The key distinction is therapeutic function: apparatus designed to treat a medical condition through ozone, oxygen, aerosol, or artificial respiration belongs here, while equipment that merely supplies or measures gas flow (e.g., industrial oxygen regulators) typically falls under Chapter 84 or other Chapter 90 headings. CBP binding rulings and the Explanatory Notes to heading 9019 are the primary reference points; a licensed customs broker can help assess borderline devices.

CPAP and BiPAP devices are Class II medical devices regulated by FDA's CDRH and generally require 510(k) premarket notification clearance. The foreign manufacturer must be registered with FDA and the device listed before importation. FDA may detain shipments at the port of entry if clearance documentation is not in order. Importers should work with a regulatory affairs specialist to confirm device classification and clearance status prior to shipment.