version of this fact sheet (PDF,
If one pound or more (more than one fluid ounce or two tablespoons) has
been spilled and gets into the environment, i.e., outdoors, sewer,
groundwater or surface water, or that threatens public health, it must be
reported immediately. Call the Wisconsin
Department of Natural Resources Spill Response hotline at 800-943-0003.
Before cleaning any mercury spills, be sure to read and
follow the precautions
found in the general mercury spill fact sheet.
Evacuate the Spill Area
Before people leave the spill site, be sure they had not come in contact with or
stepped in the mercury. When directing people out of the area, be sure to
avoid traffic going through the spill site. Those who may have come into
contact with mercury should be directed to the nearest safe location and
asked to stay there until contamination can be assessed and clean up
completed. Once immediately outside of the spill area, contaminated
(direct contact with mercury) shoes and clothes should be removed,
double-bagged and sealed. Not doing so can result in mercury being tracked
around the building or home, making the situation worse.
Seek Professional Assistance for Clean-Up
Call either the local fire department or a contractor listed under Resources.
Spills of this size require specialized equipment and demanding control measures.
It is also likely larger spills will release dangerous levels of vapors
into air and specialized protective equipment, such as self contained
breathing apparatus, will be necessary for responders.
Test Clothing/Personal Belongings
Clothing and personal belongings that were contaminated or suspected of
being contaminated can be placed in a plastic bag, which should then be
sealed and allowed to sit for about an hour. Test the headspace of the air
in the bag with a mercury vapor analyzer capable of reliably detecting
concentrations less than 0.1 ug/m3. If the level in the headspace in the
bag is less than 10 ug/m3, the clothes and belongings can be returned to
the owners. Other procedural guidance for decontamination can be found at
the Ohio EPA website.
It should be noted that the cost to clean and monitor clothes and
belongings could exceed the value of those items. Clean up cost should be
weighed against item value to prevent unnecessary expense.
Ventilate as much as possible to completely air out the room or spill
zone with outside air.
Air in the spill area should be tested using NIOSH Method 6009 (exit
similar method with comparable limit of detection. Levels should be below
1 ug/m3 for residential environments and 3 ug/m3 for commercial
Inventory All Remaining Mercury-Containing Devices and Replace Them
With Mercury Free Alternatives
The best way to address a mercury spill is to prevent it from ever
happening in the first place. For assistance with reducing mercury use
contact Wisconsin Department of Natural Resources at 608-267-7639.
If significant exposure is believed to have occurred, you should
discuss with your family doctor whether urine mercury tests should
be conducted for the people who use the area the most. Results should not
be above 20 micrograms per liter of urine (20 ug/L).
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September 04, 2014