This case is one of a number of cases involved with the interpretation of section 63 (1) of the Factories Act
In the this case, the employer argued that the extractor had been installed as soon as it had been thought of. The Court of Appeal held that the employer could not be held liable, as for a measure to be "practicable" meant that it had to be known about, especially by experts, so that it could be applied by people in the industry.
1.This case refers to duties placed on employers relating to "dust and fumes". The decision refers to the standard of "practicability" which it claims is that of "current knowledge and invention". Once something is found to be practicable, as in ventilation systems, it is feasible. It must then be done no matter how expensive or inconvenient. However, this also means that an employer cannot be liable for failing to use a safety device which was not invented at the time of the accident but appeared subsequent to it.
2.Where safety measures are qualified by the expression "practicable" this denotes a stricter standard than "reasonably practicable". It means "possible to be accomplished with known means or resources" or "feasible". Cost is probably not a factor to consider but no measure can be "practicable" if, at the time the employers' conduct is called into question, the measure is not known to science or if a known measure has not been thought of in connection with an existing
Statute Factories Act 1937, s.47; then FA 1961, s.63