While dangers such as asbestos have been phased out of construction, many of the industry’s biggest risks are still under-appreciated. A macho culture and frustration with the ‘red tape’ of safety legislation can lead to corner-cutting, ‘common sense approaches’, and a lack of awareness about previously common practices that are now deemed to be unsafe.
Chief amongst these is the danger of silica dust, and the potential for respiratory illness in construction workers. While respirable dust is a major cause of illness within the industry, there remains a gulf in the knowledge of why it is dangerous, how the illnesses are acquired, and how to prevent them from occurring. While many businesses have now wised up, some are still directly contravening OSHA guidelines, and harming their employees in the process.
Effects of RCS
We’re all well aware of the dangers of asbestos, and the legacy its use has left in construction. Its use in everything from insulation to gaskets to toilet seats will continue to contaminate brownfield sites and older builds for decades, while many houses around the world still feature asbestos-containing textured walls and ceilings. In the US, asbestos continues to be manufactured and imported today, although its use is better controlled than the post-war period.
What’s less well appreciated is the danger of respirable dust, such as you might encounter everyday on most building sites. While many forms of dust pose some danger to health - flour and wood dust can exacerbate and even cause occupational asthma - the most dangerous form is respirable crystalline silica (RCS) dust. RCS is derived primarily from stone, but is present in concrete, mortar, slate, brick, limestone, marble and other materials.
Much like asbestos, these materials are perfectly benign when left alone, though they are less easily damaged than asbestos on the whole. The danger comes when they are disturbed and destroyed in a manner that creates dust, visible or not. Common scenarios include:
The nature of RCS dust is such that the finest dust can cause the greatest harm. These microscopic rock particles are jagged-edged, and cause substantial damage when they become lodged in the recesses of your lungs. This damage forms scar tissue over time, which can subsequently develop into cancerous cells. Being outside does not inherently protect you from exposure to RCS dust or any other form of contaminants.
The most common lung condition for people affected by RCS is called Silicosis, and results in impaired lung function. This damage is irreversible, and can increase the likelihood of developing diseases such as tuberculosis, kidney disease and arthritis. Acute silicosis can develop from high RCS intake over a very short period, and has dramatic, lifelong complications.
After a lengthy period of consultation, OSHA has recently introduced two new standards for the construction and general industries. The new permissible exposure limit (PEL) for construction is 50µg/m3. This halving of the previous limit is the first change to the RCS PEL in more than forty years. Most other countries, including the United Kingdom, still adhere to the 100µg/m3 standard. The UK’s Health & Safety Executive has stated that this is because 100 is a more reachable standard, with evidence that many companies do not even come close to this.
Controlling RCS dust
The HSE’s slightly defeatist approach ignores the fact that there are many viable ways to greatly reduce RCS exposure, if not eliminate it altogether. The benefits of doing so are not just to avoid litigation, of course. Setting an example by properly protecting your workers has the potential to improve your reputation, making it more likely that talented tradesman will want to work with and for your company.
A key first step is to eliminate opportunities for exposure through design. Proper planning should minimise the need for cutting or drilling of concrete and masonry on site, with pre-built recesses or even different materials. Comprehensive risk assessments should also be carried out, with information relayed to workers ahead of time. Online safety training for workers may be beneficial in order to communicate the dangers of RCS, as well as best practices for identification and control.
Different tools can be used to assist in RCS dust extraction, depending on the nature of the site. For static sites, dust extraction vacuum pipes or arms can be attached to either powerful freestanding units, or more systemic extraction systems. On a more typical building site or project, small extraction units can be applied directly to many tools, allowing for functional extraction at the point of release.
These tools should also be complemented with properly supplied and applied respiratory protective equipment (RPE). Steps must be taken to ensure that this gear is properly fitted, with allowances in purchasing made to accommodate every employee; female employees for example often require PPE and RPE with a different fit. Face fit tester training can provide workers with the skillset to carry out this fitting properly, and ensure that the PPE or RPE is effective.
Where possible, dust release should also be controlled by wetting or dampening the dust, allowing it to be more easily contained and captured. New foam suppressors are far more efficient than traditional water suppression systems, although these are often more viable for portable use. Automated systems can also be fitted to vehicles such as tankers and trucks, preventing dust from being dispersed by wind and movement.
Dust suppression and prevention need not be a dramatic expense for your business, and produce numerous benefits in the long run, namely a healthier and more productive workforce. Striving for a dust free site will put you ahead of the curve, ensuring that you remain fully OSHA or HSE compliant while also satisfying your employees and clients.