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Silica—The Next Environmental Issue

Jeff Slivka | April 1, 2005

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Construction worker sandblasting beams

Like a floodlight with a bad electrical connection, the issue of silica has been flickering for major attention for the past 2 or 3 years. Although an occupational hazard and known killer since the 1960s, silica is again gaining popularity with the trial lawyers and, as a result, is having somewhat of an impact on the insurance industry. Although at this point it is only a "blip" on the radar screen, nonetheless, it is causing some insurers to reassess and exclude coverage where such coverage was once provided. Sound familiar?

Some would argue that it is because of the upcoming restrictions being forced on sufferers of asbestos-related diseases. Others would argue that the resulting dust from the collapse of the World Trade Centers reopened the issue. Still others are taking a simpler or cynical position—now that we somewhat have our arms around the "toxic" mold thing, we need some new environmental issue to abuse.

Silica, the Mineral

Keep in mind, the intent of this article is to provide the reader with some basic knowledge on the subject matter for those in the insurance industry and not to create any kind of "technical" or scientific article on the subject.

When we refer to "silica," we are usually referring mostly to the crystalline form otherwise known as silicon dioxide (SiO2). There are other, noncrystalline forms of silica but since most of the issues are centered on the inhalation of the crystalline form, we'll focus on that form.

There are three major forms of crystalline silica that are most common in the workplace. They are quartz, tridymite, and crystobailite. The most common we can probably all relate to is quartz. Quartz can be found in virtually all soil in nearly every part of the country. The "rock" sandstone is composed of quartz and can be found in many areas throughout the country except for southern coastal areas where most beaches are made up of limestone.

Tridymite and crystobalite are simply polymorphs of quartz. In other words, they are composed of the same elements but have different chemical structures. An easy example to help understand what is meant by polymorph would be tridymite. Tridymite, while somewhat rare, can be found in many volcanic rocks. In this example, the heat associated with volcanoes acts as the catalyst that "morphs" or changes the chemical structure of the quartz into rocks containing tridymite. Crystobalite is not too different than tridymite.

To put this into some type of context and to bring some vision to this issue, consider the eruption of Mount St. Helens back in the 1980s. Those people that may have been exposed to silica and contracted silica-related respiratory injuries would most likely have been inhaling tridymite or crystobalite in the dust after the explosions. Those people in and around the collapse of the World Trade Centers in 2001 would mostly be inhaling quartz coming from the concrete dust. The point is simple. Although all are different in chemical structure, all forms of crystalline silica can eventually be deadly.

Silica, the Killer

Silica is a known carcinogen. The most common disease resulting from overexposure to silica is silicosis. Silicosis is a disease that scars the tissue of the lung, making breathing a burden because the lung's ability to extract oxygen from the air is impeded. The scarring occurs as a result of the body's continual and unsuccessful fight to rid the silica particles. This can eventually lead to other diseases and death. As a matter of fact, the U.S. Department of Labor (DOL) estimates that 300 people die each year from silica-related disease.

Symptoms are fairly well known. The most common is shortness of breath, even with simple activities, and related coughing or wheezing. Others include fever, fatigue, loss of appetite, and occasional bluish coloring of the skin at the ear lobes or lips. Subsequently, silicosis makes the sufferer more susceptible to other diseases and infections such as tuberculosis and lung cancer. There are three different types of silicosis. All have similar symptoms but different "latency" periods, as described in the following exhibit.

Types of Silicosis

  • Chronic silicosis. The most common of all types of silicosis. Symptoms usually occur after 10 years of mild exposure. It is not uncommon for symptoms to arise up to 45 years after exposure. A common chest X-ray can reveal symptoms in the lungs.
  • Accelerated silicosis. Also known as progressive massive fibrosis, accelerated silicosis is most likely the rarest form of silicosis. Symptoms develop quicker than Chronic Silicosis—5 to 10 years—and typically result from moderate overexposure. Usually results in death after only a few years of its development.
  • Acute silicosis. Acute silicosis is the most rapidly developing of the three—causing massive lung damage in a very short period of time. Symptoms typically develop within weeks up to 5 years of inhaling very large amounts of silica. Acute silicosis does not progress to the chronic stages. There is limited hope for patients with acute silicosis—typically including a lung transplant.

Silica, the Workplace Hazard

Silica related products/materials can be found in many workplace environments throughout various industries. Some of the materials that contain silica include bricks, concrete, blasting abrasives, mortar, sandstone, topsoil, and asphalt. The more prominent industries would include manufacturing, mining, farming, and construction, to name just a few. In general, according to the National Institute of Occupational Safety and Health (NIOSH), over 1.7 million U.S. workers are exposed to respirable crystalline silica on a daily basis. Additionally, an undetermined portion of the 3.7 million agricultural workers may be exposed to silica containing dust. The tough part about these numbers is they are based on information provided back in the early 1990s. It is expected that these numbers would be a bit higher today.

Taking a closer look at the exposure potential for specific industries, the U.S. Department of Labor's Silica Adviser has actually statistically labeled some industries with varying risk of death. In the table below, they have labeled each industry with the associated potential mortality rate (PMR), which is the observed number of deaths from silicosis divided by the expected number of deaths. According to the U.S. DOL, a value of 1 indicates no additional risk. A value of 10 would indicate a risk 10 times greater than normal risk of silicosis. If you are curious about the potential levels of silica in a specific workplace, the DOL has created a site—"Comparing Your Exposure to OSHA's Limit"—to measure those levels against the permissible exposure limit (PEL) for silica.

Table 1

U.S. Department of Labor's Silica Advisor illustration

Silica, the Insurance Problem?

Over the past 6 or 7 years, silica had popped up every so often as another environmental issue with catastrophic potential. The issue would be debated, but no action was taken. That was the good news. However, last year the industry saw some insurers start attaching silica exclusions to standard liability policies to ensure they did not cover third-party liability associated with exposure to the mineral. Although the number of insurers attaching exclusions are few, the question still is, why now? We've known this to be an issue for many years, so why now is there concern enough to start attaching exclusions where coverage was once provided? Most likely, it's the culmination of the three major and individual events: "toxic" mold, the World Trade Center collapse, and the proposed restrictions on asbestos-related lawsuits.

Unless you were hiding under a rock on the bottom of the ocean, we all witnessed the "toxic" mold craze of the past 3 to 4 years. The explosion of claims related to mold is still on the minds of many insurers. So much so that we'll probably never see those exclusions come off either property or liability policies. However, in terms of actual medical causation, silica has a much deeper bite. Being a known carcinogen (no species of mold is a verified or documented carcinogen), silica has a much greater potential to inflict irreversible respiratory injury than mold ever will (at least based on the knowledge we have of mold today). Based on this alone, there is justification.

Couple this with the increase in silica-related lawsuits, and it appears to strengthen the case. However, this concern is drastically mitigated since the population exposed to silica is nowhere near the population exposed to the entire "toxic" mold thing, and those lawsuits may have ulterior motives.

Another issue that comes to mind is the collapse of the World Trade Center (WTC). In addition to other airborne contaminants, silica dust was a major concern created by the actual collapse of the buildings in that section of the city. The population exposed to those contaminants could easily reach into the millions when you think of the people that directly inhaled the dust during emergency response and evacuation, during the post-collapse demolition, and through contaminated ventilation systems of buildings in the area. While tragic, the mitigating factor here is the concentration of exposure—primarily limited to lower Manhattan.

The last but most current happening is the restrictions being proposed under the Fairness in Asbestos Injury Resolution Act (FAIR). One of the proposals under the FAIR is the establishment of the Asbestos Injury Resolution Fund. To keep it simple, the fund proposes a cap on compensation to sufferers of asbestos-related disease, and attorney fees. Industry experts are now concerned that silica will become a litigation strategy for plaintiff attorneys in the event the FAIR is enacted and asbestos is literally capped. Attorneys may attempt to link asbestos with silica and circumvent FAIR.

This is not fact, however. According to Kirk Kolbo with the law firm of Maslon Edelman Borman & Brand, LLP, in Minneapolis, the number of silica-related lawsuits increased from about an average of 1,000 per year to almost 20,000 in 2003 nationwide. No documentation was provided for 2004 but expectations are the same. Those kinds of jumps make you think. It's even more amazing when you consider that there have been no major changes or occurrences in the industry to allow these numbers to make sense.

Since we are on the topic of insurance and third-party liability, keep in mind that the environmental insurance marketplace does not limit coverage for silica under basic contractors pollution liability (CPL) and pollution legal liability (PLL). Silica, as with other contaminants, is considered a pollutant by definition. The following discussion sheds a little more light on the basic CPL and PLL products.

Contractors Pollution Liability

The contractors pollution liability or CPL policy is available to all types of contractors—environmental and non-environmental. It is a third-party policy that provides coverage for bodily injury, property damage, defense, and cleanup that results from covered operations performed by or on behalf of the insured. The CPL policy can be provided with either an occurrence or claims-made insuring agreement. Coverage can be offered with coverage for mold or microbial matter. The capacity available for CPL in the current marketplace well exceeds $300 million, with the most any one insurer can offer to be $150 million. Forms can be written with either deductibles or self-insured retentions. The amount of such is determined by the financial strength of the insured.

The CPL can be structured for all operations on an annual basis or "blanket" coverage, part of a wrap-up, or just straight project insurance. The policy term for blanket coverage is limited to 1 year, while the term for projects or wrap-ups is 10, with longer terms being negotiated on a case-by-case basis.

Lastly, it would be prudent for any contractor entertaining CPL coverage to pursue the cost of adding pollution coverage for the following.

  • Owned/leased premises
  • Transportation by or on behalf of the insured
  • Mold liability
  • Disposal liability

Pollution Legal Liability

The pollution legal liability (PLL) policy is offered to virtually any organization that owns, leases, rents, acquires, or divests real estate or property. It is a third-party policy that provides coverage for bodily injury, property damage, defense, and cleanup that results from pollution conditions (both sudden/accidental and gradual) or events at, on, under, or emanating from a covered location. The PLL can be offered for one or multiple locations under one policy. The PLL is provided with a claims-made insuring agreement. Coverage can be offered with coverage for mold or microbial matter and can include bodily injury, property damage, and/or mold cleanup cost. Under a typical PLL policy, there should be no retroactive date. However, many insurers will attach one to control their exposure. The retroactive date greatly limits the gradual coverage afforded under the policy, so it is imperative that it be removed or taken back to a more defined period (associated with an environmental assessment or other occurrence).

The capacity available for PLL in the current marketplace well exceeds $300 million, with the most any one insurer can offer to be $150 million. Forms can be written with either deductibles or self-insured retentions. The amount of such is determined by the financial strength of the insured.

The policy term is determined by the type of risk, client need, and insurer comfort, and can be offered up to 10 years. Longer terms may be negotiated on an individual basis.

Lastly, it would be prudent for any organization pursuing PLL to investigate the cost of adding the following coverage enhancements (if applicable).

  • Transportation by or on behalf of the insured
  • Remove retroactive date
  • Business interruption
  • Onsite cleanup coverage
  • Builders soft cost (if construction is occurring)
  • Mold liability
  • Products pollution
  • Disposal liability

The Silica "Risk Profile"

There is no cure for silica-related disease but it can easily be prevented. The first step in any process is identifying the exposure. An easy way to identify if an organization is exposed to either first- or third-party liability from silica is to create a risk profile, specifically, an environmental risk profile (ERP). This can easily be completed with a basic understanding of an organization's operations. The ERP can simply consist of the process or activity in which silica is used. But if you want to complete a comprehensive ERP, create a simple matrix with additional information such as potential impact to the worker and organization, personnel responsible, selected management techniques, historic information (if any), and response protocol.

Managing worker exposure can be fairly easy with some basic techniques.

  • Educate employees. All personnel involved or around those activities, operations, or processes that use silica and silica-related products should be trained, at minimum, on proper usage, personal protective equipment (PPE), preventative measures, and emergency response protocol.
  • Use a substitute for silica. Where possible, substitute the silica for a product that does not have silica. Organizations can look to eliminate the use of abrasive blasting materials that contain more than 1 percent crystalline silica. By applying this technique, you actually eliminate the hazard all together. From walnut shells to steel shot, there may be alternatives that can be substituted.
  • Suppress dust. For manufacturing processes, use dust control methods such as blast cabinets and wet drilling or sawing. For construction, similar methods may be used for operations such as dry cutting concrete, demolition, sand blasting, and excavation.
  • Use personal protective equipment. It is amazing after all we have learned on the issue that concrete cutters still blow dust all over the place with absolutely no PPE whatsoever. Wearing disposable or washable protective clothing and utilizing proper respirators that will capture and prevent inhalation of the crystalline silica can help protect workers.
  • Conduct regular air monitoring to ensure that control systems are working. This can provide early indications and prevent further damage.
  • Post warning signs around areas contaminated with silica dust.
  • Avoid any type of eating or drinking in areas where silica containing material or dust exists.

Managing third-party exposure may be a bit more difficult.

  • Educate employees. Similar to the above, employees should be trained on preventative measures and emergency response in the event silica containing material is released from a project site via sand blasting a bridge or some other structure.
  • Use a substitute for silica. As discussed above, this eliminates the exposure all together.
  • Suppress dust. This may be a bit more difficult but dusty conditions may be prevented during demolition, dry cutting concrete, excavation, and so forth by applying water mists or wet cutting, and creating a protective property "buffer" around project sites to reduce the number of third parties in the area during those activities.
  • Monitoring air quality. On project sites, air monitoring in the area during the activity of concern can (1) act as an earlier response indicator and (2) act as viable documentation in the event third parties sue for frivolous damages.
  • Post warning notices. Depending on your philosophy toward liability, this may or may not be a good idea. One school of thought would argue that warning signs are a sound preventative measure; the other school of thought may conclude that while warning signs may prevent third parties from entering an area where there is a hazard, it may also attract unnecessary attention and resulting liability.
  • Use medical monitoring. Entrance physicals can also be used as a baseline to determine if employees had preexisting issues prior to working for the organization. Exit physicals may be used to document the employee's health during the course of employment. This documentation can be crucial in the event a former employee sues claiming the silica exposure occurred during their tenure with the organization.


Silica—much ado about nothing? In the grand scheme of things, I don't think so. As you can see, disease resulting from silica exposure can be extremely debilitating not to mention deadly. However, I think there is a lot of unnecessary "new" talk in the insurance industry about an issue that (1) has been around for years, (2) regulatory agencies acknowledge as a carcinogen, (3) society acknowledges as a deadly concern, and (4) many industries have addressed by instilling preventative measures to reduce or eliminate a worker's exposure to silica. The one remaining question is this: are these industries addressing third-party exposure? Many organizations in the construction, agricultural and mining industries still face third-party liability associated with day-to-day operations, even if the worker exposure is minimal. From dust generated during mining operations or demolition to simple excavation activities, organizations must assess this risk. This exposure cannot be overlooked and must be addressed on an organization-specific basis.

Lastly, spring is upon us and we all want to get outside. So when you go for that walk downtown to get some of that "fresh air," watch what you are breathing. When you see those guys cutting up the concrete to replace the sidewalk with dust flying everywhere, and those workers have absolutely no protection on, that doesn't mean a hazard doesn't exist. Think about holding your breath as you walk past. And move fast!

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