The answer is not determined by the job title or the industry — it is determined by the dust. Under COSHH 2002, the classification of the extraction equipment must match the hazard level of the substance being extracted. Choose by the dust, not by what seems appropriate for the work.
The three dust classes
L-Class — low hazard. Minimum 99% filtration. For dust with a Workplace Exposure Limit above 1mg/m³. General workshop cleaning, plaster, gypsum, general debris.
M-Class — medium hazard. Minimum 99.9% filtration at 1 micron. Required for dust with a WEL of 0.1mg/m³ or above — silica (RCS) at 0.1mg/m³, hardwood dust at 3mg/m³, flour dust at 3mg/m³ (respirable). The standard for most UK construction dust extraction.
H-Class — high hazard. Minimum 99.995% at 0.3 microns with H14 HEPA. Required for carcinogenic dusts, biological agents and chemical hazards. The class for mould, asbestos, isocyanates and healthcare environments.
Choose M-Class for
- Stone, concrete, brick and block cutting and drilling — silica dust (RCS)
- Hardwood sanding and cutting — carcinogen, WEL 3mg/m³
- Floor grinding, scarifying and scabbling — high-volume RCS
- General occupied building cleaning under IAQ 2027
- Flour and grain dust in food production
Choose H-Class for
- Mould remediation — Hazard Group 2 biological agent under COSHH. H-Class is the legal requirement.
- Asbestos — licensed contractor specification. H-Class Type H required.
- Healthcare construction — ICRA Class III and IV environments.
- Isocyanates and spray painting environments.
- Any dust where risk assessment determines M-Class is insufficient.
When in doubt, step up
H-Class is never wrong — only more expensive. If your risk assessment is unclear about which class is required, specifying H-Class provides a higher level of protection without any compliance risk. The reverse is not true: specifying M-Class for a task that requires H-Class is a COSHH breach.
The classification mark is the evidence
The M-Class or H-Class mark must appear on the machine — tested as a complete unit to EN 60335-2-69, not just the filter. When an HSE inspector asks what extraction equipment is being used, the classification mark on the machine is what they are looking for. A machine described as HEPA or fine dust capable without a classification mark does not satisfy the standard.
| Class | Filtration | Choose for | V-TUF range |
|---|---|---|---|
| M-Class | 99.9% | Silica, hardwood, flour, general construction dust | MINI HSV X2, MIGHTY HSV, MIGHTY XL HSV, tufVAC |
| H-Class | 99.995% | Mould, asbestos, healthcare, biological hazards | MIDI H, MIDI HSV, GRINDEX, MAXi H-Class, RUCKVAC HSV |
- M-Class and H-Class health rated vacuums →
- Health rated vacuum guide →
- M-Class hub →
- H-Class hub →
- COSHH Regulations 2002 →
- Industrial vacuum cleaners buyer's guide →
This article is for general guidance. Your COSHH risk assessment determines the classification required for your specific task and environment.
