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
“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.”
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.