Mercury
Mercury is a silvery liquid metal that slowly gives off an invisible, odorless vapor at room temperature. Breathing that vapor over time can damage your brain, nerves and kidneys. Workers most often meet it when removing old thermostats, switches, gauges and lamps, or when one breaks.
- Construction
- HVAC
- Demolition
- General Industry
Where mercury is found
- Old thermostats with a glass bulb (common before about 2000)
- Tilt switches in older appliances, sump pumps and car hood lights
- Fluorescent tubes, compact fluorescent lamps (CFLs) and some high-intensity discharge lamps
- Manometers, barometers, pressure gauges and old thermometers
- Old gas meter regulators, some older flow meters and lab equipment
- Dental offices, chlor-alkali plants, gold processing and lamp recycling
Health effects
- Short term, high exposure (like heating mercury): coughing, chest pain, breathing trouble
- Long term: shaky hands (tremors), mood swings, irritability, memory and sleep problems, gum problems and kidney damage
- Mercury can harm an unborn baby’s developing brain. Pregnant workers should avoid exposure. See Reproductive Hazards.
OSHA’s limit is a ceiling of 0.1 milligrams per cubic meter, and NIOSH recommends a lower limit of 0.05 mg/m³ for mercury vapor. Spilled mercury can exceed these levels in a closed room. See Exposure Limits.
Removing mercury-containing equipment
- Survey before demolition or renovation and remove thermostats, switches, gauges and lamps intact before walls come down.
- Pack them so they can’t break, and label them for recycling.
- Many of these items are “universal waste” and must be recycled or disposed of under EPA and state rules, not thrown in the dumpster.
- Never heat, cut, grind or torch anything that may contain mercury. Heat greatly increases the vapor.
If mercury spills
- Don’t vacuum it. The vacuum spreads vapor and contaminates the machine.
- Don’t sweep it with a broom or pour it down a drain.
- Don’t walk through it and track it around.
Small spills (like one thermometer): keep people and pets away, open windows, and turn off central heating and air. Wearing gloves, push droplets together with stiff paper, pick them up with an eyedropper or tape, and seal everything in a jar or zip bag. Label it and call your local waste agency.
Bigger spills, or any spill at work: leave the area, close it off and call your supervisor. Trained responders with mercury vapor meters and special cleanup kits should handle it. See Spill Response.
Broken fluorescent lamps
Air out the room for 5 to 10 minutes, turn off central air, scoop pieces with stiff paper, pick up fine pieces and powder with tape, and seal them in a jar or bag. Don’t vacuum unless glass remains after you’ve picked it up.
Protect your family
Mercury can stick to clothes and shoes. Change before going home after any spill or removal work. See Take-Home Contamination.
Mercury removal checklist
- Items with mercury identified before demolition
- Removed whole, without breaking
- Packed, labeled and set aside for recycling
- Spill kit available
- No heating, cutting or crushing of mercury items
Standards & references
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