Code of Practice for Dental Radiology: ORS C4

Scope

C4 2024 applies to radiation practices associated with radiological equipment used for intraoral, panoramic and cephalometric dental procedures. Practices associated with cone beam computed tomography equipment are dealt with in the Code of Practice for Diagnostic and Interventional Radiology: ORS C1 .

Practices can include: manufacture, possess, control, manage, use, service and repair, transport, store, export, import, sell, supply and disposal of equipment.

Compliance with C4 2024 does not imply compliance in related areas such as health practitioners’ clinical competence, occupational safety, hazards in the workplace, resource management and transport of hazardous substances. 

Consultation and notification

In May 2023, the Ministry of Health reviewed the now revoked C4 2018 and concluded that revisions were required. In August 2024, a second round of consultation was conducted on the changes made to the public consultation version of C4 as a result of the submissions received.  

On 19 November 2024, the Director for Radiation Safety gave notice in the New Zealand Gazette that C4 2024 is issued to come into force on 1 December 2024.

Changes in C4 2024

Holder of a source licence

C4 2024 replaces the term ‘managing entity’ used in the revoked C4 2018 with terms referred to in the Act. In almost all cases, the new term used is ‘holder of a source licence’.  

Radiation Safety Officer

C4 2024 introduces a new requirement for the holder of a source licence to appoint a radiation safety officer (RSO). This change means that appointing an RSO is now a general requirement of radiation safety codes of practice. The training requirements for an RSO are set out in a new Appendix 2. 

The Director for Radiation Safety considers that, for the purposes of C4 2024 only, people who are, or deemed to be, registered with the Dental Council of New Zealand, and who hold an annual practicing certificate, can be considered to have met the training requirements for an RSO. This condition applies only for the activities specified for the registered practitioner in Schedule 3 of the Radiation Safety Regulations 2016. 

On this basis, a registered practitioner who meets these conditions can be appointed as an RSO by virtue of being deemed to meet the training requirements set out in Appendix 2 of C4 2024. The holder of the source licence can still appoint an RSO who is not a registered practitioner who meets these conditions, however,  such an RSO would need to meet the training requirements set out in Appendix 2 of C4 2024.  

Radiation risk assessment

C4 2024 introduces a new requirement for the holder of a source licence to carry out and maintain a radiation risk assessment. This change means that radiation risk assessments are now a general requirement of radiation safety codes of practice. Radiation risk assessments form the basis for establishing a management system to enhance radiation protection and safety. Establishing a management system to enhance radiation protection and safety was a requirement of the revoked C4 2018 that has been retained for C4 2024.  

Diagnostic reference levels in optimisation

C4 2024 introduces explicit requirements to use, generate or compare diagnostic reference levels (as the situation requires) for optimisation purposes when equipment is commissioned, serviced, or modified (including software updates). This change means that diagnostic reference levels will be used in optimisation activities under all diagnostic and interventional radiology codes of practice. The use of diagnostic reference levels are the primary means to ensure optimisation of radiation safety. Optimisation of radiation safety were requirements of the revoked C4 2018 which have been retained for C4 2024.   

Justification of occupational and public exposures

C4 2024 introduces an explicit requirement for the holder of a source licence, in conjunction with the dental practitioner, to consider occupational and public exposures, as well as patient exposures, when justifying each radiological exposure. This change means that the fundamental requirement set out in section 9(1) of the Radiation Safety Act 2016 is reflected in the justification requirements of C4 2024. 

Other changes

C4 2024 makes a significant number of technical clarifications and wording changes to improve readability and clarity of meaning. 

What the changes mean for dental practice

The Director for Radiation Safety has aimed to make the minimum amount of change for the people who must comply with C4 2024 while addressing the issues raised in the review of the now revoked C4 2018. In many instances, the new, explicit, requirements of C4 2024 formalise what has been implied by the related, but more general, requirements of the revoked C4 2018. 

Guidance notes

The changes made for C4 2024 mean that the Compliance Guide for Dental Radiology including Dental Cone Beam CT: ORS G4 (G4 2021)  and the Diagnostic X-ray Testing Frequency Guidelines (G1 2021) have been superseded. The Director for Radiation Safety intends to publish updated guidance to compliment C4 2024 in due course. Please contact [email protected] if you require a copy of a superseded compliance guide. 
 

Application of revoked C4 2018

On 1 December 2024, ORS C4 2018 was revoked. The provisions of the revoked C4 2018 no longer apply. However, the provisions of the revoked C4 2018 may apply to any matter that occurred while it was in force from 28 June 2018 to 31 October 2024. 

MIL OSI