Silica Dust 101 – What It Is and Why It’s Harmful

Tony Ferraro | March 31, 2014

Silica is a common sedimentary component of rocks, sand, and other natural earth materials. In its purest form, it is most often seen as quartz, but it exists in many other types of materials. As one of the basic building blocks of many rocks (in fact, silicon, which makes up silica, is the second most abundant element on earth next to oxygen), silica itself is not at all harmful to the human body. The danger from silica, then, come from its being chipped or crushed into a particle dust that is fine enough to become airborne, and then inhaled. Silica then causes a threat in both being carcinogenic (cancer-causing) and physically abrasive (causing scarring in the lungs). Health complications can be both long-onset and acute, and are not always properly diagnosed, with an estimated thousands of cases going undiagnosed or misdiagnosed every year.

According to Silica-Safe.org, there are between 3,600 and 7,300 new confirmed cases each year in the United States alone, with only two states having comprehensive programs to keep track of cases accurately. As an employer, it can fall under your responsibilities to keep your workers safe from silica dust inhalation in the same way you work to protect them from other hazards. Before we get into that, let’s take a closer look at the exact health risks and complications crystalline silica inhalation can be responsible for.

Associated Health Complications

One of the hardest things about raising awareness for the seriousness of silica exposure, also called silicosis, is that victims can remain symptomless for years (sometimes for over a decade). When symptoms do present themselves, they are usually in the form of chronic coughing, chest discomfort, and trouble breathing which can range from mild to severe. When investigated via x-ray scans, silicosis presents itself as small, white nodules on the patient’s lungs – normally concentrated in the upper regions. Additionally, those with silicosis might exhibit fever, chest pain, ongoing fatigue, and weight loss/loss of appetite. Consequences vary as well with the type of silicosis presenting itself:

Acute Silicosis: Acute silicosis will develop anywhere from just a few weeks to five years after one is exposed to breathable silica. In order for the onset of acute silicosis, exposure concentrations must have been high and sustained. Unfortunately, this form of silicosis often leads to death and the common symptoms, trouble breathing, etc., are presented in their most severe forms. As safety is improving, we are likely to see less and less acute cases.

Accelerated Silicosis: Accelerated silicosis occurs five to ten years after the initial exposure. Concentrations necessary to bring about accelerated silicosis are medium to high, and will generally progress at a slower rate than its acute counterpart. While symptoms present, they may not be as obvious or may go unreported for longer due to their not inhibiting day to day life.

Chronic Simple Silicosis: With this variety of silicosis, workers can be exposed to relatively low concentrations of silica dust for over ten years before the condition properly forms. This form is the slowest developing and most common variety of silicosis, and most people might not know they have the condition before they’ve carried it for years. It is usually detected by x-ray only after initial symptoms have presented.

Complicated Silicosis: Silicosis can lead to easier infections and the development of other lung-related diseases, and when this happens it becomes known as “complicated silicosis.” Whether a result of the silicosis or just chance, the development of another condition can compound the silicosis symptoms and their severity. Complicated silicosis is more common when the patient suffers from acute or accelerated silicosis, rather than chronic.

Unfortunately, no matter the type, silicosis is a permanent affliction and has no known cures. Treatments can help to alleviate symptoms, but that’s about it. For this reason, being proactive and preventative in avoiding silica exposure is key.

How Silica Exposure Occurs

In the workplace, silicosis is extremely common among contractors and construction workers. Because concrete, rocks, sands, and other common building materials contain silica, airborne particles are common when these substances are poured, crushed, cut, or drilled. Another common exposure risk is through sandblasting (in the removal of paints and finishes, for example). Tunnel workers are also at an extremely high risk due to their work directly involving the disturbing of silica-containing earth. In non-construction settings, the same risks apply and are common in manufacturing in which stone and similar materials are used. Warehouses and lumberyards stocking cement, concrete, and other powered mixes also put workers at risk, especially if bags or packaging becomes ripped open. Additionally, silica can be found in a number of household substances ranging from glass, to paint, to soaps, to commonly-used adhesives (though these compounds may be less likely to contain free-floating particles that can be inhaled). While modern safety measures and personal protection equipment have helped to reduce incidence rates, the disease is still common (though many cases may be “sleeper” instances in which symptoms have only now occurred after exposure has long since passed).

What Employers Can Do

According to Silica-Safe.org,

Planning is key to reducing exposures and protecting workers. Before work begins, an employer should create a job-specific plan that identifies the materials and tasks that could expose workers to silica dust, the equipment and controls that will be used to control the dust and prevent exposures, and the employee onsite who will make sure the silica plan is followed. In addition, the employer should train all employees…

-silica-safe.org – FAQ on Silica Safety

In addition to rigorous training and planning, the best thing employers can do to immediately reduce or eliminate worker exposure to crystalline silica is to find safer substitutes to use in their manufacturing and/or construction processes. Crushed glass without silica and other materials can be substituted for certain gravel and filler mixtures. For contractors and their workers specifically, buy pre-cut surfaces such as counter tops, facades, and stone wall materials when possible, rather than having to custom cut them later on to fit fixtures. This means your own workers don’t have to release silica crystals in the process of cutting.

Of course, when exposure is unavoidable, it should be mitigated as much as possible by the use of proper personal protection equipment. Depending on exposure level and type, this can range from simple face masks to full respirators in order to filter air of any dangerous particles. In addition to breathing apparatuses, temporary clothes or disposable work suits should be worn; if dust clings to an employee’s clothes they might be putting themselves at risk after they leave the job site and take off their mask, especially when getting into their car to head home, an act which simultaneously unsettles dust and puts them in an enclosed breathing space. Lastly, employers should use PPE signs or a face mask required sign to communicate to employees to wear proper PPE when working in hazardous areas.

As with all ailments, treatments for silica exposure are being constantly developed and researched, but for the time being the best solution by far remains taking preventative measures. Encourage employees to do their part as well, by washing their hands after handling silica-containing materials and again before eating or drinking; they should also commit to wearing proper PPE at all times. Good luck!

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Additional Resources

Safety Solutions | PPESafety
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