[kllrnohj]

Which seems intentionally nitpicky given that "HEPA" is defined and the Ikea one doesn't meet it while the others do. Therefore, "true-HEPA" almost certainly just means "HEPA", and the "true" just means "is actually HEPA" not some other special definition.

The rest of the article's points are good, but this one comes across as just axe grinding.

[rahimnathwani]

Yeah. I'd assumed that 'true-HEPA' was a made-up term intended to trick people into thinking something is HEPA when it's actually worse. But that doesn't seem to be the case.

[wlonkly]

The Wikipedia HEPA article[1] says it's actually a reaction to people doing that -- some companies advertise "HEPA-type" or "HEPA-style", and so companies with actual HEPA filters market them as "True HEPA". It's a race to the bottom.

[1] https://en.wikipedia.org/wiki/HEPA#Marketing