Wood v Esso Petroleum Co Ltd

A claimant alleging injury from inhalation of an unidentified substance must prove, on the balance of probabilities, an escape of a substance foreseeably likely to cause injury and that the escape caused the alleged injury. A smell is not a hazardous substance merely because an unusually vulnerable person reacts adversely to it. For the purposes of the Workplace (Health, Safety and Welfare) Regulations 1992, a known harmful chemical escaping may give rise to strict liability, but the claimant must first establish the relevant escape and causation. The doctrine of res ipsa loquitur does not remove the need to reach the evidential threshold identified in Lloyd v West Midlands Gas Board.

The claimant, a steel erector employed by a contractor at the defendant’s refinery, alleged that he inhaled an unidentified gas or vapour during an evacuation at the defendant’s premises on 17 June 2005. He claimed respiratory injury and consequential losses, alleging negligence and breach of statutory duty.

The court tried liability and causation separately from quantum. The central issues were whether a harmful or hazardous substance had escaped, whether the claimant suffered physical or psychological injury, whether either was caused by the incident, and whether the defendant was liable under the Workplace (Health, Safety and Welfare) Regulations 1992.

1. Liability and causation. The claim was dismissed. The claimant was an unreliable witness, and the court found that the smell lasted approximately 15 minutes. It was not hydrogen sulphide, a hydrocarbon or mercaptan, and the claimant failed to prove that it was harmful in the sense of creating a foreseeable risk of injury.
2. Medical evidence. The court preferred Dr Hines’s evidence to that of Dr Howard. The diagnostic criteria for reactive airways dysfunction syndrome were not met, particularly the requirement for exposure to a very high concentration of an irritant substance. There was no physical respiratory injury. Any psychological symptoms were not proved, on the balance of probabilities, to have been caused by the incident.
3. Statutory duty. Regulation 5 of the Workplace (Health, Safety and Welfare) Regulations 1992 imposed strict liability if a known harmful chemical escaped. The existence of reasonable or effective systems would not itself be a defence. However, “hazard” necessarily involved an element of foreseeability. An unidentified nasty smell could not be hazardous without evidence of an intrinsic property capable of causing harm.
4. Res ipsa loquitur. The claimant’s reliance on Lloyd v West Midlands Gas Board failed. The doctrine requires the claimant’s evidence to reach the point at which, if the defendant called no evidence, the case would be proved. The facts did not reach that point.
5. There was no negligence, no proved escape of a substance foreseeably likely to cause damage, no breach of statutory duty and no causative injury. The claim was dismissed.

First-instance decision. No prior or appellate decision is stated in the judgment.