A design defect is a common basis for a products liability claim, where a consumer has suffered injury as a result of using a particular product. A product with a design defect is flawed from the moment it is created; essentially, the product is designed in such a way that it is inherently unsafe for consumers in some manner, or creates an unnecessary risk of harm to the consumer. One of the keys to a products liability claim based on a design defect is that the consumer used the product only as it was intended, or in a manner that was reasonably foreseeable by the manufacturers of the product. In other words, the consumer must have been using the product in a routine manner when the injuries occurred as a result of its usage. The exact legal standard for proving the existence of a design defect varies from state to state, but generally, a consumer must show that the product design was unreasonably dangerous and/or that the manufacturer was negligent in designing the product in the manner in which it was designed.