Soil gases such as radon can seep through cracks, gaps, and openings in foundations, entering indoor air without any visible warning. You cannot see or smell these gases, yet prolonged exposure can pose serious health risks. Radon is a major concern, but chemical vapors and other hazardous soil gases can also migrate from the ground into homes. For existing homes, soil gas mitigation can be especially challenging. Unlike new construction, mitigation measures must work within the home’s existing foundation and structure. ANSI/AARST SGM-SF-2023, Soil Gas Mitigation Standards for Existing Homes establishes guidance for reducing soil gas entry and mitigating occupant exposure to radon, chemical vapors, and other hazardous gases.
Why Is Soil Gas Mitigation Important?
Soil gas mitigation prevents invisible, toxic, or explosive gases from the ground—such as radon, methane, and volatile organic compounds (VOCs)—from leaking into homes and buildings. Thus, effective mitigation is an important consideration for managing indoor environmental risks and for overall occupant health and safety. ANSI/AARST SGM-SF-2023 addresses soil gas mitigation methods, helping stop dangerous soil gases from entering living spaces.
What Is ANSI/AARST SGM-SF-2023?
ANSI/AARST SGM-SF-2023 specifies practices, minimum requirements, and general guidance for reducing soil gas entry into existing homes to mitigate occupant exposure to certain hazardous soil gases. These gases include radon, chemical vapors, and other hazardous gases.
This American National Standard applies to existing residential structures that are not more than three stories above grade, often classified as single-family structures, and contain no more than four attached dwelling units on a contiguous foundation.
ANSI/AARST SGM-SF-2023 is applicable to both rented and owned existing homes and addresses a range of mitigation considerations, helping professionals approach soil gas mitigation in a consistent manner.
Why Is Radon a Concern?
Radon is an invisible, odorless radioactive gas that naturally forms in soil and rock and can seep into homes through cracks and openings in floors and foundations. According to the U.S. Environmental Protection Agency (EPA), nearly 1 in 15 U.S. homes has elevated radon levels. This statistic warrants concern since radon is the second leading cause of lung cancer (first is smoking) in the United States.
Because any home can have elevated radon levels—regardless of age, construction, or whether it has a basement—the EPA recommends testing homes and taking action when levels reach 4 pCi/L or higher. ANSI/AARST SGM-SF-2023 can help guide practices for reducing soil gas entry and occupant exposure.
Where to Find ANSI/AARST SGM-SF-2023
ANSI/AARST SGM-SF-2023, Soil Gas Mitigation Standards for Existing Homes is available on the ANSI Webstore, the best place to buy AARST standards.
ANSI/AARST SGM-SF-2023 was developed by the American Association of Radon Scientists and Technologists (AARST).