A chemical leak at a high school in Adelaide's eastern suburbs turns out to have been a false alarm.

Emergency crews were called to Marryatville High School around 9.45am to attend to a suspected hydrogen sulfide leak.

It was thought the chemicals leaked in a science lab.

An MFS crew, in protective gear, checked the scene but found no traces of toxic materials, the Advertiser reports.

“Nothing that could cause harm to anyone was found at the scene, it was simply a bad smell,” an MFS spokeswoman said.

“It was a routine cleaning of the kitchen and lab areas which caused the smell in this case, there was absolutely nothing harmful there.”