Used tires can harbor soil, water, and invasive insects—particularly wood-boring beetles—in their treads and interiors. USDA APHIS may require inspection or treatment to prevent the introduction of quarantine pests, and some shipments require advance permits. Importers should coordinate with a licensed customs broker and confirm current APHIS requirements before shipping.

Retreaded tires (401211–401219) are pneumatic casings that have had new tread bonded onto a used carcass; they retain an air chamber. Solid and cushion tires have no air chamber at all—they are either fully solid rubber or filled with a cushioning compound—and are classified under 401290 along with interchangeable tire treads and flaps. The presence or absence of an air-retaining structure is the key classification criterion.