For air filters, I think standards compliance is a big deal. Vendors wave labels about with gay abandon but if they say something is compliant with an international standard, they should be able to show a test certificate and are putting their necks on the block rather more.
For hepa filters H13 is the number.
It means 99.95% of those 0.3um are caught.
H14 means 99.995% of those 0.3um particles are caught (so 10x better).
But true HEPA filters are pricey, need a fairly powerful fan to push the air through, and tend to be bulky too like for like.
If you are working with hazardous silica dust, etc maybe necessary, but for DIY woodwork, I do wonder if that's overkill and maybe an F14 filter (older standards terminology, I'm not sure what the current euro equivalent is) would be enough. Those are typically considered good enough for welding fumes and car exhaust fumes, so pretty fine, and definitely cheaper.
I looked at the link to the dewalt above. It says H11. That's probably why they don't import it.
H11 is hundred times poorer than H13 so I doubt it qualifies as a "standards compliant" HEPA filter, certainly under the ISO worldwide standard, the American standards aren't much different so it wouldn't quality there either.
https://en.wikipedia.org/wiki/HEPA
