A Toronto high school principal is enforcing mandatory breathalyzer tests before school dances, and says she has yet to send a student home for being drunk.

Students at Malvern Collegiate Institute will have to provide a clean breathalyzer sample before entering their prom Friday. If any alcohol is detected they won’t be allowed in.

“We’ve always breathalyzed at our functions,” principal Line Pinard told CTV Toronto’s Seamus O’Regan.

She said prior to arriving to the school there had been concerns with students drinking before school dances and jeopardizing the safety of their classmates and staff.

“The parents really wanted the proms and the dances and the semi-formals to be supervised by school administration and staff, so they offered at the time to purchase breathalyzers.”

Pinard said she hasn’t heard any complaints from students about the breathalyzers in the eight years that she’s been principal at the high school.

“It’s good because it’s worked its way into their culture and their understanding about the implications of what can happen when you go to an event and consume alcohol,” she said.

Student Jackson Steinwall said he doesn’t have an issue with the breathalyzer rule.

“Prom is something you want to remember, and if you’re intoxicated, I don’t know how much you’re going to remember,” he told CTV News. “Say somebody gets drunk, can’t control themselves and gets hit by a car or something -- it’s the school’s responsibility.”

Classmate Sam Agro agrees.

“If you’re clear you go right in and that’s all there is to it. It doesn’t really take much time.”

The move to mandatory breathalyzer tests has garnered praise from safety advocates.

Mothers Against Drunk Driving representative Carolyn Swinson says drunk driving is a concern particularly around prom season, and that parents, teachers and students should all take responsibility to combat the trend.

"It is a high risk time. We certainly know that every year there are 400 young people between 15 and 19 years of age that are killed in impaired driving crashes. The summer months are the worse months," Swinson told CTV News Channel on Thursday.

"If the school is supportive of it and the students are supportive of it, a breathalyzer is certainly one good way that you can maintain that students are going to have a safe prom."

According to numbers released by MADD, one in eight road crashes involve a teenager, and two out of every five teens killed in a collision has been drinking.

Swinson said that it is not the first time a breathalyzer has been employed at school proms in Ontario. In some other cases, students planning to attend the event are asked to sign promissory notes supporting a dry, safe environment.

Still, Swinson says there could be a few students who decide to attend the event and drink alcohol.

"In any situation where there is a large group of people, you are going to have people that are the risk takers, and those are the ones you have to look out for," Swinson said.

"Students, staff and parents all need to take a part in keeping those young people safe."