Also known as: Quicksilver, Liquid Silver
Chemical reference number (CAS): 7439-97-6

Mercury is a heavy, silvery-white metal element. It can exist as a liquid at room temperature or as a solid crystal salt. The liquid metal form gives off invisible, odorless, toxic vapors. Mercury can also be found in organic (with carbon) compounds. Commonly, metallic mercury can be found in thermometers, barometers, electrical switches, thermostats and in dental fillings. (Information on cleaning up mercury spills). Mercury has also been found in some skin products sold abroad.

When mercury is released from industries into the air, it can travel long distances and be deposited on soil and in lakes. In lakes, small organisms change the mercury to a form of organic mercury (methylmercury) that builds up in the bodies of fish. Some lakes in Wisconsin have health advisories that recommend against eating too much of certain types of fish containing high levels of methylmercury.

Organic mercury is the most poisonous form. It is used as a fungicide and preservative for seeds, wood products, and paper products. In homes, organic mercury can be found in latex paints, and metallic mercury is sometimes used in religious rituals.

Wisconsin Poison Control Center, 800-222-1222

Your local health department

Division of Public Health, BEOH
1 West Wilson Street
Madison, WI 53701-2659

The Agency for Toxic Substances and Disease Registry (ATSDR) Information Center toll-free at 1-888-422-8737 or e-mail

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Last Revised: March 10, 2017

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