Many working in the geotechnical industry are at risk from developing long term illnesses through exposure to silica dust but how can companies protect staff from one of the construction industry’s biggest killers?
The Health and Safety Executive (HSE) 2016/17 injury and ill-health statistics, published in November 2017, show exposure to harmful dust causes 12,000 lung disease-related deaths a year, many of them in construction. About 800 deaths are caused by exposure to respirable silica dust; second only to asbestos.
It should come as no surprise that geotechnical workers are at significant risk. Drilling, coring and breaking out concrete, brick and stone for boreholes and trial pits and when trimming piles, as well as installing new foundations in enclosed areas, such as basements, all generate silica dust.
Minimising the amount of dust produced, and controlling exposure to that dust (including for how long workers are exposed) is, of course, crucial. Control measures must keep exposure below the workplace exposure limit (WEL) of 0.1mg/m3 of respirable dust, averaged over eight hours.
Dust can be controlled by fitting water suppression devices to cutting tools to damp down dust and by using on-tool extraction systems. Operatives should also be provided with respiratory protective equipment, such as dust masks, and it is also important to ensure work areas are well-ventilated and regularly cleaned.
According to HSE’s Construction Information Sheet (CIS69) Controlling construction dust with on-tool extraction, extraction systems and vacuum cleaners must be high or medium class devices, because only these are capable of trapping more than 99.9% of dust with a particle size of less than two microns, such as respirable silica.
So, while standard domestic vacuum cleaners are sometimes used on site, they are only suitable for filtering lower-toxicity dusts, such as gypsum in plasterboard.
Eliminating dust entirely is, of course, extremely difficult. Respiratory protective equipment (RPE) must also be provided. RPE comes in all shapes and sizes, giving different levels of protection, from small disposable masks with filters, to those systems providing complete respiratory, head, eye and face protection, with power-assisted respirators or breathing apparatus.
RPE is given a filter classification, ranging from FFP1 to FFP3 (the highest level), which is equivalent to an Assigned Protection Factor (APF), denoting how much protection it offers. RPE with a FFP3 filter and an APF of 20 cuts exposure to dust by a factor of 20 and is the minimum requirement to protect against respirable silica.
Getting a good fit is critical, as poorly-fitting RPE is the biggest cause of leaks and, if it is not comfortable, workers may not wear it. COSHH requires face-fit testing and many suppliers sell kits to enable mask fitting to be checked properly before work begins.
it is not enough to just provide the minimum levels of protection to meet legal requirements, however. It is crucial that staff are educated in how they are potentially being exposed to harmful dust (including respirable silica), the implications of that exposure and what they should be doing to protect their long term health and wellbeing. This can be achieved through training, toolbox talks and regular checks and reviews during projects.
While improvements in RPE and vacuum technology mean geotechnical teams should be better protected than ever-before, lung disease remains a serious issue for the sector and the construction industry as a whole.
The HSE is clearly concerned: its latest construction inspection campaign, launched last October, focuses on the control of harmful dust, with a demand for proportionate, appropriate and risk-based advice from suppliers.
So, if companies are unsure of the level of protection required, they should seek advice from a specialist supplier that can offer independent advice on the best way to keep workers safe from harm.
- Damian Lynes is sales director at On Site Support