State Certification and Licensure Laws 101

In the United States, 19 states (with one pending) have laws or regulations in place that require some form of proficiency qualifications for professionals doing radon work in the marketplace. Nine states offer regulation through certification, requiring that radon work be performed by persons who have earned certification from an EPA-recognized proficiency program (National Radon Proficiency Program and National Radon Safety Board). Some of the “regulation through certification” states require a state-issued credential (license or certificate) that documents state oversight of the credential provided by the proficiency program. Eleven states operate state-based licensing systems, through which state regulations define state-specific terms and conditions (rules) under which licensees will secure, renew, and retain radon credentials.

States’ continuing oversight of professionals’ radon credentials is a central element of radon risk reduction. These regulatory structures encourage compliance with recognized standards of practice and ethical professional behavior to ensure citizen protection and enable enforcement. Some of the trouble spots for state regulatory programs can be statutory and regulatory references to outdated standards, failure to ensure that multifamily projects comply with 100% testing of ground floor units as required in the ANSI-AARST standard, and the absence of requirements pertaining to approved radon measurement devices and/or quality control.

While all EPA-funded radon programs publicize listings of radon professionals credentialed by the EPA-recognized proficiency programs, in 30 non-regulated states untrained contractors have unlimited access to unsuspecting consumers. The absence of proficiency requirements in these states allows unqualified personnel to conduct radon-related services and disregard established consensus standards.

To counter the proliferation of fly-by-night contractors performing substandard, unprofessional radon work, AARST Chapters, state leaders and others have been working to secure recognition of national consensus standards and regulation through recognized private certification programs that require adherence to such standards. As the Radon Reporter goes to press, the Colorado legislature has taken the final step to enact regulation through certification as requested by Rocky Mountain AARST; New Jersey’s Department of Environmental Protection has proposed adoption of the ANSI-AARST standards; the task force in New York State is gearing up to review radon credential options, and regulators and chapters in other states are considering related policies.

The State of the Industry: State Credentialing Policies

In 2021, 9 states require certification (or certification plus licensure) and 11 states require only a state license.

Spotlight: Indiana’s Regulatory and Compliance Breakthrough

In 2020, both the Indiana legislature and the Indiana State Department of Health (ISDH) recognized the need to sharpen the state radon program’s relevance and effectiveness. The statute specifically required the use of outdated and retired EPA protocols that even EPA no longer maintains; it was necessary to amend the statute to allow adoption of the EPA-recommended ANSI-AARST standards. Also, the state needed to modernize and clarify certain details of the program.

In February, to authorize regulatory updates, the General Assembly enacted HEA 1334, which was signed by the governor and enacted as Public Law 25.

Summary of Public Law 25 of 2020

Radon mitigation: Provides the state department of health (state department) with emergency rulemaking authority to amend provisions in the state department’s administrative rules concerning radon. Requires the state department to amend provisions in the state department’s administrative rules concerning radon using the regular rulemaking process before December 31, 2021. Provides that the provisions added by the bill expire July 1, 2022.

Since before the legislative process unfolded, the leadership of ISDH’s Lead and Healthy Homes Division had been working on a major overhaul to its requirements to bring the program into the 21st century.  Statutory authorization enabled rapid executive branch action to implement change in 2020.

 Key elements of Indiana’s regulation via certification policy include:

  • As a condition of licensure, radon contractors are required to maintain certification through a certification program recognized by the EPA.
  • All measurement, mitigation, and QA/QC activities must be conducted in accordance with the applicable AARST/ANSI standard.
  • A non-licensed person may only perform measurement and/or mitigation on a building that they own and occupy.

Also in 2020, ISDH took action to confront a long-term gap in the radon program: the lack of any mechanism for compliance monitoring of mitigation services to ensure radon mitigation systems are installed in a high-quality professional manner in accordance with industry standards. ISDH issued a request for proposals for contract radon inspection services. First, the program needed a baseline assessment of the quality of work being performed by Indiana radon mitigators and specifically its compliance with the old EPA protocols. Second, it needed to evaluate how much of a performance leap would be necessary for compliance with the ANSI-AARST Soil Gas Mitigation Standard. Third, it wanted to establish a means for ongoing compliance monitoring.
Since AARST had recently taken steps to strengthen its capacity for radon compliance enforcement and had developed initial plans for a mitigation compliance inspection credential, AARST submitted a proposal to provide contract radon inspection services for ISDH in a pilot project utilizing experienced trained professionals to inspect systems based on ISDH’s random selection of addresses from mitigator reports. ISDH accepted the proposal. Following development of a detailed checklist and electronic form, the pilot project was implemented January – April 2021. AARST contacted the current occupants of homes on the ISDH address list and obtained permission for radon system inspection. AARST contractors inspected 55 mitigation systems and documented (numerous) observed deficiencies, which covered the entire spectrum of components from labels and alarms to sealing and installation. ISDH and AARST are discussing expansion to measurement inspections.

Spotlight: Colorado’s New Regulation through Certification Law

In response to longstanding concerns about careless and/or incompetent performance of radon measurement and mitigation in Colorado, the Rocky Mountain Chapter of AARST won state regulation of CO radon professionals through certification.

Timeline and Milestones


  • Rocky Mountain Chapter of AARST obtained a “sunrise” review of radon regulation by the Colorado Office of Policy, Research and Regulatory Reform within the Department of Regulatory Agencies (DORA) to explore whether there is a need to regulate the profession.
  • DORA uncovered “significant evidence of harm to consumers in Colorado” from unregulated radon measurement and mitigation specialists and concluded that regulation is necessary against “unscrupulous service providers.”


  • Rocky Mountain and its lobbyist worked with its legislators, legislative counsel, allies and AARST to craft and perfect a proposed bill.
  • Although there were willing bill sponsors and substantial agreement, COVID shut down the CO legislature before it was possible to introduce the bill.


  • March 4: The Regulation of Radon Professionals Act, HB 21-1195, was introduced in the House.
  • April 29: HB 21-1195 passed the House (after approvals by the House Committees on Public and Behavioral Health and Human Services; Finance; Appropriations).
  • May 27: HB 21-1195 passed the Senate (after approvals by the Senate Committees on Business, Labor and Technology; Finance; Appropriations).
  • June: HB 21-1195 signed into Law.

The key rationales in both the DORA report and the chapter’s advocacy were:

  • Radon is a health risk.
  • Not requiring a license for measurement and mitigation places families at risk of inaccurate testing and incorrect mitigation systems, which escalate the risk of developing lung cancer.
  • Requiring that radon professionals follow standards developed by a process accredited by the American National Standards Institute (ANSI) ensures that commonly accepted, evidence-based methods are used.
  • Requiring that radon professionals possess certification by an EPA-recognized proficiency program is the optimum way to ensure that professionals are qualified for the work.

Summary of the Law

The law creates a regulatory framework for individuals interested in practicing as a radon measurement professional or a radon mitigation professional. On and after July 1, 2022, an individual is prohibited from practicing as a radon measurement professional or radon mitigation professional unless the individual is licensed by the Department of Regulatory Agencies. The law requires private certification to qualify for and maintain a license and disciplinary action against licensees for grounds established by the law.

The State of the Industry: Radon Professionals

In 2021, nearly 8000 individuals possess a certification, license, or both.

NRPP’s ISO 17024 Application Update

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. 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.

The NRPP took its first steps toward ANSI-ISO 17024 accreditation in 2018. With the assistance of psychometrician consultants, a new certification scheme, job task analysis, exam content development (aligned with the relevant ANSI-AARST consensus standards), and standard-setting for pass/fail have all been completed.  The new Radon Measurement Professional and Mitigation Specialist Exams went live on May 1.  The Measurement Field Technician and Mitigation Installer Certifications and Exams will launch on August 1.

To build internal capacity, four staff completed the ANSI Personnel Certification Accreditation Workshop. This spring, NRPP underwent a preliminary internal audit of policies, practices, and procedures as NRPP prepared to provide ANSI with the necessary evidence of compliance with its specific eligibility requirements. This preparation and scrutiny facilitated the submission of NRPP’s initial application for ISO 17024 accreditation at the end of June.

Once that preliminary application is approved, NRPP will have a maximum of 12 months to complete the formal application process, including a detailed onsite assessment and evaluation. The NRPP Certification Council and staff expect to achieve the goal of ANSI-ISO Accredited radon certification credentials by early 2022.

Third-party recognition of compliance to an ISO standard is a prestigious accomplishment. Accreditation under an ISO standard is used by government agencies and multinational employers as a reliable way to ensure that personnel certifications are sufficiently rigorous.


NRPP Certifications in 2021

Measurement Certifications

Radon Measurement Field Technician

The NRPP Radon Measurement Field Technician (RMFT) certification is geared toward a measurement technician who deploys and retrieves approved measurement devices, implements device placement, and ensures building conditions for residential testing and assessment. A Certified RMFT must work under the direction and QA/QC oversight of a Certified Measurement Professional.

Mitigation Certifications

Radon Mitigation Installer

The NRPP Radon Mitigation Installer (RMI) certification is geared toward individuals who install soil depressurization systems in residences and implement measures to protect themselves, co-workers, and occupants from hazards related to the mitigation process. A Certified RMI must work under supervision provided by a Certified Radon Mitigation Specialist.

Radon Measurement Professional (equivalent to current Radon Measurement Provider certification)
The NRPP Radon Measurement Professional (RMP) certification is designed to assess the knowledge and skills necessary for the evaluation of residential radon measurement results, including but not limited to client report generation, development and execution of QA/QC plans and worker exposure surveillance. A Certified RMP may function as the key person for analytical labs and oversight of work conducted by Radon Measurement Field Technicians.
Radon Mitigation Specialist (equivalent to the current Radon Mitigation Provider certification)
The NRPP Radon Mitigation Specialist (RMS) certification is designed to assess the knowledge and skills necessary for the design and ultimate compliance of residential radon reduction systems, and for the implementation of worker safety/ surveillance programs. A Certified RMS may provide supervision and oversight of work conducted by Radon Mitigation Installers.

On the Horizon: EPA Recognition of Certification Bodies

EPA announced its plan to establish new voluntary criteria outlining a standard of competence for organizations that credential radon service providers in “Voluntary Criteria for Radon Credentialing Organizations,” Docket ID EPA-HQ-OAR-2017-0430, at 82 FR 39993-39997, on August 23, 2017, and invited public comments. Four years later, radon stakeholders still await the emergence of EPA’s plan based on its review of the submitted comments as well as further research.

EPA’s most recent recognition of credentialing bodies occurred in 2002.

  • In 1988, Congress directed EPA to operate “a voluntary proficiency program for rating the effectiveness of radon measurement devices and methods, the effectiveness of radon mitigation devices and methods, and the effectiveness of private firms and individuals offering radon-related architecture, design, engineering, measurement, and mitigation services.” (L. 100-551)
  • EPA operated proficiency services for a couple of years, then abandoned its operation in 1998.
  • In 2002, NRSB and NRPP were recognized by EPA and became responsible for credentialing radon service providers in any state that lacked a state run regulatory program.

Renewed EPA action on credentialing is certainly overdue, and not a radical change but rather a continuation of the 1988 Congressionally directed policy intended to ensure that consumers have access to a proficient and qualified workforce of radon professionals nationwide.

  • Congress has never rescinded the directive for an EPA-led proficiency program.

Congress instructed EPA in appropriations bill report language to create criteria and recognize proficiency programs Consistency across credentialing bodies will be central to the likelihood of success for this next installment in EPA’s approach to fulfilling its statutory responsibility, especially in foundational components such as:

  • Standards: ANSI-AARST voluntary consensus standards, which are not only EPA-recommended, but also have been adopted by HUD, most regulatory states, and other standards bodies. There are no other current standards.
  • Accreditation: Credentialing body accreditation under the ANSI standard ISO 17024 Conformity assessment: General requirements for bodies operating certification of persons. Using third party, private sector accreditation systems, consistent with the 1996 Technology Transfer Act (L. 104-113), EPA can increase accountability and transparency quality assurance for well-qualified radon service providers offer services.
  • Scope: Certification “schemes” and job-task-analyses for positions such as technicians and specialists.

A new EPA framework will build upon existing resources such as state regulatory programs, current training providers and courses; proficiency program-approved device lists, exams, and course approvals; the ANSI-AARST standards. By effectively defining the expected standard of competence for entities that credential radon service providers, EPA will be positioned to increase accountability and consistency across the US, facilitate constructive change where needed, and encourage progress in the 30 states that lack credentialing programs.


US Congress, Interior-Environment Appropriations Act

House Report 114-632

Indoor Air and Radiation.—The Administrator shall take the following actions to meet the increased demand for radon services as a result of the National Radon Action Plan: (1) establish criteria for recognition of national proficiency certification programs that use ongoing performance review processes, with provision for discontinuation of certifications for cause, to ensure the effectiveness of private firms and individuals offering radon-related measurement and mitigation services utilizing consensus American National Standards; recognize qualified programs; and encourage States to require certification by qualified programs.

P.L.115-31; continued by P.L.115-141, P.L116-6