Radiation Health and Safety Practice Test

Prepare for your test with realistic questions.

The Dental Assisting National Board (DANB) offers the Radiation Health and Safety (RHS) Exam as a way for candidates to demonstrate their expertise in the proper safety procedures for taking X-rays. Many states require the certification in order for a dental assistant to provide this service but even in states that don’t require it, having it will give you a distinct advantage over other applicants and potentially qualify you to earn a higher salary.

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RHS Exam Outline

The Radiation Health and Safety exam contains 75 multiple-choice questions, and you will be given 1 hour to complete the exam.

The questions are split into three domains:

I. Purpose and Technique (50%)

The questions in this domain assess your knowledge in the following areas:

Anatomical landmarks, conditions, and materials observed on images
  • Apical pathology
  • Caries
  • Dental anomalies
  • Dental implants
  • Edentulous arches
  • Localization of impacted teeth and foreign objects
  • Periodontal conditions
  • Sinus areas
  • Temporomandibular joint
Purpose of dental images
  • Periapical
  • Bitewing
  • Full mouth series
  • Full mouth survey
  • Occlusal
  • Panoramic
  • Cephalometric
  • Cone-beam computed tomography (CBCT)
Technique to acquire dental images
  • Review patient medical and dental histories for contraindications, including medications
  • Intraoral techniques
  • Extraoral techniques
  • Technique modifications based on anatomical variations and clinical conditions
  • Error correction
  • Purpose and maintenance of radiographic equipment
  • Patient management techniques
  • Image viewing and mounting
  • Legal requirements for maintaining dental images

II. Radiation Protection (25%)

The questions in this domain test your knowledge in the following areas:

Radiation physics
  • Factors affecting x-ray production
  • Radiation characteristics
  • Radiation physics
Radiation biology
  • Cell and tissue radiation sensitivity
  • Type of exposure
  • Biological effect periods
  • Biological effects
  • Units of radiation measurement
Radiation protection
  • Oral healthcare provider exposure to radiation
  • Patient exposure to radiation
  • Causes of unnecessary radiation exposure
  • Factors affecting radiation protection
  • Patient concerns about exposure to radiation
  • Informed consent or patient refusal of exposure to radiation
  • Protocol for suspected x-ray unit malfunctions

III. Infection Prevention and Control (25%)

The questions in this domain test your knowledge in the following areas:

Standard precautions for equipment and supplies according to ADA, CDC and OSHA
  • Breakdown and setup of treatment room
  • Barriers
  • Position indicating and beam alignment devices
  • Clinical contact surfaces
  • Critical and semi-critical instrument sterilization
Standard precautions for patients and operators according to ADA, CDC and OSHA
  • Hand hygiene
  • Personal Protective Equipment (PPE)
  • Cross contamination

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RHS Exam Registration

Before you register for the exam, you should decide whether or not you want to take the exam in-person at a testing center or remotely via an online proctor. The differences between these testing options will be outlined below.

You can apply for the exam online, or by mail or fax if you are taking the in-person test. When you send in your application, you will also need to send in the nonrefundable $75 application fee. Once you have sent in your application, it generally takes about 2-4 weeks for be processed by DANB.

Once your application is approved, you will be sent a confirmation email with a link to schedule your exam. You must schedule your appointment within 60 days of receiving the authorization to test. When you schedule your exam, you will need to pay the $270 exam fee.

Test Day

Test day will look different depending on your testing method of choice.

In-person Testing

You should arrive at the testing center 15-30 minutes early. Once you arrive, you will be asked to provide a valid photo ID, and you may be asked to scan your fingerprint and/or palm for identification purposes.

Before you enter the testing room, you will be asked to leave all personal items in a secure locker outside the room. Personal items include things like your phone, bags, food, notes, books, pencils, and any electronic devices.

Once you begin the exam, you will only be able to leave the testing room to use the restroom, but the timer will not be stopped during your break.

Remote Testing

You should log in to your account 15-30 minutes before the scheduled exam time to ensure there is enough time to finish the check-in process. The check-in process involves providing a valid photo ID, scanning your room with your webcam, run and pass the OnVUE system check, and sign a non-disclosure agreement (NDA). Once the NDA has been signed, the exam will begin.

Note that you are not allowed to wear a jacket during the exam, no other person is allowed in your room, and the following items are prohibited:

  • Bags
  • Notes
  • Mobile electronic devices (your cell phone is allowed but must be placed at a considerable distance from your testing area)
  • Pens and pencils
  • Food
  • Weapons
  • Books

How the RHS Exam is Scored

This exam is computer-adaptive, so depending on your performance, the difficulty of your test will increase or decrease as you go on.

Here’s a look at how it works:

A flowchart that shows the adaptive nature of the exam

The first question is judged to be of medium difficulty, and depending on your performance, the next question may be easier or harder. If you do well in the first question, the second question will be harder; conversely, if you do poorly on the first question, the second question will be easy.

The questions on the exam are rated on a scale of 100-999. The higher a question is rated, the harder the question is (e.g., a question marked as 740 will be more difficult than a question marked 355).

To pass the exam, your final question must be on or above the 400 mark. If your final question is below this mark, you will not pass the exam, even if you have answered some questions above the 400 mark at some point during the exam. This is because the computer has rated the difficulty of your final question based on how you answered the previous questions.

If you passed, your official exam results are provided by DANB within one to three weeks after taking the exam by mail. Your score report is uploaded to your online account if you did not pass.

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How to Pass the DANB RHS Exam

How to Study Effectively

Your success on Radiation Health and Safety test day depends not only on how many hours you put into preparing but also on whether you prepared the right way. It’s good to check along the way to see whether your studying is paying off. One of the most effective ways to do this is by taking Radiation Health and Safety practice tests to evaluate your progress. Practice tests are useful because they show exactly where you need to improve. Every time you take a free Radiation Health and Safety exam practice test, pay special attention to these three groups of questions:

  • The questions you got wrong
  • The ones you had to guess on, even if you guessed right
  • The ones you found difficult or slow to work through

This will show you exactly what your weak areas are and where you need to devote more study time. Ask yourself why each of these questions gave you trouble. Was it because you didn’t understand the material? Was it because you didn’t remember the vocabulary? Do you need more repetitions on this type of question to build speed and confidence? Dig into those questions and figure out how you can strengthen your weak areas as you go back to review the material.

Answer Explanations

Additionally, many DANB RHS practice tests have a section explaining the answer choices. It can be tempting to read the explanation and think that you now have a good understanding of the concept. However, an explanation likely only covers part of the question’s broader context. Even if the explanation makes sense, go back and investigate every concept related to the question until you’re positive you have a thorough understanding.

Comprehend Each Topic

As you go along, keep in mind that the DANB RHS practice test is just that: practice. Memorizing these questions and answers will not be very helpful on the actual test because it is unlikely to have any of the same exact questions. If you only know the right answers to the sample questions, you won’t be prepared for the real thing. Study the concepts until you understand them fully, and then you’ll be able to answer any question that shows up on the test.

Strategy for RHS Practice

When you’re ready to start taking practice tests, follow this strategy:

  • Remove Limitations. Take the first test with no time constraints and with your notes and RHS study guide handy. Take your time and focus on applying the strategies you’ve learned.
  • Time Yourself. Take the second practice test “open book” as well, but set a timer and practice pacing yourself to finish in time.
  • Simulate Test Day. Take any other practice tests as if it were test day. Set a timer and put away your study materials. Sit at a table or desk in a quiet room, imagine yourself at the testing center, and answer questions as quickly and accurately as possible.
  • Keep Practicing. Keep taking practice tests on a regular basis until you run out of practice tests or it’s time for the actual test. Your mind will be ready for the schedule and stress of test day, and you’ll be able to focus on recalling the material you’ve learned.



How many questions are on the DANB RHS exam?


There are 75 multiple-choice questions on the exam.


How long is the DANB RHS exam?


The time limit for this exam is 1 hour.


What is a passing score for the DANB RHS exam?


To pass this exam, you must achieve a score of at least 400.


How much does the DNAB RHS exam cost?


The application fee is $75, and the examination fee is $270.

By Kate Nockunas

Kate has been Mometrix’s Nursing and Medical Editor for over four years. She has a bachelor’s degree in Communications from Vanderbilt University, a bachelor’s degree in Nursing from Marymount University, and a master’s degree in Education from Johns Hopkins. Kate is a critical care registered nurse who still works occasionally in the ICU and PACU.


by Mometrix Test Preparation | This Page Last Updated: April 11, 2024

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