Passengers may use the FAA-approved ____________ oxygen.

Passengers are allowed to use FAA-approved therapeutic oxygen during flights to accommodate their medical needs. This type of oxygen is specifically designed and approved by the FAA for use in the cabin environment, ensuring that it meets safety and regulatory standards for in-flight use. Therapeutic oxygen is necessary for individuals with certain medical conditions who require additional oxygen to maintain proper levels while flying, due to the lower atmospheric pressure at high altitudes.

In contrast to therapeutic oxygen, the other types mentioned, such as emergency, supplemental, and portable oxygen, are not intended for passenger use in the same context. Emergency oxygen is typically meant for crew use only during emergency situations. Supplemental oxygen may imply extra oxygen that is provided to crew members under specific conditions but does not specifically address passenger needs in therapy. Portable oxygen may refer to the physical aspect of being mobile, but without FAA approval for therapeutic purposes, it wouldn’t be permissible for passengers to use it.