EPA and OSHA have no jurisdiction in Africa, Asia and Latin America. As such, companies that locate in those countries don't bear all production costs borne by American firms. That gives them a competitive edge. Whether our business and labor regulations are good or bad for us is one question, and their cost is another. One benefit of free trade is that regulatory costs are revealed.
Trade restrictions kill the messenger.
By the way, neither the agreements associated with the World Trade Organization nor those associated with the North America Free Trade Agreement is truly free trade. These agreements contain thousands of pages of specifications. You don't need thousands of pages to tell people they can trade freely. Here's a free trade agreement I like. That's an agreement that helped make us a rich nation and, if applied to the world, we and everybody else would be richer.