Dryden v Johnson Matthey Plc [2018] UKSC 18

C were employed by D, working in factories producing catalytic converters. In breach of its duty under health and safety regulations and the common law, D failed to ensure the factories were properly cleaned and C were exposed to platinum salts. C developed platinum salt sensitisation, an asymptomatic condition. Further exposure to chlorinated platinum salts would likely cause C to develop an allergic reaction involving running eyes or nose, skin irritation, and bronchial problems. During a routine skin test screening, C’s sensitisation was discovered. They were no longer permitted to work in areas where further exposure could occur. C collectively asserted that each of them suffered financially because of their sensitisation, being unable to take work in any environment (whether with D or another employer) where further exposure might occur.

• Did sensitisation to platinum salts constitute a physical change amounting to material damage, thus making it an actionable personal injury?
• Failing that, could C recover damages for economic loss under an implied contractual term and/or in negligence?

Finding for C, that sensitisation to platinum salts was an actionable personal injury. Although the concept was not defined in the authorities, personal injury had been seen as including a physical change which made the sufferer appreciably worse off in respect of their health or capability; an impairment; and an injury to the sufferer’s physical capacity to enjoy life. An allergy to platinum salts, which was already agreed to be a personal injury, can only be developed by someone who prior developed sensitisation. D cannot escape liability by removing C from places where exposure could occur. Developing a platinum salt allergy is a two-stage process, and D’s negligence and breach of duty has already led the first stage to occur. The argument that platinum salts are not something encountered in everyday life, and thus sensitisation does not amount to actionable injury, rings hollow. For C, ordinary everyday life involved work of a type which, by virtue of their sensitisation, is no longer possible for them.

An asymptomatic physical change can constitute actionable personal injury when it makes the claimant materially worse off in health or capability. Platinum-salt sensitisation qualified because it impaired the workers' ability to continue their ordinary work safely; pain or outward symptoms were not essential.

Dryden distinguishes actionable impairment from a harmless marker of exposure. The sensitised workers had already suffered a bodily change which restricted their working lives, rather than merely fearing a future disease. Compare Rothwell, where pleural plaques did not themselves impair function. The distinction turns on the present consequences of the physical change, not simply on whether a medical test detects something or whether earnings have subsequently fallen.