Olson v. Prosoco, Inc.
522 N.W.2d 284 (Iowa 1994)


  • Olson was a bricklayer foreman who spotted a 15-gallon drum of mortar cleaner on the ground at work.
  • To prevent it from freezing to the ground, he moved it onto a nearby pallet.
  • When he did so, hydrochloric acid (manufactured by Prosoco) splashed into his eye, causing him to lose sight in his right eye.
  • He sued under theories of strict liability and negligence for failure to warn.

The jury found Prosoco 100% at fault under both theories.

  • Prosoco contended the submission of instructions on both strict liability and negligence theories was duplicative and confusing, resulting in prejudicial error.

Whether, in a product liability case for failure to warn, it is error to instruct the jury on both strict liability and negligence theories.

Yes. However, no prejudicial error. Affirmed.


  • Basically there’s no distinction between the two – both instructions essentially required the jury to determine whether the defendant negligently failed to warn users of the dangers in moving or using a product.
  • “We believe that the correct submission of instructions regarding a failure to warn claim for damages is under a theory of negligence and the claim should NOT be submitted as a theory of strict liability.”
    • In testing the defendant’s liability for negligence in failing to warn, the defendant should be held to the standard of care of an expert in its field.
    • The relevant inquiry therefore is whether the reasonable manufacturer knew or should have known of the danger, in light of the generally recognized and prevailing best scientific knowledge, yet failed to provide adequate warning to users or consumers.
  • Here, it was harmless error because the jury found Prosoco 100% negligent on both theories.

Rule: Failure to warn claims should be submitted to jury under a theory of negligence and NOT submitted under a theory of strict liability.