Back in 2006, Irving Pulp and Paper unilaterally imposed such a policy and local 30 of the Communications, Energy and Paperworkers Union filed a grievance.
The worker who was tested had a blood alcohol level of zero and called the experience unfair and humiliating.
The company says it will review the court's decision.
The court left open the door for such a policy to be implemented if it's part of a collective agreement.
