In IDFA v. Boggs, the United States Court of Appeals for the Sixth Circuit ruled in its Sep. 30, 2010 (3-0) decision overturning Ohio's ban on milk labels such as "rBGH free" or "artificial hormone free":

“On the one hand is milk from cows never given rbST, which in turn cannot produce milk that has rbST as a matter of fact. The composition claim ‘rbST free’ is therefore demonstrably true as applied to this milk. On the other hand, milk from cows treated with rbST might contain the artificial hormone, although there is currently no way to determine whether that is the case. But even if rbST is not present in conventional milk, there is still evidence that it contains increased levels of IGF-1 and might be compositionally of a lesser quality. A compositional difference thus exists between the two types of milk, although the extent of this difference—namely whether conventional milk does in fact contain rbST—is still very much an open question… Under these circumstances, we conclude that composition claims like ‘rbST free’ are not inherently misleading.”

Sep. 30, 2010 - IDFA v. Boggs