Ohio released and implemented the new law, which sets out guidance on labeling of dairy products, on February 8, but a public hearing of testimony is taking place today.
The law's stated aim is to counter false and misleading statements and give consumers clear and consistent information.
While it allows that the state department of agriculture will approve labels if a claim that the milk is derived from cows not supplemented with rbST is verifiable, they must also include a FDA disclaimer saying that "no significant difference has been shown between milk derived from rbST-supplemented and non-rbST supplemented cows" .
RbST is an artificial growth hormone that is administered to cows by injection in order to increase milk production.
According to OTA Caron Wilcox, executive director of the Organic Trade Association (OTA) Ohio is set to become the only state seeming to regulate dairy labeling in an interstate shipment.
However other states, including Utah and Pennsylvania, have also been mulling the issue.
Wilcox fears that a patchwork of different rules will emerge, making it expensive and inefficient - and maybe even impossible - to ship dairy products from state to state.
"We hope that Ohio recognizes that there needs to be uniformity and consistency between states and regions relative to organic," she wrote in a letter to governor Ted Strickland.
"The proposed rule could do exactly the opposite if allowed to go forward.
It could create a series of confusing restrictions on truthful organic labeling.
This could eventually lead to a diminution of choice for consumers in Ohio."
The OTA says that the law it would also prevent dairy farmers and processors from making truthful communications on organic production practices.
Under the 1990 Organic Food Production Act, animals on an organic farm may not receive antibiotics or growth hormones.
Other groups, however, have been positive about the Ohio rule.
The Ohio Dairy Producers Association last month called the ruling "responsible and appropriate".
It believes it could go further however, and would like the statement "from cows not supplemented with rbST " to be disallowed.
"Our position is that this claim has the potential to mislead consumers into believing there is a compositional or safety difference between dairy products when in fact none exists, and we would like to see the FDA guidelines changed," it said.
The law was issued under an emergency ruling valid for 90 days and was said to have followed "months of input from consumers and industry stakeholders" , but the department of agriculture is today holding a public hearing of testimony relating to the administrative rule as part of the statutory rule-making process.