In Lenhardt v. Ford Motor Co., the Supreme Court of Washington held that evidence of industry custom is inadmissible in a strict product liability case. The Washington court held that the custom of the industry is not always a relevant factor in determining the reasonable expectations of the ordinary consumer. The court reasoned that admitting evidence of industry or manufacturers' customs and practices would improperly shift the inquiry from the reasonableness of the buyer's expectations to the reasonableness of the seller's conduct. The court recognized that this shift in focus would introduce concepts of fault that are relevant in a negligence, but not in a strict liability, action.
Kathleen M. Doyle,
Relevance of Industry Custom in Strict Product Liability,
60 Wash. L. Rev.
Available at: https://digitalcommons.law.uw.edu/wlr/vol60/iss1/12