"HEPA" on a box is not a guarantee. The grade, H13 or H14, is what tells you how much a filter catches. Looser phrases such as "HEPA-type" tell you very little.
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Work out my CADRThe terms
| Label | What it means |
|---|---|
| H13 | A European standard grade (EN 1822). It must stop at least 99.95% of particles at the size the filter is least efficient at. |
| H14 | The next grade up. At least 99.995% at the same test, so roughly ten times fewer particles get through than H13. |
| "True HEPA" | A common marketing phrase. It separates a real HEPA filter from looser claims but does not tell you the grade. |
| "HEPA-type", "HEPA-style", "HEPA-like" | No stated standard or efficiency. These phrases do not show the filter meets H13 or H14. |
You may also see "99.97%". That comes from the US convention, which tests at 0.3 micrometres. It is a different test from the European grades, so do not compare 99.97% with 99.95% as if they were the same measure.
Does H14 matter for a home?
For most homes the difference between a well-sealed H13 and H14 filter is small next to other factors: whether the purifier moves enough air for your room (the CADR), whether the filter seals properly so air cannot bypass it, and whether you replace it on time. A genuine H13 filter in the right size of machine is a sensible target. Pay more for H14 if you have a specific reason, such as a very sensitive household.
What matters alongside the grade
- CADR for your room. See room size and CADR.
- Filter life and cost. A cheap purifier with expensive filters can cost more over time.
- Carbon. HEPA catches particles, not smells. Odours need activated carbon, and the amount varies a lot.
- Ozone and ionisers. Prefer a model without them. Some ionisers can produce ozone.
How we label filters
- H13 or H14 confirmed only where a source confirms the grade.
- Grade not confirmed where a listing says "HEPA" without a grade. This is most of the purifiers we list today, because UK listings often do not give the grade.
- Not a True HEPA filter where the product makes no such claim.
When a maker does not state a grade, ask. A maker with a real H13 or H14 filter will normally say so. Browse the purifiers we list and see how we choose.
Sources: Digit, HEPA H13, H14, True HEPA: what these air purifier labels actually mean, for the EN 1822 grades and efficiencies. The 0.3 micrometre convention is general industry knowledge. The "roughly ten times fewer" comparison follows from 0.05% against 0.005% penetration.