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Radon professionals in Delaware

Who tests and fixes radon in Delaware, what Delaware's own program says about licensing, and how to check a credential before you hire.

Updated October 2, 2026

Short answer

Radon professionals in Delaware, in brief

No business that Delaware itself licenses or certifies is listed on Radon411 yet. Ask Delaware Division of Public Health Radon Office what it requires before you hire.

25 businesses with an address in Delaware appear in a separate list because another state's registry lists them. That does not mean Delaware licenses them.

The rule

Does Delaware license radon professionals?

Delaware's radon program page, checked on September 25, 2026, does not say whether the state licenses or certifies radon professionals. Ask the program before you hire.

Delaware is not on the list of states with radon credentialing programs that EPA's state contacts page publishes. 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 Delaware; Delaware's radon program is the place to ask who works there.

State program

Delaware's radon program

The state's own radon program: the place to ask who may work in the state.

Delaware Division of Public Health Radon Office

Delaware Division of Public Health

Its page covers free or discounted test kits.

Phone 1-800-464-HELP

Visit the program's page (opens in a new tab)Read September 25, 2026

The directory

Radon professionals listed for Delaware

None that Delaware licenses yet. The businesses below have an address here and another state licenses them.

By city

4 cities in Delaware with a listed business address.

No business licensed by Delaware is listed here yet. Where Delaware licenses radon professionals, its own list is the complete one.

Located in Delaware, licensed by another state

These businesses have an address in Delaware, and another state's registry lists them. That does not mean Delaware licenses them: check with Delaware's radon program before hiring one for work here.

25 professionals located in Delaware and listed by another state. Showing 1 to 1224.

On this page: 3 testing and mitigation, 921 testing

Testing and mitigation (3)

Testing (921)

Show 12 more on this page

Nearby

Listed professionals in states next to Delaware

A business licensed in a neighboring state is licensed there, not necessarily in Delaware. Check Delaware's rule above before you hire one.

Before you hire

How to check a credential in Delaware

  1. Delaware's own list

    Start with Delaware's radon program. Licensing is done by the state, and most states can give you a list of radon service providers working there.

  2. 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.

  3. 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.

  4. 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 Delaware

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.

What a professional test involves

A mitigation contractor

Get more than one estimate, contact references, and ask for a written proposal and a contract before any work starts.

How to choose a contractor

Questions

Common questions about Delaware

Does Delaware require radon professionals to be licensed?

Delaware's radon program page, checked on September 25, 2026, does not say whether the state licenses or certifies radon professionals. Ask the program before you hire.

Delaware is not on the list of states with radon credentialing programs that EPA's state contacts page publishes.

How do I find a certified radon mitigator in Delaware?

No business is listed for mitigation in Delaware 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.

How to choose a mitigation contractor

Who tests for radon in Delaware?

No business is listed for radon measurement in Delaware 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.

What a professional radon test involves

Does Delaware offer free or discounted radon test kits?

Delaware Division of Public Health Radon Office's page, checked on September 25, 2026, says:

Delaware Residents click HERE for your free radon test kit.

Free and discounted test kits by state

How current are the Delaware listings?

Radon411 reads no licensing list for Delaware; Delaware's radon program is the place to ask who works there.

Is every business on this page licensed in Delaware?

No listing here is a license. The first list holds businesses Delaware's own registry lists, or that confirmed their own listing; each card names its source.

25 businesses with an address in Delaware appear in a separate list because another state's registry lists them. That does not mean Delaware 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 Delaware? Claim your listing.

Next steps

Where to go next