Question 1

What is the RHS exam?

Accepted Answer

The Radiation Health and Safety (RHS®) exam is administered by the Dental Assisting National Board (DANB). It is both a standalone national certification and one of the three component exams — alongside General Chairside (GC) and Infection Control (ICE) — that make up the full Certified Dental Assistant (CDA®) credential. Many states require RHS certification before a dental assistant may legally expose dental radiographs.

Question 2

What content areas does the RHS exam cover?

Accepted Answer

The DANB RHS blueprint is weighted across four domains: Radiation Physics & Equipment (35%), Radiographic Technique (30%), Radiation Safety & Protection (25%), and Infection Control (10%). Radiation Physics & Equipment is the highest-weighted domain.

Question 3

What is the ALARA principle and why does it matter?

Accepted Answer

ALARA stands for 'As Low As Reasonably Achievable' — the guiding principle of radiation safety: keep patient and operator exposure as low as possible while still obtaining diagnostic images. ALARA underlies exam questions on collimation, filtration, kVp/mA settings, exposure time, and protective barriers.

Question 4

How do I register for the RHS exam?

Accepted Answer

Register at danb.org. Create a My DANB account, verify your eligibility, complete the application, and pay the exam fee. After approval, schedule your exam through Pearson VUE at a testing center near you.

Question 5

How long should I study for the RHS exam?

Accepted Answer

Most candidates spend 2–3 weeks on focused RHS preparation. If you take radiographs chairside, much of the technique content will be familiar. Prioritize radiation physics and safety principles, which together account for 60% of the exam.

DANB RHS Exam FAQ (2026)

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