In an effort to improve worker safety, the United States Occupational Health and Safety Association (OSHA) has issued a Final Rule to limit occupational exposure to respirable crystalline silica (RCS). The Rule went into effect for the construction industry on September 23, 2017. Employers that fail to comply are putting their workers at risk and will face stiff OSHA penalties.
This blog discusses RCS and the dangers of exposure as well as employer requirements, what employees can do to limit exposure and methods of compliance.
What is RCS?
Crystalline silica is a naturally occurring mineral found in the earth’s crust. It is present in many materials used in construction and demolition processes such as brick, concrete, ceramic tiles, mortar, rock, sand, soil and stone.
Why is RCS dangerous?
Crystalline silica is classified as a human lung carcinogen. Inhaling crystalline silica dust can lead to serious health conditions including lung cancer, chronic obstructive pulmonary disease (COPD), silicosis, and kidney disease.
- The types of equipment and tools associated with exposure
- Employer requirements
- Silica dust exposure level thresholds
- Preferred compliance methods
- Workers’ rights
- Compliance timeline by industry
- Nonconformance penalties
How are workers exposed?
Worker exposure to RCS occurs during many construction-related activities performed on materials that contain crystalline silica such as abrasive blasting, jackhammering, drilling, tunneling, concrete mixing, crushing and cutting. During these processes, hazardous RCS dust — typically one hundred times smaller than ordinary sand found on beaches or playgrounds — is released and suspended in the air, where the particles may be inhaled by workers. These particles can penetrate and embed deep into the lungs and other organs.
While the concerns associated with crystalline silica have been recognized since the first half of the twentieth century, formalized regulations were not created until the 1970s, with the formation of OSHA. At that time, suitable regulations were put in place, but as time passed and technology developed, those regulations became outdated.
In 2013, OSHA embarked on an extensive evaluation of the issue of crystalline silica exposure — analyzing scientific data, reviewing industry standards and considering input from an array of stakeholders —culminating in the proposal of the Final Rule.
In the United States alone, approximately 2.3 million workers are exposed to respirable crystalline silica and almost 90% of them work in the construction industry.
“OSHA estimates that the Final Rule will save over 600 lives and prevent more than 900 new cases of silicosis each year, once its effects are fully realized. The Rule is projected to provide net annual benefits of as much as $7.7 billion to society in terms of reduced costs associated with preventing and treating silica-related illnesses.”
— Occupational Health and Safety Association (OSHA)
The Final Rule requires construction employers to limit worker exposures to RCS and take other steps to protect workers and ensure their safety including:
- Implement a written exposure control plan.
- Restrict practices that expose workers to silica where feasible alternatives are available.
- Use a preferred control method.
- Provide respiratory protection when required.
- Offer medical exams and keep records.
- Comply with OSHA’s Hazard Communication Standard (HCS) (29 CFR 1910.1200). The HCS requires employers to inform employees about hazardous chemicals in the workplace through their written hazard communication programs.
How employees can minimize risks
Workers can reduce their exposure by applying OSHA recommended precautions:
- If a respirator is required, wear one that is N95 NIOSH certified.
- Don’t wear a tight-fitting respirator if you have facial hair because it could prevent a good seal between the respirator and your face.
- Understand the health risks associated with exposure to RCS as well as the job tasks that create CSR exposure.
- Wear work clothes that are disposable or washable. Before leaving the site, vacuum or change out of your work clothes.
- Do not eat, drink or smoke where crystalline silica dust may be present.
Methods of compliance
Employers following alternative exposure control methods must first comply with the requirements of the Standard to protect employees following the hierarchy of controls, a long-standing OSHA policy. These include engineering and work practice controls for reducing exposure. Respirators may be used when reductions to acceptable levels of crystalline silica cannot be achieved to an acceptable level.
There are two main types of engineering controls:
Local exhaust ventilation and isolation
Local exhaust ventilation removes dust by capturing it at or near the point where it is created. Isolation separates employees from the dust source by containing the dust or isolating employees. One such example of exhaust ventilation is a properly ventilated cab on heavy equipment.
Wet method/water delivery systems
Wet methods involve applying water or foam at the point of dust generation. The water grounds the dust before it becomes an airborne health hazard. NOTE: Pre-wetting the work area is ineffective and does not comply with the standard.
Parker Hannifin’s recently introduced Twinhammer Hose, is specifically designed to comply with OSHA wet method dust control. The hose is a unitized, chemically bonded dual air/water hose assembly designed to simultaneously transfer air to power jackhammers and water to suppress silica dust during tool operation, to 212°F and 300 psi.
By using this engineered equipment in a manner following a specific work practice, the risks of crystalline silica are substantially reduced.
This blog was contributed by Dennis Daniel, technical services and marketing services manager Hose Products Division, Parker Hannifin.