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When most of us think of hazardous materials, we tend to picture poisonous gases or other substances we wouldn’t want to go near. However, there’s a hazardous substance that many workers are exposed to on a daily basis that doesn’t look hazardous at all. It looks like common materials such as bricks or stone, and it’s called silica.
We’ll cover this common substance, the potential dangers of it, how you can stay safe and how you can comply with the regulations set forth by the Occupational Health and Safety Administration (OSHA) now.
What Is Silica?
Silica, also called silicon dioxide, is a family of minerals with the chemical formula SiO2. It’s one of the main components that make up the earth’s crust and abounds in a variety of natural, everyday materials. It comes in two basic forms: noncrystalline and crystalline.
- Noncrystalline: Another term for a noncrystalline solid is amorphous. Unlike crystalline solids, amorphous solids are not made up of defined, rigid shapes. Noncrystalline silica is found in materials like silicon carbide, glass and silicone. This type of silica is not as much of a health concern.
- Crystalline: Crystalline silica is more of a health concern than noncrystalline. It’s most prevalent in the form of quartz. This natural substance is found in many different types of rock and building materials, such as sand, gravel, granite, sandstone, clay, concrete, asphalt, bricks and more.
Another term you may hear is “respirable crystalline silica.” This term means the silica particles are small enough that you could inhale them. Consider the difference between sand particles on the beach that do not become airborne and tinier specks of dust that can easily settle in your lungs. These silica dust particles are 100 times smaller than granules of sand. In this article, we’ll be focusing on respirable crystalline silica since it’s the material workers should be concerned about when it comes to their health.
What Are the Hazards of Silica?
You may be wondering how something so common could be hazardous. After all, people interact with materials that contain silica every day. Whether you’re building a sand castle or constructing a house, your hands are coming into contact with silica. The reality is that materials containing silica are not dangerous in and of themselves, which is why they’re not hazardous to hold and work with. That said, if you inhale silica particles, it can be hazardous to your health.
Silica dust particles enter the air when you saw, grind, drill or otherwise cause a material to shed dust. Unlike normal dust, which will likely do no more than make you sneeze or get you a little dirty, silica dust — also called respirable crystalline silica particles — can cause more serious problems. These problems tend to develop over time, making silica a quiet, insidious threat.
People who inhale silica may experience a number of serious health complications, including the following.
The danger most associated with silica is silicosis. This disease is directly related to inhaling silica dust. As the dust enters into the lungs, it causes scar tissue to form. This tissue makes it hard to breathe properly and get all the necessary oxygen.
Even moderate exposures to respirable crystalline silica can cause a person to eventually develop silicosis. It usually takes about 15 to 20 years of occupational exposure to silica dust before silicosis develops, though a person could develop silicosis more rapidly if they were exposed to a high level of silica dust. If the condition develops within 10 years, it’s called accelerated silicosis. If it develops within a few years or less, it’s known as acute silicosis.
When a person develops chronic silicosis — meaning it takes a decade or more since the initial exposure — they may not notice obvious symptoms. It can happen subtly. Sadly, silicosis can lead to other health complications and can even be fatal. There is no known cure, so prevention is key.
2. Lung Cancer
Multiple studies have shown an unmistakable relationship between exposure to silica dust and the risk for lung cancer. Silica dust causes the lungs to scar, and this scarring can lead to lung cancer. A person develops lung cancer when abnormal cells multiply in their lungs and form tumors.
Cancer can start in your lungs and travel, or metastasize, to other areas of your body if it isn’t caught early. Lung cancer isn’t the only type of cancer a person could get from exposure to silica either. Studies also show that a person who has breathed in silica particles is at an increased risk of developing esophageal, stomach and skin cancer.
3. Chronic Obstructive Pulmonary Disease (COPD)
Chronic Obstructive Pulmonary Disease, usually shortened to COPD, encompasses several diseases that affect the lungs, the most common of which are emphysema and chronic bronchitis.Emphysema is the issue a person experiences when the tiny air sacs in the lungs, known as alveoli, are severely damaged by the individual inhaling harmful gasses or particles, such as cigarette smoke or silica. Chronic bronchitis involves inflamed lining of the bronchial tubes that carry air to and from the alveoli, again from inhaling harmful substances.
A person with COPD typically experiences shortness of breath, wheezing and coughing. COPD is typically irreversible and may only get worse. However, it is treatable with the proper medication and management.
4. Kidney Disease
Another health complication a person could experience from being exposed to silica is kidney disease. There are two types of kidney disease: acute an chronic. Acute kidney problems are caused by something sudden, like an injury. In the case of silica exposure, you have a risk of suffering chronic kidney disease, which develops over time rather than suddenly. One clinical study revealed that the longer you are exposed to silica, the greater your chance of developing chronic kidney disease is.
Your kidneys have the important job of filtering waste and excess water out of your blood, so when you have kidney disease, you may have to take certain medications. In the later stages of kidney disease, the kidneys shut down entirely. In this case, the only course of treatment is dialysis.
What Industries Deal With Silica?
Since silica is abundant in so many materials, a wide range of industries may be exposed to it. Because it’s only a hazard when it becomes airborne due to activities like grinding or sawing, it affects some industries more than others. The following industries all deal with silica and should, therefore, be on their guard against its hazards:
- Stone quarry
- Ceramics, clay and pottery
- Concrete mixing and tunneling
- Rolling and finishing mills
- Rail-track setting, laying or repairing
Of all of these industries, construction tends to get the most attention, and rightly so. Nearly countless activities and tasks within the construction industry involve silica. Consider the fact that building materials like bricks, concrete, stone and more all contain silica. Every time a worker saws, drills, grinds, jackhammers, mills, crushes or sands one of these materials, silica dust quickly becomes a problem.
We’re going to focus on the construction industry, though it’s important to understand that silica exposure can affect a wide range of industries. Construction workers, however, tend to have the highest risk of experiencing health problems from inhaling silica on the job. As we’ve seen, these risks are serious, so it’s important to understand how you can stay safe, even when you’re in an industry where silica dust is prevalent.
How Can You Prevent Silica Exposure?
Once you understand the hazards of silica and how prevalent it is in some industries, you’ll want to focus on how to prevent silica exposure. Understanding which types of activities and materials can expose you to silica is the first step. Now you know to be cautious when doing something like drilling into concrete or sawing stone, for instance. The good news is that even when you’re performing a task sure to create some silica dust, there are ways you can protect yourself.
Let’s look at some respirable silica exposure prevention tips to help you stay safe on the job:
- Replace materials: One tip is to swap out materials that contain crystalline silica for other materials that don’t. For abrasive blasting, OSHA has a long list of silica-free materials to consider. That said, substituting materials may not always be a valid option, which is why we have other tips.
- Avoid wearing work clothes home: Clothing can hold onto a lot of silica dust, so when you’re ready to head home, you should change out of your dusty work clothes and into clean clothes. If you can’t change, vacuum as much dust from your clothes as possible.
- Use water spray: Keeping materials wet is a great way to keep dust at a minimum. Using a water spray can help you keep a material like concrete from throwing up an abundance of dust when you cut into it. Note that wet methods are not safe around electrical equipment.
- Take advantage of an LEV: A local exhaust ventilation (LEV) is a piece of equipment that can hook onto other pieces of equipment you use that may produce silica dust. An LEV vacuums up the dust closest to its source, eliminating the chance for these particles to become airborne.
- Stay away from dangerous activities: When you’re working and know silica dust is present in the air, you should not eat or drink in the area. You also shouldn’t smoke or even apply lip balm. If you need to do any of these things, leave the dusty site and wash your hands and face first.
- Wear a respirator: A respirator is a device you can wear that controls what you inhale from the air. In some cases, OSHA requires respirator protection. However, wearing a respirator should be seen as a last resort if you can’t otherwise avoid being exposed to a high level of silica.
What Are the Regulations for Workplace Silica Exposure?
It isn’t just a good idea for employers to protect their workers from crystalline silica exposure — it’s a legal requirement. The Department of Labor has been concerned about the hazards of silica for workers since as far back as the 1930s. For the past several decades, OSHA has published and updated regulations regarding silica exposure, including an official permissible exposure limit (PEL) and methods for protecting workers.
Currently, OSHA has two official standards regarding silica in the workplace. One is specifically tailored to the construction industry, and the other applies to general industry and maritimecontexts. Both standards share the same PEL and many other requirements. The PEL in every case is 50 μg/m3, which means an employee should not be exposed to more than 50 micrograms of silica per cubic meter of air averaged over an eight-hour work shift.
As much as possible, you should shoot for keeping silica exposure closer to the action level, which is half of the PEL: 25 micrograms per square meter. The PEL of 50 micrograms is extremely low, and the action level is significantly lower. Over the years, OSHA has lowered the PEL and action level, as it’s become more apparent just how dangerous silica can be.
Both standards don’t just stop at specifying a permissible exposure limit. They also require employers to take action by:
- Writing and implementing a plan to minimize silica exposure
- Employing methods such as the ones we discussed in the previous section to control silica dust as much as possible
- Training workers on the best ways to protect themselves from silica exposure
- Providing medical exams, including chest X-rays and lung-function tests, every three years to workers who have been exposed to silica over the action level for at least 30 days a year
- Keeping reliable records of the level of silica workers have been exposed to and any related medical exams or treatment
Not complying with all aspects of the OSHA standards can result in some hefty fees. It’s understandable that OSHA is concerned with enforcing their standards since, as we’ve seen, too much silica exposure can cause serious problems for workers.
How Do You Test the Air for Silica?
To determine silica levels, you must test the air. The most reliable way to do so is to hire a certified specialist to conduct testing. The specialist should place sampling devices on multiple employees or on just one, which will collect respirable silica dust in the air over the course of the worker’s eight-hour shift. The device uses a cyclone assembly and a sampling pump to collect the dust. Make sure you don’t alter your work practices when you’re being tested — you want accurate results.
After the eight-hour period has passed, the specialist, who is typically an industrial hygienist, will come back to turn off the sampling pumps and send the filters to a lab to be evaluated. Make sure you use a laboratory with a history of quality work and reliable results. The lab should report the amount of silica that workers are currently being exposed to so you know whether you’re staying safely under the PEL or need to implement more protection measures.
Hazmat School — Your Source for Silica Certification
You need to be silica-certified if you want to avoid OSHA fees and stay safe. Whether you’re an employee concerned about protecting yourself on the job, a human resources manager worried about being silica-certified or any other person who cares about making the world a safer place by protecting yourself and others from respirable crystalline silica exposure, reading this article is just the beginning.
The next step is to take a training course that delves into the details and provides you with the certification to prove that you have been trained, according to the OSHA requirement, on the hazards of silica and best practices for prevention. At Hazmat School, you’ll find all the courses you need to stay safe on the job and get the certification you require.
Both our OSHA’s Silica in Construction Course for Exposed Workers and OSHA’s Silica in Construction for Competent Persons online training courses are packed with helpful information you need to know to stay safe and up-to-date on OSHA’s standards. If you have questions about how Hazmat School can help, contact us today to learn more.
Manages Hazmat School’s E-Learning courses and blog. Kirstie has extensive experience in the online training and education industry. Kirstie has worked with courses that offer a variety of safety and environmental certifications that satisfy OSHA, EPA and DOT requirements.