[News] RECALL THREAD-- IMPORTANT PHILIPS DREAMSTATION & SYSTEM ONE USERS

[b.e.wilson]

I'm a chemist, and have been looking at the chemistry of the polyester-based polyurethane foam degradation process. I haven't found anything authoritative yet, but there are two degradation pathways, one by water, one by fungus, both resulting in the same degradation products. The product that is a gas would be isocyanic acid, HNCO, H-N=C=O. It is a poison, more acidic than vinegar, reacts with amino acids, so it is a danger to the lungs. It's present in smog and cigarette smoke. In dry and cool environments, in the dark, the foam is stable.

Here's the odd thing: if there is enough humidity around to cause the degradation, the isocyanic acid will remain soluble in the water. I think it's the heat part that is important, because hot water would lower the solubility of the acid and drive it back into the air. So the combination of very high humidity then a cycle of heat would be needed. I suppose that could happen if the machine is used at night in a non-air-conditioned space, then sits during the hot day.

Or give it ozone. That stuff reacts with everything. You'll recognize the smell of ozone easily; it's the smell of a kitchen motor (the kind that makes sparks in the back) or a Xerox machine.

I think there might be some small possibility that phenyl-isocyanate could be the gas, but I'd want to see some headspace analysis of the foam first.

[cathyf]

Here's the odd thing: if there is enough humidity around to cause the degradation, the isocyanic acid will remain soluble in the water. I think it's the heat part that is important, because hot water would lower the solubility of the acid and drive it back into the air. So the combination of very high humidity then a cycle of heat would be needed. I suppose that could happen if the machine is used at night in a non-air-conditioned space, then sits during the hot day.

Hey don't just think about the weather -- most of us run these machines with humidifiers which use heat to increase the humidity. Quite a bit of the electrical power that these guys consume in dedicated to the task of vaporizing warm water into the air that is being pushed through.

The normal operating environment of a CPAP is "swamp".

(When I first started CPAP I was in the throes of menopause and had an amazing internal furnace -- as in I kept my thermostat at 60 in the winter so that it would be cool enough for me to wear long sleeves! I found the warm air was pretty bad, and I kept edging down the temperature. When I hit 60 degrees and the humidity set to 8 I woke up with a pool of water in my mask "Rainout" is such a polite mamby-pamby term -- I had a freaking cloudburst in there!)

[Guilhermedico]

Or give it ozone. That stuff reacts with everything. You'll recognize the smell of ozone easily; it's the smell of a kitchen motor (the kind that makes sparks in the back) or a Xerox machine.

Indeed. I, for one, would not let the manufacturers of these ozone-generating devices off the hook in this Philips-Respironics PAP device foam outgassing recall fiasco.

In January 2021, I started using a new generic ozone-generating "CPAP Cleaner" I had ordered from Amazon (see device in photo), which filled the bedroom with a pungent odor, even though it was connected by tubing sequentially to my 15-year-old Respironics M-Series Auto BiPAP machine and, during a second 20-minute treatment, to a mask that was contained within a drawstring bag. Also beginning January 1, I changed out my 3 old Resmed Mirage Quattro masks for new ones. 

I became alarmed when, by the end of February, the base of the mask cushion and the forehead protective piece of all 3 Resmed Mirage Quattro masks had turned a bright yellow color (see the 3 masks at the left side of the photo). Also, at the end of February 2021, my ancient Respironics M-Series Auto BiPAP device died and I replaced it with the purchase of the successor unit, a Philips-Respironics DreamStation Auto BiPAP. I read the instructions in the accompanying booklet warning against using ozone to clean the machine. With that, along with my concern about the mask discoloration, I stopped using the ozone-generating CPAP Cleaner.

In early March 2021, I read positive reviews on this Forum about the Resmed successor mask to the Mirage Quattro full-face mask, i.e., the AirFit F20. I have been using the latter mask for 4 months. Note on the right side of the photo, that the color of the AirFit F20 cushion, which has never been exposed to ozone, is still clear-white, in contrast to the yellow discoloration of the 3 Mirage Quattro cushions and forehead piece, following just 2 months of ozone exposure.

I was planning to discard the Mirage Quattro masks -- and, in fact, I thought I had already done so -- but I think I'll hold on to them now. The discoloration may be a useful piece of evidence in some future class action, as to the effect of some ozone-generators on plastic polymers, if not on the sound insulating polymer foam in question.

[WakeUpTime]

Am also disgusted by all online sellers of Cpaps raising their prices by 50%. I find this to be price gouging, which is against the law. I may have to enter the slimy world of lawyers and give these companies a rude awakening.

For just a little more effort by that lawyer, they'll have up to 3.5M clients as the result of a class action.  This incident is shining a spotlight on the industry.  It'll be interesting where it leads.

Except for Philips toothbrush/dental products division, (which they admit is extremely profitable) Philips decided last year to focus almost entirely on the health care medical devices industry (dropping appliances, etc.).

[Ratchick]

Hey don't just think about the weather -- most of us run these machines with humidifiers which use heat to increase the humidity. Quite a bit of the electrical power that these guys consume in dedicated to the task of vaporizing warm water into the air that is being pushed through.

I imagine that's going to depend on the exact model perhaps? Some may have the humidifier after the foam right? At least I assume they might, based on the Resmed. In the A10, the humidifier would have no effect on the foam around the motor because the airflow is going in the opposite direction. The only humidity that would have an effect, if that were the case, would be whatever humidity was already in the air being drawn into the machine. So if you had an external humidifier right next to the CPAP to pre-moisten the air either instead of, or in addition to, a build-in humidifier that sits after the motor in the air pathway, then that might make the foam damper... but not the built-in humidifier.  I can't find a pneumatic flow diagram for the Philips machines with a quick google, though.

That said, though, if it needs heat as well as moisture, then it's probably not going to be a major issue with just one or the other.

b.e.wilson's summary was pretty much exactly the conclusion that I and my mother had come to, so I'm glad to see another chemist who feels the same way. AFAIK, these ozone "cleaners" are used while the motor is OFF, so the ozone can spread into areas of the system where humidity from normal use can't, because of the direction of the airflow).

[DaveL]

So...I'm not clear.

Where is the insulation? Are the contaminants in the airstream we breath through the mask?

[SarcasticDave94]

It would sound like the foam is in the path of the airflow in these Respironics. I've solved it for me, myself, and I. Don't accept a Respironics. ResMed isn't identical in this foam issues and isn't affected like Respironics.

[btreger]

I just received this email today at 11:07 AM Eastern from:

email-promotions@soclean.com

Buy a Replacement Filter for Your Soclean 2 Today

Help your SoClean 2 run at peak performance with a new filter

15% Off Filter Kits

Expires 6/30/21

There are absolutely no regulations in place that cover this area of medical equipment. Saying this like the Wild West gives the Wild West a

bad name.

[cathyf]

So...I'm not clear.  

Where is the insulation?  Are the contaminants in the airstream we breath through the mask?

Dave -- this youtube was linked to earlier in the thread: https://youtu.be/TPX-SDSUW7E

It's a video of a guy replacing the motor in a dreamstation -- if you go forward to about the 8 minute mark, you see how the air flows -- there's a plastic housing that's kind of a ring and the motor is in the middle. The air is sucked into the machine, spirals around through the ring, through the motor, and out to the humidifier and hose. (Ok, I may have that backwards -- air may start in the motor and get pushed through the spiral rather than being pulled.) But the foam is inside the plastic housing, and the air is passing around it. It looks like the foam is deadening the sound of the rushing air by being inside the air passage in direct contact with the air.

(My husband is a college physics professor, and our best friend is a chemistry professor. So to add a 3rd and 4th data point to b.e.wilson and Ratchick's mom -- "Crap! Ozone?!? Well that's pretty reactive!")

The point about corrosion is that everything is additive.

• Clean it with ozone.
  
• Run it in a hot muggy environment.
  
• Don't change the filter often enough, including not appreciating circumstances where you need to change the filter more often than monthly.
  
• Run in a very dusty or pollen-rich environment where more than minuscule amounts of crud makes it in through unfiltered cracks.
  
• Run it in polluted environments. Not just smoke, but poor ventilation, nearby industrial pollution, etc.
  
• Not giving the machine enough clearance, so that the heat from the motor heats things up more than engineered for.
  
• Not accounting for heat transferring to the rest of the machine from the humidifier and/or heated hose.
  
• The engineers designed these for 5-year lifespans. Six or seven years is one thing, ten or fifteen is quite different.
  
• Long storage times mean that a low-hour machine may be quite old. (And as the commercial says, "Rust never sleeps." Or in the words of the Second Law of Thermodynamics, "time runs forward.")
  

The whole "good vs evil" dichotomy doesn't account for those situations where any one factor is innocuous, but when they add up you're in trouble. (For Green Acres fans, "adds up to more than seven". For all of you who will be humming the Green Acres theme song for the next week, "you're welcome!")

[SarcasticDave94]

If the PAP you have keeps biting you, wouldn't it be wise to get rid of it? Just say No to Respironics. Your lungs will thank you.