Nick,
The store where you bought the ballast should be able to tell you if the "no residential" restriction is based on the FCC classification or some other code requirement.
The "correct" answer is probably to call your local building inspector, explain the circumstances, and see what your options are.
Depending on where your shop is, you might also try installing one of the ballast and see if it screws up any nearby radio, tv, ham radios, pacemakers. As long as you do not have a bed and/or kitchen in your shop, I think you have a good case that it is not "residence."
Usual disclaimer: :eusa_hand:eusa_hand I am neither a lawyer nor electrician, nor do I play one on TV. Take my thoughts for what they are worth -- which probably is not much.
Hope this is helpful.
Ray