Crystalline silica is a common mineral found in the earth's crust. Materials like sand, stone, concrete, and mortar contain crystalline silica. It is also used to make products such as glass, pottery, ceramics, bricks, and artificial stone. Silica is a mineral made up of silicon and oxygen, two of the most common elements on the planet. It comes in several forms, although by far the most common is crystalline silica. Crystalline silica is so abundant that it makes up over 12% of the earth’s crust, making it the second-most common mineral on the planet.
Respirable crystalline silica means quartz and quartz are the most common of these, which transform into cristobalite when heated at high temperatures (over 1450 °C). The presence of Cristobalite, and/or tridymite, which are contained in airborne particles, can be determined to be respirable size particles by performing a specific type of air sampling. The air sampling device used must be one specifically designed to meet the characteristics of respirable particles, it must be size-selective and be one that is specified in the International Organization for Standardization (ISO) 7708:1995: Air Quality-Particle Size Fraction Definitions for Health-Related Sampling.
Respirable crystalline silica are very small particles that are at least 100 times smaller than ordinary sand you might find on beaches and playgrounds. It is created when cutting, sawing, grinding, drilling, and crushing stone, rock, concrete, brick, block, and mortar. Activities such as abrasive blasting with sand; sawing brick or concrete; sanding or drilling into concrete walls; grinding mortar; manufacturing brick, concrete blocks, stone countertops, or ceramic products; and cutting or crushing stone can result in unprotected workers being exposed to respirable crystalline silica dust. Industrial sand used in certain operations, such as foundry work and hydraulic fracturing (fracking), is also a source of respirable crystalline silica exposure. About 2.3 million people in the U.S. are exposed to silica at work.
Workers who inhale these very small crystalline silica particles are at increased risk of developing serious silica-related diseases, including:
To protect workers exposed to respirable crystalline silica, OSHA has issued two respirable crystalline silica standards: one for construction, and the other for general industry and maritime. The recently updated standard lowered the permissible exposure limit for the employee and provides the employer options in determining and developing the best control methods for their work sites.
With the new changes to the standard, employers in the construction industry must now try to decide what option for protecting their workers is the best for their projects. Many employers have questions concerning how to implement the control measures outlined in the standard and whether or not they will be able to provide adequate protection for their workers. This webinar will begin to sort through the standard and provide some real-life examples of how the standard can be implemented and what options are available to best protect the health of the workers.
In the construction industry, workers are exposed to silica dust nearly every day on worksites. Examples of the most severe exposures to crystalline silica result from sandblasting to removing paint and rust from stone buildings, metal bridges, tanks, and other surfaces. Other activities that are likely to produce crystalline silica dust exposure include jackhammering, rock/well drilling, concrete mixing, concrete drilling, and brick and concrete block cutting and sawing. Also, tunneling operations; repair or replacement of linings of rotary kilns and cupola furnaces; along with setting, laying and repair of railroad tracks are also potential sources of crystalline silica exposure.
Often workers are more driven on work completion to ensure their job security in order to meet project schedules and budget compliance, therefore finding workers certified to use protective equipment like respirators or training workers to properly use any protective equipment is often considered a burden on the overall project. Knowledge is power in a subject like this because most of the time a person does not realize what is being inhaled or the potential health dangers. Breathing crystalline silica dust can cause silicosis, which in severe cases can be disabling, or even fatal. When silica dust enters the lungs, it causes the formation of scar tissue, which hamper your lungs to take in oxygen. Currently, there is no cure for silicosis.
Because silicosis affects the immune system, exposure to silica increases the risk of lung infections, such as tuberculosis. In addition, while smoking causes lung damage it will also compound and exacerbate any existing damage caused by breathing silica dust.
In rare instances, individuals exposed to very high concentrations of respirable crystalline silica can develop typical silicosis symptoms as well as fever and weight loss within weeks instead of years. In these cases, a medical evaluation should be performed as soon as possible. However, these symptoms can be mistaken for other malaise more common to the attending physician unless the physician is familiar with the symptoms of silicosis. It would be important to select a physician with an industrial practice or training background.
The current OSHA standard provides employers the option of using a control method(s) outlined in the standard or measuring workers' exposure and developing their own negative exposure assessment or other engineering controls to best limit or eliminate employee exposure. This webinar will discuss the options outlined in the standard, as well as, discuss some actual worksite scenarios to help employers develop the most effective plan for their employees.