Volenti non fit injuria, [Latin: no wrong is done to one who consents] The defence that the plaintiff consented to the injury or (more usually) to the risk of being injured.
Court of Appeal
The plaintiff and his brother were were certificated and experienced shotfirers employed by ICI Ltd in a quarry owned by the defendant company. Part of the brothers' work included wiring up detonators and checking the electrical circuits. There was an old practice where a galvanometer was applied directly to each detonator for testing purposes. This practice was known to be dangerous and was outlawed by statutory regulation. The plaintiff claimed his brother was 50 per cent to blame for the explosion and the employer was vicariously liable. The plaintiff was awarded half of the total amount of damages. The defendant appealed.
The plaintiff and his brother were both experts. They freely and
voluntarily assumed the risk involved in using the galvanometer.
There was no pressure from any other source. To the contrary, they
were specifically warned about complying with the new safety
The defence of volenti non-fit injuria will apply when there is true and free consent to the risk.
The employers were not liable because -
(1) the employers not being themselves in breach of duty, any liability of theirs would be vicarious liability for the fault of J, and to such liability (whether for negligence or for breach of statutory duty) the principle volenti non fit injuria afforded a defence, where, as here, the facts showed that G and J knew and accepted the risk (albeit a remote risk) of testing in a way that contravened their employers' instructions and the statutory regulations.
(2) each of them, G and J, (the brothers) emerged from their joint enterprise as author of his own injury, and neither should be regarded as having contributed a separate wrongful act injuring the other.
The defence of volenti non fit injuria should be available where the employer is not himself in breach of statutory duty and is not vicariously in breach of any statutory duty through neglect of some person of superior rank to the plaintiff and whose commands the plaintiff is bound to obey, or who has some special and different duty of care.