MCL: 0.002 ppm
Source: Mercury is naturally occurring in rocks and minerals. It is used in thermometers, barometers, dental implants, and pesticides.
Water Treatment: https://tdb.epa.gov/tdb/contaminant?id=10341>
Summary: Mercury is element 80 on the periodic table. It is notorious for being a toxic liquid metal at room temperature, and is incredibly dense at 13.5336 g/mL. It forms alloys with other metals that are known as amalgams. Some of these amalgams are used in dental fillings and batteries, although mercury in batteries has been phased out. Mercury has uses in scientific equipment such as thermometers and barometers. It is also used in vapor lamps and fluorescent street signs. Other uses include a role in the pigment known as vermilion, mercury switches, and in the production of some pesticides. In the environment, mercury may react with organic carbon to produce methylmercury. Mercury will bioaccumulate in organisms.
GHS Hazard Statement: H290, H300, H317, H319, H330, H341, H360, H360D, H360FD, H370, H372, H400, H410, GHS05, GHS06, GHS07, GHS08, GHS09