Regulation · Radiation and safety
IR(ME)R 2017
Referrer, practitioner, operator, employer. Four defined roles decide whether a medical exposure happens at all, and each one carries a duty that is written down.
The Ionising Radiation (Medical Exposure) Regulations 2017, SI 2017 No. 1322, known as IR(ME)R 2017, is the statutory instrument that governs every medical exposure to ionising radiation in the United Kingdom. As the Care Quality Commission (CQC) puts it in its IR(ME)R annual report 2020/21, the regulations "provide a regulatory framework to protect people against the dangers from being exposed to ionising radiation in a healthcare setting", and they state that exposures "need to be individually justified and optimised to ensure that the benefit for the patient outweighs the risk". The text itself runs to 22 regulations and 4 schedules on legislation.gov.uk.
When did IR(ME)R 2017 come into force, and what did it replace?
According to the CQC, in a notice published on 30 January 2018 and updated on 12 May 2022, "IR(ME)R2017 comes into force on 6 February 2018, revoking and replacing the Ionising Radiation (Medical Exposure) Regulations 2000 (IR(ME)R2000) and subsequent amendments, the Medicines (Administration of Radioactive Substances) Regulations 1978 and the Medicines (Radioactive Substances) Order 1978". The same CQC notice lists what was new in the 2017 text: licensing for nuclear medicine, non-medical imaging using medical equipment, medical physics experts, communicating benefits and risks to patients, and an amendment to definitions surrounding "much greater than intended". More background on the institutions behind this switch is covered elsewhere on this site.
Who does what under the regulations?
Regulation 2 of the instrument defines four roles, and every exposure sits somewhere between them. The referrer and the practitioner meet at the point of the referral, where the request is made and responsibility for the exposure is taken on. The employer, meanwhile, must put in place the written procedures and quality assurance programmes required by reg. 6 and Schedule 2.
| Role | Definition in the regulations, summarised |
|---|---|
| Referrer | A registered health care professional entitled, under the employer's procedures, to refer individuals for exposure to a practitioner. |
| Practitioner | A registered health care professional entitled, under the employer's procedures, to take responsibility for an individual exposure. |
| Operator | Any person entitled under the employer's procedures to carry out practical aspects, including those to whom practical aspects have been allocated, medical physics experts and, except where they work under the direct supervision of an adequately trained person, persons participating in practical aspects as part of practical training. |
| Employer | Any person who, in the course of a trade, business or other undertaking, carries out (other than as an employee), or engages others to carry out, the exposures described in regulation 3 or practical aspects, at a given radiological installation. |
How is an exposure justified and then optimised?
Regulation 11 sets out the justification of individual exposures, and it is where the weighing happens. The CQC describes the outcome of that weighing in the annual report quoted above: the benefit for the patient must outweigh the risk. Regulation 12 then deals with optimisation, requiring in its own words that doses are kept "as low as reasonably practicable consistent with the intended purpose". The optimisation duty brings particular attention to bear on children, on health screening programmes, and on individuals where a pregnancy cannot be excluded. The numerical side of this balance, the radiation doses themselves, is treated in a separate article on this site.
Regulation 2 also defines diagnostic reference levels as "dose levels in medical radiodiagnostic or interventional radiology practices, or, in the case of radio-pharmaceuticals, levels of activity, for typical examinations for groups of standard-sized individuals or standard phantoms for broadly defined types of equipment". These levels feed into the employer's written procedures under Schedule 2, which require "the use and review of such diagnostic reference levels as the employer may have established".
What must the employer write down?
Schedule 2 lists the written procedures the employer must maintain, and the schedule is remarkably concrete. It requires procedures to identify correctly the individual to be exposed to ionising radiation; to identify individuals entitled to act as referrer, practitioner or operator within a specified scope of practice; for making enquiries of individuals of childbearing potential to establish whether the individual is or may be pregnant or breastfeeding; for the assessment of patient dose and administered activity; and for the carrying out and recording of an evaluation for each exposure, including where appropriate factors relevant to patient dose. The schedule also requires a procedure "providing that wherever practicable, and prior to an exposure taking place, the individual to be exposed or their representative is provided with adequate information relating to the benefits and risks associated with the radiation dose from the exposure", which is one of the novelties the CQC highlighted in its January 2018 notice. Further procedures address the reduction of accidental or unintended exposure "so far as reasonably practicable" and dose constraints for carers and comforters.
Beyond procedures, the employer owes duties under reg. 7 for clinical audit, and reg. 17 covers training. Regulation 14 covers expert advice, and the medical physics expert is a legal role in its own right: reg. 2 defines such an expert as "an individual or a group of individuals, having the knowledge, training and experience to act or give advice on matters relating to radiation physics applied to exposure, whose competence in this respect is recognised by the Secretary of State". In nuclear medicine, a separate licensing regime applies: reg. 4 creates a Licensing Authority and reg. 5 a requirement to hold a licence, with ARSAC's "notes for guidance: good clinical practice in nuclear medicine", published on 17 April 2014 and updated on 14 July 2026, providing guidance on licencing and best use of radiopharmaceuticals and sealed radioactive sources in diagnosis, treatment or research.
Who enforces IR(ME)R 2017, and how?
In England the regulator is the CQC. Its IR(ME)R annual report 2020/21, a page updated on 10 August 2022, states that "CQC enforces the regulations in England by carrying out inspections, acting on information from other areas of our work and by reviewing statutory notifications from healthcare services about significant accidental or unintended exposures to patients". At national level, guidance for "employers and health professionals who carry out medical radiological procedures" was published by the Department of Health and Social Care on 27 June 2018 and updated on 4 September 2024, describing safeguards for individuals exposed to ionising radiation from medical equipment for imaging, treatment or research purposes.
Checked against the source
- IR(ME)R 2017 is SI 2017 No. 1322, with 22 regulations and 4 schedules (legislation.gov.uk).
- The regulations came into force on 6 February 2018, revoking IR(ME)R 2000 (CQC, 30 January 2018, updated 12 May 2022).
- The four roles of referrer, practitioner, operator and employer are defined at regulation 2 (legislation.gov.uk).
- The Department of Health and Social Care guidance was published on 27 June 2018 and updated on 4 September 2024 (gov.uk).
- IRR 2017 is SI 2017 No. 1075, also in force on 6 February 2018, with 43 regulations in 7 parts and 9 schedules (legislation.gov.uk).
Two regulations, often merged
IR(ME)R 2017, SI 2017 No. 1322, protects the person being exposed in a healthcare setting: the patient, or someone exposed for imaging, treatment or research purposes. Its core duties are the justification of each individual exposure and its optimisation, and its defined roles of referrer, practitioner, operator and employer all revolve around the individual exposure.
IRR 2017, the Ionising Radiations Regulations 2017, SI 2017 No. 1075, is a different instrument with a different object of protection: workers and the public. It runs to 43 regulations in 7 parts and 9 schedules covering notifications, risk assessments, dose limitation, controlled and supervised areas, the classification and surveillance of persons, and the control of radioactive substances and equipment. Both instruments came into force on 6 February 2018, which is one reason the two are so easily muddled.