Oxygen Concentrator: How It Works, Types, Who Needs One, and Safety Tips
Updated: 6 days ago
Written and medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: October 2026 · How we review
Quick Answer: What is an oxygen concentrator?
An oxygen concentrator is a prescribed medical device that pulls in room air, filters out nitrogen, and delivers 90% to 95% pure oxygen through a nasal cannula or mask. It helps people with lung or heart conditions breathe easier. Stationary models plug into the wall; portable ones run on batteries. Keep it at least 10 feet from flames and heat. [1]
What the research says
Long-term oxygen did not help people with COPD whose oxygen drop was only moderate. In a randomized trial of 738 patients at 42 centers, followed for 1 to 6 years, long-term supplemental oxygen did not lengthen the time to death or first hospitalization compared with no oxygen (hazard ratio 0.94; 95% CI 0.79 to 1.12), and it gave no lasting gains in quality of life, lung function, or walking distance. (Albert et al., N Engl J Med, 2016) [2]
Remote monitoring support may reduce hospital readmissions for people on home oxygen. A meta-analysis of 8 randomized trials with 1,275 patients with COPD found that telehealth-supported home oxygen therapy reduced hospital readmissions (standardized mean difference −0.40) and improved health-related quality of life (0.49), but did not improve how consistently people used their oxygen. (Hu et al., J Med Internet Res, 2025) [3]
Smoking while using home oxygen can cause serious, sometimes fatal burns. Among 55 people admitted to one regional burn center over 6 years for burns from smoking while on home oxygen, 96% used oxygen for COPD, 51% needed a breathing tube, and 14.5% died in the hospital. (Carlos et al., Respiration, 2016) [4]
Key takeaways
An oxygen concentrator makes its own oxygen from room air, so it never needs refilling as long as it has power. [1]
There are two main types: stationary (about 22 lb, plugs into the wall) and portable (lighter, battery-powered, usually lower output). [1]
Most people who need supplemental oxygen use it at least 15 hours a day; some need it around the clock. [1]
Use one only with a prescription. Breathing pure oxygen when you don't need it can damage your lungs over time. [1]
Keep the device at least 10 feet from flames, heat, and flammable products, and never smoke or vape while using oxygen. [1][4]
How does an oxygen concentrator work?
An oxygen concentrator works by drawing in room air, squeezing it under pressure, and passing it through special filters that trap nitrogen and let oxygen through. [1]
Everyday air is only about 20% oxygen. Most of the rest is nitrogen, plus tiny amounts of other gases. [1]
Here is what happens inside the machine, step by step: [1]
Air comes in. The device pulls room air through an air filter.
Air is compressed. A compressor pressurizes the air, a bit like blowing air into a balloon.
Nitrogen is removed. The pressurized air moves into special filters. Oxygen molecules are smaller than nitrogen molecules, so the filters trap the nitrogen and let the oxygen pass.
Oxygen is stored. The oxygen collects in a small tank inside the device.
Oxygen reaches you. It flows out through an oxygen outlet to a mask over your nose and mouth or a nasal cannula, a thin tube with two prongs that sit in your nostrils.
How is an oxygen concentrator different from an oxygen tank?
An oxygen concentrator is different from an oxygen tank because it continuously makes oxygen from the air around you instead of storing a fixed supply that runs out. [1]
Compressed oxygen tanks and liquid oxygen tanks must be replaced or refilled when they are empty. A concentrator, sometimes called an oxygen generator, keeps working as long as it has electricity or charged batteries. [1][5]
Feature | Oxygen concentrator | Compressed or liquid oxygen tank |
Where the oxygen comes from | Made continuously from room air | Stored inside the tank |
Refills | Not needed | Must be replaced or refilled when empty |
What it depends on | A power source (outlet or batteries) | The amount of oxygen left in the tank |
Oxygen purity | 90% to 95% | Varies by system |
What are the types of oxygen concentrators?
The two main types of oxygen concentrators are stationary units for home use and portable units for activity and travel. [1]
Stationary oxygen concentrators weigh about 22 pounds (10 kilograms). They have handles or wheels and plug into a wall outlet. Some brands include a battery backup or a backup compressed oxygen tank, so oxygen keeps flowing during a power outage. [1]
Portable oxygen concentrators are smaller and lighter, which makes it easier to stay active or travel. Their oxygen output is usually lower than a stationary unit's. Most run on rechargeable lithium-ion batteries. [1]
Feature | Stationary | Portable |
Power | Wall outlet (some with battery or tank backup) | Rechargeable lithium-ion batteries (most models) |
Weight | About 22 lb (10 kg) | Smaller and lighter |
Oxygen output | Usually higher | Usually lower |
Run time | As long as your home has power | About 2–6 hours on one battery; about 5–13 hours on two |
Best for | Home use | Activity and travel |
Sources: [1]
Who needs an oxygen concentrator?
People need an oxygen concentrator when a lung, heart, or breathing condition keeps their body from getting enough oxygen and a healthcare provider prescribes supplemental oxygen. [1]
A provider may prescribe one for: [1]
Type of condition | Examples |
Long-term lung diseases | Asthma, chronic obstructive pulmonary disease (COPD), emphysema, cystic fibrosis |
Infections and inflammation | Bronchitis, pneumonia |
Heart conditions | |
Cancer | Lung cancer |
Chest injuries | Rib fracture, collapsed lung, bruised lung |
Sleep-related breathing problems | Sleep apnea |
Some people, especially athletes, also use an oxygen concentrator when they visit high-altitude areas. When your body can't get enough oxygen during hard exercise, your cells turn carbohydrates into lactic acid for quick energy. Extra oxygen helps limit lactic acid build-up, which may boost energy, reduce fatigue, and support training. [1]
Oxygen concentrators are common. More than 1.5 million people in the United States use some form of supplemental oxygen, including concentrators. [1]
Important: Don't use an oxygen concentrator unless a healthcare provider prescribes one. Breathing in pure oxygen when your body doesn't need it can cause long-term lung damage. [1]
How many hours a day should you use an oxygen concentrator?
Most people who need supplemental oxygen use it for at least 15 hours every day, and some need it 24 hours a day. [1]
Your provider will tell you how often to use it and which output setting is right for you. [1]
How long does an oxygen concentrator battery last?
An oxygen concentrator battery usually lasts 2 to 6 hours on a single-battery model and 5 to 13 hours on a double-battery model. [1]
The exact time depends on the make, the model, your oxygen setting, and how many batteries the unit uses. A plug-in concentrator runs for as long as your home has power. [1]
Setup | Typical run time |
Single battery | 2 to 6 hours |
Double battery | 5 to 13 hours |
Plugged into a wall outlet | As long as power is available |
Sources: [1]
What are the benefits of an oxygen concentrator?
The main benefit of an oxygen concentrator is that it helps you breathe more easily. [1]
It isn't a cure for the condition behind your low oxygen, and it may not take away all shortness of breath. Still, breathing should feel easier. Higher blood oxygen levels can also give you more energy and help you sleep better. [1]
Another benefit is convenience. Unlike other oxygen tanks, a concentrator never needs refilling, so you have an unlimited oxygen supply as long as it has a power source. [1]
What are the risks and disadvantages of an oxygen concentrator?
The main risks of an oxygen concentrator are losing your oxygen supply during a power failure and the higher fire risk that concentrated oxygen creates. [1]
Power dependence. A concentrator needs a power source to work. Keep at least one set of fully charged batteries or a compressed oxygen tank on hand, with enough to last at least a few days if the power goes out. [1]
Fire risk. Pure oxygen isn't flammable, but it makes fire burn hotter and faster, and it can cause an explosion. Smoking while using home oxygen is a well-documented cause of serious burns. [1][4]
Keep your concentrator at least 10 feet away from: [1]
Heat and flame sources | Flammable products | Spark-prone electrical items (avoid using nearby) |
Cigarettes and cigars | Gasoline | Hair dryers |
Fires | Oil | Electric blankets |
Ovens | Paints and paint thinner | Space heaters |
Grills | Rubbing alcohol | Electric razors |
— | Oil-based products such as petroleum jelly | Vape pens |
Sources: [1]
For more practical guidance, see this step-by-step guide to getting started with a home oxygen concentrator and this consumer update on pulse oximeters and at-home oxygen therapy.
When should you call a doctor while using an oxygen concentrator?
You should call a healthcare provider while using an oxygen concentrator if you notice signs of getting too much oxygen (oxygen poisoning) or too little oxygen (hypoxia), or if you think the device isn't working properly. [1]
Too much oxygen (oxygen poisoning) | Too little oxygen (hypoxia) |
Dizziness | Restlessness |
Confusion | Confusion |
Memory loss | Headaches |
Headaches | Slow heart rate (bradycardia) |
Nausea and vomiting | Blue tint to the skin, lips, gums, nails, or around the eyes (cyanosis) |
Sources: [1]
Low blood oxygen can become an emergency. Learn the warning signs in our guide to hypoxemia.
Tips for staying on track: [1]
Get a pulse oximeter. This small, painless clip goes on a finger or toe and measures your blood oxygen level.
Watch for device alerts. Many concentrators sound an alert when oxygen purity falls below 80%.
Schedule routine checks. Have a provider check your concentrator regularly to make sure it works correctly.
Is an oxygen concentrator the same as an oxygen machine?
An oxygen concentrator is not the same as an "oxygen machine" in the sense of mechanical ventilation. [1]
A concentrator supplies extra oxygen while you breathe on your own. A mechanical ventilator breathes for you when you can't breathe by yourself, and it is a form of life support. [1]
Should you buy or rent an oxygen concentrator?
Whether you should buy or rent an oxygen concentrator depends on how long you'll need it and your situation. [1]
Feature | Renting | Buying |
Best for | Short-term conditions | Long-term conditions |
Cost | Lower up-front cost | High up-front cost, but may be cheaper over time |
Device condition | Often used; may be near the end of its life cycle or more likely to fail | Brand new |
Upkeep | Arranged with the rental | Warranties often cover normal repairs, but you may pay for professional servicing |
Sources: [1]
Talk with your healthcare provider. They can recommend the best concentrator for your condition, situation, and lifestyle. [1]
Conclusion
An oxygen concentrator is a reliable way to get the oxygen your body needs at home and on the go. It makes oxygen from room air, never needs refilling, and can help you breathe easier, sleep better, and feel more energetic. [1] Use it only as prescribed, follow your provider's settings and daily hours, and treat fire safety as non-negotiable. Keep backup power ready, watch your oxygen level with a pulse oximeter, and call your provider if you notice signs of too much or too little oxygen. [1]
Next step: If you or someone you care for has just been prescribed home oxygen, bookmark this guide and share it with your household so everyone knows the 10-foot rule. Then keep learning with our related guides:
FAQ
Do you need a prescription for an oxygen concentrator?
Yes. An oxygen concentrator should be used only when a healthcare provider prescribes it, because breathing pure oxygen when you don't need it can cause long-term lung damage. Your provider also sets your output and how many hours a day to use it.
How pure is the oxygen from an oxygen concentrator?
An oxygen concentrator delivers about 90% to 95% pure oxygen. Everyday room air contains only about 20% oxygen, so the device concentrates oxygen by removing nitrogen.
How many hours a day should I use my oxygen concentrator?
Most people on supplemental oxygen use it at least 15 hours a day, and some need it 24 hours a day. Always follow the schedule and setting your provider prescribes.
How long does a portable oxygen concentrator battery last?
A single-battery oxygen concentrator usually runs 2 to 6 hours, and a double-battery model about 5 to 13 hours. Run time depends on the make, model, oxygen setting, and number of batteries.
Can I use an oxygen concentrator during a power outage?
A stationary oxygen concentrator stops working without electricity unless it has a battery backup. Keep fully charged batteries or a compressed oxygen tank on hand, with enough to last at least a few days.
Is it safe to smoke or cook near an oxygen concentrator?
No. Concentrated oxygen makes fire burn hotter and faster, so keep the device at least 10 feet from cigarettes, cigars, open flames, ovens, and grills. Never smoke or vape while using oxygen.
What are the signs of getting too much or too little oxygen?
Signs of too much oxygen include dizziness, confusion, memory loss, headaches, nausea, and vomiting. Signs of too little oxygen include restlessness, confusion, headaches, a slow heart rate, and a blue tint to the skin, lips, or nails; call your provider if you notice either.
Is it better to buy or rent an oxygen concentrator?
Renting an oxygen concentrator often makes sense for a short-term condition, while buying may cost less over time for a long-term condition. A purchased unit is brand new, but rented units are often used.
Can you sleep with an oxygen concentrator on?
Yes, if your provider prescribes oxygen during sleep. Use the flow rate you were given and place the unit where it has open space for air.
Can you fly with a portable oxygen concentrator?
Yes, most airlines allow FAA-approved portable oxygen concentrators. Contact the airline ahead of time and bring enough charged batteries for the whole trip.
Related Reading
Oxygen Tank: Types, How to Use It Safely, and When to Call a Doctor explains compressed and liquid oxygen tanks and how to use them safely.
Nasal Cannula: A Comprehensive Guide to Supplemental Oxygen Therapy shows how a nasal cannula delivers oxygen and how to use it comfortably.
Pulse Oximetry: Normal Oxygen Levels, How It Works and What Affects Accuracy explains how a fingertip sensor measures blood oxygen levels.
Oxygen Therapy: Types, Benefits, Risks and Home Safety covers who needs oxygen therapy, its benefits and safety rules.
References
Cleveland Clinic. Oxygen Concentrators: Function, Settings & Results. Cleveland Clinic. Last updated August 4, 2023. https://my.clevelandclinic.org/health/treatments/25183-oxygen-concentrators
Long-Term Oxygen Treatment Trial Research Group; Albert RK, Au DH, Blackford AL, et al. A Randomized Trial of Long-Term Oxygen for COPD with Moderate Desaturation. N Engl J Med. 2016;375(17):1617-1627. PMID 27783918. https://doi.org/10.1056/NEJMoa1604344
Hu C, Liao X, Fang Y, et al. Clinical and Cost-Effectiveness of Telehealth-Supported Home Oxygen Therapy on Adherence, Hospital Readmission, and Health-Related Quality of Life in Patients With Chronic Obstructive Pulmonary Disease: Systematic Review and Meta-Analysis of Randomized Controlled Trials. J Med Internet Res. 2025;27:e73010. PMID 40631803. https://doi.org/10.2196/73010
Carlos WG, Baker MS, McPherson KA, et al. Smoking-Related Home Oxygen Burn Injuries: Continued Cause for Alarm. Respiration. 2016;91(2):151-155. PMID 26812246. https://doi.org/10.1159/000443798
Hardavella G, Karampinis I, Frille A, et al. Oxygen devices and delivery systems. Breathe (Sheff). 2019;15(3):e108-e116. PMID 31777573. https://doi.org/10.1183/20734735.0204-2019
Medical disclaimer
This article is for general education and does not replace advice from your doctor or another qualified healthcare provider. Use supplemental oxygen only as prescribed, and seek emergency care right away if you have severe shortness of breath, confusion, or a blue tint to your lips or skin.
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