Ecosense Lab
Irvine, CA
Listed for: Laboratory
Verified: Pennsylvania state license
Professionals
Radon professionals in California
Who tests and fixes radon in California, what California's own program says about licensing, and how to check a credential before you hire.
Updated October 2, 2026
Short answer
Radon professionals in California, in brief
No business that California itself licenses or certifies is listed on Radon411 yet. California's radon program says the state licenses or certifies radon professionals.
3 businesses with an address in California appear in a separate list because another state's registry lists them. That does not mean California licenses them.
The rule
Does California license radon professionals?
Yes. California's radon program page, checked on September 25, 2026, says:
The Radon Program certifies all radon service providers operating in California.
EPA's state contacts page lists California among the states with radon credentialing programs. Licensing is done by the state, not by the national programs, and EPA requires states that receive radon grants to give the public a list of only those providers credentialed by the state or by NRPP or NRSB.
Radon411 reads no licensing list for California; California's radon program is the place to ask who works there.
State program
California's radon program
The state's own radon program: the place to ask who may work in the state.
California Indoor Radon Program
California Department of Public Health
Its page covers free or discounted test kits and who may test and fix radon in the state.
Phone 1-800-745-7236 · Email Radonprogram@cdph.ca.gov
Visit the program's page (opens in a new tab)Read September 25, 2026
The directory
Radon professionals listed for California
None that California licenses yet. The businesses below have an address here and another state licenses them.
No business licensed by California is listed here yet. Where California licenses radon professionals, its own list is the complete one.
Located in California, licensed by another state
These businesses have an address in California, and another state's registry lists them. That does not mean California licenses them: check with California's radon program before hiring one for work here.
3 professionals located in California and listed by another state.
Ecosense
San Jose, CA
Listed for: Testing
Verified: Illinois state license
Lee, James - Ecosense Lab
Irvine, CA
Listed for: Laboratory
Verified: Pennsylvania state license
Before you hire
How to check a credential in California
California's own list
Start with California's radon program. Licensing is done by the state, and most states can give you a list of radon service providers working there.NRPP's search
The National Radon Proficiency Program's search finds its Certified Mitigation Specialists and Certified Measurement Professionals by area, by name, or by the 6-digit NRPP ID number a professional can give you.NRSB's search
The National Radon Safety Board's search finds a professional in your area, or confirms that a named professional is NRSB certified.The ID card
The programs usually issue a photo ID card showing the holder's qualifications and its expiry date. Ask to see it, and if in doubt, check with the body that issued it.
Hiring
Hiring in California
A tester
Ask for the credential and ID card, how the test will be guarded against interference, and when the report will come. EPA recommends an independent, qualified tester for the test after a system is installed.
A mitigation contractor
Get more than one estimate, contact references, and ask for a written proposal and a contract before any work starts.
Questions
Common questions about California
- Does California require radon professionals to be licensed?
Yes. California's radon program page, checked on September 25, 2026, says.
EPA's state contacts page lists California among the states with radon credentialing programs.
The Radon Program certifies all radon service providers operating in California.
- How do I find a certified radon mitigator in California?
No business is listed for mitigation in California on Radon411 yet.
Your state radon program can help you find qualified professionals in the state, and NRPP and NRSB, the two national proficiency programs EPA names, each publish a search of the professionals they certify.
- Who tests for radon in California?
No business is listed for radon measurement in California on Radon411 yet.
A qualified radon tester is very often a home inspector, and your state radon office can give you its approved list of radon testing companies.
- Does California offer free or discounted radon test kits?
California Indoor Radon Program's page, checked on September 25, 2026, says:
Discounted test kits can be purchased through our partner laboratory, Alpha Energy, for $14.95.
- How current are the California listings?
Radon411 reads no licensing list for California; California's radon program is the place to ask who works there.
- Is every business on this page licensed in California?
No listing here is a license. The first list holds businesses California's own registry lists, or that confirmed their own listing; each card names its source.
3 businesses with an address in California appear in a separate list because another state's registry lists them. That does not mean California licenses them.
No business pays to be listed, labelled or placed higher here, and Radon411 sells no leads. How listings are verified. Run a radon business in California? Claim your listing.
Next steps