Not really- it was a condition of employment in a safety sensitive position and part of the employment contract that both parties agreed to enter. It protects both parties.

Violating the contract for a clause that has zero tolerance is all that matters. You can't allow an employee show up to a safety sensitive position with the possibility of being high as there's simply too much liability.

Until we have a test that shows you are not currently under the influence this is the agreement we have to have.