--preliminary tests in Britain by the medical device regulatory agency (and others here?) suggest that foam off gassing was only liable to occur in the first 24 hours of a machine's operation
--not all foam degrades in all machines
--have you noticed black specks in your mask or water tub? the guy from Supplier #1 said that they had only heard one complaint about this over the years. that would be an indicator of foam degrading in your machine
It may turn out that the health hazards are minimal or even non existent for the majority of users. preliminary info suggests that the risks are very small. Recall that the British agency is an independent body that ran their own tests. One would assume that tests were run on the foam by PR at least prior to the release of the affected machines. One would think that they had to meet certain standards for safety. this would be standard procedure for people making medical devices.
I say this to suggest that anxiety may not be warranted at all. If new, worse info emerges, people can start worrying then, I suppose. and then inform their doctors to be on the lookout for any issues.