The classification turns on the medium in which the polymer binder is dissolved or dispersed. If the continuous phase is an organic solvent, the product falls under 3208. If the binder is dissolved or dispersed in water, it falls under 3209. Emulsion paints that use water as the carrier but contain a synthetic polymer binder go to 3209, not 3208, even if they contain minor solvent additions.

While customs classification is handled by CBP, solvent-borne coatings containing volatile organic compounds (VOCs) may be subject to EPA regulations and state air-quality rules governing VOC content. Importers distributing into states with stricter standards (such as California's CARB rules) should verify that the product's VOC content complies with applicable limits before sale or use.