⏱️ Fact-checked and updated by our editorial team in July 2026. Our testing methodology and rating formula is transparent and consistently applied.

What Is a HEPA Filter? H11 vs H12 vs H13 vs H14 True HEPA Explained

HEPA filters aren’t all the same. We explain the difference between True HEPA, H13 medical grade, and why cheap HEPA-type filters don’t cut it.

The Short Version

HEPA = High Efficiency Particulate Air. It’s a standard, not a brand. If you see it on a box it (by the US DOE): removes ≥99.97% of 0.3 μm particles, the hardest size capture mechanically.

HEPA H11 vs H12 vs H13 vs H14: The Real Differences

• HEPA H11: 95% at MPPS. Found in cheap car cabin air purifiers. Better than nothing, not allergy use. Barely minimum.
• True HEPA (EN 1822-2011 Grade H12/H13 → US “True HEPA” standard: 99.97% down to 0.3 micron single-pass. Most common Coway/Levoit/Blueair/Honeywell are this.
• H13 Medical Grade: 99.95% at MPPS, which is actually a tighter spec than the US True HEPA standard and captures more of the smaller-than-0.3 micron that True HEPA struggles with. Good for MCS / immuno-compromised.
• H14 ULPA / HyperHEPA: IQAir level, 99.995%+ at MPPS. Overkill for most homes.

The Marketing Scams to Spot

• ‘HEPA-Type’: meaningless marketing words with no recognized standard test.
• 99% effective — without the 0.3μm number is 99% capture. It captures everything bigger than 2 micron, basically captures 1/100 the true claim.
• HEPA-Style / HEPA-Like: meaningless. Ignore.

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