Two national organizations certify radon professionals in the United States: the National Radon Proficiency Program (NRPP) and the National Radon Safety Board (NRSB). Both are EPA-recognized, both administer examinations and continuing education requirements, and both maintain searchable directories of currently certified professionals. Knowing which certification to look for — and how to verify it — protects you from uncertified contractors and ensures your test results or installation will be accepted by real estate transactions, state programs, and regulatory authorities.
NRPP: National Radon Proficiency Program
NRPP is administered by the American Association of Radon Scientists and Technologists (AARST). It is the larger of the two national certification programs, with thousands of currently certified professionals across measurement and mitigation disciplines.
NRPP Certification Categories
- Radon Measurement Professional (RMP): Certified to conduct radon measurements in residential and commercial buildings using EPA-approved and AARST-standard protocols. Required for conducting certified real estate measurements in most states.
- Radon Mitigation Specialist (RMS): Certified to design and install radon mitigation systems per AARST-ANSI standards (SGM-SF for slab/basement, RMS-LB for large buildings). Required for mitigation work in states with licensing requirements.
- Radon Service Provider (RSP): Business-level certification allowing a company to offer radon services under a certified individual’s license.
NRPP Certification Requirements
- Approved training course completion
- Written examination with passing score
- Continuing education (16 hours per 2-year certification cycle)
- Current certification renewal every 2 years
Verify NRPP Certification
Search the NRPP directory at nrpp.info. Enter the professional’s name or certification number to confirm current status and discipline (measurement vs. mitigation). Certification can lapse — always verify before engaging a professional, not after the work is complete.
NRSB: National Radon Safety Board
NRSB is an independent certification body unaffiliated with AARST. It is the smaller of the two national programs but is equally recognized by EPA and most state radon programs. Some states specify acceptance of NRSB, NRPP, or both.
NRSB Certification Categories
- Radon Measurement Technician (RMT): Entry-level measurement certification
- Certified Radon Measurement Professional (CRMP): Advanced measurement certification with additional requirements
- Radon Mitigation Technician (RMiT): Entry-level mitigation certification
- Certified Radon Mitigation Professional (CRMiP): Advanced mitigation certification
Verify NRSB Certification
Search the NRSB directory at nrsb.org. Enter name or certification number to confirm current status.
State Certification Programs
Many states have their own radon certification or licensing requirements that operate alongside or instead of NRPP/NRSB. States with independent radon certification programs include Illinois, Iowa, Minnesota, New Jersey, New York, Pennsylvania, and others. In these states:
- A state license may be required in addition to NRPP/NRSB certification
- A state license alone (without NRPP/NRSB) may be sufficient for in-state work
- Real estate transaction tests may specifically require state-licensed professionals
Check your state health department’s radon program website for current state-specific licensing requirements. Requirements change — information from multiple years ago may be outdated.
Measurement vs. Mitigation Certification: Important Distinction
Radon certification is discipline-specific. A Radon Measurement Professional (NRPP) is certified to test — not to install systems. A Radon Mitigation Specialist (NRPP) is certified to install — not necessarily to conduct certified measurements. Some professionals hold both certifications; many hold only one.
This distinction matters because: allowing the installing contractor to conduct the post-mitigation test removes the independent verification that gives the result credibility. Best practice is independent post-mitigation testing by a certified measurement professional separate from the installing contractor — particularly for real estate transactions and warranty documentation.
When Certification Is Required
- Real estate transactions: Most states that mandate testing specify certified professional testing. Even in states without mandates, buyers and their agents routinely require it.
- State-regulated rental property testing: States with landlord testing requirements typically specify certified professional measurement.
- Federally assisted housing: HUD radon protocols require certified professionals for testing and mitigation in applicable properties.
- Schools and public buildings: EPA’s school radon guidance and AARST-ANSI SGM-SF standard specify certified measurement professionals for school testing programs.
- Mitigation under state licensing laws: In states with radon contractor licensing requirements, performing mitigation work without a license is illegal regardless of NRPP/NRSB status.
Frequently Asked Questions
What is the difference between NRPP and NRSB certification?
Both are EPA-recognized national radon certification programs. NRPP is administered by AARST and is the larger program; NRSB is an independent organization. Both require examination, approved training, and continuing education. For practical purposes, a currently certified professional from either program meets the requirements for most real estate and state program contexts — though individual state programs may specify a preference. When in doubt, verify that your state’s radon program accepts the specific certification held by the professional you are engaging.
Can a radon mitigator also test for radon?
Only if they hold both a Radon Mitigation Specialist certification and a Radon Measurement Professional certification. Mitigation-only certification does not authorize certified measurement work. In states that specifically prohibit the installing contractor from conducting the post-mitigation test, even dual-certified professionals may not be permitted to self-certify their own installation results.
How do I verify a radon contractor’s certification?
Request the contractor’s NRPP or NRSB certification number and verify it directly at nrpp.info (NRPP) or nrsb.org (NRSB). Both sites have searchable real-time directories. A contractor who cannot or will not provide a verifiable certification number should not be engaged for certified measurement or mitigation work.
Leave a Reply