Can I use purified water in my Continuous Positive Airway Pressure (CPAP) machine?

Using Purified Water in CPAP Machines

Purified water can be used in CPAP machines, but distilled water is the preferred option for optimal humidifier performance and to minimize potential respiratory complications. 1

Types of Water for CPAP Humidifiers

• Sterile water is the gold standard for bubbling humidifiers in respiratory devices and is recommended for medical-grade respiratory equipment 1
• Distilled water is acceptable for CPAP humidifiers and is specifically mentioned in guidelines for heated humidification in sleep apnea treatment 1, 2
• Purified water can be used as an alternative to distilled water, though it may contain more minerals than distilled water which could lead to mineral buildup in the humidifier chamber over time 2
• Tap water is generally not recommended due to potential mineral content and microorganisms, though some research suggests it may be safe in certain types of humidifiers 3

Evidence-Based Recommendations

• The American Academy of Sleep Medicine recommends using heated humidification with CPAP devices to reduce side effects such as dry mouth, nasal congestion, and sore throat 1
• Guidelines indicate that sterile, distilled, or even tap water can be used to fill wick humidifiers in medical settings, but CPAP humidifiers typically use a different mechanism 1
• Research has shown that inadequate humidification is a primary cause of dry mouth and other upper airway symptoms in PAP therapy 4

Potential Risks of Improper Water Choice

• Using water with high mineral content can lead to mineral deposits in the humidifier chamber, potentially reducing the effectiveness of the device and requiring more frequent cleaning 2
• Contaminated water in humidifiers has been associated with increased risk of upper respiratory infections in CPAP users 5
• Studies have shown that bacteria can be aerosolized from contaminated humidifier water in some circumstances, potentially increasing infection risk 6

Best Practices for CPAP Humidifier Use

• Replace water in the humidifier chamber daily to prevent bacterial growth 7
• Clean the humidifier chamber regularly according to manufacturer's instructions to prevent biofilm formation 7, 5
• Use only the type of water recommended by your specific CPAP manufacturer, which is typically distilled water 1, 2
• Monitor for symptoms of respiratory irritation or infection, which may indicate contamination of the humidifier system 4, 5

Common Pitfalls to Avoid

• Using tap water in areas with hard water can lead to rapid mineral buildup in the humidifier chamber 2
• Inadequate cleaning of CPAP equipment has been associated with increased respiratory symptoms and infections 7, 5
• Assuming that all water labeled as "purified" meets the same standards - purification methods vary and may leave different levels of minerals and potential contaminants 2

While purified water is generally acceptable for CPAP humidifiers, distilled water remains the preferred option recommended by most manufacturers and clinical guidelines to minimize mineral buildup and potential respiratory complications 1, 2.