Mercury is a metallic element that, in its pure form, is a heavy,
silver-colored liquid. Mercury occurs naturally in ores and other geologic
formations and is also released into the environment through various human
activities. Mercury can be found at low levels throughout the environment and is
carried across whole continents by upper atmospheric air currents.
Mercury has significant public health and wildlife impacts, primarily from
consumption of mercury-contaminated fish. It can permanently affect fetal and
child development and can damage the brain, kidneys and lungs. Whereas mercury
released into the environment is primarily inorganic or elemental by nature,
when in the environment, it is converted by bacteria to a methylated or organic
form, which is the most toxic and bioaccumulative form of mercury. Once formed,
methyl mercury can be readily passed through the food chain. Mercury’s
designation as a “persistent, bioaccumulative and toxic (PBT)” pollutant and its
widespread prevalence in the environment have made it a high-priority pollutant
at both the state and national level.
Mercury is used in many common household products, including thermometers,
fluorescent light tubes, thermostats, batteries, dental fillings and vehicle
How to reduce mercury that gets into the environment
- Mercury-containing thermostats: Replace your mercury-containing
thermostat with an energy-efficient digital thermostat.
- Mercury thermometers: Exchange your mercury-containing thermometer
for a digital thermometer.
- Mercury-containing vehicle switches: Check to see if your vehicle has
mercury-containing convenience light switches. Replace them with non-mercury
- Prohibition Against Mercury Thermostat
Oregon state law (Oregon Revised Statutes 455.355,
implemented by Oregon Administrative Rules 918-440-0500-510) makes it illegal
for contractors to install thermostats containing mercury in homes or commercial
establishments. HVAC contractors are also required by state law to properly
manage mercury thermostats so that mercury does not become part of the solid
waste stream. Each mercury thermostat contains about four grams of mercury, and
because there are so many in use, mercury thermostats are one of the largest
sources of disposed mercury.