M Class and H Class Industrial Vacuum Cleaners are designed to collect dusts that are potentially hazardous to health.

The Health & Safety Executive (HSE) mandates that owners, operators and employers use appropriately rated vacuum cleaners to clean hazardous construction dust. What differentiates M Class and H Class vacuum cleaners from those designed for general use is primarily:- the level of filtration the machine provides, an indicator to show that the filtration is still working effectively and is not blocked, and the ability to collect in to a disposable bag.

The categories represent the following specifications
M Class < 0.1% filter penetration of dusts with maximum allowable concentrations ≥ 0.1 mg/m³
H Class < 0.005% filter penetration of dusts with maximum allowable concentrations < 0.1 mg/m³
In addition H Class machines must undergo a different level of filter testing before being placed on the market.

The BVC range of Industrial Vacuum Cleaners includes several machines that area available with M Class and H Class ratings, and these are illustrated below.