Dust control, dust suppression and dust prevention FAQs

1. Which tasks create the most dust?
2. How far do I need to be away from someone else creating dust to be safe?
3. Do air purifiers remove dust?
4. What does COSHH cover?
5. How much dust can harm me?
6. How do hazardous substances enter the body?
7. How do I control construction dust?
8. What is LEV?
9. How to reduce dust when grinding concrete?
10. Why is PPE important?
11. Are members of the public at risk from breathing in construction dust?
12. Where can I get more information about dust and other risks to my lungs?

Which tasks create the most dust?

Dust can be produced in a number of ways, including when:

• Using tools that produce a lot of dust particles, such as cut-off saws, hand grinding machines, industrial bench grinders, and chasing machines. 
• Cleaning with compressed air cleaning guns, or when dry sweeping.

The amount of dust that a task produces will also increase when:

• Working in an enclosed space with little or no ventilation, which will allow a greater amount of dust to build up in the air.
• Spending a long time working in one area - it seems obvious, but spending more time performing a task that creates dust will lead to more dust being created!

How far do I need to be away from someone else creating dust to be safe?

It is difficult to give a definitive answer for every situation. However, when working around dust, it is advised that:

• When working outside, you stay away from dust clouds and avoid working downwind from sources of dust.
• When working inside, you stay out of areas where dust is visible in the air. This can be hard to judge as fine particles (sometimes called invisible dust) can remain airborne for a long time and are difficult to spot without a dust lamp.

While staying away from dust is important, HSE guidance suggests that controlling dust creation is a far more effective practice than attempting to avoid dusty areas of work.

Do air purifiers remove dust?

Air purifiers do remove dust from air, but their effectiveness depends on the environment they are used in. For example, many models are designed for use at home and are not capable of purifying air that contains large amounts of dust.

Typically, air purifiers will collect large dust particles from the air using a type of mechanical filtration, such as a HEPA filter.

For workplaces that create large amounts of dust or need to control dust and emissions during construction and demolition, an industrial air purifier or LEV (local exhaust ventilation) system is more appropriate.

What substances are covered by COSHH?

Hazardous substances covered by the Control of Substances Hazardous to Health Regulations include:

• Chemicals.
• Products containing chemicals.
• Fumes.
• Dusts.
• Mists.
• Vapours.
• Nanotechnology.
• Gases.
• Biological agents (germs).

Many people think that COSHH covers the control of asbestos, lead and radioactive agents, but these are actually covered by their own legislation. For more information on COSHH, consider taking our COSHH Awareness Training course.

How much dust can harm me?

The amount of dust that is safe to breathe in depends on the nature of the substance. The Control of Substances Hazardous to Health (COSHH) Regulations set a limit on how much is safe for particularly dangerous dusts. This is called the workplace exposure limit (WEL).

A WEL is the legal maximum amount of a substance workers are allowed to be exposed to after control measures have been put in place.

These limits are often very low. For example, the amount of silica dust considered safe to breathe is compared to a one pence piece in the image below:

How do hazardous substances enter the body?

Hazardous substances can enter the body in a number of ways. There are four ways that dust tends to enter the body.

• Breathing in particles:
  • It is easy to breathe in particles that are floating in the air. Too much dust inhalation can lead to breathing problems including lung disease.
  • There are two types of dust that can be breathed in: inhalable and respirable dust. Total inhalable dust is larger and usually gets trapped in the mouth, nose or throat, where it causes damage. Respirable particles are smaller and can build up in the lungs, leading to lung damage.
• Swallowing:
  • When dust is breathed in it can become trapped in mucus. This is usually either spat out or swallowed.
  • When it is swallowed it can cause gastrointestinal irritation or enter the blood, which in turn allows it to cause problems elsewhere in the body.
• Eye contact:
  • Particles produced during cutting, grinding and drilling can cause eye damage and irritation. Some substances may cause eye damage due to their chemical nature.
• Skin contact:
  • Some substances are irritating or damaging to the skin. They can cause rashes or ulceration on contact.

How do I control construction dust?

Controlling construction dust is not always easy. However, limiting the amount of dust created by changing how a task is done is a good start. Some examples of how to do so include:

• Using the right size of building materials so less cutting and preparation is required.
• Using less powerful tools. For example, a block splitter could be used instead of a cut-off saw.
• Using alternative work methods. For example, nail guns can be used with wood to avoid having to drill holes.

Some work that creates a lot of dust is inevitable. In these situations, a suppression system or an extraction system should be used to stop or limit the amount of dust that gets into the air:

• Water suppression systems: Water suppression systems use a constant flow of water to damp down particles and stop them from becoming airborne. It is important for the flow of water to be sufficient - damping down an area before beginning work will not be enough to reduce the amount of airborne particles.
• Local exhaust ventilation (LEV): LEV systems can be attached to hand-held or static tools to remove the dust they create and take it elsewhere for filtration or disposal.

What is LEV?

Local exhaust ventilation (LEV) is a dust extraction system used to reduce dust exposure in the workplace. As the name implies, an LEV system is installed at the source of the dust in order to remove it before it can cause harm.

LEV extraction combines two key systems: an air extraction system and air filtration system. It is usually installed where stationary tools, such as pedestal grinders, are in use.

The diagram below shows the key elements of an LEV system:

It is important that LEV systems are correctly installed, ideally by a trained professional, so that they can effectively act as a dust prevention measure. Further information on LEV installation and use can be found here. 

How to reduce dust when grinding concrete

Grinding concrete releases respirable crystalline silica (silica dust) into the air. Find out about the danger of silica dust here.

A dust suppression system that is commonly employed when working with concrete uses water to stop particles from becoming airborne. There are two types of this system: a water suppression bottle system and a mains water system.

The first uses a dust suppression water bottle and is more portable than the other which relies on a mains water supply.

Why is PPE important?

Personal protective equipment, or PPE, is the last line of defence against hazardous substances in the workplace. The importance of PPE in the workplace cannot be understated.

When other dust control measures do not reduce exposure to a satisfactory level, PPE and RPE (respiratory protective equipment) must be employed. 

PPE may include disposable coveralls to protect personal clothing and skin, eye protection, or a full face dust mask to offer respiratory protection.

In short, PPE helps to prevent too much dust inhalation, skin contact and eye contact.

Are members of the public at risk from breathing in construction dust?

No, the harm that construction dust inhalation causes usually develops over a long period of time when a person is repeatedly and regularly exposed. That said, breathing in dust even for a short period of time is unpleasant, and can cause a reaction in people with asthma or other respiratory problems.

Adequate measures of dust control should always be taken and members of the public should be kept away from work that creates dust.

Where can I get more information about dust and other risks to my lungs?

This article offers an in-depth guide to respirable crystalline silica, and the HSE offers guidance on how to control hazardous substances here.

You can find further information and guidance on the dangers of dust and how to control dust in the workplace in our:

Dust Awareness Training Course