Last reviewed 27 February 2013

Phrases such as “as low as reasonably practicable” and “so far as is reasonably practicable” feature often in the world of health and safety. This does not mean that they are well understood. Mike Ellerby discusses what it really means to meet these standards.

Some employers take health and safety seriously and are prepared to invest to keep their workers healthy and safe; some employers choose to ignore health and safety while others wish to do only the minimum that they can get away with. With respect to risk assessments in particular, and health and safety in general, it is not uncommon to hear phrases from employers such as:

  • “I only want to do what I have to”

  • “What’s the minimum I must do to be legal?”

  • “What can I get away with doing?”

As we shall see, the minimum, ie meeting the standards of “as low as reasonably practicable” (ALARP) and “so far as is reasonably practicable” (SFARP), requires the employer to do a great deal more than many might consider to be “the minimum”.

The legal interpretation

The most common duty, with respect to health and safety at work, is to reduce the level of risk to ALARP. There are some cases where a higher standard is required, but most cases fall under the auspices of ss.2 and 3 of the Health and Safety at Work, etc Act 1974 (HSWA), which may be paraphrased as “to ensure the health and safety of employees (and non-employees who may be affected by the undertaking), so far as is reasonably practicable”. HSWA does not define the meaning of the latter phrase, but various cases have addressed the matter.

In Edwards v National Coal Board [1949] 1 All ER 743 CA, Lord Justice Asquith stated: “Reasonably practicable, as traditionally interpreted, is a narrower term than ‘physically possible’ and implies that a computation must be made in which the quantum of risk is placed in one scale and the sacrifice, whether in money, time or trouble involved in the measures necessary to avert the risk is placed in the other; and that, if it be shown that there is a gross disproportion between them, the risk being insignificant in relation to the sacrifice, the person upon who the duty is laid discharges the burden of proving that compliance was not reasonably practicable. This computation falls to be made at a point of time anterior to the happening of the incident complained of.”

This statement has been approved in several other cases, including the House of Lords in Marshall v Gotham Co Ltd [1954] 1 All ER 937.

What does this all mean?

An employer must do what any reasonable employer would do to protect the employee in question, bearing in mind the nature of the hazard, persons at risk, the degree of danger etc, measured against the cost and practicability of safety measures/control measures. This is reinforced by various regulations made under HSWA that require risk assessments. Employers as a basic minimum must follow the law, any relevant Code of Practice and guidance notes (or be doing something at least as good), and follow best practice and advice.

All employers are required by regulation 3 of the Management of Health and Safety at Work Regulations 1999 (MHSW), as amended, to undertake assessments of the risks (to employees and to non-employees) arising from their undertaking. One way of thinking about these risk assessments is that they are the means by which the employer can meet the general duties imposed under ss.2(1) and 3(1) of HSWA. The duty to carry out these risk assessments is absolute: in other words the employer must ensure that these risk assessments are carried out.

After determining the level of risk, SFARP has the effect of helping to determine how far to go with the control measures that need to be introduced to reduce the risks down to ALARP. When considered in this light, the questions raised at the start of this article become pertinent. Doing the minimum actually means reaching quite a high standard of health and safety, as the only defence to not doing more is that it is not reasonably practicable to do so.

Unfortunately, there is no simple formula for calculating exactly what is ALARP (or SFARP). In essence, making sure a risk has been reduced to ALARP is about weighing the risk against the sacrifice needed to further reduce it. The decision is weighted in favour of health and safety because the presumption is that the employer should implement the risk reduction measure. To avoid having to make this sacrifice, the employer must be able to show that it would be grossly disproportionate to the benefits of risk reduction that would be achieved. Thus, the process is not one of balancing the costs and benefits of measures but, rather, of adopting measures except where they are ruled out because they involve grossly disproportionate sacrifices. The Health and Safety Executive (HSE) cites some extreme examples.

  • Spending £1 million to prevent a few staff suffering bruised knees is obviously grossly disproportionate.

  • Spending £1 million to prevent a major explosion capable of killing or injuring more than 100 people is obviously proportionate.

The reality is that most decisions about risk and the controls that are needed to achieve ALARP are not so obvious. Other factors come into play, including: the on-going costs of supervision, equipment and machinery checks, and servicing; the remote chances of one-off events; the daily expense and supervision time required to ensure that, for example, employees wear ear defenders set against a chance of developing hearing loss at some time in the future. It requires judgment.

The hierarchy of control measures

Schedule 1 to the MHSW specifies a hierarchy to be followed when contemplating risks and introducing measures to control those risks.

  1. Avoid the risks.

  2. Evaluate the risks that cannot be avoided.

  3. Combat the risks at source.

  4. Adapt the work to the individual, especially as regards the design of workplaces and the choice of work equipment and working and production methods, with a view, in particular, to alleviating monotonous work and work at a predetermined work-rate and to reducing their effect on health.

  5. Adapt to technical progress.

  6. Replace the dangerous with the non-dangerous or the less dangerous.

  7. Develop a coherent overall prevention policy that covers technology, organisation of work, working environment, social relationships and the influence of factors relating to the working environment.

  8. Give collective protective measures priority over individual protective measures.

  9. Give appropriate instructions to employees.

When working with a hierarchy, the point is to start at the top and work down. The only reason for not implementing the control measure at the top is that it is not reasonably practicable to do so.

An example of the concept

By way of example, consider the hierarchy above in respect to the use of a highly toxic chemical in some sort of coating process. It is not adequate to merely provide a respirator in this case. The reasonably practicable approach may involve the substitution of a safer substance used within a suitable enclosure with a suitable, maintained and tested extraction system coupled to workplace monitoring and health surveillance. Typical control measures that may be proposed and about which the employer will need to make (informed) decisions include the following.


Avoid the risk:

  • avoid the need to do the coating operation, eg by the use of a different substrate (plastic in place of metal)

  • do without the benefit that the coating provides.


Do a risk assessment covering all risks:

  • chemical

  • fire and explosion risks

  • manual handling

  • pressurised systems

  • machinery and mechanical risks, etc.


Combat the risk at source, eg with extraction:

  • full or partial enclosure of the coating operation

  • provision of extraction system

  • provision of scrubbing system.


Adapt the work to the individual:

  • consider posture in spraying

  • consider loads to be lifted, held, manoeuvred, etc

  • look at space, including headroom

  • examine workplace temperature, lighting, ventilation, etc.


Stay in touch with changing technology and best practice and introduce them as appropriate to the workplace:

  • eg low-air/high-solids applicators that reduce the amount of material sprayed and the amount of substance that may be released as overspray

  • lower pressure spraying systems.


Replace the toxic coating chemical:

  • with a less dangerous substance

  • or (better still) with one that is not classified as hazardous.


Actively manage the issues arising and use more than one approach:

  • review of risk assessments

  • active workplace monitoring (are control measures working, are they used, are they enforced?)

  • check the operation of extraction equipment (daily, weekly, monthly operator checks and 14-monthly statutory examinations).


Give collective protective measures priority:

  • eg ensure that exposure to inhalation of toxic materials is controlled by enclosure and by local exhaust ventilation rather than by reliance on personal protective equipment such as respirators.



  • principles of control, risk assessment, COSHH (Control of Substances Hazardous to Health Regulations 2002) assessment

  • safe working practices

  • use and provision of welfare facilities

  • the need for good standards of personal hygiene, etc.


Even doing the minimum to reduce risks down to ALARP means doing a lot, with respect to health and safety. Consideration must be given to the risks presented by a task, workplace, operation, and so on. After the risk assessment, suitable control measures must be identified and implemented that address the risks identified and that work in accordance with the hierarchy of control. Risk assessment needs to be holistic: all factors need to be considered, including any new risks created by the introduction of the control measures. For example:

  • a small reduction in the toxicity of a substance should be weighed against the increased risks associated with flammability

  • the reduction in manual handling risks brought about by the use of mechanical handling (such as a fork lift truck or a conveyor system) need to be balanced against the increased risks arising from vehicle movement, falling loads and mechanical risks, etc.

So those who state “I only want to do what I have to” probably do not realise how much is involved. In many cases, achieving the minimum means going a long way.