I found a good post over at the Portland Personal Injury Lawyer blog that provides a crisp definition of products liability law. Here it is:

If a defective product causes an accident that results in death, injury or property damage, the manufacturer, distributor, retailer, and lessor of the product may be liable for the damages caused by the product. The party suffering injury or damage is called the plaintiff, and the party sued for damages is called the defendant.

The plaintiff must establish that a product has a defect that made it unreasonably dangerous at the time the product left the control of the defendant.