We have received a number of calls from school clients regarding mercury spills in their workplaces. The spills usually involve small amounts of mercury, typically brought in from the outside by students or from the school storage area.

When these spills occur, some districts are not prepared to respond. The following information should prove helpful in the event of a mercury spill:

Understanding Mercury & Its Associated Health Hazards

There are three major forms of mercury: elemental, organic and inorganic. Human exposure to mercury generally occurs through the ingestion of food containing mercury or through the use of mercury in a laboratory or industrial setting.

Chronic exposure to elemental mercury vapor affects the central nervous system. Symptoms may include tremors and enlargement of the thyroid.

Chronic exposure to any of the three types may cause tremors, chronic spasms of the extremities, loss of memory, ulceration, fever, skin irritation or swelling of the spleen and lymphnodes.

Most epidemics of human mercury poisoning have resulted from the misuse of organic mercury compounds that are used as fungicides to protect cereal grains. Such fungicides were commonly used in the past due to their effectiveness and low cost.

The most serious effects of mercury are due to chronic exposure; however, mercury is also a skin irritant. Direct contact with the skin should be avoided. Any work done with mercury should be conducted in a fume hood with filter masks and gloves.

Cleaning Up Mercury Spills

Before beginning the clean-up process, make sure there has been no exposure to students or staff. If there has been an exposure, contact your local poison center or 911.

Make sure you have mercury spill kits available. These can be purchased from any local laboratory safety supply company. Most spill kits have a special mixture of a metal and an activating agent which, when wetted and applied to a liquid mercury spill, will form a mercury metal that can be picked up by a scraper and dust pan.

Mercury sponges coated with a special powder are also available. These can be used for final decontamination of the spill area.

The following steps and precautions should be followed when attempting to clean up a simple mercury spill (less than 30 milliliters or one pound of mercury located on a non-porous surface):

• Evacuate personnel from area of spill. Children, pregnant women, or people with a history of kidney damage should be kept away from the spill area until clean-up is complete.

• Wear appropriate protective equipment, i.e. gloves and goggles. Prior to clean up, remove all gold and silver rings, watches and bracelets.

• Avoid skin contact with mercury at all times.

• Sprinkle the powder provided in most spill kits over the surface of the mercury.

• Wet the powder with water.

• Work the powder into the mercury with a scraper.

• Scrape the mixture into dust pan and place in disposal bag.

• If activated sponge is provided, wipe area with sponge and place in disposal bag.

• Transfer disposal bag to a sturdy container.

• Do not handle mercury over sinks where it could spill down the drain.

Since disposal of hazardous waste is controlled by local, state and federal laws, consult authorities for guidance.

Note: A mercury spill is complex if it involves a spill greater than 30 milliliters or one pound of mercury, is located on a porous surface, is not easily cleaned up or is widely spread. Contact your state/local environmental health and safety office if a complex spill is suspected.