Toilet cleaning with acid - fumes affect students

In an incident reported, fumes from toilet cleaning with acid in a religious place affected students in the adjacent school causing hospitalization. Some students vomited while the teacher became unconscious.

Status on the persons cleaning the toilet is not known. 

It's my personal experience wherein acidic fumes during toilet cleaning cause severe lung congestion, respiratory problems, etc and we stopped using acid and instead we are using toilet cleaners that are mild and also have perfume smell. 

Further, frequent cleaning does not require application of more acid.

http://www.thehindu.com/news/states/andhra-pradesh/six-teachers-33-students-hospitalised-after-inhaling-acid-fumes/article4226807.ece