Introduction to Health and Safety at Work

1.9.3 Reasonably 
practicable
This is the most common level of duty in health and safety 
law and was defi ned by Judge Asquith in Edwards v. 
the National Coal Board (1949) as follows:
‘Reasonably practicable’ is a narrower term 
than ‘physically possible’, and seems to me to 
imply that computation must be made by the 
owner in which the quantum of risk is placed 
on one scale and the sacrifi ce involved in 
the measures necessary for averting the risk 
(whether in time, money or trouble) is placed 
in the other, and that, if it be shown that there 
is a gross disproportion between them – the 
risk being insignifi cant in relation to the sac-
rifi ce – the defendants discharge the onus 
on them.
In other words, if the risk of injury is very small compared 
to the cost, time and effort required to reduce the risk, 
then no action is necessary. It is important to note that 
money, time and trouble must ‘grossly outweigh’ not bal-
ance the risk. This duty requires judgment on the part 
of the employer (or his adviser) and clearly needs a risk 
assessment to be undertaken with conclusions noted. 
Continual monitoring is also required to ensure that risks 
do not increase. There are numerous examples of this 
level of duty, including the Manual Handling Operations 
Regulations and The Control of Substances Hazardous 
to Health Regulations. If organizations follow ‘good prac-
tice’, defi ned by the HSE as ‘those standards which sat-
isfy the law’, then they are likely to satisfy the ‘reasonably 
practicable’ test. Approved codes of practice and guid-
ance published by the HSE describe and defi ne many of 
these standards. The term ‘suitable and suffi cient’ is used 
to defi ne the scope and extent required for health and 
safety risk assessment and may be interpreted in a similar 
way to reasonably practicable. More information is given 
on this defi nition in Chapter 5.