"Wouldn't a run of the mill Home Depot filter mask and some sort of sealed eye protection be really useful for hazards not associated with a direct chemical attack on your person?"

That's very true, but there have been some recent posts on safety if that Bird Flu becomes a pandemic, and if you had to care for a family member (etc) that had it, you would probably want some of the disposable masks that prevent the inhaling of viruses, as well as goggles.

For debris dust, volcano ash (maybe smoke ash) and stuff like that, the regular WallyWorld masks would probably be fine.

Sue