Radon is a colorless, odorless and tasteless radioactive gas that is formed from the natural radioactive decay of uranium found in many rocks, soils and water. It is a known human carcinogen; in fact, as the second leading cause of lung cancer behind smoking, it presents a serious health risk to those exposed.

Radon exposure is most dangerous where radon concentrations are confined, enclosed or restricted in a space such as a basement, mine, cave, utility service duct or tunnel. Radon gas levels can vary by day, season and geographic area. Because natural ventilation dilutes radon gas levels, employees working in open air excavation or trenching work sites are not likely to be exposed to hazardous concentrations of radon except in rare circumstances. However, any employees working underground or in enclosed ground-level areas where the ground emits radon face an increased risk of lung cancer, depending on their time of exposure and the level of radiation.

Responsibilities of the Employer

As an employer, you are responsible for protecting your employees against the hazards of radon gas. The Occupational Safety and Health Administration (OSHA) requires that employers test for hazardous atmospheres before employees enter excavations deeper than four feet. If radon exposures are hazardous, employers must take adequate precautions to prevent employee exposure, including providing respiratory protection or ventilation.

Official OSHA regulations prohibit employee exposure to more than 100 picoCuries per liter (pCiL) of radon for more than 40 hours in any workweek of seven consecutive days.

The Environmental Protection Agency (EPA) recommends remediation when the radon level in a space is 4 pCi/L or higher; however, it warns that levels still lower than this can pose a risk and should be reduced.

Measuring Radon Levels

Generally, you can test for radon yourself or use a qualified radon professional, using the method of testing most appropriate to your time constraints. Testing can be passive—such as using charcoal canisters or alpha-track detectors, which are relatively inexpensive and readily available—or active—using continuous radon monitors, which are used by radon professionals. Testing lasts a minimum of 48 hours and can exceed a period of 90 days.

The EPA recommends, but does not require, that you contact a qualified radon-reduction contractor and take action whenever levels of radon are shown to exceed 4 pCi/L.

Exposure

There are no discernable early signs of radon poisoning. However, you should always be mindful of early signs of lung cancer, which can be caused by continued exposure to radon gas. If any of your employees complain of a worsening cough, chest pain, coughing up blood, shortness of breath, wheezing or repeated respiratory infections, consider sending them to a doctor for diagnostic care.

For more energy and risk management resouces, contact INSURICA today.

This is not intended to be exhaustive nor should any discussion or opinions be construed as legal advice. Readers should contact legal counsel or an insurance professional for appropriate advice. ©2025 Zywave, Inc. All rights reserved