A variety of positive airway pressure (PAP) devices made by Philips Respironics Inc. have been subject to a lengthy and expensive recall due to the use of a problematic material in acoustic insulation foam, but now the company has a new headache in connection with its offerings. The FDA said this latest safety notification is due to the possible presence of a plastic that is contaminated with a non-compatible material, although this recall affects fewer than 400 units.