Mercury: Information for Health Professionals

Mercury spills are serious and should be addressed immediately. Small spills may be cleaned up by individuals; however, cleaning up large spills (more than 2 tablespoons or 1 fluid ounce) requires expert help from contractors. Local health departments can get help from the Department of Health Services (608-266-1120) or from the Department of Natural Resources Spill Response (800-943-0003).

If anyone came into contact with mercury, call the Wisconsin Poison Control Center at 800-222-1222

Exposure levels

Units of measure are very important in evaluating mercury spills. Airborne levels are reported in weight per cubic meter of air (m3). Weight can be expressed as milligrams (mg), micrograms (µg) or nanograms (ng).

Reference concentrations for airborne mercury exposure
Agency Exposure value (micrograms per cubic meter) Comments
National Institute for Occupational Safety and Health (NIOSH) 10,000 µg/m3 Immediately dangerous to life or health (IDLH) value allowable for a maximum of 30 minutes in emergency situations only
Occupational Safety and Health Administration (OSHA) 100 µg/m3 Enforceable workplace standard, assuming 8 hours a day, 40 hours a week
NIOSH 50 µg/m3 Workplace recommendation
Agency for Toxic Substances and Disease Registry (ATSDR) 10 µg/m3 Level at which residents are advised to not occupy the affected area. Also a screening level for bagged clothes
ATSDR 3 µg/m3 Target cleanup level for commercial environments
ATSDR 1 µg/m3 Target cleanup level for residential environments
ATSDR 0.200 µg/m3 Chronic level of exposure at which adverse effects would not be expected. Assumes exposure time of 24 hours of day for 30 years
N/A 0.01 µg/m3 Typical background level
Last Revised: January 15, 2019