What is the minimum duration required for a long-term radon test?

The minimum duration required for a long-term radon test is 91 days. Long-term tests are designed to measure the radon levels over an extended period, providing a more accurate representation of radon exposure levels in a dwelling. A testing period of at least 91 days allows for variations in radon concentrations due to seasonal changes, differences in environmental conditions, and the overall variability of radon levels in a home.

Shorter testing durations, such as 30 or 60 days, typically do not capture the full range of possible radon concentrations and are generally classified as short-term tests. The designation of 91 days for long-term tests aligns with guidelines from organizations such as the Environmental Protection Agency (EPA) and the American National Standards Institute (ANSI), ensuring the results are reliable and reflective of actual exposure over time. This extended duration helps homeowners and professionals make informed decisions regarding radon mitigation and health risks.