Students and staff at Diamond Jenness Secondary School in Hay River, N.W.T., can breathe easy: a substance found over the weekend in the building was not asbestos, according to tests ordered by the territorial government.

Officials with the N.W.T. Public Works Department said air samples sent to Edmonton on Monday came back with no sign of asbestos contamination.

Tests were also done on damaged pipe insulation that was suspected to contain asbestos, but those tests came back with no sign of the carcinogenic material. Crews are now working on the pipe and replacing the damaged insulation.

"Basically, they're dressed up in a suit and with goggles and with the breathing apparatus, and they remove the material and they bag it, and identify the area where they picked it up from," Richard Mercredi, regional superintendent of public works, told CBC News late Wednesday.

"As well, we have the air monitoring machines taking samples, and we send samples out daily, just to make sure that there's no hazardous material in the air."

Students are still not allowed back into the school this week. They were sent home Monday when school and government officials were alerted to the suspect substance.

The school is expected to reopen Monday, if cleanup efforts go well.