Explained: From Dust Classes to Extractors

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In all lines of industrial work, dust poses an enormous health risk. Regardless of health and safety measures you may already have in place, you can never be too careful when it comes to preparing for different types of hazardous dust.

In this guide, we will take a closer look at the different classes of harmful dust, and will consider the best ways to remove them from your working atmosphere. 

What is Dust Extraction?

Dust extraction helps to remove harmful or hazardous dust from the atmosphere. That doesn’t mean it is just placed somewhere else for others to deal with. It is retained so that it can be disposed of safely at a later date.

All good safety tools and extraction equipment will ensure dust is kept from transferring into the air around you.
Festool power tools are designed to maximise dust extraction. Our equipment is built so that you can funnel extracted dust away while working with sensitive materials. It is always a good idea to use power tools which give you greater control over dust dispersal, and which can be used with dust extractors.

Why is Dust Extraction Important?

Not extracting dust could lead to serious health problems. Microscopic particles in fine dust from concrete, stone, wood and metal can settle in your lungs. That could potentially create scar tissue and could lead to long-term conditions such as Silicosis. It is not merely enough to wear individual ventilators or to ventilate an area. Dust extraction catches harmful particles before they get into the air to be disposed of safely.
That said, some materials and work may produce dust considered more or less dangerous than others. Before we look at what you’ll need from a hard-working extraction unit, let’s consider the different dust classifications.

What are the Main Dust Classes?

There are three main classes of industrial dust you should be aware of. These are ranked based on the particle size, and the risk they can pose to your health. The smaller the particles, the more chance you have of breathing them in, which is where there's greater risk of dangerous particles settling in your lungs and causing damage. 
It’s important to know a little bit about dust classes. When buying power tools and/or extractors, you will find that they are designed for use with various types of dust. Instead of taking your chances, always make sure you know what classes of dust you are likely to be working with. 
Here are the main dust classes currently observed:

  • Dust Class L (Low risk, largest particles)

  • Dust Class M (Medium risk, small particles)

  • Dust Class H (High risk, microscopic particles)

It is not enough to have one extraction tool to help remove dust from your working area. You will still need to remain vigilant and to make use of industry-recognised procedures.

Dust Class L

L-Class dust is considered some of the least harmful and can be commonly found in the home. Everyday house and soil dust, for example, would fall under ‘L’. Therefore, there is a smaller long-term risk in you breathing this in, though you must still take precautions.

Class L extractors operate at 99% efficiency and therefore work to an occupational exposure limit of 1mg per metre cubed. 

Festool products that offer L-Class filtration include: 


Dust Class M

M-Class dust is considered medium risk. While this type may not pose the same long-term health risks of class H, it is still highly recommended that you protect against it. Dust class M is common in most industrial workspaces as a result of materials which can generate it. 
Wood and quartz-based materials are likely to be the most common cause of the spread of M-class dust. You may experience this dust class while working with any of the following:

  • Stone
  • ​MDF
  • Cement (standard or tile)
  • Concrete
  • Mortar
  • Repair compound
  • Paint (oil and latex)

M class extractors come fitted with a flow sensor and alarm that advises the user when a dust bag or system is full, or if attention is required. As this dust class is considered more hazardous, it is vital that hardware is kept running at an optimal level at all times.

Class M extractors and filters operate at 99.9% efficiency. That means there is an occupational exposure limit of 0.1mg per meter cubed.

Festool products that offer L-Class filtration include: 


Dust Class H

H-Class dust is regarded as the most dangerous. This type of dust can travel the furthest into your lungs, and therefore may be considered carcinogenic, or at greatest risk of causing cell necrosis. 

Materials likely to create H-class dust and respirable silica may include:

  • ​Mortar
  • Ceramic
  • Stone
  • Concrete
  • Mould spores
  • Mineral and artificial fibre
  • Asbestos
  • Bitumen

Class H filtration and extraction systems operate to 99.995% efficiency and occupational exposure of 0.1mg per metre squared. 

Festool products that offer H-Class filtration include: 


More Information on Extraction

It is also essential to know a little bit about how extraction and filtration systems work.

  • Festool dust extractors are compatible with various types of filters and bags. 

  • Failure to use a bag during extraction may result in dust re-entering the atmosphere. What's more, you would also need to clean your hardware regularly.

  • Filter bags are ideal for use with all dust classes. Long life bags help with class L in particular, though self-cleaning bags are ideal for all-around support.

  • There are also tools available which offer local exhaust ventilation, or LEV.

Find Out More

Whether you work in construction, demolition, or anywhere in between, extraction and filtration is essential.  Understanding the classes and types of dust you will be working with, too, will allow you to make the most effective choices concerning tools and equipment.

It is important to work with power tools that capture and control dust while you work. Festool’s high-quality equipment is designed and built so that you can work with high-risk materials with complete confidence. While extraction is always recommended, for greater all-around control, you should be thinking about the tools you are using to cut and grind with too.

If you are working with harmful dust on a regular basis, consider auditing your current equipment and tools. Are they doing enough to keep the air clear of dust, whether Class L, M or H? If you have any concerns about performance and safety, consider a Festool system - we offer free tool demonstrations so you can test the products first-hand. 

Festool is the leading name in Australian power tools and safety equipment. If you are in the process of setting up a new project or need help with dust extraction, our team is here to help. Don’t risk the health of those around you. Go hard on dust!

Disclaimer: This information is not endorsed by any Work Health and Safety governing body and shouldn't be interpreted as any form of legal or health advice. All regulatory and compliance enquiries must go to the relevant Worksafe organisation responsible for each region of Australia. All health-based enquiries should be discussed with and handled by a Medical Professional. Information provided in this article is accurate as of August 2019.