Are Mercury Thermometers Safe?

Are Mercury Thermometers Safe?

There are some items synonymous with old school home medical care and the mercury thermometer is one of those. These days, mercury in glass thermometers are going the way of other outdated practices and items though, as it’s now known to be extremely dangerous and even potentially fatal when used the wrong way.

Thankfully, there are modern thermometers now available that make it easy and safe to care for your family. Whether it’s a digital electronic thermometer or some other type of safer liquid used in glass, there are plenty of better options out there.

However, some homes might still have their mercury thermometer laying around and wonder is it really all that bad? We’re going to explore how these devices are made and why they come with so many health and safety risks, especially if you’re unlucky enough to break one in your home.

Why Mercury Is Used In The Thermometer

Mercury Thermometer

The role of a thermometer is an important one, and when used it home it can be the one diagnostic tool that tells us whether we’re sick or not. The key thing with thermometers is that they must be accurate and also be able to detect a change in temperature to the smallest degree, and that’s why mercury was first used.

Mercury is a metal, and like other metals, it’s a very capable conductor of heat. When looking at other metals though, they will turn back to their solid state when at room temperature. This isn’t true for mercury however, as it remains in this liquid state no matter what the heat level.

This means that when mercury detects a slight change in temperature, it can let us know. It has a high coefficient of expansion which means it can move quickly and easily. Therefore, when we’re using it to check our temperature and need to know of even the smallest increase or decrease in the amount, it will be able to do so.

Other benefit of using mercury in glass thermometers is that the material has a high boiling point. Therefore, it’s capable of reading very high temperatures without breaking. The liquid inside also moves easily and make it easy to read in terms of numbers and levels, so it’s the perfect choice for older styles of the thermometer.

What Happens With A Broken Mercury Thermometer?

Mercury Leaking From Thermometer

The main reason why mercury thermometers are being phased out is because of how dangerous they are when broken. Mercury and its compounds have the ability to cause severe neurological problems and other serious symptoms in humans when they are exposed to it.

Because the mercury is only contained by the glass, they can easily break and have the potential to cause fatal risks to those around them.

Considering we put these thermometers in our mouth and other parts of the body, the risk is heightened even further. Therefore, new standards mean that their manufacturing is no longer allowed and most national agencies have been lobbying for their total ban.

Mercury thermometers are extremely dangerous when broken because of the hazardous liquids contained inside. These can easily spill when dropped or cracked and will pose a serious threat to those in the area. In addition to the mercury, the broken glass poses an issue on its own and can be harmful to anyone who comes into contact with it.

The health problems connected with mercury usually arise from inhaling the vapors. They can easily be absorbed into the body and will show immediate effects. This could be as mild as coughing and a sore throat, or as serious as vomiting and chest pain. Knowing how to clean up a broken thermometer correctly is the only way to protect yourself.

How To Dispose Of Mercury Thermometers Safely

Dropping Thermometer

For homes still living in the dark ages and using mercury thermometers, you’re operating with a huge risk in the house. If the worse should happen and the thermometer drops, cracks, or breaks, this is how to need to take care of it.

  • Make sure all family members and pets leave the area immediately and don’t let anywhere go near the spill
  • Put on latex or rubber gloves before you get started cleaning up
  • Depending on the surface, different approaches should be taken. With carpet, curtains, and other absorbent materials, they have to be disposed of completely. For tiles, wood, and others, you can clean them by hand with care
  • Pick up any pieces of glass and dispose of them first. Place them on a paper towel and then seal them into a bag
  • Look for larger beads of mercury that will still be stuck together. For smaller pieces, use a flashlight to locate where they are on the floor
  • Using either cardboard or a special sponge, collect the beads and place them also into a zip lock bag. For smaller beads, you may have to use an eye dropper to collect them. Place all mercury onto a wet paper towel, cover, and then place into a sealable bag
  • Never use a vacuum cleaner for mercury as it can heat up and create vapors. Likewise, never pour mercury down the drain
  • For any remaining pieces, you can carefully dot with shaving cream to collect them and dispose of correctly


With the latest range of digital and electronic thermometers now available, there’s no reason why any home should still be using a mercury in glass one. These devices used to be the only option but now there are so many better ways, and none of them as dangerous as this substance.

Just seeing the detailed effort it takes to clean up mercury should highlight how dangerous it is, especially when used around children. using one. Digital and electronic thermometers are affordable and high quality, so there’s no reason not to invest in one today and avoid the risk altogether.



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