Start Here · 3 min read
Exam Overview
The Radiation Health and Safety (RHS) Exam is a national-level assessment designed to evaluate your knowledge of dental radiography and radiation protection. The exam measures whether you can perform radiographic procedures safely, legally, and accurately in a dental setting.
The exam is administered by the Dental Assisting National Board and is recognized by many U.S. states as a requirement for dental assistants who take dental radiographs.
Passing this exam demonstrates that you meet nationally accepted standards for radiation safety and patient protection.
Exam Pattern and Format
The RHS exam follows a standardized computer-based testing format.
Key features include:
- Multiple-choice questions
- Single best answer per question
- Scenario-based and knowledge-based items
- No penalty for incorrect answers
Questions assess both recall and application of concepts commonly used in clinical practice.
Number of Questions and Time Limit
| Exam Feature | Details |
|---|---|
| Total questions | 75 multiple-choice questions |
| Time limit | 60 minutes |
| Question format | Single best answer from four choices |
| Content | Digital radiography only (current outline) |
| Scoring | Scaled score from 100 to 900; 400 or higher passes |
| Unscored items | A small number of pretest questions may be included |
| Domain | Share | Guide sections |
|---|---|---|
| I. Purpose and Technique | 50% | Sections 2 (digital receptors, image quality), 3, 4 (records), 5 and 6 |
| II. Radiation Characteristics and Protection | 25% | Sections 1 and 2, plus informed consent in Section 4 |
| III. Infection Prevention and Control | 25% | Section 7 |
Time management is critical.
You should plan to spend less than one minute per question.
Scoring System
The RHS exam uses a scaled scoring system.
Key points:
- Scores range from 100 to 900
- A scaled score of 400 is required to pass
- Raw scores are converted to scaled scores
- All questions are weighted equally
Your score reflects overall performance, not performance by section.
Exam Administration and Delivery
The exam is:
- Delivered by computer at Pearson VUE test centers
- Some DANB exams can also be taken by online remote proctoring; check the current RHS application for the options available to you
- Results are posted to your online DANB account, usually within a few business days
You schedule the exam after completing registration and eligibility requirements.
Importance of the RHS Exam
This exam plays a critical role in dental assisting practice.
It is important because it:
- Confirms competency in radiation safety
- Protects patients from unnecessary radiation exposure
- Ensures compliance with state regulations
- Supports legal and ethical dental practice
- Enhances professional credibility
In many states, you cannot legally take dental X-rays without meeting radiation certification requirements.
Role in Career Advancement
Passing the RHS exam can:
- Expand your clinical responsibilities
- Improve employability
- Support eligibility for advanced credentials
- Demonstrate commitment to patient safety
RHS is also one of the three component exams of DANB's Certified Dental Assistant (CDA) certification, together with General Chairside Assisting (GC) and Infection Control (ICE).
What This Means for Your Preparation
You must focus on:
- Understanding radiation principles
- Applying safety standards correctly
- Recognizing legal responsibilities
- Interpreting radiographic outcomes
This study guide is structured to match the exam expectations and help you prepare with accuracy and confidence.
Finished reading?
Next, start the first chapter.