Two separate sets of rules govern commercial radon work in Pennsylvania: EPA guidance, which sets the health-based action level and the testing and mitigation standards of practice used nationwide, and Pennsylvania’s own state law, which controls who is legally allowed to perform radon testing and mitigation for a fee. Understanding both is the difference between a compliant radon program and one that just looks like it.
The EPA Action Level: 4.0 pCi/L
The EPA’s radon action level is 4.0 picocuries per liter (pCi/L), and it applies consistently across building types — homes, schools, and commercial buildings alike. At or above that level, the EPA recommends taking action to reduce radon. Between 2 and 4 pCi/L, the EPA also recommends considering mitigation, since no level of radon exposure is considered completely without risk.
The scale of the exposure is well documented for schools specifically: EPA’s national survey found that roughly one in five schools has at least one room testing above the 4.0 pCi/L action level, and the agency estimates more than 70,000 occupied schoolrooms nationwide currently have elevated short-term radon readings. That’s a useful reference point for any commercial building with similar ground-floor, slab-on-grade construction — schools aren’t uniquely vulnerable, they’re just one of the few building types where testing has been studied at national scale.
EPA Standards of Practice for Testing and Mitigation
Beyond the action level itself, the EPA points to ANSI/AARST consensus standards as the technical benchmark for how radon testing and mitigation should be performed. For existing multifamily, school, commercial, and mixed-use buildings specifically, the relevant standard is the Soil Gas Mitigation Standards for Existing Multifamily, School, Commercial and Mixed-Use Buildings (ANSI/AARST SGM-MFLB), which sets minimum requirements for how a mitigation system should be designed and installed to actually protect occupants, not just install a fan and call it done. A certified contractor working on a commercial building in PA should be designing and documenting the system against this standard, not a residential-only protocol.
Large-building testing follows its own protocol as well: rather than a single test kit, EPA-aligned large-building protocols call for testing across multiple occupied zones, since radon concentrations vary meaningfully between rooms, floors, and building sections in ways a single-family home’s basement doesn’t. Two deployment approaches are recognized: an extended protocol, which places one device in each test location plus a percentage of duplicate and blank devices for quality control, then follows up on any location that reads elevated; and a time-sensitive protocol, which places two devices per test location up front so no follow-up round is needed. Which one a certified contractor uses depends on your timeline and how quickly you need a defensible result — a due-diligence deadline on a real estate deal, for example, usually favors the time-sensitive approach.
Pennsylvania’s Radon Certification Law
Where EPA sets the technical bar, Pennsylvania law controls who’s allowed to do the work. Since September 21, 1988, state regulation has required that anyone performing radon testing, mitigation, or laboratory analysis for compensation — other than a building owner testing or fixing their own building — hold certification from the PA Department of Environmental Protection. This requirement is codified in Title 25 of the Pennsylvania Code, Chapter 240, and it applies to all three radon-related activities as distinct certifications: testing, mitigation, and lab analysis.
A few specifics worth knowing if you’re a commercial property owner vetting a contractor:
- Individual and firm certification are both required. A company performing radon work must employ at least one individual certified for that specific activity, and that person is responsible for the work performed under the firm’s name.
- Membership in a national professional organization does not substitute for DEP certification. A contractor who belongs to AARST or NRPP but isn’t DEP-certified is not legally permitted to test or mitigate for hire in Pennsylvania.
- Training requirements go beyond a weekend course. DEP-approved training covers radon physics, measurement methodology, system design, ANSI/AARST installation standards, and Pennsylvania-specific regulatory requirements, not just how to run a test kit.
- The building-owner exemption is narrow. It applies to owners testing or mitigating a building they own or occupy themselves. It does not extend to a property manager, general contractor, or handyman performing the work on someone else’s behalf.
Why This Matters Beyond Compliance
For a commercial property owner, hiring an uncertified tester isn’t just a legal exposure, it’s a practical one. Results from an uncertified test typically won’t satisfy a lender’s environmental due diligence requirements, won’t carry weight in a real estate negotiation, and offer no assurance the testing protocol followed EPA or AARST large-building guidance in the first place. See our guide to commercial real estate radon testing before you buy or lease for how this plays out specifically in a transaction.
It also matters for any commercial building simply operating day to day. Whether you own an office, retail space, warehouse, or multi-tenant building, PA law treats radon testing and mitigation for that building the same way regardless of use. See our guide to whether commercial buildings in PA need radon testing for how the requirement applies to your specific property type.
How to Verify a Contractor Is Actually Certified
Pennsylvania publishes its list of certified radon professionals, broken out by testing, mitigation, and lab analysis certification, through the DEP’s radon certification program. Before signing a contract for commercial radon work, ask directly which certifications the assigned technician holds, confirm the firm employs at least one certified individual for the service being performed, and don’t accept a national-organization membership card as a substitute for state certification.
Working With a Certified Team
PA Radon Pros’ technicians are trained and certified to the standards this page covers, and our commercial systems are designed against the same ANSI/AARST framework the EPA points to for multifamily, school, and commercial buildings. For a full walkthrough of the process from testing through mitigation, read our complete guide to commercial radon testing and mitigation in Pennsylvania, or reach out directly through our commercial radon testing or commercial radon mitigation pages. Request a free quote or call (844) 945-4329 to talk to a certified team about your building.
