Formaldehyde

Formaldehyde, or sometimes called formalin, is a tiny molecule made up of carbon, hydrogen, and oxygen atoms. It's so tiny that you can't even see it with your eyes, but it can be found in many different things around us.

Sometimes it's used as a preservative for dead animals, like bugs, so they can be studied and looked at under a microscope. But it can also be found in things like furniture, carpets, and even some clothes.

When you breathe in formaldehyde, it can make you cough or feel like your eyes and nose are irritated. This is because when formaldehyde gets into your body, it reacts with the moisture in your body and makes a gas that causes irritation. That's why it's important to be careful and avoid breathing it in too much.

Some people are more sensitive to it than others, and if they breathe in too much, it can cause even more serious health problems. But if you just avoid breathing in too much formaldehyde and let grown-ups take care of it, you'll be okay!