Mercury Spill Management

This guidance document is prepared by MnDOT personnel and is intended only for use on MnDOT projects, including partnership projects, and MnDOT Maintenance Operations.

Any optional procedures will be indicated in the document. Any deviation from procedures contained in this document must be discussed with the Regulated Materials Unit personnel prior to implementation.

This document should not be construed as a full description of all regulations pertaining to the subject matter. Contact the Regulated Materials Unit in the MnDOT Office of Environmental Stewardship for additional information or legal requirements.

Background

Mercury is a naturally occurring element found in rocks, soil, water, air and living things. Mercury is the only metal that is liquid at room temperature. In its pure form (often called metallic or elemental), mercury is a shiny, silver-white, odorless liquid. If heated, mercury vaporizes into a toxic, colorless, odorless gas. Metallic mercury is found in items like thermometers, thermostats, fluorescent lights, switches, batteries, manometers and other equipment.

Exposure

Mercury is a hazardous chemical that can damage the central nervous system, kidneys and liver. Both high level/short-term and low level/long-term exposures can lead to serious health problems. Mercury exposure can occur from absorption through the skin, inhalation of mercury vapor and ingestion.

Spill Response Procedure

Immediately isolate the spill and ventilate the area. Notify your supervisor and District Safety Administrator.
Keep all employees away from the spill area.
Immediately open windows and exterior doors.
Close all interior doors between the room where the mercury was spilled and the rest of the work area.
Close all cold air returns. Turn down heaters and turn up room air conditioners.
Do not use central air conditioning.
Turn off fans unless they vent to the outdoors. Turn on fans if they vent directly outdoors to disperse mercury-contaminated air outside.

Call a poison control center if someone has inhaled mercury vapors. Phone 911 or the Poison Control Center at 800-222-1222 from anywhere in the state.

If the mercury spill is greater than 2 tablespoons or 1 pound call the Minnesota Pollution Control Agency through the Minnesota Duty Officer immediately at 651-649-5451 or 1-800-422-0798. A duty officer is available 24 hours a day.

Remove mercury from shoes, clothing and skin.
If mercury has touched your skin, shoes, or clothing, stay still and have someone bring you a plastic trash bag and wet paper towels.
Wipe off visible beads of mercury with wet paper towels and put them into the trash bag. Check your shirt and pants pockets for mercury drops.
Remove contaminated shoes and clothing and place them in the trash bag. Seal the bag.
Dispose of clothing properly and shower well. See Disposal and Recycling section below for proper disposal procedure.

Notify your supervisor and District Safety Administrator immediately to determine whether you should attempt to clean up the spilled mercury yourself or contact an environmental contractor to perform the cleanup.

Equipment for Cleanup of Small Spills (less than 2 tablespoons or 1 pound)

Nitrile Gloves
Paper Towels
Flashlight
Zipper Style Plastic Bags
Rubber Squeegee
Plastic Dust Pan
Plastic Trash Bags
Wide-mouth plastic container with screw on lid Large tray or box
Eye dropper, turkey baster
Index cards, playing cards, rigid paper
Sulfur Powder
Electrical or Duct Tape

Clean Up Procedure

MnDOT should only initiate cleanup of spills less than 2 tablespoons or 1 pound.

If the mercury spill is greater than 2 tablespoons or 1 pound, MnDOT personnel should contact the Minnesota Duty Officer at 1-800-422-0798 immediately to report the spill. Contact the District Safety Administrator or OES to arrange for a contractor to perform the cleanup.

To prevent spreading contamination, do not allow employees with mercury contaminated clothing to walk around.
Have the affected person remain in the room where the incident occurred.
Remove shoes and clothing that have been contaminated and place in a plastic bag.
Do not launder the clothes.
See Disposal and Recycling section below for proper disposal procedure.
Anyone coming into contact with mercury should shower well with soap and water.
Use the equipment listed above to clean up the spill.
Do not use a vacuum, broom or paint brush to clean up the spill. These methods can spread the mercury to other areas.
Change into old clothing (you may need to dispose of clothing after the cleanup operation) and remove all jewelry. Mercury can adhere to metal.
Wear nitrile gloves during cleanup procedure to prevent skin exposure.
Use tongs to carefully collect any broken glass. Place glass on cardboard or paper towel and place the materials into the plastic container.
Begin picking up the mercury from outside the spill area and work towards the center of the spill. This helps to minimize spreading the contamination.
Push beads of mercury together while using two razor blades, stiff cardboard, rubber squeegee, index cards, playing cards or rigid paper.
Prevent mercury from moving into drains, cracks or crevices in the floor.
Use a flashlight to search for glass & mercury. Light will reflect off of the mercury.
Pick up beads by pushing them into a dustpan or onto stiff cardboard or paper.
Use an eye dropper to help pick up small beads of mercury.
Pick up remaining droplets with tape, cotton ball or moist paper towel.
To investigate cracks and crevices, turn off lights and use a flashlight to detect the presence of mercury. Use tape, cotton ball, or moist paper towel to collect any mercury in cracks/crevices.
Place container and all items used for cleanup in the plastic bag.
Remove gloves by turning them inside out, place gloves in plastic bag and seal the plastic bag.
Place sealed bag into a five gallon bucket or drum with a sealed lid.
Label container: “Mercury Containing Debris”.

Contact District Safety Administrator for guidance on cleaning up porous items like carpet, rugs or sofas.

An environmental laboratory can be retained to determine if mercury has vaporized. This is required for large spills.

Sulfur powder may be used to verify if any mercury is still present following cleanup. If the yellow sulfur powder turns brown, mercury contamination still exists. If additional cleaning is necessary, follow the same cleaning procedure.

Wash thoroughly before eating, taking breaks during the cleanup procedure and when the cleanup process has been completed.

Recommendation

Whenever feasible replace mercury containing items with non-mercury alternatives.

Disposal & Recycling

The hazardous waste contract is not required for recycling mercury. The District Waste Management Coordinator has a list of facilities approved by the MnDOT Office of Environmental Stewardship that can accept mercury for recycling and disposal.

Storage Guidelines

Place the contaminated material container in the District hazardous waste storage building.

Transportation and Documentation

Mercury can be transported by MnDOT personnel but must be recorded on a MnDOT shipping paper or a waste-tracking invoice that contains the following information: date of shipment, storage location and drop-off destination, quantity of mercury shipped (in weight or number of items).

A copy of the shipping paper or waste-tracking invoice should be kept in the District waste management file for a minimum of three years. After three years the files can be brought to OES for permanent storage.

Sources:

Exposure to elemental mercury – Minnesota Department of Health
Cleaning up home mercury spills – Minnesota Pollution Control Agency