These requirements cover highway emergency signals intended to be carried on commercial automotive vehicles and to be used as emergency traffic warning signals in the event of enforced parking of the vehicle on a highway. These requirements cover three types of warning signals: Liquid-Burning Flares, Red Electric Warning Lanterns, and Fuses. A product that contains features, characteristics, components, materials, or systems new or different from those in use when the standard was developed, and that involves a risk of fire, electric shock, or injury to persons shall be evaluated using the appropriate additional component and end-product requirements as determined necessary to maintain the level of safety for the user of the product as originally anticipated by the intent of this standard.