If your home as tested above 4.0 pCi/L or above, it is recommended to contact a certified radon professional to lower your radon levels. It is recommended by the EPA to find a radon professional certified by the National Radon Proficiency Program (NRPP) or the National Radon Safety Board (NRSB). Credentialing indicates the radon service professional has the mastery of of the specific skills required to successfully complete radon testing and remedial services. Achieving and maintaining certification requires continued documentation of competence, expertise, and performance to demonstrate skill, knowledge and quality control.