Reasonably practicable – definition, the quantum of risk test
Court of Appeal
Coal Mines Act 1911
Mr Edwards was killed when an unsupported section of a travelling road in a mine gave way. Only about half the whole length of the road was shored up. The company argued that the cost of shoring up all roads in every mine was prohibitive when compared to the risk.
The question at issue was not the cost of shoring up all roads in every mine operated by the company. The issue was the cost of making safe the section of road that fell. Some roads are secure and show no signs of failing. Others may already have fallen and have already been repaired. The section in question was already supported by timber along half its length. The cost of making it safe was not great compared to the risk of injury and loss of life
Note¹
“Reasonably practicable 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
involved in the measures necessary for averting the risk (whether in
time, trouble or money) is placed in the other and that, if it be
shown that there is a great disproportion between them – the risk
being insignificant in relation to the sacrifice – the person upon
whom the obligation is imposed discharges the onus which is upon
him.”
Asquith LJ
Note²
The Act requires employers to ensure "so far as is reasonably
practicable" employees, (Section 2) and non-employees, (Section 3),
are not exposed to risks to their health and safety from the
employer's undertaking (ie business).
The test for what is reasonably practicable was set out in this
case.The case established the risk must be balanced against the
'sacrifice', whether in money, time or trouble, needed to avert or
mitigate the risk. By carrying out this exercise the employer can
determine what measures are reasonable to take. This is effectively
an implied requirement for risk assessment.