Hydro-what?

My sister was entertaining me with an incident that happened at the school where she works as a laboratory assistant.

There’s a new science teacher there they call 'Gary Giggles' because he is a total idiot. Last week, he was burning fuel sticks without any safety equipment. My sister told her senior and she went in and said, “Uhm, shouldn’t you be wearing goggles?”
“Yeah, the goggles are around here somewhere,” the teacher answered distractedly, and just closed the door again.

Next time my sister looks outside the lab, there are clouds of smoke filling the corridor. She goes outside and 'Gary Giggles' has opened the classroom door to ‘air’ the room! The caretaker comes down the corridor, muttering to himself about the smoke and setting off the smoke alarms (which in turn calls the Fire Brigade that the school has to pay for). Suddenly, everyone troops out of the classroom, coughing and choking, and the teacher tells my sister, “It‘s getting a bit smoky in there so we’re coming outside for a bit.”

I said to her, “Is this guy a proper teacher?!”
She sighs, “I dunno. He’s just doing my head in.”

The guy sounds like he’s forgotten everything he ever learnt at school! Only today he queried the Head of Science as to whether creating clouds of hydrochloric acid was dangerous…