How to clean your CPAP properly

A CPAP mask does not need to be sterile. It needs skin oil washed off the cushion, standing water emptied from the humidifier, and parts dry before the next night. Manufacturer instructions and CDC device-hygiene guidance both point to soap, water, and drying. Ozone and UV boxes sell a different story: that more kill-power means a safer machine. That frame is wrong, and it has a federal paper trail.

Why is “more sterile” the wrong way to think about a home CPAP?

Hospital sterilizers exist for instruments that enter sterile body cavities. A CPAP is a home respiratory device. The hygiene problem is ordinary: facial oils that crack silicone and wreck the seal, saliva in the cushion, mineral scale in a water chamber, and biofilm in parts that stay wet.

ResMed’s United States cleaning page, which we opened for this article, tells patients to use a sink, warm drinking-quality water around 86°F (30°C), mild liquid detergent, and a towel. Daily work is the cushion and the humidifier tub. Weekly work is the frame, headgear, and tubing. That is the manufacturer’s intended-use cleaning, not an optional extra for people who like chores.

The U.S. Food and Drug Administration’s 27 February 2020 safety communication, issued in the agency’s own press release, said the same thing in different words: follow the CPAP manufacturer’s cleaning instructions, which normally include regular cleaning with soap and water. The agency was writing because a market had grown around devices that claimed to clean, disinfect, or sanitize CPAPs with ozone gas or ultraviolet light. Those claims were the product. Soap was the actual instruction.

If you already use CPAP therapy, treat cleaning as part of the prescription. A dirty cushion leaks. A crusted humidifier rattles and aerosolizes whatever grew in the water. Neither problem is solved by a box that smells like a thunderstorm.

What should you wash daily, and what can wait for the week?

Follow the user guide that shipped with your exact mask and machine. Brands differ, and foam cushions are not silicone. ResMed’s published schedule for the masks it lists (AirFit, Swift, Mirage, Quattro, Pixi) is a useful default for silicone gear:

• Daily: mask cushion. Unplug the device. Take the mask apart into cushion, frame, and headgear. Wash the cushion in mild liquid detergent and warm drinking-quality water to remove oils. Rinse. Dry on a towel out of direct sun.
• Daily: humidifier tub. Empty it. Wipe with a clean disposable cloth. Leave it dry and out of sun. ResMed wants the tub clean, clear, and free of discoloration.
• Weekly: frame and headgear, in the same mild detergent bath.
• Weekly: air tubing (including ClimateLineAir, SlimLine, and standard tube on that page). Rinse inside and out with mild dishwashing liquid and warm drinking-quality water, then rinse again and dry flat.
• Weekly, humidifier tub: soak in warm water with mild dishwashing liquid, or in one part vinegar to nine parts water at room temperature, then rinse thoroughly.

ResMed’s same page lists a replacement cadence and notes that insurers set their own reimbursement schedules. Replacement is wear, not a hygiene ritual. Inspect for cracks, stickiness, clouding, and tears when you wash.

AirTouch-style memory-foam cushions are a different material. ResMed’s cleaning page marks the AirTouch F20 cushion as an exception and says those cushions are not cleaned the way silicone is. If that is your cushion, the user guide for that mask is the document, not a blog’s soap-and-water paragraph.

What should you not put on the mask?

ResMed discourages aromatic or scented oils (eucalyptus and essential oils are named), antibacterial soaps, dish detergent in the “do not use” list even while the tubing section mentions mild dishwashing liquid, alcohol, bleach, strong-smelling citrus soaps, and the washing machine or dryer. Residual vapors can be inhaled. Harsh cleaners crack silicone. Heat wrecks headgear. Ironing headgear is specifically forbidden because the fabric is heat-sensitive.

That internal tension on “dishwashing liquid” is why your model’s user guide wins. The point is mild, unscented, thoroughly rinsed. Antibacterial soap is not an upgrade. It is a listed way to damage the cushion.

If a product is sold as a “CPAP wipe” or “CPAP soap,” check whether the mask manufacturer named it. Convenience wipes do not replace a weekly wash of tubing and a daily wash of the cushion. They also do not make ozone safe.

What water belongs in the humidifier?

The chamber is the highest-yield hygiene surface in the system because it holds water for hours and then turns that water into mist you breathe. CDC’s home guidance on preventing waterborne germs, updated 15 March 2024, has a dedicated CPAP section. Germs can live in CPAP humidifiers and connected parts and spread through the mist. CDC’s prevention steps are regular cleaning of mask, humidifier, and tubing; use and maintain the machine per the manufacturer; check the instructions for water type (most manufacturers recommend distilled water); and replace humidifier water on the manufacturer’s schedule.

Tap water in the United States is treated to drinking standards. It is not sterile. CDC is explicit: a small number of environmental germs can remain, generally at levels safe to drink, and still be a problem when water is aerosolized or sent up the nose. Named organisms in that page’s biofilm discussion include nontuberculous mycobacteria, Legionella, Pseudomonas aeruginosa, Naegleria fowleri, and Acanthamoeba.

A 2023 CDC Emerging Infectious Diseases survey found that 42% of respondents thought tap water could be used in respiratory devices, and 24% reported filling humidifiers or CPAP machines with tap water. The authors recommended distilled water, or water boiled and then cooled, plus regular cleaning. They also noted that boiling for five minutes then cooling can sterilize water for home medical use in the laboratory work they cited; CDC’s separate sinus-rinse boil times differ. For a CPAP humidifier, start with the manufacturer’s water instruction. Distilled water is the usual answer because it also reduces mineral scale.

A March 2025 CDC MMWR field note described a fatal Acanthamoeba encephalitis in a 66-year-old New Mexico patient who regularly used tap water in an electronic nasal irrigator and a CPAP. The same genotype was found in brain tissue, the irrigator, and the CPAP water receptacle. The patient had diabetes, obstructive sleep apnea, alcohol use disorder, and ulcerative colitis after colectomy. CDC’s implication was to follow manufacturer water and cleaning instructions. Distilled, sterile, or boiled and cooled tap water can be used in nasal irrigation devices. The case is rare and concentrated in people with impaired immunity. It is still a reason not to shrug at tap water in a humidifier.

What did FDA actually find about ozone and UV CPAP boxes?

On 27 February 2020, FDA told patients and clinicians that devices claiming to clean, disinfect, or sanitize CPAPs or accessories with ozone gas or UV light were not legally marketed for that use in the United States, so safety and effectiveness for CPAP accessories were unknown. William H. Maisel, then director of the Office of Product Evaluation and Quality in FDA’s Center for Devices and Radiological Health, said the agency had identified manufacturers marketing those products, that high ozone can worsen chronic respiratory disease or increase the chance of respiratory infection, and that UV products could cause burns, eye damage, or raise skin-cancer risk with overexposure.

The same communication reported 11 adverse-event reports from 2017 to 2019 in patients using ozone-based CPAP cleaners: cough, difficult breathing, nasal irritation, headaches, asthma attacks, and other breathing complaints. FDA had not received UV-cleaner adverse-event reports at that time. Ozone has to be present at concentrations far above what is considered safe for humans in order to kill bacteria. Manufacturers claimed the gas stayed inside the machine. FDA noted leaks at tubing connections, filters, or accessory containers, and said room ozone can rise to unsafe levels in a small or poorly ventilated room. Using the CPAP before leftover ozone has been flushed can mean inhaling the gas.

FDA ran its own preliminary lab tests on several illegally marketed products. Ozone devices generated ambient ozone above limits considered safe for human exposure. Ozone levels in CPAP machines and tubing remained high even after the wait time the ozone-device maker recommended. UV cleaners varied widely in light power and exposure time. Weak UV or short cycles can leave components inadequately disinfected.

UV has a second, physical problem FDA named: the light may not penetrate plastic tubing, masks, and connectors. Shadowed plastic is not a UV chamber. A glowing box is not a process specification.

Soap removes the organic film bacteria live in. Ozone oxidizes whatever it reaches, including silicone, tubing, and, in some older machines, internal foams. “Sterile” is the marketing word. Residual ozone in the hose is the measured one.

Didn’t one ozone box get FDA clearance later?

FDA’s De Novo database lists SoClean 3+ Bacterial Reduction Device, SoClean, Inc., DEN210037, decision date 12 August 2024. That is a real classification decision. It is not a license to skip soap.

ResMed’s cleaning page, updated to address that De Novo, tells users to follow ResMed’s instructions for use. Those user guides instruct patients to clean ResMed products with mild detergent and warm water only. ResMed states that SoClean 3+ has not been tested or approved by ResMed for use with ResMed products. If the device causes damage, including discoloration, replacement is not covered by ResMed’s limited warranty. Separately, ResMed has observed that prolonged and repeated use of an ozone device may eventually cause internal damage to a ResMed machine, including increased motor noise, and the limited warranty excludes ozone-device damage.

So the current, careful sentence is this: one adjunct bacterial-reduction product received a De Novo classification in 2024; manufacturer cleaning with detergent and water remains the required process; ResMed does not warrant ozone damage; and the 2020 FDA findings about residual ozone and unproven UV boxes still describe the rest of that product category. If a salesperson says the box replaces washing, they are contradicting both FDA’s original advice and ResMed’s IFU.

We did not independently open a full SoClean 3+ labeling PDF for compatible mask and hose lists. the exact compatible accessories and the “adjunct after cleaning” intended-use sentence from the DEN210037 decision summary before quoting them as labeling. The ResMed warranty language above is from ResMed’s page, which we did open.

When is cleaning not the issue?

A sour smell after skipping a week of washes is a cleaning problem. A red ridge on the bridge of the nose, rainout in the tube, or a leak that appears the night you overtighten the straps is a fit and humidity problem. Those belong in clinic, not in a second bottle of vinegar.

Westerville Sleep Center can walk through the download, the mask, and the humidifier settings. Forms and education materials live under patient resources. If the machine is in a cupboard because the mask smells or the face is raw, call (614) 898-9340 during weekday hours, or use the contact page, and bring the mask and tub to the visit. Dr. Mahmoud Qadoom, MD, would rather see a stained cushion than a month of untreated apnea while someone waits for an ozone box to make the plastic “safe.”

Clean the parts that touch your face and hold water. Dry them. Use the water the manufacturer named. Leave the germicidal theater to people who are not breathing the leftover gas.