This is just a heads up for those wishing to take the NRPP exam for Radon measurement.
The nachi Radon course has been approved as a pre-testing course. It is not listed on the NRPP website. But I did get confirmation from them that it will work. Whilst the Nachi course is ok it is too in depth for exam prep. If your prepping for the exam then my recommendations are the following:

  1. Do the Nachi Radon Course
  2. Do the Nachi Radon course again.
  3. Learn in detail about the different types of testing methods.
  4. Learn about the pros & cons for each testing method.
  5. Learn about what if’s i.e. one above 4pCi/L one below 4pCi/L with regards to real estate transactions.

Hope this helps


Thanks for the info!

Thanks …Much appreciated … Roy

Is the NACHI course also recognized for the NRPP continuing education requirements?

Dennis Palmer
Full Spectrum Inspections

Thank you for this information! There is very little online about this exam, length of exam, number of questions, content ect. It has been nerve racking preparing to take the exam because there are so few resources out there to help.

Thank you for posting.


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Hi everyone,

I recently took the NRPP exam and wanted to throw in my opinion as well. I do agree that the Nachi course is far to spread out on topics and detailed to be a good study guide. Below is a breakdown of the actual subjects they question you on. I am sure this changes slightly from test to test.

Physics of Radon - 14 Questions
Health Effects of radon - 10 Questions
Radon Entry into the home - 10 Questions
Conducting Measurements - 16 Questions
Interpret Non Real Estate - 5 Questions
Interpret Real estate - 6 Questions
QA/QC - 11 Questions
Passive Devices - 13 Questions
Active Devices - 5 Questions
Basic Mitigation Approach - 6 Questions
Radon in Water - 1 Question
Standards of Conduct - 3 Questions

I completed both the radon measurement service provider course and advanced radon measurement service provider course through Internachi with no problems and pretty quickly. Treating that as my study and going to take the proctored exam was my mistake. I am going to retake the exam after building myself a study guide based on the above NRPP format.


This test is no joke! I passed it though!

The InterNACHI Advanced Radon Measurement Service Provider Course follows the exact same format/sections of the NRPP Residential Radon Measurement Provider Examination.

With that being said the others who said the InterNACHI course was too broad on the topics I would agree. However, if you study and memorize everything you should be good.

Hint: The answers to a lot of the questions are in the long boring parts.

Parker, Colorado Home Inspector


Greetings all.

I (barely) passed my NRPP exam today with knowledge exclusively based on InterNACHI’s Advanced Radon Measurement Service Provider Course. The exam was way harder than expected. I may not have put enough time into it if not for the warnings above, so heed their advice. I squeaked by with 73% but got it done first try. If it was not so expensive, I’d study again and re-take to feel better about my score. 2/4 on ethics! Wow.

Many questions seemed to have multiple right answers. Example, which device is more susceptible to air movement: AT, LS, EL, GS, … - I thought they were all affected by moving air like in ventilation, no? The questions are also thoughtful. 100 questions, 2 hours which was plenty. The less you know the more time you’ll have :slight_smile: Formulas and calculator are provided. Very little math. Know how to figure which is more exposure: 52 years in 4 pCi/L at 0.4 ER versus 7 years at 30 pCi/L at 0.6 ER, etc.

I agree with all comments above that the NACHI course is not an ideal basis for NRPP exam, however its all in there including the long boring parts.

My tips:
(1) Download the Advanced Radon study guide - there is a link to it near the top of the course. It is easier to re-read in PDF format than to step through the course page-by-page again.
(2) Many questions are based on the EPA Radon guides. Those are in the NACHI course, or get them at
(3) There were more questions about mitigation than I expected. I skimped on those since that’s not what I’ll be doing. Mistake.
(4) Know all the device types, not just the one you use/plan to use.

Point is, you really have to cover all elements of the course.

Good luck.


Thanks to all who have provided guidance. I realize this was an old thread that was resurrected earlier this year, and could be considered old again by now. I’m going to be taking my exam soon and appreciate the insights. I’ll post again with my own thoughts after I take the exam.

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Thanks. taking the State test next week.

Yes it is. Scroll down this page: It’s under “Web Based Courses.”

Boy, I’m sure glad they fixed it after 5 years!

I just took this test after completing the InterNACHI Advance Radon course. I must have gotten the hardest version. A ton of math and physics. I agree about learning the details of each device type etc. Good luck all.

Seems to be a shame there is nothing to properly prepare anyone for either of the exams and the exams really cover anything you will ever use in the field… and the costs to take the exams is also nuts…

I feel like the test is designed to ensure a sufficient number of people pay for it more than once.

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NRPP now has an online guide available for their radon test. Wish I would have had it the first time I took the exam.

You’re correct! The NRPP is a bitch depending on the version test you get. Took me twice. NHIE only once. Now the fun part that they dont tell you - I just went through it myself. If you are in a state that requires a license, some of those states require membership in either AARST-NRPP or NRSB. Each one of those have a separate certification costs and hoops to jump through. Each of those will require your first radon device to go thru a Device Performance Test (DPT) at an approved Radon Chamber- I went thru Kansas State Univ. (Recalibration every year, new DPT every 2 years) Again, another cost. Don’t be confused like I was. “You” are not being tested, the device is. Send them the device, they will run a 48 hour measurement and send your device back. You then read your device for the average pCI/L and complete a form which you send back via email. They will do the IRE math and tell you whether your reading is within 25% (PASS/FAIL) of the known value in the radon chamber. Once done, apply for your certification. Once that is done, apply for your state license. The fun factor expired after failing the NRPP exam the first time.

Bureaucratic nightmare. And testing is not rocket science, as much as they like to portray it to be. I don’t have a problem with the state licensing and a test to show you know what you are doing. But the AARST, NRPP, NRSB certification requirement is a bit over the top.


Yep. My state code doesn’t say anything about being a member of any org, but gives the program director broad authority, so they require NRPP or NRSB certification, a detail QA Plan, a Radiological Safety Plan, etc etc but only a $50 license fee. LOL

Did you recently take the exam? Any current tips for someone planning to take it in the next month or 2? Any feedback would be greatly appreciated.