Wednesday, December 11, 2013

What should I do if there is a mercury spill in my building?

Mercury is a very heavy liquid metal element, silvery in color and is a liquid at room temperature.  Mercury will slowly evaporate at room temperature and these vapors are invisible, odorless, and, at high levels, very toxic.  Mercury vapors can harm the nervous system, cardiovascular system, digestive tract, kidneys.  To find mercury in everyday life one has to look no further than thermometers, barometers, electrical switches, and thermostats.  Once mercury is no longer contained or once it spills it will bead up and spread rapidly.  The amount of vapor mercury produces is related to the amount spilled, surface area (amount of beads produced), temperature (vapors increase with warmer air), air flow and physical disturbance of the spilled material.



Mercury spills can be very serious and must be handled promptly as well as properly.  Cleanup is important, but what is equally important is WHAT NOT to do when cleaning mercury.  When cleaning up a minor mercury spill from a broken thermometer, remember to never attempt to vacuum up the mercury.  Vacuuming will further disrupt the mercury turning it into vapor and releasing it back into the air, increasing exposure.  To gather the beads up after a spill, never use a broom.  A broom can once again break the mercury down into smaller pieces and release harmful vapors.  The EPA recommends a squeegee or piece of cardboard to gently and slowly gather the beads together.  Never pour mercury down a drain to dispose of it.  Mercury can become lodged in the plumbing and cause future problems.  Furthermore, if the mercury is discharged it can lead to pollution of the septic tank as well as the sewage treatment facility.  If mercury comes in contact with any shoes or clothes during clean up there is no cleaning them; they must be disposed of.  Once mercury becomes dislodged in the washing machine it can result in contaminating the entire machine as well as polluting the sewage. 

The proper way to clean a small scale mercury spill, like a broken thermometer will require: gloves, paper towels, zip-lock bags, squeegee, eyedropper and a few other optional supplies.  Be sure to always wear rubber, nitrile or latex glove before ever handling mercury.  If the spill contains broken glass be sure to carefully pick it up and place in a paper towel then in a zip-lock bag with a proper label according to local or state regulations.  After locating larger beads use a squeegee or piece of cardboard to very gently sweep beads into a paper towel, then again, into the zip-lock bag.  Remember that mercury can move quickly on flat surfaces so be sure to check the entire room for visible beads.  An eyedropper can also be used to pick up small beads.  For smaller, hard to see beads, a paint brush topped with shaving cream or a piece of duct tape can be rolled through the area to pick up any leftover hard to see mercury.  If after all that there is still mercury spilled, there is a commercially available sulfur powder which can make it easier to clean. First, the sulfur will turn the mercury from a yellow to a brown, making it easier to see.  Also, the sulfur will bind the element together to make a more thorough cleanup as well as suppress the vapor.  The sulfur can be purchased in a mercury spill kit as a “mercury vapor absorbent”.  If the kit cannot be found or if the certainty is not enough of a guarantee, contact a contractor who can come and monitor the mercury vapor with special equipment to make sure the threat is gone. 

For spills larger than a thermometer there are only a few steps.  First, make everyone leave the area.  Open all windows and doors to the outside while closing all doors to the rest of the building.  Turn down the temperature in the building and call the local or state environmental agency. 
If there is a spill greater than one pound the National Response Center (NRC) must be notified immediately at 1-800-424-8802.  It is also important to remember that mercury is a very heavy dense substance and it only takes about 2 tablespoons to weigh a pound. 

Mercury as a vapor can be very harmful to anyone who comes in contact with its fumes, and can also damage plumbing, septic tanks and even treatment plants.  For these reasons it is important to follow these steps for a safe cleanup of mercury as well containing the hazard. 

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