Dust FAQs

5 frequently asked questions about dust

dust faqs

What is dust?

Dust is tiny, dry particles in the air. It is produced by many work activities, including the cutting, drilling, demolishing and sanding of materials.

Exposure to dust is a serious health hazard and can lead to the development of illnesses such as lung cancer and asthma. However, it is not always an obvious hazard because the particles that cause the most damage are often invisible to the naked eye, and the health effects of exposure can take years to develop.

How is dust created?

Dust can be created by a wide range of activities. These include:

  • Filling or emptying bags.
  • Weighing loose powders.
  • Cutting materials.
  • Sieving and screening operations.
  • Conveying materials, either mechanically or by hand.
  • Stockpiling large volumes of processed materials.
  • Crushing and grading.
  • Milling, grinding and sanding.
  • Cleaning and clearing up spillages.
  • Feeding livestock from bags or conveyor systems.

How is dust harmful?

There are four main ways in which a person can be exposed to dust:


Inhaling dust can lead to breathing problems, such as asthma and bronchitis. Dust that can be breathed in is split into two main types:

  • Inhalable dust, which is visible to the naked eye. This dust is typically trapped in the nose, mouth, throat or upper respiratory tract.
  • Respirable dust, which is very small and invisible to the naked eye. As a result of its size, this dust travels deep into the lungs when inhaled.


Some dust can be swallowed. This often happens when it becomes trapped in the mucus that lines the nose, mouth and throat, which itself is swallowed.

Dust that has been swallowed can enter the digestive tract, causing issues such as gastrointestinal tract irritation, or the bloodstream, resulting in irritation to multiple organs and tissues.

Eye contact

Dust particles produced when cutting, grinding and drilling materials can enter the eye and cause damage or irritation.

Also, some dust can harm eyes due to their chemical nature. For example, powdered bleach can cause chemical burns to the surface of the eye and lead to lasting vision loss.

Skin contact

Some dust can cause ulceration and irritation of the skin upon contact. Also, contact with dust such as epoxy resins, rubber processing chemicals, wood dust and fibreglass can cause dermatitis.

What are the different types of dust?

A person can be exposed to several different kinds of dust at work, some of which will be more harmful than others. For example, exposure to household dust is unlikely to pose a significant health risk to most people, but exposure to asbestos fibres can result in the development of mesothelioma and asbestos-related lung cancer.

There are several forms of hazardous dust that are often present in certain workplaces:


Asbestos is a fibre-like material that was commonly used in insulation, flooring and roofing in buildings built before 2000. When asbestos-containing materials are damaged, it releases a fine dust containing asbestos fibres that can enter the lungs and gradually damage them over time.

If a person is exposed to asbestos fibres over a long period, they can develop a number of fatal and serious asbestos-related diseases including mesothelioma, lung cancer, asbestosis and pleural thickening.

If you work with asbestos, or are likely to come into contact with it at work, consider taking our asbestos awareness training course.


Those that work in bakeries, flour mills and kitchens are often exposed to flour dust. This dust is the second most common cause of occupational asthma, and can also cause dermatitis.

Further information on flour dust, produced by the HSE, can be viewed by clicking here.


Grain dust is produced when harvesting, drying, handling, storing and processing grains (such as barley, wheat, oats, maize and rye). This dust contains small particles of the grain itself, as well as any contaminants or additives present (such as bacteria, fungal spores, insect debris and pesticide residues).

Those that work with grains may frequently inhale grain dust. This leads to the development of respiratory diseases, such as occupational asthma, which can cause permanent breathing problems and make a person unable to work.


Silica is a natural substance that is found in most rocks, sand and clay, and in products such as bricks, concrete and plastic. When processed, these materials release a fine dust called respirable crystalline silica that can be inhaled deep into the lungs. To find out more about Silica RCS please read our detailed article: Respirable Crystalline Silica (RCS) In-Depth Guide 

Long-term exposure to respirable crystalline silica can lead to the development of several lung diseases, including:

  • Silicosis, which makes breathing more difficult and increases the risk of lung infections.
  • Chronic obstructive pulmonary disease, a group of lung diseases including bronchitis and emphysema, that cause severe breathlessness and prolonged coughing.
  • Lung cancer, which is more likely to occur in people who already suffer from silicosis.


Exposure to excess amounts of wood dust can cause serious health problems including asthma, a condition that carpenters and joiners are four times more likely to suffer from than other UK workers.

Also, exposure to hardwood dust can increase the risk of developing several forms of cancer, including nasal, sinus and nasopharyngeal cancer.

What are workplace exposure limits?

The Control of Substances Hazardous to Health (COSHH) 2002 Regulations are designed to protect workers from exposure to hazardous substances. They require employers to control exposure to hazardous substances in the workplace, including the vast majority of dusts, and set out how this should be done. For more information on COSHH risk assessments and the control measures that can be used to manage dust exposure, click here to view our article on controlling dust.

COSHH applies to all dust that is present at a certain concentration in air (10mg/m3 for inhalable dust or 4mg/m3 for respirable dust). For some particularly hazardous dusts, COSHH sets out a specific workplace exposure limit that dictates the maximum concentration of the dust that can be present in the air, averaged over a certain time period.

If you would like to learn more about COSHH consider taking our course: COSHH Awareness Online Level 2

Usually, the two time periods that are used are:

  • 8 hours, which is used to calculate the long-term exposure limit.
  • 15 minutes, which is used to calculate the short-term exposure limit.

For example, flour dust has a long-term exposure limit of 10mg/m3, and a short-term exposure limit of 30mg/m3. This means that the air a worker breathes in must not contain an average of more than 10mg/m3 of flour dust over an 8 hour day, and not contain an average of more than 30mg/m3 over any given 15 minute period.

At Commodious, we offer a great value, RoSPA-assured Dust Awareness course that explores what dust is, and outlines some of the measures that can be used to control it. To find out more about it, use the link below: