The rules of origin for the U.S. Chemical industry. This information is part of "A Basic Guide to Exporting", provided by the U.S. Commercial Service, to assist companies in exporting.
Last Published: 10/20/2016
The U.S. chemical industry uses the same Rules of Origin for all agreements.

For that purpose they created simplified versions of the rules of origin for Chapters 28 to 39 of the North America Free Trade Agreement.
http://www.sice.oas.org/trade/nafta/anx401a1.asp