Respiratory - Stage 2: Assess health risks

This section deals with how to identify and assess the risks of developing a respiratory disease.

Construction is an industry that is likely to have an increased risk of both silicosis and chronic obstructive pulmonary disorder (COPD).

Silicosis and COPD

‘Inhalable dust' is airborne material that is breathed into the airways and deposits in the respiratory tract. Inhalable dust is usually cleared by mucus.

‘Respirable dust' is finer material that is small enough to penetrate deep into the lungs. Stone dust often contains a high level of silica which is called respirable crystalline silica (RCS). RCS can cause lung scar tissue which leads to silicosis.

Research shows that construction workers have an increased risk of developing silicosis because of exposure to high levels of silica dust for certain tasks, and there may also be a risk of COPD. If high-speed cutting tools are used on high-silica-content materials without suitable controls, RCS exposures can be very high. Exposures to freshly cut surfaces of RCS occur in many common industrial tasks found in construction such as cutting, blasting, drilling and grinding. It doesn't matter whether the parent material is granite, sandstone, slate, or a manufactured product such as brick or concrete.

Examples where RCS exposure can be high include:

• cutting kerbstones;
• stonemasonry;
• scabbling and surface grinding;
• tunnelling;
• crushing and screening demolition material;
• clearing and removing rubble; and
• chasing out mortar before repointing.

Asthma

Construction tasks that involve a risk of developing asthma include:

• laying epoxy floors; and
• carpentry.

Risk assessment

A risk assessment is a careful, structured examination of what could harm people at work. The assessment is a tool to help clarify the nature of hazards and then weigh up whether you have taken enough precautions to prevent harm, or need to do more. You may wish to use the COSHH Essentials approach.

As a minimum, you should ask:

• What is the nature of materials that my workers use?
• Who is likely to be exposed and how?
• What tasks are known to give rise to risks of respiratory disease?
• Am I doing enough to control the risk, or do I need to do more?
• Does my risk assessment clearly record the answer to these questions?

Table 1 Examples of silica-containing materials

Substance	% Silica content
Brick	Up to 30
Concrete, cement, mortar	25 to 70
Tile	30 to 45
Sandstone, gritstone, quartzite	More than 70
Granite	Up to 30
Sand, gravel, flint	More than 70
Slate	Up to 40
Flint	More than 80

To check for asthmagens, read labels and look at safety data sheets. The relevant phrase to look for is ‘R42 may cause sensitisation by inhalation'.

Have you identified any respiratory problems?

Do your workers need to undergo any health surveillance?

Example: Risk assessment: Kerb cutting

Step	Title	Description
1	Identify the hazards	At the design stage, kerb materials could be specified as silica-free or low silica. If silica-containing stone is used for kerbs, uncontrolled high-speed cutting will release large quantities of RCS into the breathing zone of the kerb cutter and any surrounding workers. As well as the risk of silicosis, there is also a risk of COPD from exposure to general dust. This means that even with the use of low-silica stone dust, control measures are needed.
2	Decide who might be harmed and how	Kerb cutting generates thick clouds of dust, some of which will be respirable, and is able to penetrate the lower reaches of the lung. Both the operator and other workers in the vicinity will be exposed to high levels of RCS and general dust. Exposure may result in silicosis or COPD depending on the type of stone being cut. The risk of these diseases developing can be prevented.
3	Evaluate the risks and decide on precautions	A kerb cutter could be exposed to RCS levels of more than 30 times the legal limit (Guidance Note CIS 36 ). Workers or members of public who are nearby will also be exposed to high levels of RCS. Consult the HSE Silica Essentials sheet on kerbstone cutting.The risk can be reduced by using: pre-cut lengths to minimise cutting on site; compression cutting equipment; on-tool extraction where available; water to suppress dust. Tools fitted with water suppression are widely available, but this must be managed by ensuring an adequate supply of water; controlled access to the area to prevent exposure of those not cutting; extraction and filtration for restricted work areas; respiratory protective equipment (RPE). This may be needed even if water suppression is provided. This can be assessed from sampling data, published information or from previous experience. If RPE is needed, ensure that it suits the wearer, is properly face-fitted and is suitable for the job and the work environment; and workers who are properly trained in the use of equipment, controls, and the maintenance of RPE.
4	Record your findings and implement them	The control measures need to be recorded and details should be kept where they can easily be referred to. Workers must be informed about the health risks and trained to use the controls effectively.
5	Review your risk assessment and update if necessary	The risk assessment may need updating if the work changes (eg type of stone cut, restricted ventilation, weather conditions). Also, be wary about relying on assessments from previous jobs because the specific control measures may need adjustment to ensure that risk is effectively controlled.