Alkyd Resins, Primary Forms

Alkyd resins are defined by their modification with fatty acids or drying oils, which imparts film-forming and oxidative curing properties absent in unmodified polyesters. Chapter 39 Note 3(d) specifically includes alkyd resins within the polyesters group. If a product is a straight polyester without oil or fatty acid modification, it would fall under a different polyester subheading rather than 3907.50.

Alkyd resins are generally not subject to mandatory admissibility review by a specific agency at the border, but importers should be aware that solvent-borne alkyd formulations may be subject to EPA VOC regulations once they enter commerce in the US. At the import stage, standard CBP entry requirements apply, and importers should ensure Safety Data Sheets are available for customs and downstream compliance purposes.