Skip Navigation LinksCertified-Radon-Services-Providers

Certified Radon Services Providers

Certified Radon Services Providers

The Radon Program certifies all radon service providers operating in California. California law requires all radon professionals to be approved by either the National Radon Proficiency Program (NRPP) or National Radon Safety Board (NRSB).  There are no professional groups that are currently exempt from this requirement, including Home Inspectors, Industrial Hygienists, Registered Environmental Assessors (REAs), and Licensed Geologists. 

The California Department of Public Health does not endorse or recommend any company or individual over another.  As with any home service, you are advised to get more than one estimate.


Professional testers can provide test results faster than using a do-it-yourself test kit. Use a professional tester during a real estate transaction. They are also recommended for testing multi-family housing units, schools, non-residential buildings, and anytime you want quick results. The testers listed here have met their board requirements and are certified to operate in California:

Testers (PDF)


The mitigators listed below have met their board requirements and have met specific CA Contractors License requirements. They are certified to operate in California.

Mitigators (PDF)

A note about Contractors Licenses: Mitigators must also have a valid California Contractors License in one of a few specific categories. You can look up your contractor’s license here to make sure it meets our requirements.


The testers listed below have met their board requirements and are certified to operate in California:

Laboratories (PDF)

If someone offers you radon testing or mitigation and they are not on the approved lists here, they may NOT be certified to provide radon services in California.

To confirm a certification, report a problem, or report a business selling radon services without the proper Certification, email the radon program at or call (916) 449-5674.

Any person offering radon testing services, who is not a certified professional, is in violation of CA Health and Safety Code sec 106790. Any test results would be invalid for legal purposes. Violation of this regulation is considered a misdemeanor and the individual may be fined up to $1,000, and their business will reported to the appropriate consumer protection agency or licensing board.

Page Last Updated :