A chemical hazard is like playing with fire. You know how you're not supposed to touch the stove or get too close to a campfire? That's because fire is dangerous and can hurt you.
Chemicals can be dangerous too. You might have seen grown-ups working with cleaning supplies or putting on gloves to handle certain things like bug spray. That's because those things can be harmful if they touch your skin or you breathe them in.
Just like fire needs to be handled carefully, chemicals need to be handled safely by grown-ups who know what they are doing. They might wear special clothes or masks to protect themselves from the chemicals.
It's important to always ask a grown-up for help if you want to use or touch something that you don't recognize. Just like you ask for help to stay safe around the stove or campfire, you should ask for help to stay safe around chemicals.