Where to study

Tests

Driving testsCitizenship testsSchool and university admissionsNursing, medicine and healthEnglish and French testsTeachingMoney, law and insuranceTrades and work certification and licensesPilots, drones, boats and radio

Countries

United StatesCanadaUnited KingdomAustraliaNew Zealand

United States · Certification exam

DANB RHS exam: radiation health and safety

The Radiation Health and Safety (RHS) exam is the Dental Assisting National Board’s (DANB’s) dental radiology exam, with 75 multiple-choice questions in 60 minutes. Anyone can apply, since there are no eligibility requirements, and you can take it at a Pearson VUE test center or online. The DANB RHS exam counts toward the Certified Dental Assistant (CDA) and National Entry Level Dental Assistant (NELDA) certifications, and DANB says it’s recognized or required in many states.

  • 75Multiple-choice questions
  • NoneEligibility requirements to apply
  • 60 minutesTesting time, and the clock doesn’t stop
Where to study

Updated October 2026 · Written from official sources, listed at the bottom of this page

What’s on the DANB RHS exam?

Three domains, and every candidate gets the same share of questions from each. Half the exam is about taking and reading dental images: the purpose of periapical, bitewing, full mouth series, occlusal, panoramic, cephalometric and cone-beam (CBCT) images, paralleling and bisecting angle technique, error correction, mounting and the legal rules for keeping images.

DomainShare
Purpose and technique50%
Radiation characteristics and protection25%
Infection prevention and control25%

The exam tests digital radiography only. DANB says it hasn’t tested conventional, film-based concepts since July 7, 2022.

The outline also lists the radiography terms that may appear, and its list of acronyms is available to you during the exam.

Like the ICE and GC exams, the RHS is scored from 100 to 900 and you need 400 to pass. The overview explains how DANB’s scaled scores work.

How DANB exams are scored →DANB: RHS Exam Outline and References (PDF) ↗

Is the RHS exam DANB’s radiology or x-ray certification?

In DANB’s list of national exams, the RHS exam is the radiology exam. Pass it and you earn DANB’s RHS certificate, with a digital badge issued through Credly. DANB calls these certificates of knowledge-based competence.

Whether it lets you take x-rays at work is your state’s decision. DANB says its exams give you authority to perform a duty only in states that recognize them as meeting their dental assisting requirements. Some states have their own radiology credentials that DANB administers, such as Oregon’s Radiology Certificate, so look up your state before you apply.

DANB: State Requirements ↗DANB: State Exams ↗

Taking the RHS exam alone or with other exams

You can apply for the RHS exam on its own, pair it with Infection Control (ICE) or General Chairside Assisting (GC), or take it as part of the full CDA exam. A pair costs less than two single exams. The CDA page sets out the questions, time and fee for each option.

The RHS and RHS/ICE exams are also offered in Modern Spanish.

Every DANB exam option and fee →DANB: Radiation Health and Safety exam page ↗

Is there a DANB RHS practice test?

Yes, from the DALE Foundation, which DANB calls its official affiliate. Its RHS Practice Test has more than 200 questions. DALE also sells an RHS review course and Rad Lab, a set of interactive RHS study scenarios.

DANB’s own RHS Study Guide Plan is a free download that sets out the weeks for you, and DANB’s demo exam shows the screens and navigation you’ll see on the day.

RHS practice test prices compared →The RHS Study Guide Plan →
Sources: DANB · The DALE Foundation and 5 more. Checked October 2026.

Rules and fees can change, so check the official site before your test.

Explore

Everything else, in one place

OverviewStudy optionsStudy guideCDAICE examGC examRenewal