How to check a radon firm is certified
How do you check a company is certified?
Search PA DEP's own lists. DEP publishes its certified testers, mitigators and labs in its Radon Services Directory and updates them each month. You can also call the Pennsylvania radon office at 800-237-2366.
The search above uses our copy of those lists, and shows the date we read them. For the latest, check the Radon Services Directory itself.
What should you check?
- The right certification. Testing and mitigation are separate. A company that only holds a testing certification can't install a radon system.
- The number. Every listing on this site shows it. Check it against DEP's list.
- The badge. DEP gives each certified mitigator a photo ID with their number and expiration date.
What do people ask?
Does a radon company need to be certified in Pennsylvania?
Yes. PA DEP says Pennsylvania law requires anyone testing, mitigating or analyzing radon for someone else to be certified. Homeowners may lower radon in their own home without being certified.
Source: PA DEP: Pennsylvania Citizen's Guide to Radon (2900-BK-DEP0375), checked September 26, 2026How can I check a radon mitigator's certification in person?
PA DEP gives each certified mitigator a photo ID badge with the certification number and expiration date. Ask to see it.
Source: PA DEP: Pennsylvania Consumer's Guide to Radon Reduction, checked September 26, 2026Where does this come from?
Source: PA DEP Radon Services Directory, checked September 26, 2026
Source: PA DEP: Pennsylvania Consumer's Guide to Radon Reduction, checked September 26, 2026
Source: PA DEP: Pennsylvania Citizen's Guide to Radon (2900-BK-DEP0375), checked September 26, 2026