There was a "guidance" document (not directive) issued by FDA on September 12, 2002 in collaboration with USDA. "Guidance for Industry: Drugs, Biologics, and Medical Devices Derived from Bioengineered Plants for Use in Humans and Animals"

The document asked for public comment until January. It was not a final document.

BIO adopted one proposed suggestion. (Page 9 "For such plants that outcross, you may want to consider growing them in regions of the country where little or none of its food/feed counterparts are grown".)