Despite the fact that the device of old-style medical thermometers is considered quite simple and understandable, the question of how much mercury is contained in a thermometer and whether such an amount is dangerous when bottling remains relevant today. On the one hand, the thermometer column is rather tiny, and it is basically impossible to fit a large amount of hazardous metal there, and on the other hand, mercury belongs to highly toxic substances of hazard class 1, which means that even its minimum amount can lead to irreparable consequences. So how much mercury is actually contained in the thermometer, and is the situation so terrible when it accidentally breaks? Let’s do the math!
As a rule, a classic Soviet-style thermometer contains about 2-5 grams of mercury. In modern times, the amount of mercury is reduced to 1 gram. Agree, such an amount may seem completely harmless. However, you should not breathe a sigh of relief and brush off the fragments of a broken thermometer in a trash can – even this amount may be enough for serious acute poisoning of all the tenants of the apartment. Just one gram of mercury can poison an apartment of 35 meters for 2-3 years.
It is known that mercury itself is not as dangerous as its vapors. Once in the open space of the room, the metal molecules begin to quickly turn into steam, filling the entire room. The situation is greatly aggravated if at this time in the room where the accident occurred, the air temperature is sufficiently high (above 18 degrees) – then the process of vaporization is accelerated several times. With the windows closed in an average two-room apartment (about 60 sq.m.), after a couple of hours, the concentration of mercury vapor in the air will reach 8 mg / m3. At the same time, the safe level of MPC (maximum permissible concentration) of mercury for residential premises is only 0,0003 mg/m3. Therefore, the question of how much mercury is contained in a thermometer can be given an unambiguous answer: it is enough for its bottling to negatively affect the health of all residents of the apartment.
On the Internet, quite often you can see the statement that modern thermometers do not contain mercury. And even if it crashed, it’s safe. Unfortunately, this statement is NOT TRUE. Now on sale you can find both a mercury thermometer and a thermometer without mercury. This thermometer contains “GALINSTAN” instead of mercury, a mixture alloy with the declared composition of 68.5% Gaul, 21,5 % India and 10 % tin. The content of this thermometer is absolutely safe. But the cost of this measuring instrument immediately differs significantly. For 2019, it averages from 250-800 rubles. Each manufacturer will always write wherever possible that the thermometer is safe and does not contain mercury. If this information is not on the thermometer, it contains 100% mercury.
It is also easy to distinguish mercury from galistan visually. Mercury always collects in balls; it cannot be smeared. Galinstan is just a thick, silvery liquid that spreads easily over the surface.
What to do to protect yourself from poisoning?
If you have a broken mercury thermometer, do not try to stop the accident yourself! Call the experts «mercury expert», and the manager will advise you in detail on further actions, and will also accept an application for holding control measurements and demercurization. Departure of specialists to the place of bottling is carried out as quickly as possible. This means that in most cases the air in your apartment will become perfectly clean and safe after a couple of hours.