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Guide for Appliance Recyclers June 2004 <br />the environment. (Scrap metal recyclers include used appliance dealers, appliance <br />recyclers, and scrap metal recyclers.) If mercury switches are not removed from major <br />appliances, mercury has the potential to be released to the environment when the <br />appliances are shredded and melted to make new steel. Appliance parts that have <br />mercury and are discarded in landfills may potentially release mercury into the <br />environment through the landfill leachate. <br />Improper management of discarded major appliances that contain mercury switches <br />represents a potential source of mercury release when considering the amount of <br />mercury in each switch and the large number of major appliances that reach the end of <br />their useful lives each year. Most appliance manufacturers are using alternative <br />switches in new products; however, the appliances that already contain mercury will <br />remain in use and in the waste stream for years to come. <br />What is the purpose of this manual? <br />This manual will provide general guidance to scrap metal recyclers about how to find, <br />remove, and manage mercury switches from major appliances in compliance with the <br />latest California laws and regulations. if anything in this guide is inconsistent with <br />California's laws and regulations, you. are required to follow the current laws and <br />regulations. <br />BACKGROUND <br />What is a mercury switch? <br />A mercury switch is a sealed container that holds elemental mercury and that is used for <br />completing or breaking an electric circuit, like the convenience light in a chest freezer, or <br />for opening and closing a valve, like a flame sensor. Mercury switches are relatively <br />small and come in various shapes, including bullet-shaped capsules and pellets, <br />elongated bulbs and probes, and thin capillary tubes. Mercury switches can be made of <br />steel, plastic, or glass. <br />What types of mercury switches are contained in major appliances? <br />Two types of mercury switches may be found in major appliances. <br />"Tilt," or "positional," switches measure movement. Such a switch is part of the <br />mechanism that turns a light, motor, or pump on or off by creating an electrical <br />connection inside a mercury -filled pellet that usually has a wire attached to each end. <br />The mercury moving within the switch responds to changes in position and will either <br />complete or break an electrical circuit to turn an appliance (or its light) on or off. <br />A "thermoelectrical," or "safety valve," switch is used in flame sensors in gas-fired <br />appliances. The ability of mercury to expand when heated and contract when cooled is <br />used to regulate gas flow. Mercury is contained in a probe located in the pilot flame. <br />When the pilot flame heats the mercury and causes it to expand, a diaphragm is opened <br />that allows gas to be supplied to the pilot light. If the pilot is not lit, the mercury cools <br />and shrinks, and causes the diaphragm to close and shut off the gas supply. <br />3 <br />n <br />• <br />