ZHUHAI, China—Judah Huang works deep in the global supply chain at a Chinese company that makes nonstick coatings for cookie sheets, frying pans and grills sold in stores such as Wal-Mart.

Until a few years ago, the pans and griddles were made in China, but most of the materials that went into them were not. Mr. Huang imported most of the resins, pigments and pastes for his coatings from multinational suppliers such as Dow Chemical Co. of the U.S. and Eckart Effect Pigments of Germany.

Now,...