrifice required to implement a measure and the safety improvement it provides. To reject further reduction, the sacrifice would have to be grossly disproportionate to the safety benefit: this is the gross-disproportion criterion. Simple equality between cost and benefit is not enough. Operational inconvenience or the absence of previous accidents does not demonstrate that an improvement is unnecessary.
Recognised good practice provides an important reference. Where an established solution exists for a known hazard, rejecting it requires more than stating that the risk appears small.
Tolerability and reduction
In frameworks that use tolerability regions, some risks are unacceptable, others require a demonstration of reduction, and others may be broadly acceptable. Boundaries and their interpretation depend on the regulatory context. A chart from another industry should not be copied and made into a universal criterion for workers.
Meeting a numerical threshold does not automatically end the analysis: it may still be necessary to check whether additional reasonably practicable measures are available.
Documenting the reasoning
The justification must identify scenarios, exposed people, existing controls and the improvement options considered. For each alternative, effectiveness, uncertainty, technical feasibility and any risks introduced are relevant. The decision must be connected to data and criteria, rather than an unexplained score.
The assessment also needs to consider maintenance and actual use. A barrier that is highly effective on paper may offer less protection if it depends on frequent adjustments that are not performed.
Hypothetical example
A plant reviews access to an area where objects may fall. The team compares additional signage, access control and eliminating the route beneath the load. It examines who passes through, how often and which alternatives exist. The solution is selected for its effective risk reduction and the reasons are documented, rather than simply choosing the cheapest option.
Limits and follow-up
ALARP does not mean zero risk or authorise non-compliance with a mandatory provision. The reasoning must be reviewed when more effective technologies, incidents or process changes emerge. It must also be distinguished from ALARA, used in radiological optimisation. Although both involve reduction, their frameworks and applications cannot be treated as interchangeable without analysis.
