Dust Control

Recent HSE research has estimated that silica may be responsible for the deaths of over 500 people each year who have worked in construction. HSE also estimates that around 4,000 people die every year from Chronic obstructive pulmonary disease (COPD) linked to work. Construction workers are one of the at-risk groups within this because of the dust that they breathe.

What is Construction Dust?

Construction Dust is a general term used to what may be found on a construction site. There are three main types:

• Silica dust – Silica is a natural mineral present in large amounts in things like sand, sandstone and granite. It is also commonly found in materials such as concrete and mortar. The silica is broken into very fine dust (also known as Respirable Crystalline Silica or RCS) during cutting, drilling and grinding. It is often called silica dust.
• Non-silica dust – There are a number of construction products where silica is either not found or present in very low amounts. The most common ones include gypsum, cement, limestone, marble and dolomite. This dust is also mixed with silica dust when cutting things like bricks.
• Wood dust – Wood is widely used in construction and is found in two main forms; softwood and hardwood. Wood-based products are also commonly used including MDF and chipboard.

The main dust related diseases affecting construction workers are:

• Lung cancer
• Silicosis
• Chronic Obstructive Pulmonary Disorder
• Asthma

Some lung diseases like advanced silicosis can come on quite quickly. However most others happen over a period of time, caused by regularly breathing small amounts of dust. Unfortunately, by the time the damage is apparent treatment is more difficult.
Which task create the most dust?

Many construction tasks create dust. High dust levels are caused by one of more the following:

• Equipment – using high energy tools, such as cut-off saws, grinders, wall chasers and grit blasters produce a lot of dust in a very short time.
• Work method – dry sweeping can make a lot of dust when compared to vacuuming or wet brushing
• Work area – the more enclosed a space, the more the dust will build up
• Time – the longer you work the more dust there will be.

Examples of high dust level tasks include:

• Using power tools to cut, grind, drill or prepare a surface
• Sanding taped plaster board joints
• Dry sweeping

How much dust is harmful?

The Control of Substances Hazardous to Health (COSHH) Regulations (see also COSHH) sets a limit on the amount of dust that can be breathed after all controls have been put into effect (called a Workplace Exposure Limit or WEL). Averaged over a normal working day the maximum amount of silica you can breathe is less than like a very small pinch of salt.

How should dust be controlled?

You should look at ways of limiting the amount of dust you could make before you start work. For example you could:

• Use a less powerful tool – e.g. a block splitter can sometime be used instead of a cut-off saw 
• Using a different method of work altogether – e.g. using a nail gun to direct fasten cable trays instead of drilling holes first

Even if you can stop some of the dust this way you may need to do other work that could still produce high amounts of dust. In these cases the most important thing is to stop the dust getting into the air. There are two main ways of doing this which both give very good results:

• Water – water damps down dust clouds. However, it needs to be used correctly. This means enough water for the whole time that the work is being done. Just wetting an area of ground before cutting does not work. 
• Vacuum Extraction – Specially designed tools can be fitted with an industrial vacuum unit that sucks the dust away as it is being created and stores it until emptied.

Do I need a mask as well?

Whilst alternative tools and methods may help in reducing the dust, some form of respiratory protective equipment (RPE), usually in the form of a mask, will be needed where the dust generated still exceeds the legal maximum. Examples of these high risk tasks are as follows:

• Using a cut-off saw, grinder or wall chaser on material containing silica
• Using powered cross-cut saws and sanders on hardwood, red cedar or MDF
• Sanding softwood in an enclosed space

Masks are available that provide different levels of protection. There are two main performance types you should provide when working with construction dusts: FFP2 and FFP3. FFP3 is the most advisable type to use if you are doing work that does or could create high dust levels or involves silica or wood dust (the more hazardous substances).

Why isn’t a mask good enough on its own?

Unless there are real problems doing so you should not just rely on a mask for high risk tasks. There are some very good reasons for this including:

• High risk tasks can produce so much dust that the mask cannot give the amount of protection needed. Also the filter in a mask can quickly become clogged and stop working.
• A mask only protects the person wearing it. Anyone else in the area could still be at risk from the dust if they do not wear a mask as well.
• There are many common mistakes that people make with masks. These include choosing the wrong type, not being face fit tested or not wearing them properly.

As already mentioned the main aim is to stop the dust getting into the air in the first place. If you do just rely on a mask for high risk tasks you may be asked to justify why.

Fitting a mask.

Masks rely on a tight seal with the face to work. This is so that only air going through the filter is breathed. If the mask does not fit properly the dust can slip through any gap between the mask and the face and into the airways. Dust particles can be much smaller than the width of a hair so the face seal needs to be very good.

There are many designs of masks. Not all will fit well enough to form a good seal with the face. The HSE recommends that those at risk should be face fit tested.

The dusty work I do is over very quickly. Does this mean I am OK?

No. Construction work often involves a number of quick tasks done throughout the day. Some of these tasks can still cause a large amount of dust that over a period of time will still have the potential to cause harm.

Am I OK if I am working outside?

No. People often think that construction dust is not a problem if they are working outside because it will be diluted and just blow away. While the wind will have some effect on the level of dust many tasks involve the person working close to the part of a tool where the dust is being made. With very dusty tasks this means that a lot of harmful dust will still be breathed.
Are members of the public at risk from breathing in this dust?

Whilst the risk of lung disease is linked primarily to people who regularly breathe construction dust over a period of time, this dust could cause a reaction in someone who already has asthma or another existing breathing problem. Its is also pretty unsavoury for passers by and could be classified as a nuisance.

Disposing of Dust.

The Environmental Protection (Duty of Care) Regulations 1991 (as amended)

• Places the responsibility for safe disposal of waste upon the waste producer.
• Requires all persons collecting and disposing of waste for other parties to be licenced waste carriers.
• Establishes the requirement of transfer notes with written description of the waste to be transferred.
• Requires that transfer notes must be kept for a period of two (2) years.

It is the users responsibility to:

• Assess the method of working to eliminate or reduce the effects of dust.
• Put into effect measures to control or eliminate any dust generated.
• Manage the exposure of their workforce or any other affected persons to dust.
• Dispose of any dust and debris collected

As the supplier of equipment for use on site Toga can provide you with:

• Alternative tools to do the job
• Provide you with dust extraction equipment suitable for reducing the dust circulating on site.
• Provide you with wet cutting and grinding tools with water supply units

Contains public sector information published by the Health and Safety Executive and licensed under the Open Government Licence v1.0

HSE website links.

http://www.hse.gov.uk/construction/faq-dust.htm

http://www.nationalarchives.gov.uk/doc/open-government-licence/

At TOGA Hire Centres, we take Health and Safety matters very seriously and hope that these fact sheets are of help. However, we must stress that these guidelines are not intended to be fully comprehensive instructions and the customer should, of course, be aware that it is their responsibility to ensure the health and safety of their staff at all times.