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    ALARPAs Low As Reasonably Practicable

    Definition

    As Low As Reasonably Practicable — UK principle weighing a risk against the money, time and trouble of reducing it; case law looks for gross disproportion.

    Editorial definition: The QHSE Standard, updated 3 October 2026 · https://qhsetech.com/glossary/alarp

    Scope: This is not a simple equal-cost comparison or a software-generated acceptance score.

    Sources checked: . Examples are editorial illustrations.

    What HSE and the courts say about reasonably practicable

    ALARP stands for as low as reasonably practicable. HSE explains that within the general duties of the Health and Safety at Work etc. Act 1974 dutyholders must protect people so far as is reasonably practicable, and section 2 sets that qualification on the employer's duty to employees. HSE's document Reducing risks, protecting people, known as R2P2, lists ALARP among similar qualifications, with ALARA, as low as reasonably achievable. The terms are used in different regulations, so the wording of the duty that applies should be checked.

    R2P2 singles out Edwards v National Coal Board (1949) as of particular importance. In R2P2's account the case calls for a comparison: the quantum of risk goes on one side and, on the other, the sacrifice in money, time or trouble of the measures that would avert it. Where there is gross disproportion, the risk being insignificant against the sacrifice, the person under the duty discharges the burden of showing that compliance was not reasonably practicable. R2P2 adds that courts look at all the relevant circumstances case by case. HSE believes the starting point should be the duty holder's present situation but, where options cannot be assessed that way, an option known to be reasonably practicable, such as existing good practice. R2P2 also notes that as controls are introduced the residual risk may fall so low that further measures are likely to be grossly disproportionate, though the controls should still be monitored in case the risk changes.

    HSE's tolerability of risk framework, set out in R2P2 and based on a method first published in 1988 for nuclear power stations, has three regions: unacceptable, tolerable and broadly acceptable. R2P2 says tolerable does not mean acceptable. In the tolerable region risks are accepted to secure benefits on three conditions: they are properly assessed, the residual risk is not unduly high and is kept as low as reasonably practicable, and the risks are reviewed periodically, for example for new knowledge or new techniques. HSE states that the framework is not guidance for dutyholders; it explains how HSE decides. All of this is general information, not legal advice.

    Sources opened :

    What an ALARP record holds in software

    • The hazard, the scenario and the risk before any further measure, with the controls already in place.
    • The options considered, including those not adopted.
    • For each option, the expected reduction in risk and the sacrifice in money, time or trouble, with the source of each estimate.
    • The decision and the reason: adopted, or rejected with the grounds on which the sacrifice was judged grossly disproportionate.
    • Who made the decision and why that person was competent to make it.
    • The sources of relevant good practice consulted, with the date.
    • A review trigger and date, so new knowledge or new techniques prompt a fresh comparison.
    • The monitoring that shows the adopted controls remain in place and effective.

    ALARP, SFAIRP, ALARA and the risk matrix

    ALARP and so far as is reasonably practicable are listed in R2P2 as similar qualifications, and ALARA is a third that uses the word achievable. A risk matrix ranks risks by judgement and does not decide whether another measure is reasonably practicable. Tolerable is not acceptable, and a risk in the middle region is not compliant by position alone.

    A hypothetical example: reducing overfill risk

    Everything in the following case is invented, and it describes no real site. It shows how a decision record reads. A site reviews the risk of a solvent tank overflowing. The record lists three options. A revised filling procedure costs little and gives a small reduction. An independent high-level trip gives a large reduction at moderate cost and is adopted. A fully enclosed secondary containment system would give a further reduction, but its cost, the shutdown it needs and the construction risk are very large against that extra reduction. Each option has a written estimate with its source, marked as an estimate and not a measurement, and the record states the starting point, which is the site's current arrangements.

    The record explains why the third option was rejected in terms of the extra reduction compared with the sacrifice, and names the manager who made the decision and the engineer who advised. It lists the industry guidance consulted. Two years later a supplier's new overfill detection technique triggers the review date. The team compares it, notes that it changes the sacrifice, and records the new decision with its reasoning.

    Common misunderstandings about ALARP

    • ALARP is not the cheapest acceptable option. The comparison weighs the risk against money, time and trouble, and the 1949 judgment speaks of gross disproportion.
    • The sources read for this page state no fixed ratio. A multiplier quoted in another document is not a rule unless the applicable guidance adopts it.
    • A risk in the tolerable region is not automatically acceptable. R2P2 says tolerable does not mean acceptable and conditions it on assessment, ALARP and review.
    • A colour on a risk matrix is not an ALARP demonstration. The record needs the options and the sacrifice.
    • ALARP is a UK concept. Other jurisdictions use other tests, so check the wording of the law that applies.

    How ALARP relates to other glossary terms

    ALARP is the test applied when choosing controls, so it belongs beside the terms on controls and hazard analysis.

    • Hierarchy of controls: gives the order in which measures are considered before their sacrifice is weighed.
    • HIRA: produces the risk assessment from which an ALARP comparison starts.
    • Bow-tie analysis: shows the barriers whose addition or removal is being weighed.
    • LOPA: a method for showing whether layers of protection bring a scenario to a tolerable level.

    Records and evidence that usually exist for an ALARP decision

    • The risk assessment, with its date, its reviewer and the controls in place at the time.
    • The list of options with estimates of the reduction and the sacrifice.
    • The written decision with its reasoning.
    • References to the good practice and guidance consulted.
    • Records of competence for the people who advised and decided.
    • The review date and the record of each review.
    • Monitoring records for the controls adopted.

    What a software tool needs to capture for ALARP

    • A place to record options that were rejected, with the reason, not only the controls chosen.
    • Fields for the reduction and the sacrifice of each option, with the source and date of each estimate.
    • A decision record with author, approver and date that cannot be silently edited.
    • A review trigger tied to a date and to changes such as new guidance or technology.
    • A clear label showing that the matrix rating is a screening aid and the ALARP reasoning is held separately.
    • Links to monitoring tasks for the controls adopted.
    • Export of the full comparison for an inspector or auditor.

    Catalog profiles documenting risk assessment workflows

    Listed profiles meet the risk assessment rule. Nothing here shows that a product holds option comparisons or ALARP reasoning, so ask for a worked decision in a demonstration.

    Same rule for every product: tagged “Risk Assessment” or “Risk Management”, with a sourced risk assessment or risk register capability in its record, or one the vendor stated to us, labelled as vendor-stated. Documented and conditional capabilities qualify; check the linked scope before treating a module as included.

    Tekmon pays for a sponsored placement (above); its place in this list follows the same rule as every entry. How lists are ordered

    All 38 matching profiles are shown. Documentation review, not hands-on testing or a claim of compliance.

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    Frequently asked questions

    Is ALARP the same as so far as is reasonably practicable?

    R2P2 lists ALARP as one of several similar qualifications to the duty to act so far as is reasonably practicable. Check the wording of the duty that applies, because both involve weighing the risk against the sacrifice.

    Does a risk matrix show that a risk is ALARP?

    No. A matrix helps to rank risks. Whether further measures are reasonably practicable depends on the options available and the sacrifice they involve, so those comparisons belong in the record.

    Who decides whether a risk is ALARP?

    The duty holder makes the decision, and R2P2 says the courts look at all the relevant circumstances case by case. R2P2 explains HSE's own decision process and HSE says the framework is not guidance for duty holders.

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