Philips Update on Sound Abatement Foam Which Led To Machine Recall

July 08, 2022
3 Minute read

When Philips issued a recall notice for specific ventilators, CPAP, and BiPAP machines,  many people were disgruntled. It was due to potential risk from the PE-PUR sound abatement foam in those. Let’s see what this means for loyal Philip users.

Why did Philips recall machines with PE-PUR sound abatement Foam?

Philips Respironics Dreamstation CPAP machine

The recall notification from Philips came on June 14, 2021. At this point, they had low data on the polyester-based polyurethane sound abatement foam. Only, the information about foam degradation in some Philips machines and concerns from customers about particle matter emission. 

Once they got the result of the toxicological assessment on the health risk from the sound foam, they assumed the worst-case scenario. For the safety of their customers, they ordered an immediate recall, even if there was no guarantee the foam can cause harm to the patients. The recall was mostly out of strong cautious behavior than from pure evidence of health risk.

Since then, Philips Respironics has begun a research program to test and assess the extent of the health risk from the sound abatement foam. The people on the project range from third-party expert bodies and professionals to five independent laboratories with proper certifications. At least more than 1000 people are part of the research.

The tests are still ongoing, though Philip has an update at present. They are releasing the results of the tests to appease patients, shareholders, and healthcare workers who are eagerly waiting to know if the recalled machines could come back on the market again.

What is the new update on PE-PUR Foam?

Among the five categories of devices from Philips with sound abatement foam, the first-generation DreamStation covers 68% of the devices which were suspected to have faulty foam.

As such, the DreamStation has been heavily tested and the released update centers around it. Foam deterioration appears to be way low than what was initially assumed. Additionally, both the old and new first-generation DreamStation were put through particle emission tests of respiratory material and volatile organic compound tests. The device passed both these tests, concluding that the chances of these chemicals entering the patient’s body from the degraded foam are low.

Additionally, it seems ozone cleaning is a bad choice for the sound abatement foam. It seems to accelerate the degradation process.

To determine the rate of foam degradation in first-generation Dreamstations, researchers performed a virtual assessment on 60,847 returned or used devices.

  • 11,309 of these devices had ozone cleaning.
  • There is no information on whether 13,197 of these devices went through the ozone cleaning process or not.
  • 36,341 never had any kind of contact with ozone.

These devices were primarily collected from the Canada and US.

  • Out of 36,341 of the devices which were never cleaned with ozone according to self-report, 164 showed degradations of the foam to a visible level.
  • Out of the 11,309 with ozone cleaning, 777 showed foam degradation at a greater level.
  • Out of 60,847, 422 devices were originally reported to have foam degradation by the owners. However, the test showed that only 18 of those devices had what could be considered as clear signs of degradation.

It is easy to see from the device percentage that foam degradation is startlingly low and not close to what everyone assumed initially.

Even with devices where foam degradation is visible, the shape the foam deterioration takes is interesting. The foam turns into a sticky, moisturized version of itself as it degrades. There is a loss of volume and more density as the foam turns into a thick liquid. The liquid foam sticks to the airpath within the device.

As such, the device in a normal environment won’t send harmful particles into the air. It is only when a patient connects a CPAP mask and inhales the air from the tube that they can encounter harmful particles from the foam.

The Volatile Organic Compounds (VOCs) test was performed to understand how much VOC emission was occurring along with the health risk if a person were to be exposed to these VOCs in a measurable quantity.

In accordance with a previous update on December 23, 2021, VOC emission is lower than the established rule of ISO 18562-3. Exposure to the compounds should not result in patients developing any kind of long-term health problems.

The Particulate Matter (PM) test was done according to ISO 18562-2 standards. Both new Dreamstations and old ones with foam degradation went through these tests. As such, the PM emission does not break the threshold limit.

More importantly, degraded foam devices didn’t statistically emit more particles than the ones with absolutely good quality sound abatement foam.

It was also noted that the average rate of Particulate Matter happens to be bigger in Dreamstations that didn’t meet the cleanliness standard than in those that did.

What other tests are ongoing?

At present, biocompatibility testing is going on for degraded sound abatement foams. The standard testing for this method is in accordance with ISO 10993. The focus here is on determining the toxicology level of particulates from degraded foam.

Additionally, the other devices that Philips is performing tests on and fall under the recall notice are:

  • Dreamstation Go
  • SystemOne
  • Trilogy 100/200
  • OmniLab/A-Series BiPAP

All 4 of the last device types listed have gone through VOC and PM tests according to standards before ISO 18562. Currently, the devices are going through the ISO 18562 tests.

Final Thoughts

Philips Respironics estimates the testing on all the affected devices would be complete within the last couple of months. The test results have been positive so far. The goal is to ensure that the PE-PUR sound abatement foam doesn’t degrade in future devices.  They might determine whether to replace the foam type completely. Additionally, about 2.7 million replacement devices have been sent to the market to replace the potentially degraded foam ones.

It is recommended that if you are a health care provider, stakeholder, or patient, you read the entire update instead of overall summaries.

Written by The Sleeplay Team

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