Filters decide whether dust stays captured or returns to the workspace. In source capture systems they also dictate airflow under load, so the right media and maintenance plan are essential for both safety and performance.

Match filter class to the hazard

For general construction and wood dust, M-Class filtration is a typical baseline. For fine or carcinogenic dusts such as respirable crystalline silica, welding fume, or lead, use H-Class units with HEPA. HSE guidance expects H14 for fine/carcinogenic or respirable dusts where high efficiency is critical. The goal is simple: collect and contain, not re-emit.

Stage filtration to protect airflow

Use pre-filters and cyclonic separation to capture coarse material before it hits the final filter. This reduces loading and keeps extraction stable over a shift. Cartridge or panel filters should seal against gaskets; any bypass undermines efficiency regardless of rating. Clean features (shaker or pulse) help, but do not replace timely filter changes.

Maintain under-load performance

As filters load, airflow drops and capture suffers. Track differential pressure to know when to clean or replace. Empty bags and bins before they are packed solid, and handle waste in a way that avoids re-aerosolising dust. After maintenance, check for leaks around seals and latches.

Prove effectiveness

Simple smoke checks show capture direction; a particulate meter shows whether airborne levels fall after maintenance or filter changes. If source capture alone cannot control residual dust, add an air scrubber or negative air machine with high-efficiency filtration and tighten housekeeping with an H-Class industrial vacuum.

Practical takeaways

• Select filter class by hazard; use H-Class with H14 where respirable or carcinogenic dusts are present.
• Stage filtration to reduce loading and protect airflow.
• Seal matters: check gaskets, clips, and doors after every service.
• Use pressure gauges to trigger maintenance, not guesswork.
• Validate results with a PM meter and adjust the plan accordingly.

Keep WELs in mind (e.g. RCS at 0.1 mg/m³ per HSE EH40), but focus daily effort on filter integrity and steady airflow at the task.