The bill amends Chapter 5-20.8 of the General Laws, specifically adding a new section that mandates radon inspection and mitigation in residential real estate transactions. It defines key terms such as "radon," "radon test," "residential real estate transaction," and "unsafe radon levels," which is set at radon levels exceeding the Environmental Protection Agency action level of 4.0 picocuries per liter (pCi/L). The bill outlines that certain transactions, such as those by lenders after foreclosure, sheriff’s sales, tax sales, or sales by court-appointed trustees, and transfers for non-residential use or demolition, as well as transfers by will or inheritance, are exempt from the radon testing requirement.

The bill requires that a radon test be performed no more than one year prior to the closing date of a residential real estate transaction, with the results made available to all parties involved, including any designated lender. The seller is responsible for the cost of the radon test and must allow the buyer to conduct an independent test at their own expense if requested. If unsafe radon levels are detected, the seller must install a radon mitigation system before closing, at their own expense. After installation, another radon test must be conducted to ensure the system's effectiveness, with the seller covering the cost. The buyer may also conduct an additional test at their own expense. The act will take effect upon passage.