When making a claim for strict liability in a product liability case, it is necessary to prove that the product was defective by proving that it was "unreasonably dangerous for its intended use" as a result of a defect. Note that a product may be inherently dangerous but have substantial value, or "utility" such that the danger is one which would not be considered "unreasonable." For instance, gasoline is an inherently dangerous product, but its utility far outweighs any danger posed by its use. Therefore, the law does not consider gasoline to be unreasonably dangerous for its intended use. If there were an alternative, less dangerous, and less costly fuel available, the law would likely permit a product liability action to prove that gasoline is an unreasonably dangerous product, and therefore, defective. Similarly, a knife is a dangerous product, but the law wouldn't consider it "unreasonably" dangerous unless it were manufactured with a handle so fragile that it will snap during ordinary use.
Certain types of products, such as medical drugs, may be considered unavoidably unsafe. There are many drugs used in the treatment of serious and fatal diseases which themselves may cause serious injury and even death. Although these products may be clearly "dangerous," they may not be considered "unreasonably dangerous" if proper information and warnings are given to users.
In general, there are three types of defects which could render a product unreasonably dangerous:
Manufacturing defects are defects that typically occur in a relatively low number of units of a given product, since the defects occur during the manufacturing process of a product. Any number of problems can occur during production and assembly of complex products — a screw may not be adequately tightened, a bolt may be missing, wires may be crossed, or pieces may be incorrectly soldered, for example. As a result, the product comes off the assembly line in defective condition.
Example: A transistor is improperly installed into a hair dryer, causing the unit to smoke and eventually burn up. The manufacturing defect poses a risk of electrical shock, as well as a fire hazard. If it causes a shock or a fire in your home, the manufacturer will be liable for injury and damages which result.
Design defects are inherent flaws in the design of a product, such that even if a product is assembled and produced perfectly, it will always leave the factory in dangerous condition. An automobile that will explode upon impact, as was the case with the Ford Pinto, would be considered to have a design defect.
Example: A ladder is constructed of lightweight aluminum, which can bend, or cause the ladder to tip with little force. Even if every such ladder is assembled correctly, it will still create a dangerous situation for users of the ladders. Such a ladder is considered to have a design defect.
Design defects also apply to the way products are packaged. For example, if an insect poison is sold in a bottle that is prone to leaking, or requires a user's hands to come in contact with the poison, the manufacturer could be liable for injuries which result from the defective design. Much of today's product liability litigation consists of design defect cases, and this field is broad enough to cover such claims as asbestos litigation, vaccine and other drug litigation, flammable fabric litigation, dangerous power tool or appliance litigation, defective medical implant litigation (including breast implants), and any other area in which a product's design makes it unreasonably dangerous for its intended use, thereby causing injury.
Inadequate instructions and warnings are also a basis by which a product can be determined to be defective. Inadequate warnings generally are those which fail to prevent the improper use or assembly of a product. Product manufacturers have a responsibility to provide consumers with clear and complete instructions to ensure the safe use of a product. This is particularly important where the product is "intrinsically dangerous," i.e., of such a character to be harmful in its ordinary use absent proper caution. In that case, the manufacturer must adequately warn consumers of the potential dangers, and the alert must be explicit and written in language that is easily comprehensible to the average person. Failure to adequately and properly warn, with regards to use, handling, dangers, and other effects of a product is a common basis for product liability lawsuits. An otherwise useful product carrying inherent risks may be determined to be unreasonably dangerous for its intended use solely due to the absence of an adequate warning alerting the user to the danger.