HEPA filter (and Class H vacuum)
HEPA removes 99.97% of 0.3 micron particles. AS/NZS 60335.2.69 Class H vacuums add sealed housing and airflow for silica, asbestos and regulated dusts.
Ask Chalkline about this →A HEPA filter (High-Efficiency Particulate Air filter) is a filter that removes at least 99.97 per cent of airborne particles down to 0.3 microns, the size most difficult to capture. In construction it is the filter rating required on vacuums and extraction equipment used with respirable crystalline silica, asbestos, lead paint, and other regulated dusts. The construction-grade designation is Class H under AS/NZS 60335.2.69, which adds requirements above the bare HEPA element.
HEPA vs Class H vacuum
- HEPA is a filter spec: captures 99.97% of 0.3 micron particles.
- Class H is a whole-machine spec under AS/NZS 60335.2.69, the highest of three dust classes (L, M, H). Class H adds:
- Sealed filter housing so dust cannot bypass.
- Filter test port or visual condition indicator.
- Airflow to drive LEV at the cutting tool.
- Bag-in / bag-out emptying so the operator isn’t dust-exposed.
A vacuum can be HEPA-fitted but not Class H. The law typically calls up Class H.
Where it’s required
- Silica cutting: on-tool extraction to Class H + Class H site vacuum (to meet WEL).
- Asbestos removal (A and B): Class H minimum; some tasks need asbestos-rated extraction beyond Class H.
- Lead paint: Class H clean-up + HEPA-filtered LEV at source.
For a builder
- Pair the saw to the vacuum airflow. A dust shroud is only as good as the vacuum behind it.
- Change the filter on schedule. A clogged HEPA drops airflow and silently moves work outside the WEL.
- No household vacuums. A “HEPA” sticker isn’t enough; it has to be Class H.
Category: WHS / dust controls.
Related
- Silica dust controls
- Respirable crystalline silica
- Local exhaust ventilation
- WEL (Workplace Exposure Limit)
See also
Last updated: 2026-05-29. Verified: 2026-05-29. Quarterly review for currency.