The DANB RHS exam for dental x-ray duties

A pass earns a certificate of knowledge-based competence in radiation health and safety, not a certification. The difference matters when an employer or a board asks what you hold: the certificate shows you passed one knowledge exam, while a certification (such as the DANB CDA) carries eligibility rules and yearly renewal.

The same exam is also a component of that certification (GC + RHS + ICE). A radiography pass counts toward it when the other two parts are passed within 5 years, so assistants who plan to certify later lose nothing by starting here.

What the certificate does not do is authorize x-rays on its own. Permission to expose images comes from the state dental board, which may name this exam, its own course or exam, or a combination; the state table further down shows what DANB lists for each state.

Anyone can apply. There is no diploma, program, work-hour or CPR requirement, so students and assistants in their first weeks can take it before anything else. The other exam that starts without prerequisites is Infection Control (ICE); the General Chairside part of the certification is the one that asks for an education or work pathway.

There is nothing to renew: the certificate does not expire, and no continuing education is attached to it. A state can still put its own clock on a result; New Mexico is one example. There, radiography certification is earned by passing the RHS exam or a board-approved course with an exam, each valid for 24 months (in effect April 21, 2026).

Three domains make up the outline effective March 12, 2025:

• Purpose and Technique, 50%: reading images, choosing the right image type, positioning, receptor holders, paralleling and bisecting technique, and correcting errors.
• Radiation Characteristics and Protection, 25%: how the beam is produced, radiation biology, dose units and limits, and protecting the operator and the patient.
• Infection Prevention and Control, 25%: barriers, disinfection and handling of sensors, phosphor plates and imaging equipment.

Every question assumes digital receptors. Darkroom chemistry and film processing are gone from the exam, so a guide built around them teaches content you will not be asked.

California and Texas are missing from this table on purpose: DANB's pages for both list the DANB CDA application but not this exam, and both states run their own radiography training.

Three listed states add a radiography credential of their own alongside the national exam or in its place:

• DANB also lists Maryland's Dental Radiation Technologist requirements.
• DANB also lists a combined New York Professional Dental Assisting, RHS and ICE exam (NYPDA/RHS/ICE).
• DANB also lists the Oregon Radiologic Proficiency (ORCR) certificate, Pathways I and II.

Ohio is not in the table. DANB lists no RHS exam application for Ohio; it lists its RHS Review course and an Affidavit of Ohio Clinical Radiography Training form.

Rules on who may take x-rays also shift with supervision law, as in Connecticut. A dentist who delegates dental x-rays to a dental assistant takes responsibility for them but need not stay on site (in effect October 1, 2026). Check the board before you rely on any row here.