Dust filter Rating Explained by ASC

Dust filter Rating Explained Updated on Wednesday, June 22, 2022

Dust filter Rating ExplainedThere are 3 commonly known classes of dust filtration categories.

Each is defined and simplified below:

  • L is for Light Dust
  • M is for Medium Dust 
  • H is for Hight dust concentrations.

The Higher the grade of the dust filters the finer the dust filtration. The dust type that you intend sweeping will determine which of these categories is best suited for your environment. 

Dust Extraction using an L, M, or H Class type filter will trap dust without discharging it into the air.

If you have hazardous dust you want to sweep it’s best to assess the most relevant dust filtration system (also known as a dust extraction System) with your local ASC representative who can guide you through the suitability of the various categories based on your specific application.

Should you be in a hazardous environment, there are many classifications of filtering systems available.

The main 3 classes to choose from include:

  • L Class: ≤ 1.0% Dusts with maximum allowable concentrations (MAC) > 1 mg/m³
  • M Class: < 0.1% Dusts with maximum allowable concentrations (MAC) ≥ 0.1 mg/m³
  • H Class: < 0.005% Dusts with maximum allowable concentrations (MAC) < 0.1 mg/m³

But what is the difference between each class rating? 

The L, M and H stand for Low, Medium and High, respectively.

L Class filters are usually the most affordable option, and it can make sense for many organisations to decide to pick this one. This class is fine for when sweeping up fine dust and material. L Class filters are what’s found in a typical sweeper.

There are numerous benefits of choosing the correct dust filtration for your particular application. The filter type is designed for trapping general dust which won’t create any harm in the long run.

M Class Dust filters are a much higher class of filtration that traps nearly all fine dust–( 99.9%).

It’s significantly more efficient at keeping harmful dust particles from entering back out into the air you breathe.

Generally speaking, an M Class filter won’t necessarily have a higher rate of suction than an L Class, but the filtration system is more efficient, however, you will need to be aware when the filter gets clogged.

M Class dust filters are the most recommended rating onsite by HSE guidelines when sweeping in hazardous conditions.

H-Class filters mean ‘high hazards’ and are usually used for higher hazardous dust which poses a more serious health risk. Examples include carcinogenic dust such as lead, carbon, tar, nickel, cobalt and copper.

General Summation.

It is very important to use a dust-rated sweeper filtration system. This ensures the safe collection and capture of harmful dust.

Unrated sweepers can create problems by exhausting large amounts of respirable dust. Once this dust has bypassed the filtration system it can seriously damage machine components like the electrics and motors. If the dust, if not filtered correctly, will travel back into the breathing space of the operator and can remain airborne for up to 8 hours.

Why Do I Need M Class Dust Filter Sweeper?

If you can see dust, chances are you’re breathing it in. Exposure to harmful dust can cause serious long-term damage, it’s as simple as that. That is why we stress the importance of Class  M dust filters.

Rated sweeper filter systems ensure the safe collection, capture and disposal of harmful dust.

HEPA Filters are not recommended at all on any sweeper. The reason is that it clogs up almost immediately.

HEPA Filters are made from ultra-fine paper which is designed to block very quickly. As they are an uncleanable material you as the client will have not only maintenance issues on your hands but a huge financial cost associated with replacing these filters every 1 to 3 hours of use.