Silica Dust Exposure: What Employers Must Do

• Silica dust exposure can lead to serious health issues like silicosis, COPD and lung cancer, making risk management essential.
• Employers must comply with multiple regulations, including COSHH and CDM, to control silica dust risks.
• Risk assessments and implementing the hierarchy of controls are critical for managing exposure.
• Training, information and health surveillance help protect workers from the long-term effects of silica dust exposure.

Silica is a naturally occurring mineral found in stone, sand and clay, which means it’s in most construction materials, including:

• Marble
• Brick
• Slate
• Granite
• Concrete
• Sandstone

When construction materials containing silica are cut or processed, silica dust is released. This dust is known as respirable crystalline silica (RCS).

RCS particles are tiny (the average particle is finer than a human hair), which makes them impossible to see with the naked eye. It also means they can be inhaled inadvertently.

After inhalation, RCS particles become embedded in the pleura – the soft tissues lining the lung. In response, special cells known as macrophages swarm the embedded particles in an attempt to flush them out.

However, silica dust is difficult for the body to deal with. If exposure levels are high enough, lung tissues will be permanently scarred and the immune response RCS triggers will actually damage cells. Over time, this can cause a range of respiratory illnesses, such as:

• Silicosis – A progressive condition that causes chronic coughing, shortness of breath and potentially respiratory failure.
• Chronic Obstructive Pulmonary Disease (COPD) – A group of lung diseases that includes bronchitis, emphysema and asthma. All diseases make it difficult to breathe and can also cause respiratory failure.
• Lung cancer – Silica dust exposure is known to increase the risk of developing lung cancer.

Each of these conditions also develops over time, making early diagnosis difficult. This can also lead to a false sense of security. Workers who breathe in RCS won’t immediately become sick or even notice until it’s potentially too late.

Anyone who works with or around materials containing silica is at risk. Construction workers are the most vulnerable group, but professionals in demolition, mining and masonry are also at risk.

RCS can also harm people who work with ceramic tiles or worktops, particularly if they use artificial products that contain higher concentrations of silica.

Even a small amount of RCS can cause health problems, but workers who are regularly exposed are in the most danger.

As a recognised health risk, employers must control silica dust exposure.

Your duties to keep silica dust within safe levels are spread out across multiple pieces of legislation.

The Health and Safety at Work Act 1974 (HSWA) creates the legal framework for occupational health and safety in the UK.

Under the HSWA, employers must ensure a safe working environment and protect staff from work-related risks.

The HSWA also sets duties for employees. They must also follow agreed procedures and take reasonable steps to protect themselves while working.

The Management of Health and Safety at Work Regulations 1999 were passed in support of the HSWA and set out in more detail what employers must do to ensure safety.

Your first and most important duty is to carry out a workplace risk assessment to identify hazards that might cause harm and plan how to eliminate or manage them.

Risk management also includes providing workers with the necessary information, training and equipment to do their jobs safely.

The Control of Substances Hazardous to Health Regulations (COSHH) establishes what employers must do to protect workers from “hazardous substances” – a category which includes RCS.

COSHH reinforces the duty to assess and manage RCS risks. It also sets the allowable silica dust exposure level, known as the workplace exposure limit (WEL).

The Construction (Design and Management) Regulations 2015 (CDM) apply to all construction work.

CDM splits construction work into different phases. At each phase, hazards must be identified and subsequently eliminated or managed.

During the design phase, silica hazards should be anticipated and avoided, for example, by using materials that contain low levels of silica.

During the construction phase, any remaining silica risks must be assessed and managed.

Meeting your duties to control silica dust exposure depends on your risk assessment.

A risk assessment is a systematic evaluation of workplace hazards and how they can be managed. Regardless of the hazards involved, a risk assessment follows five key steps:

1. Identify the hazards
2. Evaluate the risk
3. Decide on risk controls
4. Record and share findings
5. Review

Start by identifying situations where workers might breathe in RCS. Look at the silica-containing materials in your workplace and the tasks they’re used for.

If you’re unsure which products contain silica or how much, refer to material safety data sheets. You can also seek advice directly from manufacturers or suppliers.

Once you’ve identified RCS hazards, you must evaluate the risk of them causing harm.

Workers who regularly come into direct contact with silica-containing materials for longer durations are more likely to breathe in RCS, so they’re at greater risk.

Risk levels also vary depending on the work being done. The more energy involved, the greater the risk. High-energy processes such as grit blasting and grinding create much more RCS than low-energy work such as hand sawing.

You must also consider the environment in which work is done. Enclosed or poorly ventilated areas increase exposure levels. Working outdoors is safer but does not eliminate the risk.

The next step is to implement risk controls to eliminate or reduce the threat of RCS. You should follow the standard hierarchy of controls for this:

1. Eliminate the risk
2. Reduce the hazard
3. Use engineering controls
4. Use safe systems of work
5. Use respiratory protective equipment (RPE)

Applying this hierarchy to silica dust exposure might involve the following:

• Eliminate – Using alternative materials or processes that don’t produce RCS.
• Reduce – Use materials with lower silica concentration.
• Engineering controls ­– Use local exhaust ventilation (LEV) to capture and remove silica dust at the source.
• Safe systems of work ­– Implement a regular cleaning schedule to prevent the build-up of silica dust.
• RPE – Provide all workers at risk with suitable respiratory protective equipment.

The aim is to make work as safe as “reasonably practicable,” which essentially means the cost, effort and time of implementing a control measure should match the risk level. For example, removing all power tools from your workplace would significantly reduce the risk of silica dust exposure, but it would also flatline productivity. So, it wouldn’t be considered reasonable.

But don’t forget safety is still the priority. You must follow the hierarchy of risk controls and explore all your options at each level before moving on to the next. Control measures can also work together. For example, using materials with low silica will help, but you might also need an LEV system to fully reduce exposure to safe levels.

You must report risk assessment findings to your workers. They need to be aware of the hazards they face and how you’ve protected them.

Any information or training necessary to use control measures (such as RPE) or follow agreed policies must also be provided.

Conditions linked to RCS aren’t immediately noticeable. Depending on exposure levels, they develop over weeks or even years.

If you oversee high-risk activities and workers are regularly exposed to RCS, health surveillance must be provided.

If you’re responsible for workplace safety, our online Silica Dust for Duty Holders training course will equip you with the tools to confidently manage silica dust risks and keep your workers safe. It provides comprehensive guidance on identifying silica hazards, assessing risks and implementing control measures to keep exposure within safe levels.