The short answer is yes. And the reason matters — it is not a recommendation or a best practice suggestion. It is a legal requirement under COSHH 2002.
Why mould requires H-Class and not M-Class
Mould is classified as a Hazard Group 2 biological agent under COSHH 2002. M-Class achieves 99.9% filtration at 1 micron — sufficient for mineral dusts. Mould spores are smaller, lighter and biological. The 0.1% that passes through an M-Class filter and is exhausted back into the room is live biological material — spores capable of causing further mould growth and respiratory illness in exposed individuals.
H-Class achieves 99.995% filtration at 0.3 microns with H14 HEPA. The exhaust air from an H-Class machine with an intact H14 HEPA filter is safe to return to an occupied environment. The exhaust from an M-Class machine during mould remediation is not.
What COSHH actually says
COSHH 2002 Regulation 7 requires employers to prevent or adequately control exposure to hazardous substances. The control hierarchy requires engineering controls before RPE. For biological agents including mould, the engineering control is H-Class extraction. A method statement that names an M-Class machine for mould vacuuming does not satisfy the COSHH requirement.
What about wiping and repainting?
Wiping mould with a cloth and repainting does not remove the mould — it distributes spores into the air and covers the surface. The colony underneath continues to grow. This is not remediation. The UKCMS Mould-Safe Code requires mechanical removal of mould-affected material followed by H-Class vacuuming of the affected surface and surrounding area before any treatment is applied.
Awaab's Law and housing associations
Awaab's Law Phase 2 applies from 30 November 2026. Housing associations commissioning remediation work must ensure contractors use compliant equipment — H-Class extraction. A housing association that commissions a contractor using M-Class for mould vacuuming is exposed to liability if the remediation fails or if an operative or resident suffers health consequences.
The V-TUF specification
The GRINDEX H-Class range uses Longopac sealed continuous bagging — the bag seals before opening, eliminating filter exposure during emptying. The MIDI HSV is the compact H-Class specification for smaller remediation projects. An AEROMAX air scrubber should run continuously during and after remediation to manage airborne spore concentration — on-tool H-Class captures spores at the surface, an air scrubber captures what cleaning redistributes into the air.
- Awaab's Law compliant equipment →
- H-Class extraction for mould remediation →
- Mould removal standards and UKCMS →
- Awaab's Law full guidance →
- COSHH Regulations 2002 →
This article is for general guidance. Confirm your specific COSHH assessment requirements with a qualified occupational hygienist or safety adviser.
