Mercury spills: Less than or equal to the amount in a thermometer
When liquid mercury (also known as elemental or metallic mercury) is spilled,
it forms droplets that can accumulate in the tiniest of spaces and then emit vapors into the air.
Mercury vapor in the air is odorless, colorless, and very toxic.
Most mercury exposures occur by breathing vapors,
by direct skin contact or by eating food or drinking water contaminated with mercury.
What NEVER to do with a mercury spill:
* Never use a vacuum cleaner to clean up mercury.
The vacuum will put mercury into the air and increase exposure.
The vacuum appliance will be contaminated and have to be thrown away.
* Never use a broom to clean up mercury.
It will break the mercury into smaller droplets and spread them.
* Never pour mercury down a drain. It may lodge in the plumbing and cause future
problems during plumbing repairs. If discharged, it can cause pollution
of the septic tank or sewage treatment plant.
* Never wash mercury-contaminated items in a washing machine.
Mercury may contaminate the machine and/or pollute sewage.
* Never walk around if your shoes might be contaminated with mercury.
Contaminated clothing can also spread mercury around.
http://www.epa.gov/epaoswer/hazwaste/mercury/faq/spills.htm