Gotta' agree with the Budman on both his posts.
Going back to my days in Dealer Training when we were developing Operator Training Programs & Train-The Trainer Programs I recall that: Only the employer is in the position to "police" an operator and pull his permitting (aka certification), if necessary. And part of the complete training is to evaluate the operator's skills in the work environment where they will be actual working and isolated from other employees - no OJT and if they are moved to another area that requires different skills they need to be re-evaluated.