Daily Trust learnt that the chemical substance engulfed the entire school causing others to flee their classes.
Source said the effected students allegedly collapsed one after the other before the teachers took notice of the situation.
Those who were not affected were said to have used clothes to cover their faces so as not to be inhale the offensive fume.
It was also gathered some brave teachers who stayed back to evacuate four of the students to Blue Cross Hospital, Ijaiye Road while the others were attended to by some emergency officials from the Lagos state General hospital .
A witness who spoke on the condition of anonymity , said the incident happened around 1.OO pm
The man said he was coming inside the school when suddenly he saw some teachers and pupils running away from the school premises shouting that some pupils had fainted
“I can’t say the exact number of pupils affected but they were over 20. A few minutes later, emergency officials came around to attend to the victims.”
He said some rescue officials went around the compound in a bid to identify where the smell emanated from.
Director, Lagos State Fire Service, Razaq Fadipe, said it was discovered that a laboratory located in a shopping complex was emitting the substance.
He said, “On getting to the school, 22 students were unconscious. LASAMBUS was able to revive most of them and their parents took them home.
