Johnson v. Honeywell International Inc.

“A manufacturer is not liable to a sophisticated user of its product for failure to warn of a risk, harm, or danger, if the sophisticated user knew or should have known of that risk, harm, or danger.” (Johnson v. American Standard, Inc. (2008) 43 Cal.4th 56, 71 [ 74 Cal.Rptr.3d 108 , 179 P.3d 905 ] (hereinafter, American Standard).) This is the sophisticated user defense, and it applies to negligence and strict liability warning defect claims. (Id. at p. 65.)

In this case, which comes to us after a demurrer was sustained without leave to amend, we are asked to determine whether the defense also applies to a cause of action for negligence for failure to warn on a theory of negligence per se, or to a cause of action for strict liability/design defect under the risk-benefit analysis. We find that the defense does apply to the negligence cause of action, but does not apply to the strict liability cause of action.

We thus reverse the judgment in favor of respondents Honeywell International Inc., E. I. DuPont de Nemours and Company, and W.W. Grainger, Inc., on appellant William Keith Johnson’s complaint against them.

BACKGROUND

Johnson is an EPA (Environmental Protection…