LBNL Lessons Learned Statement

Mercury Filled Thermometers

January 5, 2001



Mercury thermometers, commonly found throughout the Laboratory, pose a problem because they are fragile and can be easily broken.  When a thermometer breaks, the mercury can scatter over a large area.  This presents a potential health risk to personnel in the work area and requires time consuming decontamination and costly waste disposal. 



Mercury spills can impact your work and can affect you financially.  Spill clean ups involve special remediation and air monitoring which need to be conducted by EH&S personnel.  Normally, access to the affected work area must be restricted until the spill has been decontaminated, which can result in significant “down times”.  While cleaning floors and counter tops doesn’t pose a major technical challenge, decontaminating equipment is an entirely different matter.  Recently, a researcher had to sacrifice an expensive incubator because it could not be adequately decontaminated.


Corrective Actions

When ordering new equipment, make sure you specify non-mercury containing thermometers and components.  If you already have mercury thermometers, you should replace them.  The EH&S Waste Management Group will provide general-purpose organic filled thermometers in exchange for your unbroken mercury thermometers at no cost. Also, no paperwork is required.  Two temperature ranges are currently available: -20oC to 110oC and -20oC to 150oC.  Exchanging precision thermometers and other mercury containing equipment will be addressed by the Waste Management Group on case by case basis.


Regarding accuracy: mercury and organic filled thermometers perform similarly.  For example, general-purpose mercury and organic filled thermometers with a -20oC to 110oC temperature range have tolerances of ±1o and ±3o C, respectively. For precision thermometers in the same temperature range (i.e., -20oC to 110oC), both mercury and organic filled thermometers meet the same stringent tolerance of ±0.1oC.


Procedure for Exchanging Thermometers:

Check your work area to identify mercury thermometers that can be replaced.  Give them to your Division’s ES&H Coordinator. Make sure your area Radiological Control Technician swipes and releases them from controlled areas beforehand.  Your ES&H Coordinator will get replacements.  A list of the Laboratory’s Division ES&H Coordinators can be found at


Further Information

If you have questions regarding the EH&S Waste Management Group’s mercury thermometer exchange program, contact Shelley Worsham at extension 6123.  If you need further information about mercury or have questions about spill clean ups contact Larry McLouth at extension 5286.