Published April 2026

CPAP Foam Particles: What Happens When You Inhale or Ingest Them

Medically reviewed by licensed healthcare professionals · Legally reviewed by mass tort litigation specialists · Last updated: April 2026

One of the most disturbing aspects of the Philips CPAP recall is that users were sleeping with a machine actively delivering contaminated air directly into their lungs — night after night, for years. Understanding what the degraded foam actually does to the body helps explain why this recall has generated hundreds of thousands of injury claims.

How the Foam Degradation Works

The polyester-based polyurethane (PE-PUR) foam used in Philips CPAP, BiPAP, and ventilator devices was designed as a sound abatement layer — its purpose was to reduce the noise of the machine's motor. What Philips knew — and according to litigation claims, had known for years — was that this foam was subject to degradation, particularly when exposed to heat, humidity, and ozone-based cleaners.

As the foam degrades, it breaks down in two ways: it releases solid particles (small pieces of foam material) and it off-gases volatile organic compounds (VOCs). Both pathways deliver potentially harmful materials directly into the airway via the pressurized air stream the CPAP delivers to the patient. Users breathe these materials deep into their lungs throughout the night.

What Foam Particles Do in the Respiratory System

Inhaled solid particles from degraded PE-PUR foam can cause a range of respiratory effects depending on particle size and duration of exposure. Fine particles that reach the lower airways and alveoli (the small air sacs where gas exchange occurs) can cause:

• Chronic airway inflammation — particles trigger an immune response that, with repeated exposure, leads to persistent inflammation in bronchial tissue
• Granuloma formation — the body may wall off particles it cannot clear in inflammatory nodules called granulomas
• Fibrotic tissue changes — long-term inflammation can lead to scarring (fibrosis) in lung tissue, reducing respiratory capacity
• Worsening of pre-existing respiratory conditions — patients with asthma, COPD, or other lung diseases may experience accelerated deterioration

Many CPAP users who noticed black particles in their tubing or mask were actually observing degraded foam that had been circulating through their airway. The visible particles are only part of the problem — submicron particles that are not visible to the naked eye may represent an equal or greater exposure burden.

Volatile Organic Compound (VOC) Exposure

The gases released by degrading PE-PUR foam present their own concerns. Testing of recalled Philips devices identified several VOCs including:

• Diethylene glycol — a VOC associated with kidney toxicity and other systemic effects
• Toluene diisocyanate (TDI) — a known respiratory sensitizer and possible carcinogen; a breakdown product of polyurethane foam
• Dimethyl diazenecarboxylate — detected in off-gas testing and associated with toxic effects in animal studies

The health concern is not a single large exposure, but years of repeated, chronic low-level exposure during the most vulnerable physiological state — sleep, when the body is in recovery mode and breathing deeply throughout the night.

Gastrointestinal Effects: The Ingestion Pathway

Foam particles that reach the upper airways can be swallowed rather than inhaled into the lower lung — particularly in users who are mouth-breathing or who use full-face masks that direct airflow past the mouth. This creates a second exposure pathway: ingestion. Swallowed foam particles pass through the digestive system, and the chemicals they contain may be absorbed through gut mucosa.

The gastrointestinal effects reported by some CPAP recall claimants include persistent nausea, digestive complaints, and unexplained GI symptoms that began during the years they used the affected devices. While GI symptoms alone are generally not sufficient for a qualifying injury claim, they add to the picture of systemic exposure that characterizes the most serious recall injuries.

Symptoms That May Indicate Foam-Related Exposure

If you used a recalled Philips device, the following symptoms — particularly when they developed during your years of device use — are worth documenting and discussing with your physician:

• New or worsening respiratory symptoms: chronic cough, shortness of breath, wheezing
• Persistent headaches or headaches that developed with device use and improved when you stopped
• Irritation of the nose, throat, or upper airway
• New respiratory diagnoses: lung nodules, pulmonary fibrosis, bronchitis, or other findings on chest imaging
• Cancer diagnoses involving the respiratory system, head and neck, or other areas

Why Philips Knew Before the Recall

Internal Philips documents obtained through litigation discovery show that the company was aware of the foam degradation problem years before the 2021 recall. Employees reportedly flagged concerns about foam degradation as early as 2015, and the company received complaints about black particles from users well before any public action was taken. The delay between internal knowledge and public recall is a central element of the negligence and product liability claims in the litigation.