McGhee v National Coal Board [1972] UKHL 11

A worker contracted dermatitis after exposure to brick dust. His employer provided no on-site washing facilities, prolonging skin contact with the dust. As the employer's breach of duty materially increased the risk of injury, they were held liable, despite causation not being definitively proven.

Facts

The pursuer, Mr James McGhee, was employed by the defenders, the National Coal Board, to clean out brick kilns. This work exposed him to hot, abrasive brick dust. The nature of the work caused him to sweat, making the dust adhere to his skin. The defenders did not provide any washing or shower facilities at the worksite, which was a breach of their duty of care as an employer. Consequently, Mr McGhee had to cycle home each day with the dust still on his skin. He subsequently developed dermatitis. The medical evidence established that the dermatitis was caused by exposure to the brick dust but could not determine whether it was caused by the initial ‘innocent’ exposure during the workday or the extended ‘guilty’ exposure during the journey home, which resulted from the lack of washing facilities.

Issues

The central legal issue was one of causation. Was the pursuer required to prove, on the balance of probabilities, that his dermatitis was caused specifically by the extended exposure due to the lack of showers (the defenders’ breach of duty), rather than simply by the work itself? Or was it sufficient to establish liability by showing that the defenders’ breach of duty had materially increased the risk of him contracting the disease?

Judgment

The House of Lords unanimously allowed the appeal, finding in favour of Mr McGhee. They held that in circumstances where a breach of duty creates a risk, and that type of risk materialises, a strict application of the ‘but for’ test of causation was not necessary. The court could infer a causal link from the fact that the defenders’ negligence had materially increased the risk of the injury occurring.

Reasoning of the Lords

Their Lordships reasoned that the distinction between materially increasing the risk of injury and making a material contribution to the injury was overly subtle and unrealistic, particularly where medical science could not provide a definitive answer on causation. They effectively shifted the evidential burden to the defenders.

Lord Reid stated:

From a broad and practical viewpoint I can see no substantial difference between saying that what the defender did materially increased the risk of injury and saying that what the defender did was a material contribution to the injury.

Lord Wilberforce articulated the underlying principle:

But it is a sound principle that where a person has, by breach of a duty of care, created a risk, and injury occurs within the area of that risk, the loss should be borne by him unless he shows that it had some other cause.

Lord Simon of Glaisdale supported this view, concluding:

If a pursuer proves that a defender’s breach of duty has created a risk of a particular kind of injury, and the pursuer has in fact suffered that particular kind of injury, I would hold that, unless the defender can show that there was some other more probable cause of the injury, the court is entitled to find that the defender’s breach of duty was a cause of the pursuer’s injury.

Implications

The decision in McGhee v National Coal Board is a landmark in the law of delict and tort, significantly developing the principles of causation. It established that where a pursuer can prove that a defender’s breach of duty materially increased the risk of them suffering a certain injury, and that injury does occur, it is sufficient to establish causation. This ‘material increase in risk’ test is particularly important in cases involving industrial diseases, environmental exposure, and medical negligence, where scientific and medical uncertainty can make it impossible for a claimant to prove that the defendant’s negligence was the definitive cause under the traditional ‘but for’ test.

Verdict: Appeal allowed. The interlocutor of the Second Division was recalled and the interlocutor of the Lord Ordinary finding the defenders liable was restored.

Source: McGhee v National Coal Board [1972] UKHL 11