Mercury spills, usually the result of thermometer breakage in a water bath or heating block, are one of the most common accidents in research labs.

It costs approximately $110 to clean up each mercury spill. This does not take into account the cost of laboratory equipment that is often contaminated and must be thrown out, or your laboratory staff time.

Mercury spills in a laboratory sink must be cleaned up thoroughly to prevent wastewater mercury levels from exceeding 1 part per billion, the limit strictly enforced by the MWRA. Please report all spills into sinks so that residual mercury can be removed from the sink trap immediately.

Alternatives to Traditional Mercury Thermometers:

Teflon-coated mercury thermometers--breakage resistant, slightly higher price; comparable accuracy.

Spirit-filled, mercury-free thermometers--non-hazardous (filled with petroleum-based mineral spirits); comparable price; comparable accuracy.

Alcohol-based, mercury-free thermometers--non-hazardous; comparable price; tends to be less accurate than mercury thermometers.

Microprocessor-based thermometers--non-hazardous; digital readout; excellent accuracy; on the expensive side.

Alternative thermometers are available from common lab equipment suppliers, such as VWR. Please phase out the use of mercury thermometers in your lab.

In Case of a Mercury Spill:

Most small spills can be cleaned up with the aid of a mercury spill kit (available in each buildings' Emergency Spill Equipment Cabinet.). In the event of a spill, isolate the area. To protect yourself when cleaning up a broken mercury thermometer, avoid exposure and injury by wearing gloves, a lab coat, and safety glasses/goggles. See the mercury Material Safety Data Sheet for more details.

Collect the spilled mercury and broken thermometer or other contaminated objects in a leak-proof glass or plastic container (bags are not recommended, as they are easily punctured). Label the container with a hazardous waste label, mercury spill cleanup debris, toxic, corrosive, and call for hazardous waste pickup (Longwood Campus 432-1720; Cambridge Campus 495-2060).

Notes:

1. Clean up the spilled mercury immediately!

2. If the mercury spill occurred in a water bath or other heated object, turn off the equipment and move it to a fume hood to minimize evaporation and exposure.

3. Mercury easily disperses into fine particles upon impact, becoming invisible and thus much harder to collect; try to avoid dropping it or scattering it through inadvertent contact.

4. DO NOT let mercury go down the sink drain, since it then contaminates the water system. Harvard University is under strict MWRA permit restrictions to limit the amount of mercury entering the ecosystem.

5. Note that mercury easily collects in cracks and scratches in floors. For spillage onto porous surfaces, call EH&S for clean-up assistance.

6. Do not vacuum the spill with an ordinary vacuum cleaner; a special vacuum cleaner must be used. Call EH&S for spills requiring vacuuming.