Let's hope you aren't using any Eastern Bloc M17 clone surplus cheek filters with them. They are thought (not sure if it was confirmed) to contain hexavalent chromium, which can be more dangerous for you than asbestos in some cases. They may also contain asbestos, as yknow, Eastern Bloc.
Polish MP4 filters are also a potential hazard, but im not sure.
If you can, buy some US cheek filters. Doesn't matter if they're expired because you only need the particulate layer. We aren't dealing with nukes here, just a virus lol. Although if you wanna be safe, try to find some non-expired cheek filters, which will have the filtering needed for NBC/CBRN situations.
