Risk-Benefit Test in Product Liability Cases

When bringing a product liability case, there are two primary tests which may be applied for purposes of establishing liability and eventually, damages: first, the consumer expectations test; second, the risk-benefit test. The consumer expectations test requires the plaintiff to prove that the product failed to perform in a safe manner that would be expected by an ordinary consumer when the product is used as intended or in a reasonably foreseeable manner. Conversely, the risk-benefit test requires the plaintiff to establish a prima facie case of causation showing that a design feature of the product was a substantial factor in causing injury. The consumer expectations test requires a higher burden of proof for the plaintiff than does the risk-benefit test. Note that these two tests are not mutually exclusive. This post will focus on the risk-benefit test.

What does “the risk-benefit test requires the plaintiff to establish a prima facie case of causation showing that a design feature of the product was a substantial factor in causing injury” actually mean? It means that the plaintiff (the person suing) must show that a design feature of a product was a major factor in causing the injury. Prima facie is a low standard that in Latin means “at first sight.” Once the prima facie case has been established by the plaintiff, the defendant must prove that the benefits of the product design outweigh the inherent risk of the design.

As an example, suppose Tom bought a lawn mower that was designed with semi-exposed blades. Tom was cutting the grass and correctly using the lawn mower as instructed by the manufacturer. Unfortunately for Tom, he tripped and fell forward onto the lawn mower. In the process, he was severely injured by the lawn mower’s exposed blades. To recoup his medical expenses, Tom brought a products liability lawsuit against the manufacturer. Tom shows that the lawn mower was designed with semi-exposed blades. Tom also shows that the injury resulted from falling into the exposed blades, establishing a prima facie case that the design feature (the semi-exposed blades) was a substantial factor in causing his injury. Now that Tom has established a prima facie case, the manufacturer must meet the risk-benefit test to mitigate its liability. Here, the manufacturer will have to show that the benefits of the semi-exposed blades design outweighed the inherent risk of injury resulting from the use of the lawn mower with that specific design.

Despite its apparent simplicity, the risk-benefit test in product liability cases is most often a complex case.