Mercury

Mercury is easily absorbed through the lungs in the bloodstream. It can accumulative in the body, including in the brain tissue of children and developing foetuses.

Uses​

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• Mercury is used for demonstration purposes as it is the only metal that is liquid at room temperature.​
• The use of mercury-based chemical reagents still provides synthetic routes currently used.​
• Mercury is still used in thermometers and barometers and it can be found in dental fillings.​

Recommended control measures​

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Mercury and its compounds are controlled chemicals (Poison  UCL ref PA008) – see information on standards for all controlled chemicals. 

Eliminate​

• The distillation of mercury should not occur on any UCL controlled site including in vacuum pumps. If it becomes vital to a research project, it must have the written permission of the HoD and be carried out in a dedicated room and fume cupboard with full supervision at all times.​
• Alternatives to mercury should be used including but not limited to alcohol and electronic thermometers.​

Reduce exposure​

• Although mercury only evaporates at room temperature slowly, precautions must be in place to prevent this and increasing the likelihood of exposure through inhalation. ​
• Always have good ventilation, if possible work with LEV​
• Mercury is highly mobile should be bunded at all times. Carry out any work in a tray or similar item that is smooth and impervious.​

Health surveillance ​

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• Mercury levels can be found by using urine or blood samples tested by an accredited laboratory.​ 
• After the loss of containment, air monitoring should be carried out to test mercury vapour concentration. ​
• Safety Services cannot perform either of these functions so an external party will need to be contacted.​

Decontamination of Mercury​

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Spill of one thermometer or less​

Spill kit​

• 4-5 zip locking plastic bags​
• trash bags (2 to 6 mils thick)​
• rubber, nitrile or latex gloves​
• paper towels​
• cardboard or squeegee​
• eyedropper​
• shaving cream and small paint brush / duct tape​
• flashlight or small task light​
• optional: powdered sulphur

Procedure​

• Put on rubber, nitrile or latex gloves.​
• If there are any broken pieces of glass or sharp objects, pick them up with care. Place all broken objects on a paper towel. Fold the paper towel and place in a zip locking bag. Secure the bag and label it as directed by your department.​
• Locate visible mercury beads. Use a squeegee or cardboard to gather mercury beads into small mercury balls. Use slow sweeping motions to keep mercury from becoming uncontrollable. Take a flashlight, hold it at a low angle close to the floor in a darkened room and look for additional glistening beads of mercury that may be sticking to the surface or in small cracked areas of the surface. Note: Mercury can move surprising distances on hard-flat surfaces, so be sure to inspect the entire room, including any cracks in the floor, when searching.​
• Use the eyedropper to collect or draw up the mercury beads. Slowly and carefully squeeze mercury onto a damp paper towel. Alternatively, use two pieces of cardboard paper to roll the mercury beads onto the paper towel or into the bag. Place the paper towel in a zip locking bag and secure. Make sure to label the bag as directed by your local health or fire department.​
• After you remove larger beads, put shaving cream on top of a small paintbrush or a piece of duct tape and gently "dot" the affected area to pick up smaller hard-to-see beads. Place the paintbrush or duct tape in a zip-locking bag and secure. Make sure to label the bag as directed by your local health or fire department.​
• OPTIONAL STEP: Use powdered sulphur to absorb the beads that are too small to see. The sulphur does two things: ​
  • it makes the mercury easier to see since there may be a colour change from yellow to brown, and​
  • it binds the mercury so that it can be easily removed and suppresses the vapour of any missing mercury​

Spill of greater than one thermometer up to 1 lb (pound) or 0.45 Kg ​

Procedure ​

• Have everyone else leave the area; don't let anyone walk through the mercury on their way out
• Open all windows and doors to the outside.​
• Turn down the temperature
• Shut all doors in the room and leave the area
• Do not vacuum
• Call Security emergency number 222 as soon as possible​

Greater than 1lb or 0.45kg - GET OUT

Get out, secure the areas and call Security on 222.​

Chemical safety library

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> Read more about control measures for chemicals in our chemical safety library