Chapter 04 — The Pennsylvania file
Current PA DEP credentials from the official Pennsylvania roster. We group people by the county on that file. We do not invent neighborhoods. Source: PA DEP.
What a 67-county review of Pennsylvania’s radon directories found. Historical research on listed locations and what directory counts can tell you.
§ 4.1
A county appears only when at least one current listing serves it.
§ 4.3
PA DEP certifies radon work in Pennsylvania and publishes a list we import monthly. Match the name and credential number on the official page before you hire.
§ 4.4
PA DEP certifies radon work in Pennsylvania and publishes a current list with credential numbers. This site imports that list and re-checks it monthly. 791 current Pennsylvania listings appear here as of October 13, 2026.
Open the PA DEP lookup at https://www.pa.gov/agencies/dep/programs-and-services/radiation-protection/radon-division/radon-services-directory, search the name, and match the credential number digit for digit. Status can change between our monthly check on October 13, 2026 and the day you hire. If the official page disagrees with this directory, the official page is right.
Pennsylvania issues its own radon credential through PA DEP, so a national NRPP or NRSB certification is not a substitute for it. Every Pennsylvania listing on this site shows the PA DEP number, not a national one.