Ricin is classified as a CDC/USDA select agent, meaning its possession, use, and transfer are regulated under the Federal Select Agent Program. Importers must be registered with the appropriate federal select-agent program, obtain prior approval for transfer, and maintain strict security and inventory controls. Standard FDA pharmaceutical import procedures are insufficient — select-agent compliance is a separate, parallel requirement.

Classification depends on the culture's intended use and presentation. Cultures intended for therapeutic or prophylactic use in humans typically fall within Chapter 30, while cultures for industrial fermentation or research may classify elsewhere (e.g., Chapter 21 or 38). A licensed customs broker with pharmaceutical experience should review the product's technical documentation, including its intended use and regulatory status, before filing entry.