MRS OLUYOMI AYANNUGA v ONE SHOT PRODUCTS LTD

Under the Consumer Protection Act 1987, causation and defect are distinct questions. The court must consider the whole evidential picture and decide whether the claimant’s explanation is more likely than not. A finding that a product contributed to damage would not, by itself, establish a defect. Product safety is assessed objectively in all the circumstances. A drain cleaner may be defective if it is reasonably foreseeable that it will react dangerously with substances normally found in a blocked domestic drain. It is not necessarily defective where the dangerous reaction requires an unusually large quantity of an unlikely substance, particularly where the product is clearly identified as hazardous and users are warned not to use it where other chemicals are present.

The claimants sought damages for personal injury after hydrogen sulphide gas overcame members of the Ayannuga family and killed their friend while he was attempting to unblock a kitchen sink using One Shot drain cleaner. The claim was brought against the manufacturer under the Consumer Protection Act 1987.

The court tried two preliminary issues: whether the product was defective, and whether the alleged physical injuries were caused or contributed to by a defect in it. The central questions were whether One Shot materially contributed to the formation of the gas and, if so, whether its safety was below the level persons generally were entitled to expect.

1. The claim was dismissed. The court answered both preliminary issues in the negative and ordered the claimants to pay the defendant’s costs, subject to the qualified one-way costs-shifting provisions in Part II of CPR Part 44.
2. Causation had to be established on the balance of probabilities. The court applied the approach summarised in Graves v Brouwer [2015] EWCA Civ 595, considering common sense, the whole evidential picture, the competing explanations, evidential gaps and the reasons for them, and then standing back to ask whether the claimants’ explanation was more likely than not to be correct.
3. The issues of causation and defect were distinct and should not be conflated. Although the court addressed factual causation first because it was a threshold issue, a finding that One Shot had contributed to the gas would not itself establish that the product was defective.
4. The evidence did not establish that One Shot had reacted with lime sulphur. The proposed presence of lime sulphur in the blocked waste system was implausible and contradicted by the evidence. The defendant’s alternative explanation, that a pocket of sewer gas escaped when the waste pipe was removed, was scientifically sound, consistent with the sequence of events and supported by the expert evidence. The court therefore found that the use of One Shot was coincidental and did not materially contribute to the death or injuries.
5. Applying the objective assessment required by sections 3(1) and 3(2) of the Consumer Protection Act 1987, safety was a relative concept and all relevant circumstances had to be considered. The product was clearly marked as containing hazardous, corrosive sulphuric acid and warned against use where other chemicals were present. A dangerous reaction with foodstuffs or ordinary sink detritus might have supported a finding of defect. A reaction requiring sufficient lime sulphur to be poured into an already blocked sink was highly unusual and outside what could reasonably be anticipated in normal use. Even if that reaction had occurred, the product would not have been defective on the evidence.