The National Radon Proficiency Program (NRPP) was accredited by the American National Standards Institute (ANSI) National Accreditation Board for fulfilling the International Organization for Standardization (ISO) 17024 standard for certification bodies in June. NRPP’s radon measurement and mitigation certifications are the only radon industry certifications to earn ANSI recognition, which separates NRPP from the competition and distinguishes top-quality radon professionals. 

“I commend the NRPP staff for meeting the rigorous requirements of the ISO/IEC 17024 standard and joining the elite group of organizations that have achieved this distinction,” said AARST President Kyle Hoylman. “This achievement highlights AARST’s commitment to offering a high-quality certification program.”

Accreditation indicates that NRPP’s certifications have met the most respected and internationally accepted standards for personnel certification bodies. The ISO/IEC 17024 accreditation applies to the certifications for Radon Measurement Professional, Radon Mitigation Specialist, Radon Measurement Field Technician, and Radon Mitigation Installer. As NRPP adds new certifications in the future, the program will apply for a scope extension to add them to the accreditation.

The ANSI accreditation process is designed to increase the integrity, confidence, and mobility of certified professionals. It creates value for all the stakeholders including certification holders, employers, the public, and regulatory authorities. Accreditation is a formal, independent verification that a program meets established quality standards and is competent to conduct the conformity assessment tasks necessary for certification. ISO/IEC 17024 sets the requirements and the framework, at a global level, for the operation of personnel certification bodies.

“Consumers seeking radon services, who are often unaware of the distinction between a ‘certification’ and a ‘certificate,’ may be vulnerable to misleading advertising. NRPP’s achievement of reputable third-party accreditation under ISO/IEC 17024 expands the program’s credibility and offers reassurance that it has the independent oversight necessary for consumer protection,” said Marilyn Patrick, NRPP Operations and Exams Manager. “The ISO designation signals that credential holders have undergone a valid, fair, and reliable assessment to verify they have the necessary competencies to do the job.”

This significant accomplishment is the result of several years of hard work by the NRPP staff and Certification Council. The NRPP took its first steps toward ANSI-ISO 17024 accreditation in 2018. With the assistance of consultants and volunteers, a new certification scheme, job task analysis, exam content development (aligned with the relevant ANSI-AARST consensus standards), and standards-setting for exams were completed. The ISO 17024 application was submitted to the ANSI National Accreditation Board (ANAB) in November 2021. The NRPP staff participated in an intensive two-day virtual site visit with ANAB assessors and received feedback on a handful of nonconformities in April 2022. While ANAB allows certification bodies up to six months to implement corrective actions, NRPP conducted corrective actions to successfully close all citations in just five weeks.

The ISO/IEC 17024 standard specifies requirements that ensure organizations operating certification programs for professionals operate in a fair, impartial, consistent, and reliable manner. This accreditation contains rigorous requirements for examination development, maintenance, and quality management systems.


The International Standard ISO/IEC 17024 was developed to fill the need for public protection by establishing how individuals have the required competencies to perform their work. ANAB accreditation is recognized worldwide as a critical requirement for personnel certification bodies that offer certification in many industries, including public health, environment, and national security services.

NRPP is a program of the American Association of Radon Scientists and Technologists, Inc. (AARST). Recognized and demanded by federal agencies and state radon regulations, NRPP credentials indicate to building owners and service providers the mastery of the specific skills required to successfully complete radon testing and mitigation projects. The program’s credentialing policies and procedures are governed by the NRPP Certification Council, which consists of industry stakeholders such as analytic laboratories, device manufacturers, state radon programs, training providers, and radon professionals.