The Saskatchewan university says the possible exposure involved the lancet used to draw blood during the exercise.
While the part that pierces the skin was replaced after each test, the school says the holder that projects the lancet was cleaned with alcohol and then used again.
It should have been discarded as well.
The exercise was done as part of the Northern Health Science Access Program in the northern campus biology lab between 2002 and 2011.
The school says the risk is low because any viruses would have had to survive the cleaning process.