(Bloomberg) -- Koninklijke Philips NA knew about problems with noise-dampening foam inside some ventilators used for treating sleep apnea at least three years before issuing a US safety recall for the devices, newly unsealed court files show. 

A US-based company engineer disclosed that he’d gotten customer complaints about disintegrating polyurethane, which was making its way into the machine’s forced air stream, according to his email to a supplier. Amsterdam-based Philips faces about 300 lawsuits from users who say inhaling the foam particles poses a cancer risk. 

“The material sheds and is pulled into the ventilator air path,” Vincent Testa, a project mechanical engineer for Philips, said in an April 2018 email unsealed as part of consumer lawsuits overseen by a federal judge in Pittsburgh. “As you can imagine, this is not a good situation for our users,” Testa said. 

It wasn’t until June 2021 that Philips recalled 5.5 million Continuous Positive Airway Pressure (CPAP) machines and ventilators from the US market, after researchers linked the degrading foam to cancer and respiratory issues. The company has committed more than $800 million to the recall and repairs, but hasn’t disclosed estimates of litigation costs.

A company spokesperson, when asked about the unsealed emails, said that prior to 2021, Philips Respironics handled the complaints related to mechanical ventilators on a case-by-case basis. After Philips’ executive committee became aware of the issue and its significance in early 2021, the company issued a voluntary global recall notification to remediate the issue, the spokesperson said.

In March, company officials said they’d received notices from consumers about 2.6 million machines that needed to be serviced or replaced, and that it had shipped about 650,000 new units. Philips said it “aims to complete the repair and replacement program in the fourth quarter of 2022.”

Legal Fight

Consumers have accused Philips in lawsuits of violating the US Food Drug & Cosmetic Act, which requires that medical devices be safe and effective. They claim the breathing machines were defectively designed by using foam that could degrade if exposed to moisture. 

The US Food and Drug Administration has cited similar concerns. The agency said Philips had gotten more than 100 complaints about the decaying foam in the devices between 2014 and 2017, according to a May 2 letter the FDA sent to the company and made public on its website. 

Regulators found “sufficient evidence for FDA to determine there are reasonable grounds to believe the recalled devices that Philips manufactured after November 2015 were not properly manufactured with reference to the state of the art as it existed at the time,” the agency said in the letter.

Sleep apnea is a disorder in which breathing stops and starts, causing fatigue and longer-term health problems. Philips products designed to improve sleep patterns include its DreamStation CPAP machines and Trilogy ventilators. 

“These unsealed emails make Philips look pretty bad” and may support claims by consumers that machines were sold “even though they knew for years earlier there was a problem with foam used in their design,’’ said Richard Ausness, a University of Kentucky law professor who teaches about mass torts.

Foam Break-Down

In the unsealed emails, Testa, the Philips engineer, asked one of the company’s suppliers what could cause the polyurethane foam to break down. He noted that the supplier’s specification document for the substance claimed it “has excellent resistance to heat, moisture and chemicals.”

Some of the suppliers, in their internal email discussions about Testa’s queries, said that if the foam were subjected to “high humidity,” it would “exhibit signs of hydrolysis in as short a time as a year,” unsealed court filings show. Hydrolysis is the chemical breakdown of a compound due to reaction with water.

Some CPAPs and ventilators rely on distilled water to keep a user’s mouth from drying out while asleep. For years, Philips warned consumers not to use water to clean their machines. SoClean Inc., which sells cleaning products for breathing machines, sued Philips last year, accusing the Dutch company of wrongfully blaming it for the foam’s decay.

The case is IN RE Philips Recalled CPAP, Bi-Level PAP and Mechanical Ventilator Products Liability Litigation, 21-MD-3014, U.S District Court for the Western District of Pennsylvania (Pittsburgh).

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