Five Facts Construction Contractors Need to Know About Silica, Medical Exams and Testing

June 26, 2018

As contractors and construction industry employers work to comply with new OSHA regulatory silica standards that began September 23, 2017, Texas MedClinic occupational medicine experts have been engaging with employers through seminars, workshops, and one-on-one outreach to help employers understand the medical needs associated with the standards.

From a medical perspective, here is what construction companies and contractors need to know:

  1. What is silica?

    According to the Agency for Toxic Substances and Disease Registry (ATSDR), silica is another name for the chemical compound composed of silicon and oxygen with the chemical formula SiO2, or silicon dioxide.  It is one of the most common substances on earth; over 95 percent of the earth’s crust contains silica. Silica sand melts to glass and has been used throughout history to make glass. Crystal quartz forms of silica are used in jewelry, electronics, and the optical component industry. Some gemstones, such as amethyst, tiger’s eye, agate, carnelian, chalcedony, and onyx are forms of silica.

    “Silica is a natural substance in our environment, and can be found in a lot of places,” said Dr. Gude, Texas MedClinic COO and practicing physician. “If you have been to the beach, climbed a rock-formation or mountain, walked along a rocky lake shore, you have been exposed to silica. Its impact in this natural form is minimal to a person’s health.”

  2. How does silica impact humans?

    Not only is silica found in the environment, it is also used as a food additive and in drugs and vitamins. It has a low bioavailability, meaning your body will only absorb a tiny amount of silica and excrete the rest in urine. Most of the silica in your body is in a form called orthosilicic acid. It exists in your bones, tendons, aorta, liver, and kidneys.

    There is no evidence that breathing small amounts of silica compounds found in the environment causes any health effects in humans. No health effects are shown to occur in humans from eating food or drinking water exposed to silica or from exposure of the skin to these compounds.

  3. What makes silica dangerous?

    Silica is common on construction sites, including soil, sand, concrete, masonry, rock, granite, and landscaping materials.

    The dust created by cutting, grinding, drilling or otherwise disturbing silica will create crystalline silica particles.  These dust particles are very small and are not visible. This respirable silica dust or crystalline silica (c-silica) can cause lung disease, lung cancer, kidney disease and chronic obstructive pulmonary disease (COPD). It only takes a very small amount of airborne silica dust to create a health hazard.

    Health effects of c-silica in people are found in workers exposed for long periods of time or with extremely heavy exposure over a short period of time.

  4. How do we protect workers from c-silica?

    OSHA’s Respirable Crystalline Silica standard for construction requires employers to limit worker exposures to respirable crystalline silica and to take other steps to protect workers.

    One of the OSHA standards includes:

    • Offer medical exams-including chest X-rays and pulmonary function tests-every three years for workers who are required by the standard to wear a respirator for 30 or more days per year.* Please note that the 30 or more days per year is not continuous wear. OSHA’s rule indicates that each instance the respirator is donned is to be counted in the 30-day calculation. Example: If respirator is used on day 1 for 5 minutes and then a week later the respirator is used for 30 minutes in a 24-hour day, then the employer must count total usage as TWO days.

    For more details on all the standards, go to

  5. What is included in the silica medical exam?

    Texas MedClinic has created a silica exam process based on OSHA guidelines. The silica exam process is a two-part visit and includes:

    • Review of medical history and occupational exposure
    • TB Skin Test
    • One View Chest X-ray
    • Pulmonary Function Test (performed by NIOSH certified technician)
    • Medical Exam
    • Medical Clearance for Respirator Use and Silica Work where criteria are met

Please contact the Texas MedClinic Business Development and Marketing Department at or call 210-349-5577, ext. 8521 to learn more about the silica exam process or to arrange a visit with one of our representatives.

Post Views: 5017
SOURCE: Occupational Safety and Health Administration
© 2023 Texas MedClinic®. All Rights Reserved. Phone: (210) 349-5577 |
San Antonio Website Design & Development - Backyard Studios