The Ottawa-Carleton District School Board has introduced stricter cleaning rules after six students sought medical help for chemical burns caused by cleaning materials used on the seat of a toilet in a bathroom at a public school.

Five young girls told staff at east Ottawa’s Avalon Public School that they had sunburn-like rashes on their thighs and buttocks after using the same bathroom on Friday.

Another boy complained of burns to his elbows.

Neil Yorke-Slader, superintendent of instruction for the OCDSB’s east-end schools, said cleaning staff hadn’t fully wiped the chemicals they used off the toilet seats.

"Of course everybody feels terrible, these are young kids, they had to suffer for really no good reason," he said.

"I know having been in the school today that office staff are very upset. The principal and vice-principal are very upset, teachers are very upset."

Yorke-Slader said there are new cleaning rules, including a nightly check of the toilets by an area supervisor.

He added there was a similar, isolated incident a few months ago, but that cause wasn’t determined.

All six students were seen by their family doctors and the injuries aren't expected to be serious.