General Information on Mercury Spills

This information is offered to help you respond to mercury spills. Most spills associated with fever thermometers or other small spills can be cleaned up by following the guidance provided here.

Questions may be addressed to Justin Otto of the North Dakota Department of Health at 701.328.5188 or jotto@nd.gov.

You are also encouraged to contact your local public health unit.


While the amount of mercury involved with broken thermometers is usually very small, it can be enough to in some cases, to produce unhealthy exposure to mercury vapor. Quick response to any mercury spill is very important. If you have a large spill (more than 2 tablespoons or 1 fluid ounce), or are not sure about the hazards or your ability to respond, please contact your local public health unit or the North Dakota Department of Health.


About Mercury

Elemental mercury is a heavy, silvery metal element that is a liquid at room temperature. Liquid mercury evaporates at room temperature and these vapors are invisible, odorless, and, at high levels, are very toxic. Mercury vapors can harm the nervous system, cardiovascular system, digestive tract, kidneys, and the development of young children. In the home, metallic mercury is often found in thermometers, barometers, electrical switches, and thermostats. Upon spilling, it will bead up and spread readily. The amount of vapor elemental mercury produces is related to the amount spilled, surface area (amount of beads produced), temperature (vapor increases with warmer air), air flow and physical disturbance of the spilled material.

Cautions In Handling Mercury

You should respond immediately to all mercury spills. Even small spills can, in some cases, cause high levels of mercury vapors that are unsafe to breathe. Mercury vapors are readily absorbed through the lungs into the bloodstream and are therefore, particularly hazardous. Mercury vapors are also heavier than air and may linger in higher concentrations close to the floor. Children who crawl or play in these areas are at highest risk of breathing these vapors.

  • DO NOT use a vacuum to clean up mercury. The filters in household and even high efficiency vacuums will not remove mercury vapors. Of even greater concern, the vacuum exhaust will put more mercury vapor in the air. The vacuum will also be contaminated. If you already have used a vacuum to clean a spill, carefully double-bag the vacuum, seal and remove it from the building. Quickly isolate the areas as described below because there may be higher amounts of mercury vapor in air.
  • DO NOT use a broom to clean up mercury. It will break the mercury into smaller beads, further spreading it and making more vapor.
  • DO NOT allow people whose shoes have contacted mercury to take their shoes beyond the spill area. Further contamination of the building may result. The shoes should be removed and protective foot coverings, such as Tyvek booties should be provided.
  • DO NOT put mercury in the trash. Mercury can be released in the environment and will further impact human health.
  • DO NOT put mercury or mercury-containing items in a burn barrel. Vapors and smoke will be produced releasing mercury into the environment and create an exposure risk.
  • DO NOT pour or allow mercury to go down a drain. It can lodge in the trap, and produce airborne vapor creating an inhalation risk. It will also lead to mercury contamination of the wastewater system.
  • DO NOT wash mercury-contaminated items in a washing machine. Mercury may contaminate the machine and/or be discharged to the environment in wastewater.

Cleaning Up a Broken Thermometer

Isolate the Spill Area

Keep children and pets away. Avoid traffic going through the spill area. Those who may have come into contact with mercury should be directed to remove contaminated shoes or clothing, which should be placed in two bags, sealed and closed. Otherwise, mercury could be tracked around the building or home.

Note: If the mercury was vacuumed, exposed to heat or entered the ventilation system, refer to Large Spill Guidance. Higher mercury vapor levels may exist and could require additional protective equipment and professional expertise.

Assemble Clean Up Supplies

Many clean up supplies are available from hardware stores. Mercury spill kits are also available from suppliers. The following are some common household articles that could be used to construct an in-home mercury cleanup kit:

  • eye dropper - to pick up the mercury
  • plastic dustpan - to pick up the mercury
  • plastic container with lid - to hold the mercury
  • tape; wide, duct, or masking – to help pick up mercury beads
  • plastic bags with zipper seal – to store mercury-contaminated debris and equipment
  • rubber gloves - to protect hands from mercury contact
  • syringe without needle - to pick up mercury
  • trash bags - for containing mercury waste
  • playing cards or index cards - for collecting mercury beads

Pick Up All Visible Mercury Droplets

Inspect the spill area with a bright light to help illuminate any hidden droplets. Clean up any beads of mercury by using an index card and plastic dustpan. With the card, gently push the mercury droplets away from any carpet, fabric, or porous surfaces and toward other droplets to combine them into larger droplets. Slide droplets onto a sheet of rigid paper like an index card. Never use a broom or a vacuum on a mercury spill because it will only scatter the mercury droplets, making them harder to find and pick up.

Gently Place Mercury Into an Unbreakable Plastic Container

Use a plastic jar or double-bagged zip-lock baggie, to deposit the mercury into (avoid using glass because it can easily break). If necessary, suction off the droplets using an eyedropper or syringe. Adhesive tape strips may also be used to clean up any tiny remaining mercury droplets. Place the plastic container inside a plastic bag to provide additional safety. Tighten the lid securely so that liquid and vapors will be contained.

Consider Removal and Disposal of Contaminated Carpeting and Other Soft Items

It takes very little mercury in air to create unhealthy levels of vapor. Vacuuming any surface with mercury will make more vapor. Factors that affect the severity of risk from mercury in carpet or soft-surfaced items include the amount of mercury spilled, how much was recovered, the type of room and whether young children or pregnant women frequent the room. Local health units, the North Dakota Department of Health and/or spill response contractors may be able to monitor for the presence of mercury vapor on contaminated items. However, private testing may be costly. The value of the item should be weighed against such cost and the peace of mind offered by the testing and/or removal of the contaminated item. When removing contaminated items, double wrap them in plastic bags and contact your local health unit or the North Dakota Department of Health for proper disposal. Do not expose to heat or incinerate.

Check Carefully for Missed Mercury

A very bright flashlight may be used to better illuminate mercury beads in the spill area. If additional assurance is desired, sprinkling powdered sulfur (available form garden supply stores) over the spill area may also help identify missed mercury as the powder will turn brown on contact with mercury. Collect the powder as was done with mercury beads. The sulfur will bind with the mercury, reducing the amount of vapor. (Do not apply to carpet or soft items). Special precautions should be taken if mercury was spilled in a high traffic area or a confined area where children or infants play. Young children playing on the floor are particularly at risk to mercury’s effects on the central nervous system. Call your local health unit or the North Dakota Department of Health to see if additional testing or other measures may be needed.

Continue Ventilation

Ventilate as much as possible to completely air out the room or spill zone with outside air.

Set Aside Everything You Think Might be Contaminated With Mercury

Package materials securely and label as "Mercury-Contaminated." Specific labeling and disposal requirements may differ depending on whether the spill occurred at a household or at a regulated business. Clothing or personal belongings that may be contaminated can be tested following the guidance under Large Spills to see if they can be safely returned for use.

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 contact your local health unit or the North Dakota Department of Health.

Medical Testing

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 (20ug/L).

How To Handle Small Mercury Spills

A small spill is considered an amount about the size of a dime.

Contain the Spill

Mercury will bead up and spread readily. If the further spread of mercury beads is possible, place a barrier such as kitty litter, sand, towels etc. around the spill site. If powdered sulfur or uniting agent is available, use it to contain the spill. Pay close attention to floor openings such as air vents and drains. Place barriers or tape around the site to prevent traffic through it. Be sure to keep children and pets away.

Note: If the mercury was vacuumed, exposed to heat or entered the ventilation system, refer to Large Spill Guidance. Higher mercury vapor levels may exist and could require additional protective equipment and professional expertise.

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.

Turn Off Ventilating or Air Conditioning Systems

If feasible, turn off heating, ventilation or air conditioning systems for the parts of the building affected by the spill and seal the ventilation openings (both vents and returns).

Close Interior Doors to the Room

Close doors leading directly to the spill site and open exterior doors and windows of the room where the spill occurred. When not occupied, seal the door with plastic and tape.

Open Windows and Exhaust Room Air to the Outdoors

Place a fan in an exterior room window blowing air outside.

Assemble Clean Up Supplies

Many clean up supplies are available from hardware stores. Mercury spill kits area also available from suppliers (See the resource links below). The following are some common household articles that could be used to construct an in-home mercury cleanup kit:

  • eye dropper - to pick up the mercury
  • plastic container with lid - to hold the mercury
  • plastic sheeting - to provide a clean surface on which equipment can be stored
  • powdered zinc or sulfur* - to bind with the mercury
  • rubber squeegee - to help recover the mercury and spill powder
  • tape; wide, duct, or masking – to seal doors and vents and to help pick up mercury beads
  • tray or box - to hold mercury storage container
  • plastic bags with zipper seal – to store mercury-contaminated debris and equipment
  • plastic dust pan - to help recover mercury and spill powder
  • rubber gloves - to protect hands from mercury contact
  • syringe without needle - to pick up mercury
  • trash bags - for containing mercury waste
  • playing cards or index cards - for collecting mercury beads

Dress Appropriately

Wear gloves (rubber), clothes and shoes that can be discarded if they become contaminated. Wear safety goggles if available. Place Tyvek booties or use plastic bags as booties over shoes to prevent your shoes from being contaminated and allowing you to simply remove the bags from your shoes upon leaving the room.

Pick Up All Visible Mercury Droplets

Inspect the spill area with a bright light to help illuminate any hidden droplets. Clean up any beads of mercury by using a squeegee or index card and plastic dustpan. With the card, gently push the mercury droplets away from any carpet, fabric, or porous surfaces and toward other droplets to combine them into larger droplets. Slide droplets onto a sheet of rigid paper like an index card. Never use a broom on a mercury spill because it will only scatter the mercury droplets making them harder to find and pick up.

Gently Place Mercury Into an Unbreakable Plastic Container

Use a plastic jar or double-bagged ziplock baggie to deposit the mercury into (avoid using glass because it can easily break). If necessary suction off the droplets using an eyedropper or syringe. Adhesive tape strips may also be used to clean up any tiny remaining mercury droplets. Place the plastic container inside a plastic bag to provide additional safety. Tighten each lid securely so that liquid and vapors will be contained.

Consider Removal and Disposal of Contaminated Carpeting or Other Soft Items

Consider removal of carpet and other soft items that received direct mercury contact. It takes very little mercury in air to create unhealthy levels of vapor. Further, vacuuming any surface with mercury will make more vapor. Factors that affect the severity of risk from mercury in carpet or soft-surfaced items include the amount of mercury spilled, how much was recovered, the type of room and whether young children or pregnant women frequent the room. Local health departments and spill response contractors may be able to monitor for the presence of mercury vapor on contaminated items. However, private testing may be costly. The value of the item should be weighed against such cost and the piece of mind offered by the testing and/or removal of the contaminated item. When removing contaminated items, double wrap them in plastic trash bags and contact your local health unit or the North Dakota Department of Health for proper disposal. (Do not expose to heat or incinerate).

Sprinkle Powdered Sulfur or Zinc on the Spill Site

Powdered sulfur or zinc will bind to any remaining mercury. These materials are supplied in commercially available mercury spill kits. Sulfur can often be purchased separately from garden supply stores. Apply over hard to reach areas such as cracks and crevices to minimize the release of mercury vapors. In instances where furniture or carpet has been exposed to mercury, seek advice from your local health unit, the North Dakota Department of Health or a spill response contractor. Once used to collect mercury, the powder must be disposed properly. Vapor suppressing solutions are also available (The use of powders on carpets is not recommended, as later vacuuming will produce more mercury vapor).

Check Carefully for Missed Mercury

A very bright flashlight may be used to better illuminate mercury beads in the spill area. Sprinkling powdered sulfur over the spill area may also help identify missed mercury, as the powder will turn brown on contact with mercury. Collect the powder as was done with mercury beads. Special precautions should be taken if mercury was spilled in a high traffic area or a confined area where children or infants play. Young children playing on the floor are particularly at risk to mercury’s effects on the central nervous system.

Set Aside Everything You Think Might Be Contaminated With Mercury

Package materials securely and label as "Mercury-Contaminated." Specific labeling and disposal requirements may differ depending on whether the spill occurred at a household or at a regulated business. Clothing or personal belongings that may be contaminated can be tested following the guidance under Large Spills to see if they can be safely returned for use.

Monitor Spill Zone for Mercury Vapors

Even if the impacted area appears clean, there may still be microscopic beads or hidden residual quantities of mercury present that emit vapors. For larger-sized spills, it may be necessary to professionally test mercury vapor levels in the immediate area. If mercury is detected, re-clean the impacted area using previously mentioned procedures and repeat testing until levels fall to within safe parameters. If mercury vapor levels remain high even after repeated cleaning, a more aggressive action is probably needed. Guidance for acceptable levels for re-occupancy is offered below.

Continue Ventilation

Ventilate as much as possible to completely air out the room or spill zone with outside air.

How To Handle Large Mercury Spills

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.

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. 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: http://www.epa.state.oh.us/opp/mercury_pbt/mercury.pdf. 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.

Continue Ventilation

Ventilate as much as possible to completely air out the room or spill zone with outside air.

Monitor

Air in the spill area should be tested using NIOSH Method 6009 or similar method with comparable limit of detection. Levels should be below 1 ug/m3 for residential environments and 3 ug/m3 for commercial environments.

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 contact your local health unit or the North Dakota Department of Health.

Medical Testing

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 (20ug/L).


Last Updated: 12/30/2017