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Mercury Containing Devices/Products
Mercury is used in a wide variety of devices and products. These items release mercury into the environment when broken or improperly disposed. If spilled, mercury absorbs into many materials while slowly evaporating into the air over time, allowing for exposure. Knowing what products and items contain mercury and handling them properly will limit the risk of mercury exposure. Common products often have a simple and environmentally friendly alternative.
Thermometers - Mercury
is used in thermometers because it expands and contracts evenly with temperature
changes. Alternatives include the electronic (digital) or red alcohol
Switches - Shown is the simplest tilt type of mercury switch
which conducts electricity and is used in many applications including light
switches (silent type), top-loading freezers and washing machines.Some clothing irons have an
automatic shut-off switch containing mercury. Irons with mercury-free automatic
shut-off switches are available.
Thermostats - Mercury in these devices act as switches to
energize heating and cooling systems. Electronic versions are available.
Thermostat Probes - Thermostat probes or flame sensors
consist of a bulb attached to a gas-control valve by a tube containing mercury.
They are generally used to prevent gas from flowing when the pilot light of the
appliance is off.
Appliances - Mercury vapor bulbs were used in older microwave ovens.
However, new models do not contain mercury.
Vehicles - Mercury
switches are also found in vehicles to turn on lights when a trunk or engine hood is opened,
Mechanical and electronic switches are available in mercury-free versions.
Luminaries (lights) - Fluorescent, HID (High intensity discharge) lamps such as Mercury Vapor, High Pressure Sodium and Metal Halide, and Neon all contain mercury in a metallic as well as vapor form. Mercury is released when bulbs are broken or incinerated. Alternatives to older model fluorescent lamps are labeled as low-mercury lamps and often can be recognized by their green end caps or green lettering. Low-mercury lamps contain less mercury which is also released when improperly managed.
Batteries - Before 1980, most batteries used in homes contained mercury. Current mercury containing batteries are "button" shaped and are used in hearing aids,
watches and other items requiring a small battery. In the last decade, the
United States battery industry achieved a 99 percent reduction in mercury by
using alternative materials. Silver oxide, zinc-air and alkaline batteries are
the best alternatives for replacing batteries produced before 1994.
- Latex paint produced before 1992 had large amounts of mercury to prevent
fungus growth. Mercury vapors were released when paint was applied. Use latex
paint manufactured after 1992.
Toys - Children's chemistry sets were once sold with liquid mercury. Some toys contain a drop of mercury that is moved through a maze, called a mercury maze. Check chemistry sets and toys to be sure they are mercury free.
Shoes - Some shoes with flashing lights in the soles, historically, contained
Pesticides - Fungicides and biocides produced before 1994 used mercury
to kill fungus, weeds and other pests. Most new pesticides are mercury-free.
Medical products -
Sphygmomanometers (blood pressure gauge) contain almost
1.5 pounds of mercury. An aneroid blood pressure unit is a mercury-free option.
Medical products - Esophageal dilators.
How about those dilators? There is the tapered tip and the
blunt tip model. The dilator is two tubes in one. The space between the outer
and inner tubes houses the medium, typically mercury. Mercury perfectly fills the
need for a heavy, flow able substance capable of
dilating the esophagus of a
patient in response to medical conditions or treatments that cause esophageal
narrowing or tissue shrinkage. Problems encountered include mercury containment
and latex sensitivity. Like all mercury, it is recyclable. Alternatives exist
such as powdered
Medical products - Dental amalgam restorative materials
(fillings). Dental amalgam is the end result of
mixing approximately equal parts of elemental liquid mercury (43 to 54 percent)
and an alloy powder (57 to 46 percent) composed of silver, tin, copper, and
sometimes smaller amounts of zinc, palladium or indium.
Besides dental amalgam, there are many other
restorative materials that are used in dentistry. Advances in technology have
resulted in improvements that have expanded the use of these alternatives.
Medical products - Mercury may be present in fixatives, stains and chemicals that biomedical laboratories stock. The following compounds used in biomedical laboratories contain mercury:
B-5 (mercuric chloride)
Pharmaceuticals - Thimerosal (about 48% mercury) has been used in antiseptic creams and as preservatives in pharmaceutical solutions including contact lens solutions. While most antiseptics are now free of Thimerosal, it can be present in older medications and creams. Mercurochrome is a skin antiseptic used to treat cuts and abrasions. It is not commonly used. Mercury-free alternatives include Neosporin and Mycin. Talk to your pharmacist about alternatives.
The following are synonyms and trade names for Thimerosal:
The US Food and Drug Administration offers a list of
Mercury In Drug And Biologic Products.
Instruments - Barometers are instruments used to measure pressure in the
atmosphere; most of the older devices contain liquid mercury. A Bourdon tube
gauge is an alternative to mercury-containing barometers. If you are unsure if
your barometer contains mercury, a silvery substance in the tube is likely
Instruments - Hygrometers measure the moisture content in
air. A psychrometer is the most common type of hygrometer. Psychrometers are
best described as dual thermometers, one with a wet base and the other with a
dry base. Hygrometers look like industrial thermometers with the distinct
attachment of a cotton bulb. Sling psychrometers are designed to be twirled in
the air to measure ambient moisture. Hygrometers/psychrometers are found in
workplaces where ambient moisture measurements are used for predicting weather
and atmospheric conditions.
Instruments - Hydrometers measure the specific gravity
and density of a liquid. They are most commonly used in laboratories, the petroleum
and dairy industries and in the production of alcohol.
Instruments - Mercury is used as a vibration dampener in
electron microscopy because of its unique properties as a liquid metal at room
Division of Waste Management Home Page
Updated: 27 Oct. 2010