Regional Emergency Services (RES) responded to calls to downtown Canada Post offices Thursday afternoon,
Two people came into contact with six envelopes each carrying a reported substance at the office on Riedel Street.
RES transported them to the Northern Lights Regional Health Centre for further care and treatment although they showed no symptoms at the time of transport.
Nothing suspicious was found by RES and the Wood Buffalo RCMP are now investigating.
Officials ask anyone seeking more information to contact Pulse at (780) 743-7000.