The US has banned the import of clothing that contains benzidine-based dyes. These include DnPP, a phthalate used in PVC plastics, and alkanes C12-13, used as industrial lubricant. Benzidine is a synthetic chemical that does not occur naturally. It is a crystalline (sandy or sugar-like) solid that may be greyish-yellow, white, or reddish-grey in color. It will evaporate only slowly, especially from water and soil.

Benzidine and its related chemical substances are used to manufacture dyes. Benzidine-based dyes are used in the production of textiles, paints, printing inks, paper, and pharmaceuticals. They are also used as reagents and biological stains in laboratories, and have more recent uses in laser, liquid crystal displays, ink-jet printers, and electro-optical devices.

Exposure to benzidine-based dyes is of concern because benzidine dyes can be converted in the body into a chemical that is known to cause cancer. In the past, the industry used large amounts of benzidine to produce dyes for cloth, paper, and leather. Major US dye companies no longer make benzidine-based dyes. Benzidine is no longer used in medical laboratories or in the rubber and plastics industries. However, small amounts of benzidine may still be manufactured or imported for scientific research in laboratories or for other specialized uses.