Lowest-observed-adverse-effect level

The Lowest-Observed-Adverse-Effect Level or LOAEL, is a special term that scientists use to figure out how much of something could be harmful to someone's health.

Let's say you are a scientist who wants to test how much sugar someone can eat before it becomes harmful. You might give some people a little bit of sugar and then gradually increase the amount each time until they experience some negative health effects.

Maybe at some point, one person starts to feel a bit restless while another person starts to feel a bit sick. That amount where the negative effects first become noticeable is called the LOAEL. It's the lowest amount that has ever caused harm to anyone who has been tested.

This information is really important because it helps doctors and scientists figure out what's safe and what's not. By knowing the LOAEL for things like drugs, chemicals or even sugar, they can figure out a safe dose that won't cause harm to anyone.