Broken Mercury Thermometers
Laboratory thermometers contain between 1 and 3 grams of mercury. It is best to replace your mercury thermometers with non-mercury thermometers. The university has a free thermometer exchange program. http://www.dehs.umn.edu/hazwaste_mercthemom.htm
Broken thermometers can result in exposures to vapors that over time may have health effects. Exposure to mercury vapors may cause damage to the nervous system, kidney or liver. In order to limit your exposure, follow these guidelines for broken thermometers:
- Mercury from a broken thermometer can easily be spread over a wide area, increasing the surface area for mercury droplets and, as a result, the level of vapors in an area. Isolate the area of the spill and do not walk through the spill area. Droplets can be small and hard to see, so be conservative in estimating the area affected.
- If the thermometer has cracked away from the bulb, there may be little mercury released. In this case, carefully package the thermometer in a sealed plastic bag and dab the immediate area with a wet towel, which also goes in the sealed bag. Take care with the broken glass. Send the thermometer through the Chemical waste program as mercury-containing labware waste.
- More commonly the mercury will have spread droplets on a counter or floor or you will not be sure about whether mercury has been released. In these cases, isolate and leave the spill area and call DEHS. 612-626-6002/ 9-1-1 after hours (UMTC). We will send out staff with specialized monitoring, decontamination and cleanup equipment. If you have mercury droplets on your shoes or lab coat, set them aside for cleanup and monitoring.
- Occasionally, a thermometer may spill mercury onto a heated surface, such as in ovens, hot plates or other heated sources. Mercury vapors increase exponentially with temperature, so this can be an immediate hazard. Turn off the equipment and isolate the area. Close off the lab or area and do not let others in the area, until the levels have been monitored and cleanup completed.
- Releases of mercury to the environment can cause significant effects. If mercury goes down a drain, into the trash or onto the soil, DEHS will need to take extra steps to protect the environment. It is imperative that we are informed of these special circumstances.