Construction dust is not just a nuisance, it can seriously damage workers’ health and some types can eventually kill. Chris Chapman, technical support manager for the Building Safety Group, explores the issues around controlling dust risks on site.
Annually, around 3,000 workers in the construction sector suffer with “breathing and lung problems” they believe have been caused or made worse by their work.
While this equates to just 0.14% of workers in the sector, the rate is statistically significantly higher than for workers across all industries (0.08%). Almost 20% of workers reporting work-related respirator problems identified “dusts from stone, cement, bricks or concrete” as contributing to their condition.
Construction workers have a high risk of developing dust-related diseases because many common construction tasks can create high dust levels. More than 500 construction workers are believed to die from exposure to silica dust every year.
According to the Health & Safety Executive (HSE) dust is a general term used to describe different dusts that may be found on a construction site. There are three main types:
- Silica dust – created when working on silica-containing materials such as concrete, mortar and sandstone
(also known as respirable crystalline silica or RCS); - Wood dust – created when working on softwood, hardwood and wood-based products such as MDF and plywood;
- Lower toxicity dusts – created when working on materials containing very little or no silica. The most common include gypsum (for example in plasterboard), limestone, marble and dolomite.
Anyone who breathes in these dusts should know the health effects and damage they can do to the lungs and airways. The main dust-related diseases affecting construction workers are: lung cancers; silicosis; chronic obstructive pulmonary disease (COPD); asthma.
Some lung disease, including advanced silicosis or asthma, can come on quite quickly. However, most of these diseases take a long time to develop and have a high latency period. This means that dust can build up in the lungs and harm them gradually over time.
Number of dust and fume non-compliances 1 Jan-31 Dec 2016
Number of occupational health non-compliances 1 Jan-31 Dec 2016
The effects are often not immediately obvious. Unfortunately, by the time it is noticed the total damage done may already be serious and life changing. It may mean permanent disability and early death.
The amount of dust needed to cause this damage is not large. In 2015 scientists at the University of Surrey found peak concentrations of potentially harmful ultrafine particles reached up to 4,000 times local background levels when undertaking building activities such as drilling.
Inhalation of these particles is linked with serious cardiovascular and respiratory system related diseases, with ultrafine particles penetrating deeper into the lungs. The researchers also found that the greatest ultrafine particle emissions occurred during wall chasing (cutting grooves into a wall using an electrical tool, for example, to lay electrical cables).
Reductions in occupational disease in construction have also not kept pace with improvements in safety management. It is estimated that approximately 100 times as many people lose their lives from ill-health caused by working in construction compared to fatal accidents, so it is not surprising that the Health and Safety Executive (HSE) has made “occupational health” a focal point, with site blitzes expected to continue.
“A written health and safety policy is not enough. There must be efficient and effective procedures for occupational health and safety programmes to be successful.”
It also explains why the HSE is encouraging companies to work in partnership with organisations like the Building Safety Group (BSG) to help improve occupational health in the workplace.
The BSG is working with construction companies to improve occupational health management (OHM) by reducing the costs of managing ill health, sickness absence, and to prevent and remove health risks in the workplace. This should ensure that statutory responsibilities are met whilst helping construction businesses to maintain a healthy workforce.
You cannot manage what you have not measured. As far as health and safety is concerned this applies to every aspect of construction, from hazard identification to risk assessment and control.
Inspections carried out by BSG for construction companies provide a measure of the strengths and weaknesses for each site appraised. Combining the results for all companies highlights patterns and areas of health and safety in need of improvement.
In 2016 BSG conducted approximately 20,000 site inspections throughout the UK. From these inspections a total of 24,634 non-compliances were recorded (ref 1). A total of 3,966 occupational health-related non-compliances were recorded in 2016 and 33% of these were identified as dust and fume hazards.
By focusing on areas of non-compliance the inspections help to reinforce the management systems that control risk. Dust and fume management can be broken down into a series of steps:
- Identify hazards;
- Assess risks arising from those hazards;
- Control risks;
- Review and monitor to ensure effectiveness of controls and management systems.
These are explained in detail below.
Four steps to dust and fume management
Step 1 – Identify the hazards
The first step is to identify the substances that can potentially contaminate air. Examples include:
Dusts: Asbestos, silica-containing dust, wood and cement powder.
Fumes: Including diesel fumes and those arising from welding, brazing and soldering.
Vapours: From solvent-based paints.
Gases: Carbon dioxide, sulphur dioxide, nitrogen oxides and carbon dioxides from internal combustion engines.
One source of information is the label on the container. This will include a pictogram and some explanatory text.
The product safety data sheet will give you far more information. All product safety data sheets must have 16 sections that are laid out in the same way.
Examples of these sections are:
Section 2 Hazards identification. Usually, this will give a concise summary of the physical, health and environmental hazards of the product.
Section 3 Composition/information on ingredients. If the product is a mixture this section should list the hazards and percentage of each component.
Section 8 Exposure controls/personal protection. Advises on the controls necessary to reduce the risk from personal exposure.
Section 11 Toxicological information. Outlines health effects resulting from inhalation, ingestion, skin contact and
eye contact.
Section 16 Other information including the revision date. The date is important to ensure that you have an
up-to-date sheet.
Product safety data sheets will not necessarily cover hazardous substances generated as part of the process. Diesel engines, for example, emit a whole mixture of gases, vapours, liquid aerosols and particles. Diesel fumes are a class 1 carcinogen (ie a definite cause of cancer). But the product safety data sheet for diesel fuel will only give data on the health effects of the fuel itself and not diesel exhaust.
Step 2 – Assess the risk
The risk arising from a substance used in the workplace is made up of two components: the hazard; and the degree of exposure.
In the case of airborne contaminants the degree of exposure boils down to how much of the contaminant you are likely to inhale. Exposure depends on how much airborne contamination is caused by the work and the effectiveness of any controls already in place. Assessment may require measurement of the concentration of airborne contaminant for comparison against a workplace exposure limit (WEL).
Step 3 – Controlling risk
If a risk assessment shows unacceptably high levels of exposure necessitating additional control measures, in order of preference, the control options are:
- Eliminate the use of a harmful product or substance and use a safer one, such as formaldehyde-free medium density fibreboard.
- Use a safer form of the product, for example, use ready-mix mortar rather than dry cement to eliminate
dust exposure. - Change the process to emit less of the substance. For example, sweeping generates airborne dust so use a
vacuum cleaner if possible instead. - Enclose the process so that the product does not escape.
- Extract emissions of the substance near the source. For example, by using on-tool extraction when cutting stone with an angle grinder.
- Have as few workers in harm’s way as possible. For example, use job rotation to minimise “individual exposures”.
- Provide personal protective equipment (PPE) such as respiratory protective equipment when sawing or cutting.
The use of Respiratory protective equipment (RPE) should always be the last resort in the control hierarchy and should only be used if preferred options are not viable. For airborne contaminants RPE may be necessary.
It is important to stress that fit testing should be carried out only on clean shaven individuals. Facial hair can compromise the seal between face and mask. Nor is it any good shaving for the fit test and then allowing the development of even “designer stubble”. If found during an HSE inspection, this could result in a hefty Fee for Intervention (FFI).
Step 4 – Review and monitor
This step is important. For example, hazard ratings may change (diesel fumes moved up the hazard scale when its rating changed from class 2 to class 1 carcinogen). Where workers are exposed to high hazard materials health surveillance may be necessary.
HSE advice is to check the controls work by:
- Having procedures to ensure that work is done in the right way.
- Checking controls are effective. Does the work still seem dusty? You might need to carry out dust exposure monitoring.
- Involving workers. They can help identify problems and find solutions.
Maintaining equipment
- Follow instructions in maintenance manuals, regularly look for signs of damage and make repairs.
- Replace disposable masks in line with manufacturer’s recommendations.
- Properly clean, store and maintain non-disposable RPE. Change RPE filters as recommended by the supplier.
- Carry out a thorough examination and test of any on-tool extraction system at least every 14 months.
For those supervising workers, it is essential that they use the controls provided and follow the correct work method and attend any health surveillance where needed.
You may have to put a health surveillance programme in place. External audits such as BSG inspections help give an independent assessment of management systems.
A written health and safety policy is not enough. There must be efficient and effective implementation procedures for occupational health and safety programmes to be successful.
Importantly, the role of every person involved in ensuring the well-being of workers should be well defined and complement the efforts of the other towards a common goal of enhancing health and safety. Any programme which is implemented must also be constantly reviewed to help keep pace with changes in working practices which are often accompanied by new risks and hazards.
Introducing new procedures can be problematic if the company’s culture, behaviour and attitude towards health and safety is not ready to accept change. The most effective way to change behaviour is to improve knowledge and understanding; knowledge of the required health and safety practices to remain legal and compliant as well as understanding the consequences of ignoring them.
To encourage changes in practice it is vital that companies adopt a “top-down” approach to improving their safety management systems and health and safety culture. It is therefore critical for management to drive change and demonstrate their commitment, to increase the likelihood of adopting a safer company culture.
