Legal Definitions - design defect

Design Defect

A design defect refers to a flaw inherent in the blueprint or plan of a product, rather than an error made during its manufacturing. This means the product was built exactly as intended by its designers, but the design itself makes the product unreasonably dangerous or unsafe for consumers when used as intended or in a foreseeable manner.

To prove a design defect, it is often necessary to show that a reasonable alternative design existed at the time the product was made. This alternative design would have been safer, economically practical, and maintained the product's primary purpose, without significantly impairing its usefulness or cost-effectiveness.

• Example 1: An Electric Space Heater

  Imagine a specific model of electric space heater that, due to its internal layout and choice of materials, consistently overheats and poses a fire risk when operated on a carpeted surface, even though it was manufactured perfectly according to its specifications. The danger isn't from a faulty wire or a loose connection (a manufacturing defect), but from the fundamental way the heater was designed to dissipate heat and the materials chosen for its casing, making it inherently unsafe for a common use scenario. A safer alternative design might involve different internal components, a more robust heat-resistant casing, or an automatic shut-off mechanism specifically triggered by surface temperature, all of which were technologically and economically feasible at the time of design.

• Example 2: A Child's Bicycle Helmet

  Consider a child's bicycle helmet that, while appearing sturdy and manufactured without any flaws, has a strap buckle mechanism designed in such a way that it can easily unclip itself during a low-impact fall, even when properly fastened. The helmet was produced exactly as the designers intended, but the specific design of the buckle system is inherently flawed because it fails to provide adequate protection in a foreseeable accident scenario. A safer alternative design for the buckle, perhaps one with a more secure locking mechanism or a different fastening method, could have been incorporated without significantly increasing the helmet's cost or complexity.

• Example 3: A Kitchen Appliance (e.g., a Food Processor)

  Suppose a particular model of food processor is designed with a blade assembly that can be activated even when the lid is not fully secured, allowing the spinning blades to be exposed to the user's hand. The appliance was manufactured correctly, and all parts fit together as designed. However, the *design* itself lacks a crucial safety interlock mechanism that would prevent the blades from operating unless the lid is properly locked into place. This design choice creates an unreasonable risk of injury. A safer alternative design would include such an interlock, which is a common and economically feasible safety feature in similar appliances.