Roe v Minister of Health [1954] 2 QB 66 (CA)

Facts

Two patients underwent minor surgical procedures involving spinal anaesthesia. The anaesthetic was stored in glass ampoules placed in a phenol solution for sterilisation. Unknown to medical science at the time, microscopic cracks in the glass allowed phenol to contaminate the anaesthetic.

As a result, both patients suffered paralysis. They brought negligence claims against the hospital authority. At the time of treatment, however, the medical profession was unaware that phenol contamination could occur in this way.

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Issue

Can a defendant be negligent for failing to guard against a risk that was not known or reasonably discoverable at the time?

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Decision

The Court of Appeal held that the defendants were not negligent. The risk of contamination through invisible cracks in the ampoules was not known to medical science at the time. The court emphasised that negligence must be judged based on knowledge available at the time of the alleged breach, not with hindsight.

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Legal Principle

Defendants are judged according to the state of knowledge at the time of the incident. The law does not impose liability for failing to guard against unknown risks. Courts must avoid “hindsight bias” when assessing breach.

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Importance

• Leading authority on known vs unknown risks.

• Frequently cited in medical and product liability cases.

• Reinforces fairness in negligence law by preventing retrospective standards.

• Illustrates that negligence is about reasonable foresight, not perfect prediction.