What is the minimum period a radon test can be extended to if closed-building conditions were not maintained for the required 12 hours before deployment?

The correct minimum period that a radon test can be extended to if closed-building conditions were not maintained for the required 12 hours before deployment is 4 days. This is based on the guidelines which stipulate that in the event that the closed-building conditions are not maintained, the radon testing period must be extended to ensure that accurate readings are obtained.

This extension allows for the collection of sufficient data points that reflect the typical radon levels in the environment being tested. A longer testing period compensates for potential fluctuations in radon levels caused by incomplete closed-building conditions, such as opened windows or doors, or ventilation systems that could alter the indoor radon concentration.

Extending the testing period to 4 days provides a better opportunity to achieve reliable measurements, aligning with best practices for radon testing and ensuring that the results are representative of the average radon levels within the building over time. This approach is critical for assessing potential radon exposure risks accurately.