Rick was an outstandingly active teenager, playing soccer and running cross country. He thought he was invincible, as most young people think.

He started working as a bricklayer at 16—following in the footsteps of his father. Twenty years later, he was given a project to repair a large brick apartment building. It required breaking and cutting the old brick and replacing it with newer brick and cutting expansion joints into the building.

After working 6 months repairing the apartment building with just a paper mask and no other dust control measures, Rick noticed he had some difficulty breathing.

One day to his surprise, as Rick and his wife were walking home from the grocery store, he found that he was breathless and having chest pains. He had to sit down on the pavement because he just couldn’t breathe. He was also fatigued and had lost a significant amount of weight.

He had always been an active person. Hiking with his wife and playing soccer with his children were common family activities. But now, at just 38, he couldn’t walk up the stairs without losing his breath.

He knew something was wrong—he was not able to be as active as he had always been, and he was still young man.

When Rick went to the doctor, he was devastated to learn that he had a permanent, debilitating lung disease called silicosis.

Rick’s story is not an isolated one. Every year, more than 250 workers in the United States die from silicosis, an incurable, progressive lung disease caused by overexposure to dust containing silica. Hundreds more become disabled by this disease.

Health Effects of Respirable Crystalline Silica

The hazards of exposure to silica dust have been known for thousands of years. Respiratory problems from breathing silica dust date back to the Greeks and Romans. But with the invention of powerful stone-cutting tools in the 19th and 20th centuries there’s been an increase in workers developing silicosis and other lung ailments. The U.S. Department of Labor first highlighted the hazards of respirable crystalline silica in the 1930s, after a wave of worker deaths.

But it’s not just silicosis that we need to worry about. Inhaling crystalline silica dust can lead to other serious, sometimes fatal illnesses, including lung cancer, tuberculosis, and chronic obstructive pulmonary disease, or COPD. In addition, silica exposure has been linked to other illnesses, including renal disease and other cancers.

This training session will cover everything you need to know about respirable crystalline silica and how to protect yourself and others each day on the job.

How Much Do You Already Know?

Before we go any further, let’s see how much you already know. But don’t worry, we will be going over all of this and more throughout the session.

– True or False—The respirable crystalline silica rule for the construction industry requires employers protect workers from exposure to respirable silica dust.

That is True.

– True or False—Unless the dust is visible, it is not harmful.

That is False.

– True or False—Silicosis is irreversible.

That is True.

– True or False—Silica exposure can lead to a variety of health problems, including lung cancer.

That is True.

What Is Respirable Crystalline Silica?

Silica, also known as silicon dioxide, is a chemical compound that is made of the most common elements on earth, silicon and oxygen. It’s also the most abundant compound in the earth’s crust.

You’ll find silica in a lot of places. The most common form is quartz, a component of stone, concrete, sand, and the brick that Rick worked with. Simply put, silica is everywhere. If you’ve touched a rock or been to the beach, you’ve handled silica. But don’t worry—it’s not harmful when in the form of sand or rocks or even brick. Materials that contain crystalline silica are not hazardous unless they are broken into very small-sized particles that you breath into your lungs—this is called “respirable crystalline silica.” Respirable silica is created through many common activities in construction, like blasting, cutting, chipping, drilling, and grinding of materials that contain silica.

In Rick’s case, the lung doctor said that it was clear from Rick’s description of his work life that he had been exposed to significant amounts of silica dust over the years. But the brick apartment building project exposed him to the most because the older bricks he was cutting contained large amounts of crystalline silica.

Recognizing the Danger

As you can now understand, many common construction materials contain silica, and these materials are safe as they lie. But recognizing the danger is key. You can be exposed when sandblasting, cutting, grinding, or drilling any material that will release dust that can be inhaled—as it happened to Rick. It only takes a very small amount of fine respirable silica dust to create a hazard. And actually, if you can see the dust you can bet that you’ve exceeded the permissible exposure limit, or PEL.

OSHA’s Silica Rule

The Occupational Safety and Health Administration’s, or OSHA’s, permissible exposure limit, or PEL, is the legal limit that workers can be exposed to a hazardous substance, such as silica.

OSHA’s crystalline silica rule establishes a permissible exposure limit for silica and sets measures that your employer needs to take to significantly reduce the amount of silica dust that you are exposed to on the job. The rule also requires that your employer train you about the hazards of respirable silica, the jobs at the worksite that could possibly expose you to silica dust, and the steps your employer is taking to protect you from the dust.

Unfortunately, like Rick, many construction workers are unaware of the hazards of silica. That’s why the rule requires that your employer train you about them.

Where there are jobs that involve the possible release of silica dust into the air, employers are required to monitor the air, implement engineering and work practice controls, and select the proper respiratory protection, if needed, to protect you.

But you, as workers, also have responsibilities. You have to read the labels and safety data sheets, or SDSs, for the products that contain silica, and you need to participate in the required training so that you know how to perform your jobs safely.

By taking the right steps, you can reduce the possibility of your being exposed to silica dust. This is something Rick didn’t do.

Exposure in Construction

Let’s now take some time to discuss some construction activities that cause silica to become airborne.

Exposure in Construction – Brick Cutting

Let’s start with brick cutting, which is the work that Rick was performing at the apartment building project. Brick cutting generates moderate to often heavy amounts of respirable silica dust.

Exposure in Construction – Sandblasting

Another activity is sandblasting concrete. This results in high levels of silica in the air from the concrete itself, even without silica. For example:

• Sandblasting with silica sand creates extremely high levels of silica dust.
• Sandblasting on concrete with any kind of grit produces high levels of silica dust.

Exposure in Construction – Rock Drilling

Rock drilling is another construction activity that creates high levels of silica dust.

Exposure in Construction – Concrete Work

Using a jackhammer on concrete generates moderate to heavy amounts of dust.

And, power-sanding concrete also creates heavy amounts of the dust.

Exposure in Construction – Concrete Highway Work

Let’s not forget workers drilling on highways. Drilling outdoors may result in lower dust exposure because the work is sporadic and wind may blow the dust away from your breathing zone. But the exposure limit for silica can still be easily exceeded if you or your coworkers are downwind or in the dust cloud. Remember, if you can see the dust, you’ve most certainly exceeded the PEL.

Exposure in Construction – Tuck Pointing

Here’s another common task that generates heavy amounts of silica dust—tuck-pointing. Even doing this job outdoors can expose you to extremely high levels of silica dust.

How Much Are You Learning?

Now let’s take a short quiz to see how much you are learning. Choose the best word that completes the sentence correctly.

• OSHA’s permissible exposure limit is the (legal/general) limit that workers can be exposed to hazardous substances.

–OSHA’s permissible exposure limit is the legal limit that workers can be exposed to hazardous substances, such as silica.

• Inhaling crystalline silica can lead to (arthritis/COPD).

–Inhaling crystalline silica dust can lead to serious, sometimes fatal illnesses including, lung cancer, tuberculosis, and chronic obstructive pulmonary disease—or COPD.

• The respirable crystalline silica rule requires that employers train you on the (hazards/types) of respirable silica.

–The respirable crystalline silica rule requires that employers train you on the hazards of respirable silica.

• The most common form of silica is quartz, a component of (concrete/lead). –The most common form of silica is quartz, a component of stone, concrete, sand, and brick.

If you got all of the correct answers, you’re on your way to understanding the hazards of respirable crystalline silica.

If you didn’t, make sure to go back and review anything that is not 100% clear.

Ways to Reduce Exposure

We’ve discussed construction activities that create silica dust; now let’s talk about ways to reduce exposure to this hazard. Silica dust exposure can be controlled by using water or using a dust collection system like a vacuum with a high-efficiency particulate air, or HEPA, filter or a local exhaust ventilation, or LEV. Simply put, an LEV sucks the silica out of your work area.

• This worker is using a saw that is equipped with an integrated water delivery system. Water is continuously being fed to the blade and notice the difference. Had Rick known about this option for reducing the hazards, it could have saved him and his family from much pain and suffering. The amount of water used matters. If not enough water is used, operators can still be exposed to too much silica dust. Too much water, however, is also a problem. It can create disposal and cleanup problems. Be sure to follow the manufacturer’s instructions. In sandblasting, there is equipment available that uses water, but the levels of silica in the air will probably still exceed the allowable limit.
• This worker is using a vacuum with a HEPA filter to completely capture the fine dust.
• This engineering control—an LEV—operates in a manner similar to a vacuum. While this worker grinds the concrete, the fan draws the silica dust through the ventilation system into a high efficiency silica dust filter bag.

Dry Sweeping and Compressed Air

To reduce the possibility of silica dust going airborne, you should avoid dry sweeping and using compressed air on concrete when cleaning up or preparing a work area. Both of these activities just stir up large amounts of dust into the air—and that’s the danger! Instead, use a vacuum with high-efficiency—or HEPA—filters whenever possible.

Exposures can also be controlled by isolating the job being performed either by distancing it from surrounding workers or by enclosing the activity. Obviously, the best exposure control method is to not use materials that have silica. Safer substitutes include:

• Garnet;
• Glass beads;
• Aluminum oxide; or
• Iron oxide.

But substitution is often not possible in construction. So, knowing how to protect yourself from exposure is very important.

What Have You Learned?

So, what have you learned so far?

• We know that when dust is controlled, exposures are low. And, when dust isn’t controlled, exposures are high.
• We also learned that dust can easily be controlled using water or an LEV.
• And, we’ve learned that dry sweeping and using compressed air on concrete stir up large amounts of dust into the air.

Silica and Respirator Use

When the silica dust can’t be controlled with water or ventilation, you will need to use a respirator.

• Using either an air-purifying respirator with a filter or a supplied-air respirator will protect you from exposure to the dust. A supplied-air respirator should be worn for high levels of silica dust where water or ventilation can’t be used to control the dust. This type of respirator is required if the amount of silica in the air is more than the PEL.
• A one-piece dust mask can also be used, but it isn’t recommended because it doesn’t always fit properly and can leak.

Sometimes, it can be difficult to reduce the amount of silica dust to levels below the permissible limits. Respirators may still be needed when tuck-pointing or when dry sweeping and using compressed air can’t be avoided.

When respirators are used, your employer has to have a respiratory protection program in place that spells out the responsibilities and requirements of the employer.

Sandblasting Respirators

Sandblasting always requires an abrasive blasting respirator. It needs to cover your head, neck, and shoulders to protect you from rebounding abrasives. During these activities, any helper or worker nearby will also need a respirator.

Training and Fit Testing

All employees required to use a respirator need to be trained. If you’re not trained in how to use a respirator properly, you may think your respirator is providing protection when it is not.

It’s very important that your respirator fits correctly to prevent leaks around the edges. So, if you will be using a respirator, fit testing needs to be done before you first wear the respirator. You’re not allowed to wear a beard with a respirator.

You won’t get a proper fit with a beard—the respirator will leak. The only exception to the no-beard rule is when a sandblasting hood is used, since it covers the whole head.

Personal Hygiene

Another step to take to reduce your risk of exposure to harmful silica dust is following good hygiene practices.

• For example, use disposable clothes while you’re working on tasks involving silica dust. Or, if you don’t have disposables at your worksite, keep a set of washable work clothes at the site. And before removing your work clothes after your shift, vacuum them very carefully to safely remove silica particles.
• Then take a shower to remove any contaminants from your skin before putting on your street clothes.
• Of course, if you’ve been working in an area where there is silica dust, be sure to wash your hands before eating, drinking, or smoking. Common sense should tell you not to ever bring food, beverages, or cigarettes into an area that has silica-containing dust.

Your goal is to keep yourself and your family safe!

Key Points to Remember

OK, let’s sum up the most important things you should take away from this session on respirable crystalline silica.

• The health hazards of exposure to silica dust are real—even for small amounts of the dust.
• Many common construction activities generate silica dust.
• Recognizing the danger is key!
• Exposures can be controlled by using water, or a dust collection system, and by isolating the job away from other workers at the worksite.

And remember, if you see the dust, the PEL has been exceeded, for sure!