Silica dust: the site risk that shows up twenty years later

Construction safety records are built around events. A near miss happened, an incident happened, an inspection found something. Health risks do not produce events, which is why a site with an immaculate accident record can be doing serious long-term harm and have nothing on file that says so.

Respirable crystalline silica is the clearest case. It comes off concrete, brick, stone, mortar and tile whenever they are cut, ground, drilled or broken — which is to say, from most of what happens on a site — and it causes silicosis, lung cancer and COPD years after the exposure.

Why it is under-controlled rather than unknown

Nobody on site thinks silica is harmless. What happens is more ordinary than that: the control is a water suppression kit or on-tool extraction that is slower to set up than the job is to do, and the exposure produces no symptom anybody notices before the end of the shift.

• –A cut that takes four minutes does not feel like an exposure worth stopping for.
• –Water suppression needs a water supply, which the location frequently does not have.
• –On-tool extraction needs the right shroud for the right tool, and a part that has gone missing stops the control without stopping the work.
• –An RPE face-fit that was done at induction two years ago may no longer fit the person wearing it.
• –A subcontractor cutting outdoors is often assumed to be fine, and outdoors is not the same as ventilated.

Health surveillance is the part that gets skipped

Where exposure to a substance hazardous to health can cause an identifiable disease, and there is a valid way of detecting it, health surveillance is not optional. In practice it is the duty most often missed entirely on construction sites, because it has no site-level trigger.

It also belongs to the employer of the exposed person rather than to the site. On a job with twelve subcontractors that means twelve separate duties, and a principal contractor who has not asked about any of them has no idea whether they are being discharged.

Which makes it a question for subcontractor onboarding rather than for the site diary: what exposures does your work create, what controls do you bring, and who is doing your health surveillance.

What to put in the records

• –The exposure assessment behind the control, not just the control. A RAMS that says water suppression without saying for which task is not an assessment.
• –Which tasks on this job produce silica at all, decided at planning rather than at the cut.
• –Face-fit test records with dates, per person and per mask, and a prompt when they age.
• –Evidence the control was actually in use — the thing a photo in a site inspection record is good for.
• –Confirmation, per subcontractor, of who holds the health surveillance duty and that it is running.
• –Toolbox talks that name the disease rather than the dust, because the thing that changes behaviour is the consequence.

The reason to hold all of that is not only the worker. It is that an occupational disease claim arrives a decade after the project, when the site team has dispersed and the only thing left is the file — and a file that cannot show what the controls were cannot show that they were adequate.

Exposure limits, control expectations and the health surveillance threshold are HSE's and move with its guidance. Check the current position with the pages below before setting a standard on a live job.