Elemental mercury is a shiny, silver-white odorless liquid that is commonly used in laboratory instruments, thermometers, batteries, and more. Mercury can be both an acute and chronic toxin and primarily affects the brain and central nervous system.


Elemental mercury primarily poses an inhalation hazard. Absorption into the body is rapid after inhalation. Absorption rates from skin exposure and ingestion are much lower, but may still occur, especially if cuts are present. Ionic or organic forms of mercury are absorbed much more quickly through the skin.

Acute exposure to concentrated mercury vapor can affect the brain and central nervous system. In addition, this type of exposure can cause symptoms such as irritation to the lining of the mouth, airways, and lungs; increased blood pressure and heart rate; nausea, vomiting, diarrhea; skin rashes; eye irritation; and acrodynia.

Mercury is excreted from the body with a half-life of approximately one month, therefore cumulative exposure is important. Chronic exposure can lead to accumulation of mercury in the brain and kidney. This can present symptoms such as personality change, tremors, vision changes, deafness, lack of muscle coordination, loss of sensation, and memory loss.

Mercury exposure is of increased concern to pregnant women as mercury can pass the placental barrier and concentrate in the unborn child. This situation is particularly deleterious as the brain and central nervous system is still developing.

Storage and Use

  1. Containers of mercury must be closed when not in use.
  2. All work involving mercury should be performed over trays or pans with turned up edges to confine any spillage. Glass and plastic trays should have secondary containment incase the tray breaks.
  3. Mercury spills must be cleaned up immediately. The preferred method is to suction up the elemental mercury. A special vacuum cleaner for mercury spills is available from EHS. Please call for cleanup of mercury spills. Ordinary vacuum cleaners must not be used because droplets will then be dispersed more finely throughout the laboratory and then the vacuum is contaminated with mercury.
  4. Mercury monitoring can be accomplished by EHS.
  5. Adequate ventilation must be provided when working with mercury. Vapors should not be re-circulated or exhausted to other laboratories or building areas.
  6. Do not use mercury thermometers in ovens. The elevated temperatures will create very high mercury vapor concentrations should the thermometer break.

First aid

A single skin exposure or even ingestion of elemental mercury will likely not result in observable symptoms. Repeated or prolonged exposure by these modes is a much greater concern. If symptoms of exposure do occur, even months later, seek immediate medical attention and inform them of the mercury exposure.

Skin exposure.

Wash skin with soap and cool water for 15 minutes. If hands were exposed, be sure to scrub under fingernails.

Eye contact.

Holding the eyelids away from the eye, rinse eyes under the eyewash station for 15 minutes.


If it is suspected that concentrated mercury vapor was inhaled, immediately remove to fresh air and seek medical attention.