Dust extractors: L, M and H class explained

A dust class is a specification to check on the complete extractor. It does not tell you whether a hose fits your saw or how much air reaches its hood. Keep those decisions separate when comparing machines.

What the labels describe

This is an overview of the maker's descriptions, not a universal permission to handle any material in a category. Old finishes, contamination or mixed materials need their own assessment. A woodworking guide is not advice on asbestos removal.

HSE's construction guidance specifies an M- or H-class unit for on-tool extraction when cutting and sanding wood, together with an appropriate flow rate and secure, suitable hoses. It also addresses RPE. Buying an extractor alone does not complete the control measures.

Avoid a filter-only comparison

A listing might emphasise a filter's particle size, use the word HEPA or show a collection percentage. Record those claims separately from the complete extractor's dust class. Before buying, ask for the model's classification documentation and the operating instructions. Check that the supplied configuration is the one described; do not assume an optional filter changes the whole machine's classification.

Questions for a shortlist

• What exact model, voltage and supplied kit does the specification cover?
• Which dusts and tasks does the manufacturer permit?
• What airflow information is available at the working connection?
• How does the machine warn of restricted airflow, if applicable?
• Which bags and filters are required, and how are they changed?
• What is the maximum permitted load on a tool socket?

Use the shop vac comparison to distinguish equipment types. Then put the actual maker figures into the extraction planner. A higher class label cannot make an unsuitable connection or inadequate extraction arrangement effective.