P3 is a finer filter than P2, so offers better protection.I would have thought that was a given.
But getting back to my question - and with just regard to respiratory protection. How would a P3 filter in a GVS (half face) mask compare to a P2 in a powered unit such as the powercap. Clearly P3 i better than P2 but is the powered system more efficient?
Makes me wonder why the powercap does not come with a P3 filter
P2 and P3 are "standard" terms so they are comparable across companies.
BUT.
A Positive Air Pressure Respirator (or whatever PAPR stands for) is a different beast to a cheap half mask so comparing the P2 and P3 alone doesn't tell the whole story.
PAPR sets create a positive air pressure inside the mask at all times, even when breathing in. Unlike a typical half mask where the wearer breathing in creates a suction that pulls air through the filter.
With a half mask, if it doesn't fit tightly, you can suck unfiltered air in around the mask.
With a PAPR set the positive pressure means any leaks allow filtered air to leak out and never unfiltered air in.
A PAPR is much safer than a cheap mask like for like. I suspect a PAPR with a poorer P2 filter is better than a cheap mask with a P3, but in practice PAPR sets are normally used with a good P3 filter. After all, why would you cheap out on the filter after spending serious money on the powered set.
The very best protection I know of is from a full face set with an external air feed drawn from outside of any source of contamination, the sort of things used in professional spraying. These generally feed through very high grade filters, moisture traps, etc and of at least P3 grade.