private companies in a free market by their own free will could not be considered regulating (in the sense of government regulation) and it would be a binding action.
In a free market those companies selling GMO products would have to label their products with a GMO label or suffer the penalty of fraud for trying to sell their product as if it were a NATURAL product.
GMO products come with risks that should not be supported by tax payers. Those who want to take the risk of consuming GMO products should support the cost of the increased cost of having them labeled and they would if only we had a free market.
I try to change people every day. Do You?