of these product-related injuries is not obscure, nor are preventive methods lacking, but often they are not implemented. We know, for instance, that tap-water scalds in bathtubs and showers could be eliminated by limiting the maximum temperature achievable by hot-water heaters or requiring the installation of antiscald devices (2). Similarly, air bags in cars would drastically reduce the incidence ofinjury and death resulting from crashes (3), but air bags are still not available in automobiles. A poorly designed product is often the "vector" for injurious forces. In disease epidemiology, efforts are made to control the interaction between vectors (mosquitoes, for example) and man; in product-related injuries, the "vectors" are created and skillfully marketed by man. Unlike most vectors of infectious diseases, product vectors are an integral part of the stream of commerce, affecting the vested financial interests of their manufacturers and retailers. Two basic approaches commonly used with disease vectors are to eliminate the vectors or to prevent their contact with man. With product vectors, elimination of the product or preventing human contact is often impractical, but modification of the product can reduce its potential for transmitting injurious forces to man. Therefore, a vital public health concern is how to provide manufacturers with incentives for designing products that will not injure people. In examining what motivates a manufacturer in the design of a product, it is clear that the marketability of the product and the cost of its production are of primary concern, because these factors will to a large extent