Urea-formaldehyde

Urea-formaldehyde is like a toy-building material that you can mold into different shapes, just like playdoh. But instead of using water to keep the shapes together, you use a special glue called urea-formaldehyde.

Now, the glue is made up of two things - urea and formaldehyde. Think of urea as one ingredient and formaldehyde as another, just like when you use different ingredients to make a cake or pancakes.

Urea is a special powder that is made from pee (yes, pee!). You know how when you go pee, there is some yellow liquid leftover? Urea is in that yellow liquid. But don't worry, the urea used in urea-formaldehyde glue is not made from human pee - it's made in a lab using chemicals.

Formaldehyde, on the other hand, is a very strong-smelling liquid that is used to preserve and protect things. You might have seen it being used in science class to preserve animals or plants. It's a bit like a super-strong medicine that keeps things from getting damaged.

So when you mix urea and formaldehyde together, you get urea-formaldehyde glue. This glue can be used to make things like particle board, which is a kind of wood that is made from small pieces of wood glued together.

But why do people use urea-formaldehyde glue? Well, it's because it's really strong and can hold things together for a long time. However, some people worry that the formaldehyde in the glue can be dangerous if it gets into the air or if you breathe it in. So they try to use other kinds of glue instead that don't have formaldehyde in them.