Safety and recalls
Using CPAP with Supplemental Oxygen: Safety Rules
Some people need supplemental oxygen bled into their CPAP circuit, which your clinician prescribes and your supplier sets up. Manufacturers say to turn the CPAP on before the oxygen and turn the oxygen off before the CPAP, never to smoke or use oxygen near an open flame, and Philips requires a pressure valve in line for its devices.
Why oxygen is added
CPAP keeps your airway open but does not add oxygen. Some people with lung or heart conditions still have low oxygen levels on CPAP, and their clinician may prescribe oxygen to be added to the CPAP air.
How much oxygen, and how it connects, is set by your clinician and supplier. Do not add oxygen on your own.
Fire safety rules
ResMed's AirSense 11 guide says supplemental oxygen must not be used while smoking or in the presence of an open flame. Starting therapy: make sure the device is on and blowing air before turning the oxygen on. Stopping therapy: turn the oxygen off first, then the device. This keeps oxygen from accumulating inside the device and creating a fire risk.
Philips says oxygen with the DreamStation 2 must comply with local medical oxygen rules, must not come from an unregulated or high pressure source, and requires a Philips Respironics pressure valve in line between the device and oxygen source to prevent backflow when the unit is off. Philips warns that failing to use the valve could create a fire hazard.
Equipment notes
ResMed lists the AirSense 11's supplemental oxygen maximum flow as 15 L/min. Oxygen concentration delivered to you varies with pressure, leak, breathing pattern and where the oxygen enters the circuit, which is why your clinician decides the flow.
ResMed notes some on screen measurements may be inaccurate with supplemental oxygen in use.
Daily habits
Keep the machine and oxygen equipment away from heat sources, candles and stoves. Do not let anyone smoke in the room. Keep oxygen tubing untangled from the CPAP hose.
If you feel short of breath, confused, or have chest pain, seek urgent care. Call 911 for chest pain.
Frequently asked questions
Can you use oxygen with a CPAP machine?
Yes, when prescribed. Your supplier connects it per the manufacturer's instructions, and you follow the order of turning things on and off.
Which do I turn on first, CPAP or oxygen?
CPAP first, then oxygen. To stop, turn oxygen off first, then the CPAP. ResMed says this prevents oxygen building up inside the device.
Can I use an oxygen concentrator with my CPAP?
Many people do, if prescribed. Follow your machine's oxygen instructions; Philips, for example, requires an in line pressure valve.
Can I adjust my oxygen flow on CPAP?
No. Oxygen flow is a prescription. Talk to your clinician if you think it needs to change.
Sources
Last reviewed October 11, 2026. How we research · Report an error