Silica dust

Silica dust

Silica is a naturally occurring mineral found in varying amounts in most rock, sand and clay, as well as products like bricks and concrete. Sandstone contains more than 70 percent silica, while granite contains 15-45 percent silica.

These products create dust during many common construction tasks, such as cutting, sanding or grinding. Some of this dust, known as respirable crystalline silica is fine enough to get deep in to your lungs. It is also known as silica dust.

There is widespread knowledge about the risks of asbestos to construction workers, but did you know that silica is the next biggest risk to construction workers?

The amount of respirable crystalline silica you need to breathe in to cause damage to your lungs isn’t large, and the associated health risks are entirely preventable with the right controls in place.

You could develop a number of lung diseases including a type of pneumoconiosis known as silicosis, chronic obstructive pulmonary disease (COPD) and lung cancer.

COPD is a group of lung diseases including bronchitis and emphysema which cause breathlessness, prolonged coughing, chronic disability and even death.

Lung cancer can be caused by heavy and prolonged exposure to respirable crystalline silica. If silicosis is already an issue then there is a greater risk of developing cancer.

Silicosis can cause severe breathing problems and increase your risk of lung infections. Silicosis normally occurs after exposure to respirable crystalline silica over a number of years, however very high exposures can cause acute silicosis in a much shorter period of time. 

When it happens over a number of years, it is usually because silica dust is entering the worker’s breathing zone and therefore it is regularly breathed in, even small amounts of dust can be harmful. This builds up over time and causes damage to your lungs. The best way to prevent this damage is to stop the dust getting into the air. If it’s not airborne it is much harder to get it in to your lungs.

The most effective ways of doing this are with water suppression or dust extraction, either with an appropriate vacuum or local exhaust ventilation fitted to the hand-held equipment. It’s really important to use enough water for the duration of the work. The dust is continuously produced and therefore continually needs suppressed with water during this period.

Click on the following links to to watch two video clips; with water suppression and without water suppression:

With water suppression

Without water suppression

Using a power tool fitted with on-tool extraction, when used correctly will help minimize your exposure to airborne respirable crystalline silica. A vacuum fitted with an appropriate HEPA filter will also help reduce your exposure if used correctly.

Your employer must comply with the COSHH Regulation (NI) 2003. 

A COSHH risk assessment should be carried out before you start any work. You will also need to be face fitted for an appropriate filtering facepiece or mask to help protect you from breathing in the fine silica dust, if it can’t be controlled using other control measures. It’s important to remember that personal protective equipment (PPE) and respiratory protective equipment (RPE) should never be your only form of control when undertaking any sort of hazardous activity. It is there as your last form of protection should a more effective control method fail unexpectedly. Your reusable half mask/disposable mask should always be checked before use and worn appropriately. Check it is in good condition and fits correctly. You should also make sure it is cleaned, stored appropriately and properly maintained if it is a reusable mask.

Understanding what your employer is telling you and asking questions is essential. Ask if the material you are working with contains silica.

Ensure you ask how to do the job safely without putting your health at risk.  Follow all the correct procedures and make sure to use any controls that are in place appropriately. Wear appropriate protective clothing and use equipment correctly.

Never ever dry sweep

This only raises the dust back into the air where it could potentially be breathed in by you or others. It must be adequately damped down or vacuumed away using a vacuum with a HEPA filter. Never use compressed air to blow away dust from clothing or the work area, as this can result in further exposure to silica dust.