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How much time liquid mercury takes to evaporate?
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Lee Lightfoot
How much time liquid mercury takes to evaporate?
I found this statement in a paper about $\ce{Hg}$ contamination from dental work:
The evaporation rate of elemental mercury at room temperature ($\pu{20 ^\circ C}$) is approximately $\pu{50 \mu g\:cm-2h-1}$ (range of $\pu{40-60 \mu g\:cm-2h-1}$).
They cited the following work as a source for that number:
Gary N. Bigham, Wanyu R. Chan, Manuel Dekermenjian, Ali Reza, "Indoor Concentrations of $\ce{Hg}$ Vapor Following Various Spill Scenarios," Environmental Forensics2008, 9(2-3), 187-196 (https://doi.org/10.1080/15275920802121975)
German regulations (as an example) say that 0.035 µg/l of metallic mercury vapour in air pose no risk under lifelong exposition, and 0.35µg/l can be harmful under long (months?) exposition for some people. The math is full of imponderables, esp. the actual amount that was spilled and size of drops.
Swiss officials https://www.toxinfo.ch/quecksilberhaltige-fieberthermometer say that a single broken fever thermometer can lead to intoxications, but the risk can usually be averted by collecting as much as possible and ensuring proper, regular ventilation.
The following publication suggests that a properly cleaned up spill from a fever thermometer should become undetectable within several weeks, but the airborne Hg concentration can be significant in that time, and regular ventilation is highly recommendable.
E. Martin Caravati et al. Elemental mercury exposure: An evidence-based consensus guideline for out-of-hospital management, Clinical Toxicology 2008, 46:1, 1-21, https://doi.org/10.1080/15563650701664731
But one thing is quite clear: A single, large blob that you miss (under furniture, wooden floorboard etc.) can stay for a very long time, and lead to potentially harmful concentrations in the air. There are a lot of reports about little mercury puddles that were found under floorboards during laboratory renovations, even decades after the last mercury instrument had been thrown out.
I found this statement in a paper about $\ce{Hg}$ contamination from dental work:
The evaporation rate of elemental mercury at room temperature ($\pu{20 ^\circ C}$) is approximately $\pu{50 \mu g\:cm-2h-1}$ (range of $\pu{40-60 \mu g\:cm-2h-1}$).
They cited the following work as a source for that number:
Gary N. Bigham, Wanyu R. Chan, Manuel Dekermenjian, Ali Reza, "Indoor Concentrations of $\ce{Hg}$ Vapor Following Various Spill Scenarios," Environmental Forensics2008, 9(2-3), 187-196 (https://doi.org/10.1080/15275920802121975)
German regulations (as an example) say that 0.035 µg/l of metallic mercury vapour in air pose no risk under lifelong exposition, and 0.35µg/l can be harmful under long (months?) exposition for some people. The math is full of imponderables, esp. the actual amount that was spilled and size of drops.
Swiss officials https://www.toxinfo.ch/quecksilberhaltige-fieberthermometer say that a single broken fever thermometer can lead to intoxications, but the risk can usually be averted by collecting as much as possible and ensuring proper, regular ventilation.
The following publication suggests that a properly cleaned up spill from a fever thermometer should become undetectable within several weeks, but the airborne Hg concentration can be significant in that time, and regular ventilation is highly recommendable.
E. Martin Caravati et al. Elemental mercury exposure: An evidence-based consensus guideline for out-of-hospital management, Clinical Toxicology 2008, 46:1, 1-21, https://doi.org/10.1080/15563650701664731
But one thing is quite clear: A single, large blob that you miss (under furniture, wooden floorboard etc.) can stay for a very long time, and lead to potentially harmful concentrations in the air. There are a lot of reports about little mercury puddles that were found under floorboards during laboratory renovations, even decades after the last mercury instrument had been thrown out.
@imalipusram Those guidelines cover both thermometers and mercury-containing CFL bulbs or fluorescent tubes. But bulbs dont contain enough mercury to cause long term contamination. Thermometers do. And their advice on broken thermometers isnt More
Actually, no. I just found a couple of tiny drops near to my desktop (which is not the area that I broke the thermometer). They were about 1mm each.More
I found this statement in a paper about $\ce{Hg}$ contamination from dental work:
They cited the following work as a source for that number:
German regulations (as an example) say that 0.035 µg/l of metallic mercury vapour in air pose no risk under lifelong exposition, and 0.35µg/l can be harmful under long (months?) exposition for some people. The math is full of imponderables, esp. the actual amount that was spilled and size of drops.
Swiss officials https://www.toxinfo.ch/quecksilberhaltige-fieberthermometer say that a single broken fever thermometer can lead to intoxications, but the risk can usually be averted by collecting as much as possible and ensuring proper, regular ventilation.
The following publication suggests that a properly cleaned up spill from a fever thermometer should become undetectable within several weeks, but the airborne Hg concentration can be significant in that time, and regular ventilation is highly recommendable.
But one thing is quite clear: A single, large blob that you miss (under furniture, wooden floorboard etc.) can stay for a very long time, and lead to potentially harmful concentrations in the air. There are a lot of reports about little mercury puddles that were found under floorboards during laboratory renovations, even decades after the last mercury instrument had been thrown out.
I found this statement in a paper about $\ce{Hg}$ contamination from dental work:
They cited the following work as a source for that number:
German regulations (as an example) say that 0.035 µg/l of metallic mercury vapour in air pose no risk under lifelong exposition, and 0.35µg/l can be harmful under long (months?) exposition for some people. The math is full of imponderables, esp. the actual amount that was spilled and size of drops.
Swiss officials https://www.toxinfo.ch/quecksilberhaltige-fieberthermometer say that a single broken fever thermometer can lead to intoxications, but the risk can usually be averted by collecting as much as possible and ensuring proper, regular ventilation.
The following publication suggests that a properly cleaned up spill from a fever thermometer should become undetectable within several weeks, but the airborne Hg concentration can be significant in that time, and regular ventilation is highly recommendable.
But one thing is quite clear: A single, large blob that you miss (under furniture, wooden floorboard etc.) can stay for a very long time, and lead to potentially harmful concentrations in the air. There are a lot of reports about little mercury puddles that were found under floorboards during laboratory renovations, even decades after the last mercury instrument had been thrown out.
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