OSHA's New Silica Exposure Requirements

By Raza Akbar, MD, Occupational Health, Community Healthcare System

Crystalline silica, one of the most common substances on the earth’s crust, is a basic component in sand, quartz, granite, brick, and asphalt. Workers in construction, general, and maritime industries are at increased risk for serious respiratory and other potential health issues due to exposure of tiny silica particles produced through grinding, cutting, drilling, or crushing processes. Such activities produce particles more than 100 times smaller than ordinary sand, which can enter the body through inhalation and then deposit into lung tissue. Reaction to these deposited particles may lead to inflammation and scarring with decreased lung function, resulting in a disease called silicosis.

Silicosis of the lung can take different forms depending upon the type and extent of exposure.  Symptoms of the more chronic type can include productive cough and shortness of breath, leading to disability and even death. Silica has also been associated with cancer and kidney disease. In addition, silicosis is accompanied by increased risk of tuberculosis. Because there is no way to reverse silicosis, prevention is key. Limiting exposure and early detection are crucial.

According to the Occupational Safety and Health Administration, or OSHA, more than 2.3 million workers are exposed to crystalline silica annually. Given that the causes, signs and methods of prevention of silicosis have been well defined, it remains for employers to ensure adequate protection and monitoring which includes appropriate education and medical testing.

Employers must assess employee exposures to silica at an action level of at least 25 micrograms of silica per cubed meter of air. Enforcement for the construction industry’s OSHA silica standard began in September 2017. For general industry and maritime firms, the standard began to be enforced in June 2018.

The most recent updated standard given by OSHA proposes that employers first attempt engineering and administrative controls to limit employee exposure. If these do not correct exposure levels to below the Permissible Exposure Limits, or PEL, respirators are required. For those workers needing respirators more than 30 days per year, medical and respiratory surveillance will be mandatory.

Medical surveillance would include a physical at least every three years, along with lung function tests (spirometry), chest x-rays and tuberculosis screening. Respiratory surveillance is important to establish that an employee is healthy enough to use a respirator, whereas medical surveillance is the most effective way to identify any adverse health effects or catch any testing abnormalities before symptoms develop. In addition, medical surveillance helps to determine if an employee has a condition, such as COPD (Chronic Obstructive Pulmonary Disease), which would make them more sensitive to the harmful effects of silica exposure. According to the OSHA standard, any suspected abnormalities or symptoms suggesting silicosis would require prompt referral to a board-certified specialist in either pulmonary or occupational medicine.

In addition to medical surveillance, baseline testing in new employees with prior histories of silica exposure can also be useful in establishing that any ensuing medical conditions were not caused by the employees’ new workplace exposures.

Recommendations for Employers – Controlling Exposure

• Employers should first attempt engineering and administrative controls to limit employee exposure.

  • For most tools and workplace activities, this would involve dust control methods such as water delivery systems, emissions collectors, shrouds or cowlings that collect dust, and others.

• Respirators are required if control methods do not keep exposure levels below permissible limits.
• For workers needing respirators more than 30 days per year, medical and respiratory surveillance is mandatory.
• Medical surveillance would involve a physical every three years, including lung function tests (spirometry), chest x-rays, and tuberculosis screening.
• Employers are required to provide training to their employees with regard to the types of activities that result in silica exposure and ways to limit them.

Source: Community Healthcare System

Silica Can Take Your Breath Away

• From 2005 through 2014, silicosis was listed as the underlying or a contributing cause of death on over 1,100 death certificates in the United States, but most deaths from silicosis go undiagnosed and unreported.
• More workers died from silicosis in 2014 than in fires, or from being caught in or crushed by collapsing materials, such as in trench and structure collapses.

Source: BLS, CDC