Dirty CPAP

Continuous positive airway pressure therapy, or CPAP, is used in home settings to treat obstructive sleep apnea and snoring. A small air pump provides slightly pressurized air through a tube and mask to keep the soft parts of the upper airways open overnight. The machine, tube, and mask areas require periodic cleaning. In addition to being unpleasant, there are actual health dangers from using a dirty CPAP.

Fostering Microbe Growth

Different parts of the CPAP machine can become dirty in different ways.

The nose mask or face mask that covers the nose, mouth, or both comes into contact with both your hands and your face. Even if you are diligent about washing your hands before bed, the surfaces on the mask can accumulate oils and dead skin cells that are shed naturally by your body. This can be the perfect food for microbes, and the warm, moist conditions from wearing the mask can allow bacteria and fungi to flourish.1

The tube that carries the air between the bedside pump and the mask can become humid from either exhaled breath or from a humidification stage. This can lead to bacterial or fungal growth, sometimes detectable as a bad or musty smell.

Finally, the humidifier reservoir of the CPAP machine can foster microbe growth as well. A reservoir that is heated in order to provide warm, humid air through the tube and mask inadvertently creates an excellent environment for bacterial growth. Frequent water changes and cleaning are important for CPAP equipment with integrated humidifiers.

CPAP Cleaning

CPAP equipment suppliers carry CPAP cleaning supplies like CPAP hose cleaners and cleaning solutions. If you are buying a CPAP machine, remember that the cost of ownership includes cleaning and maintenance. To avoid having to use a dirty CPAP, make sure to keep a supply of sanitizing CPAP solution so that you can clean the components as needed.

If you have found a used CPAP machine for sale, make sure to replace the CPAP hose and mask. If there is a water reservoir, it should be bone dry at the time of purchase. If there is water in it, or if there is a musty smell, then if possible, find another seller. At the very least, the CPAP reservoir should be thoroughly cleaned if you do purchase it.


Can you get sick from a CPAP machine?

Infections from continuous positive airway pressure devices can occur if the CPAP machine harbors pathogens. CPAP cleaning is especially important if the CPAP device includes a hot water bath humidifier.2 The warm water in the reservoir can be the perfect environment for bacterial or fungal growth. The humidifier, ventilatory circuits, and face masks should be cleaned or replaced as appropriate. This will reduce the risk of acquiring an infection from the CPAP machine.

How do I get rid of the smell in my CPAP machine?

If there is a noticeable smell coming from your CPAP machine, there might be a few different sources. A musty or mildew-like smell might point to fungal or bacterial growth. A sour smell might also indicate microbial growth. See if you can locate the source of the smell. If the smell is coming from the humidifier reservoir, follow manufacturer instructions for cleaning this part. Be careful with harsh smelling cleaning solutions like bleach, as breathing in the smell of these strong disinfectants all night might be unpleasant.

How often should I change the water in my CPAP machine?

Guidelines for how often you should change the water in a CPAP reservoir vary depending on the make and model of CPAP machine. Some manufacturers recommend emptying and cleaning the water reservoir or tank after every use.3 Other continuous positive airway pressure machine manufacturers suggest a cleaning schedule of once every week.4 It is important to empty and clean the water reservoir on the recommended time window and not on usage. This is because, even if you only use a CPAP with a water reservoir a few nights a week, the water sitting in the reservoir still has an entire week in which microbes might grow. If you do not anticipate using your CPAP machine for an extended period of time, empty the water reservoir and allow the tubing to dry to avoid bacterial growth.

What happens if you use a dirty CPAP machine?

It is possible that a dirty CPAP machine can lead to upper airway infections. Research has found that CPAP users that regularly clean their CPAP machines have lower risk of upper airway infections like a sinus infection versus CPAP users that don’t clean their machines. There has even been a case of balls of fungus growing in the sinuses that spread from a dirty CPAP device.5

Can CPAP machines cause lung problems?

One of the most common side effects of continuous positive airway pressure therapy is a burning sensation in the lungs that is caused by dry air.6 This is why some models of CPAP machines either include an integrated humidifier or provide a simple way to couple a separate humidifier to the air tubing.


Master Sources List for CPAP Cleaning


  1. https://www.mayoclinic.org/diseases-conditions/snoring/diagnosis-treatment/drc-20377701
  2. https://www.karger.com/Article/Abstract/50555
  3. https://document.resmed.com/documents/products/machine/s9-series/welcome-guide/s9-vpap-auto-st-s-h5i_welcome-guide_amer_eng.pdf
  4. https://document.resmed.com/documents/products/machine/aircurve-series/user-guide/aircurve-10-vauto-s-st-device-with-humidifier_user-guide_amer_eng.pdf
  5. https://www.sciencedirect.com/science/article/abs/pii/S0030666500800134
  6. https://pubmed.ncbi.nlm.nih.gov/24557772/
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