It's embarrassing enough when you accidentally set off the fire sprinklers during a chemistry class, and even more so if you're the teacher.
It all started well enough..
But that's what happened to this poor chap when he decided to try and impress his pupils, but ended up evacuating the lesson.
Then the shit kind of hit the fan
One pupil at Glasgow High School in Kentucky caught the whole darn thing on camera, much to our pleasure.
To be fair to the teacher though, he did get a round of applause from his pupils - so not all bad.
The pupils decide to leg it
Scroll down to the bottom of the article to view more chemistry experiments gone wrong.