Hygiene Plan for Elemental Mercury in Laboratories

Elemental mercury has relatively low acute toxicity but does present a potentially significant long-term exposure risk. Mercury can produce colorless, odorless, and difficult to detect vapor at room temperature. Mercury spills are very difficult and expensive to clean up. This procedure outlines the minimum requirements for laboratories using or storing elemental mercury at Lock Haven University.

The use of elemental mercury should be eliminated whenever possible. EHS will take elemental mercury thermometers, switches and devices for proper disposal. Here are some alternatives to standard mercury thermometers and other mercury containing devices:

Spirit filled thermometers meeting NIST/ANSI /SAMA standards for accuracy.	-100 to +250° C
Dial thermometers (not very accurate ±1% of thermometer range).	-50 to +540° C
Digital Thermometers (accuracy and cost varies).	-70 to +1000° C
Shatterproof or fluoropolymer coated mercury filled thermometers.	- 20 to +750° C
Digital and analog vacuum gauges are available in various ranges and accuracy.

If you cannot find alternatives to mercury in your research you must use these precautions to prevent mercury spills and contamination.

• Replace standard mercury thermometers from incubators, drying ovens, and shakers with spirit filled alternatives. Never move or store equipment with mercury thermometers in place as they break easily.
• Containers of mercury must be clearly labeled and sealed at all times. Containers should only be opened within certified fume hoods. Shatterproof containers are best and they must be stored within a secondary containment bins.
• Mercury should never be allowed to enter drains or allowed to evaporate. Collect all spilled mercury promptly and protect cup sinks or drains from contamination. Used or unwanted mercury must be disposed of as a hazardous waste through EHS.
• Portable devices containing mercury (manometers, McLeod gauges) must be sealed with an airtight and leak proof seal (valve or septum etc.) when not in use. They must also be stored in secondary containment bins.
• Vacuum pumps must be protected from contamination by liquid mercury and mercury vapor through the use of inline activated carbon filters and/or suitable cold traps. Contact EHS if you have questions.
• Items that have come in contact with mercury or mercury vapor can become contaminated and must be disposed of as hazardous waste or cleaned. Contact EHS with questions on effective decontamination of non-porous items like glass, ceramic, or metal.
• All spills must be cleaned up immediately with a mercury spill kit. Contaminated debris and spill absorbents must be disposed of promptly through EHS. Contact EHS if you have a spill that has is beyond your ability to control or represents an exposure risk.
• Review the MSDS sheet for elemental mercury on the DCIS system and the EHS handout "Mercury - Minimization is Essential" found in the "Hazardous Waste Management, Minimization and Disposal Guide" for more information.

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