ELI5: Explain Like I'm 5

Coumarin

Coumarin is a chemical that smells a bit like vanilla and is often found in things that taste or smell like vanilla, like some types of plants. It's often used in things like perfumes or air fresheners to add a sweet smell.

But, there's also another side to coumarin that can be a bit more serious. When people eat or drink too much of it, it can cause problems with their liver. So, while it can make things smell or taste nice, it's important to be careful and not use or consume too much of it.