What Should Portland Demolition Contractors Know About Crystalline Silica?

demolition caution tapeIn December 2017, the U.S. Occupational Safety and Health Administration, or OSHA, issued new standards for construction, maritime and general industries regarding respirable crystalline silica, a mineral often found on construction sites. While the mineral has great properties and is present in many construction materials, inhaling the particles could lead to a serious health problems. Complying with OSHA’s latest standards will help ensure the health and safety of Portland demolition workers and the communities in which they work.

Crystalline Silica VS Respirable Crystalline Silica in Portland Demolition Sites

Crystalline silica is naturally occurring mineral in the Earth’s crust. It’s often found in materials such as sand, concrete, stone, glass, ceramics, bricks and mortar.

Respirable crystalline silica particles are at least 100 times smaller than beach sand. It’s created by cutting, grinding, drilling and crushing materials that contain crystalline silica. Portland demolition contractors may produce respirable crystalline silica with activities such as:

  • Cutting stone countertops
  • Crushing concrete, mortar and stones
  • Sandblasting
  • Grinding mortar

The Health Effects of Inhaling Respirable Crystalline Silica

Demolition jackhammer dustDemolition workers who are exposed to even small amounts of respirable crystalline silica particles are at risk of developing debilitating diseases that may affect the lungs or kidneys, including:

  • Silicosis: Silicosis often occurs among workers who have had 15 to 20 years of occupational exposure to respirable crystalline silica. When the small dust particles enter the lungs, they cause scar tissue to form, making it difficult for the organs to take in oxygen. Silicosis also puts an affected individual at risk of developing lung infections.
  • Lung cancer: Breathing in respirable crystalline silica increases an individual’s risk of developing lung cancer.
  • Chronic obstructive pulmonary disease: The lung scarring respirable crystalline silica causes makes an affected individual more at risk of developing lung diseases, including COPD, chronic bronchitis or emphysema.
  • Kidney disease: Studies have found that individuals greatly exposed to respirable crystalline silica have an increased risk of developing kidney disease. Researchers believe it occurs when silica particles come in direct contact with the kidneys. Indirect exposure may also occur when silica particles affect the lungs, prompting them to produce macrophages that attack the particles. The macrophage cells, paired with lymph node stimulation, may lead to kidney inflammation, or glomerulonephritis.

OSHA Standards about Respirable Crystalline Silica

OSHA’s latest standards require demolition companies to take steps to protect workers and limit exposure to crystalline silica particles. Employers have the choice of measuring a worker’s exposure to silica and protecting them against exposure using dust control techniques and respirators. Alternatively, they may use one of the control methods listed in Table 1.

Regardless of the choice demolition contractors make, they must:

  • Create and implement a written respirable crystalline silica control plan that details tasks that reduce exposure and protect workers.
  • Designate an individual to implement the exposure control plan.
  • Teach workers about crystalline silica exposure and mitigation practices.
  • Not employ practices that put workers at risk for silica exposure if better alternatives are feasible.
  • Provide medical exams that include lung function tests and chest x-rays every three years to workers who wear a respirator at least 30 days of the year.
  • Keep records of medical exams, exposure measurements and other information.

A Sampling of Respirable Crystalline Silica Control Methods

demolition safetyOSHA outlines a variety of control methods demolition companies in Oregon may use to reduce the hazards of crystalline silica exposure. Such methods include:

  • Handheld power saws: Apply water to a saw blade or use a saw with an integrated water delivery system to reduce dust production.
  • Handheld grinders: Apply a constant spray of water to the impact point or use a grinder equipped with an integrated water delivery system to minimize dust emissions. Alternatively, use a vacuum dust collection system (VDCS) to remove dust. When removing mortar, use a grinder with a VDCS.
  • Drills (handheld and stand-mounted): Enclose the drill in a shroud or cowling with an attached vacuum.
  • Stationary masonry saw: When using a masonry saw, pairing wet cutting with an integrated water delivery system is a great way to reduce exposure to dust. If wet methods are not feasible, use a saw equipped with a VDCS.
  • Walk-behind saw: Use wet cutting techniques that direct a continuous stream of water onto the blade.
  • Drivable saw, rig-mounted core saw, rig-mounted drill: Use a saw or drill equipped with an integrated water delivery system. Promptly clean the slurry produced before it dries and releases silica particles into the air.
  • Crushing machines: Portland demolition contractors should use water sprays or mists to suppress dust at the points where dust is generated, such as discharge points. In addition, a contractor should employ operator isolation techniques, which include using a remote control station or an enclosed booth. If an operator remains in an enclosed cab, it should be well-sealed and –ventilated.
  • Demolition-related heavy equipment and utility vehicles: Equipment and vehicle operators must be in a sealed, enclosed cab when they’re used for Oregon demolition activities. If other workers are on-site, near the equipment or vehicles, apply water or dust suppressants to minimize silica dust. Spray equipment, tank trucks and atomized misting devices aid with the application of water for dust-suppressing activities.

It is important to keep in mind: When working in an enclosed area or indoors, you may need to install extra ventilation.

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