RadonList exists because finding a legitimately certified radon testing company shouldn't require digging through government spreadsheets. We do the digging and publish the result in a form homeowners can actually use.
Every listing is compiled from official public records — primarily the NJDEP Radon Certification Program. We do not accept payment for inclusion, and we do not rank companies by who pays us.
Registry snapshot last retrieved: 2026-07-17. Certification status changes over time — always verify current status with the issuing agency before signing a contract.
New Jersey requires businesses that test for or mitigate radon to be certified by the NJDEP Radon Program — separate certifications for measurement and mitigation.
Certification means a company met the state's requirements to perform this work. It is not a guarantee of price, quality, or professionalism — get multiple quotes, ask for references, and confirm insurance.
Listing is free for every certified company, always. When homeowners request quotes through this site, we may refer those requests to licensed companies serving the area, and companies may pay us for that referral service. Referral arrangements never affect who appears in the directory or how listings are ordered.
Spot an error? Claim your listing or email us — we verify against the registry and fix it.
RadonList is an independent website. We are not affiliated with the State of New Jersey or any government agency. Currently listing 29 companies in New Jersey; more states are planned.