101a. Mercury use in Laboratory, Classrooms and Medical Labs
Mercury is a naturally occurring element with unique chemical and physical properties that make it a dangerous and often unrecognized hazard that bioaccumulates in the environment. Its persistence in that environment makes it particularly hazardous to humans and animals.
Mercury is commonly used in laboratory equipment such as thermometers, manometers, pressure gauges, switches, sphygmomanometers, and mercury containing compounds (a.k.a. Hg Compounds).
Place free mercury in a separate, unbreakable container. The container should not be larger than necessary to hold the mercury. Label as "Mercury." Any mercury-containing equipment (including mercury thermometers) should be stored carefully to prevent unintentional breakage. All mercury containers should be placed in proper secondary containment when the container allows.
When using any type of mercury-containing equipment or material, appropriate personal protective equipment (PPE) must be used. At a minimum, this includes eye protection and gloves that are appropriate to the specific type of mercury to be used. Refer to manufacturer's recommendations for glove selection. Ordinary latex gloves are not appropriate. Whenever possible, use mercury-free substitutes. While using, avoid practices that could result in unintentional spillage.
Wastes & Spills
Broken mercury thermometers are the most common cause of mercury spills in the research laboratory.
Do not mix free mercury, mercury oxide, mercuric sulfide, mercury amalgams or mercury absorbed in spill kits. Place each of these types of materials in a separate, unbreakable container and label appropriately. Whenever using a mercury thermometer, it is essential the user have utmost control at all times. If a thermometer breaks at temperatures greater than 90 degrees F., immediately evacuate the area and notify appropriate personnel. All mercury spills must be cleaned up promptly by properly trained individuals familiar with mercury cleanup practices. Such practices often involve respiratory protection, use of mercury vacuums, and appropriate air monitoring. Prior to disposal, contact the designated waste coordinator. Mercury spill kits are designated for cleanup of small, self-contained spills only and may be used to supplement the mercury vacuum. Other mercury-containing materials such as mercury-contaminated lab ware, mercury salts and spill cleanup products must be disposed in accordance with established regulatory guidelines. Currently there is limited or no disposal capacity at all in the USA for mercury salts and mercury containing compounds. Limit the volume of mercury-related waste you generate.
Laboratory personnel should be trained in the proper procedures, including reporting and handling, in the event that a mercury thermometer is broken. Cleanup of all mercury spills should only be conducted by trained individuals from the Environmental Health and Safety Office.
If you cannot replace your mercury thermometers, Teflon-coat them to minimize the release of mercury in the result of a spill. All efforts should be directed to non-mercury replacements or alternatives due to toxicity issues and the difficulty in acceptable waste disposal alternatives. If you must dispose of mercury-containing materials, you should use a permitted mercury recycling facility. For specific requirements related to storage, inspection, training, record keeping, disposal or removal, consult regulatory requirements related to mercury.