In Torres v. Skil Corporation, 2013 WL 3105815 (D. Mass. June 17, 2013), plaintiff was injured while using a circular saw when the saw’s blade guard did not automatically snap into place after he finished his cuts. Aware of the danger of putting the saw down without the blade guard in place, plaintif tried to “flick” it down with his right hand. Plaintiff’s hand missed the blade guard, however, causing his ring finger to be partially and permanently severed and the tip of his middle finger to be amputated almost fully.

Acting pro se, plaintiff sued the saw manufacturer in the United States District Court for the District of Massachusetts for negligence and breach of the implied warranty of merchantability (the Massachusetts near-equivalent of strict liability) asserting, among other claims, the saw was defectively designed. Plaintiff contended the saw should have incorporated a “kill switch” that would have stopped the rotating saw blade instantaneously upon activating the switch. Neither plaintiff nor anyone else on his behalf had inspected or tested the mechanical components of the saw for evidence of a defect; rather, plaintiff testified it was his opinion the blade guard’s failure to deploy must have been the result of a defect. The manufacturer moved for summary judgment on the ground that plaintiff had not proffered any expert testimony that the saw was defective, there was a feasible alternative design or the alleged defect caused his injury.

In granting the motion, the court explained that, except in rare circumstances where the dangers of a product are within the common knowledge of a layperson, a design defect plaintiff must present competent expert testimony that a defect in the product, present at the time it was sold, caused his injuries. This includes evidence of a safer, feasible alternative design that could have been incorporated without undue cost or interference with the product’s performance. Here, plaintiff’s reliance on his own assertions regarding the need for a kill switch to stop the spinning saw blade was insufficient to survive summary judgment because the mechanical components of the saw’s blade guard were beyond a layperson’s common knowledge. Moreover, there was evidence the saw had been designed and manufactured consistent with industry standards. While not dispositive as to the absence of a defect, this evidence was sufficient to permit a jury to find of r defendant in the absence of any evidence the industry could and should have done more to ensure a safer blade design.