A school laboratory technician who used chloroform to knock out a pupil has been jailed for two-and-a-half years.
Jared Shreeve, 41, struck at Seven Kings High School in Ilford, in east London, on 2 July 2008.
Snaresbrook Crown Court in east London heard he lured Sayeda Rahman, 17, into the laboratory before tricking her into wearing a dust mask which had been doused in chloroform.
He was found guilty of administering a poison with intent to injure or annoy.
The court heard Shreeve had invited the girl into his laboratory to help him with a stock take.
He then claimed there were dangerous vapours in the room and urged her to wear a dust mask.
It had been doused in chloroform which can knock people out but is also sometimes lethal.
She collapsed and was taken to hospital with a "dangerously low" pulse rate.
Judge William Kennedy said: "This was a truly appalling, senseless and unfathomable risk to take with the life and hope of a young woman.
"The good fortune is that this deadly chemical did not do its worst."
Shreeve's claim that he did not know the effects of chloroform was rejected.
James Bloomer, defending, said his actions were an "awful aberration" which had cost him his career.
He added: "Jared Shreeve has lost a very great deal by his dangerous and stupid behaviour that day."