Is a Broken Mercury Thermometer Dangerous?
There is a common misconception: that a broken mercury thermometer will cause the mercury concentration in the room to exceed safety standards, potentially leading to mercury poisoning. This concern has prompted many people to worry and even avoid using mercury thermometers altogether.
In reality, breaking a mercury thermometer does pose some risk, as it contains metallic mercury that expands rapidly when exposed to heat. The expansion rate is directly proportional to the temperature. However, the hazard is not as severe as the legend suggests. Acute mercury poisoning only occurs if a significant amount of mercury vapor (> 1.0 mg/m³) is inhaled within a short period. In most cases, due to the inability of the room to be completely airtight, the mercury from a broken thermometer does not instantly evaporate. Proper handling can minimize the potential harm.
Nevertheless, individuals with children at home should exercise caution to prevent them from coming into contact with scattered mercury. Children, especially younger ones, may inadvertently touch and put their hands into their mouths, leading to potential mercury poisoning. Therefore, mercury thermometers should be kept out of the reach of children.
What to Do if a Mercury Thermometer Breaks
Open Windows for Ventilation and Wear a Mask: Mercury vaporizes quickly at room temperature. Even with prompt cleaning, some mercury vapor may remain in the air. Open windows for ventilation to reduce the density of mercury vapor. Additionally, wear a mask to minimize inhalation.
Quickly Collect Scattered Mercury Beads: Using gloves, use a small damp cotton swab or tape to gently collect scattered mercury on the ground. Gather it in one place, forming a larger ball. Collect it in a small bottle, add a small amount of water, and seal the lid. Label the bottle as containing mercury to avoid accidental misuse.
Clean Unrecoverable Mercury: Do not use a broom, as it can adsorb mercury and contaminate it. Sprinkle sulfur powder or raw egg liquid on the mercury. Once covered, sprinkle sand or soil on top, then clean it.
Disposal: Do not discard cleaned mercury indiscriminately. Place it in the mercury-collecting bottle and send it to the environmental protection department or a chemical laboratory for proper treatment.
Ventilate and Disinfect: Keep the room where the thermometer broke temporarily off-limits, especially for children and pregnant women. After ventilation, use alcohol for room fumigation. For mercury-affected areas, use a 10% bleaching powder solution to wash and eliminate mercury effectively.