H Class dust extractors are specified for high-risk dusts where exposure must be tightly controlled. Think asbestos (licensed work requires specialist systems), significant lead paint removal, mould remediation, pharmaceutical powders, and scenarios with very fine or carcinogenic particulate. On construction and refurbishment projects, H Class is often the right choice for intrusive work in occupied buildings or where contamination consequences are high.

When to specify H Class

• Known or suspected asbestos: stop and follow the appropriate asbestos procedures. H Class extraction is part of a wider control regime.
• Lead paint or heavy-metal residues: on grinding or sanding, containment plus H Class extraction and suitable RPE are expected.
• High-risk RCS scenarios: prolonged indoor cutting, chasing or dry coring where airborne build-up is likely.
• Biohazard and fine powders: mould remediation, healthcare, labs and pharmaceutical handling.

Control in practice

• Source capture first: fit purpose-made shrouds and ensure a tight seal. Keep passes steady and shallow.
• System integrity: check gaskets, clips and hose cuffs before every shift. Use anti-static hoses and seal waste bags before removal.
• Filtration: choose units with high-efficiency final stages; H13 is common, with H14 preferred for fine/carcinogenic or respirable fractions.
• Room control: use air scrubbers or negative air machines with H14 filtration to keep airborne particulate down and to maintain directional airflow for containment.
• Airflow under load: verify performance with the tool connected. Manage filter loading with auto-clean and pre-filters.
• Documentation: record pre-use checks, maintenance, and waste disposal under your COSHH assessment.

Manufacturers such as MAXVAC offer H Class extractors and H14 air filtration units that can be combined to create effective source and room controls.

Compliance snapshot

HSE EH40 sets low Workplace Exposure Limits for substances like RCS (0.1 mg/m³). H Class equipment supports control, but effectiveness depends on correct methods, RPE, supervision and verification. Keep enclosure integrity, pressure differentials where used, and clear access/egress procedures.

Practical takeaways

• Use H Class for asbestos-related tasks, lead paint removal, mould, pharma powders, and high-risk RCS indoors.
• Combine tool capture with H14 room filtration and controlled waste handling.
• Prove performance under load, maintain seals, and keep COSHH records up to date.

H Class is not just a filter label; it is a control strategy. Pair robust equipment with disciplined method statements and you will keep exposures low and projects compliant.