Health and Safety at Work Act 1974
S. 40: Proving limits of what is Practicable etc.
In cases involving a duty to do something ‘so far as is practicable’ or ‘reasonably practicable’ or to use the ‘best practicable means’, the accused must prove, as the case might be, that it was...
- not practicable to do more than was done; or
- not reasonably practicable to do more than was done; or
- that there was no better practicable means than was used.