Personal care and home
What is a HEPA filter and what does it really catch?
A HEPA (High Efficiency Particulate Air) filter is a high-efficiency air filter that, under the U.S. Department of Energy definition, captures at least 99.97% of particles at 0.3 microns. It traps dust, pollen, pet dander, and fine smoke; on its own, it does not remove gases or odors.
True HEPA versus "HEPA-type"
Only a filter that meets the standard's efficiency can be called HEPA. In Europe, filters are classified under EN 1822: H13 captures at least 99.95% and H14 at least 99.995% of the hardest-to-catch particles.
"HEPA-type" or "HEPA-like" filters look similar but do not guarantee that efficiency. If the spec sheet lists no class (H13, H14) or percentage, treat the label with caution.
What it does not do
HEPA traps particles, not gases: for odors, cooking smoke, or chemicals you need an activated carbon filter, which many purifiers pair with HEPA.
A clogged filter loses effectiveness and lets less air through. It needs replacing periodically, depending on use and the manufacturer's guidance.
What to check before you buy
- Look for the filter class (H13 or H14) or the capture percentage, not just the word HEPA.
- If odors are a concern, choose a purifier with HEPA plus activated carbon.
- Check the cost and availability of replacement filters before you buy.
Guides to help you choose
Frequently asked questions
It helps reduce dust, pollen, and pet dander in a room's air. It does not replace medical treatment for allergies.