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Legal base

The main legal requirements enforced by HSE are the Ionising Radiations Regulations 1999 (IRR99). Subject to being approved by Parliament, these will be replaced by the Ionising Radiations Regulations 2017 (IRR17) from 1 January 2018. For more information go to the IRR17 draft Approved Code of Practice and guidance.

IRR99 (S.I 1999 No 3232) replaced the Ionising Radiations Regulations 1985 (IRR85)(S.I.1985 No 1333) and the Ionising Radiations (Outside Workers) Regulations 1993 (S.I 1993 No 2379). IRR99 implemented most of the revised Basic Safety Standards Directive (96/29/Euratom).

IRR99 apply to a large range of workplaces where radioactive substances and electrical equipment emitting ionising radiation are used. They also apply to work with natural radiation, including work in which people are exposed to naturally occurring radon gas and its decay products. Any employer who undertakes work with ionising radiation must comply with IRR99. Under IRR99 employers who work with ionising radiation are called radiation employers.

IRR99 requires employers to keep exposure to ionising radiations as low as reasonably practicable. Exposures must not exceed specified dose limits. Restriction of exposure should be achieved first by means of engineering control and design features. Where this is not reasonably practicable employers should introduce safe systems of work and only rely on the provision of personal protective equipment as a last resort.

Risk assessment

There is a link to the Management of Health and Safety at Work Regulations (MHSW) with the requirement for employers to undertake a risk assessment. Under IRR99 employers must undertake a prior risk assessment before they start any new activity with ionising radiation. Once the work commences, regulation 3 of MHSWR requires the recording of the assessment (if there are five or more employees) and the maintenance of the risk assessment to keep it up to date where there has been a significant change in the matters to which relates. Regulation 5 of MHSWR also requires the making of arrangements for effective planning, organisation, control, monitoring and review of preventative and protective measures.

Radioactive substances

The Environment Agencies enforce the Radioactive Substances Act 1993, which is mainly concerned with the control of radioactive waste.

High activity sealed radioactive sources

The Environment Agencies also enforce the High Activity Sealed Radioactive Sources and Orphan Sources Regulations 2005 (the HASS Regulations) with the exception of high activity sealed radioactive sources that are kept, used, accumulated and disposed of on nuclear licensed sites, where the HSE is the regulatory authority for Great Britain.

The HASS Regulations do not affect a user’s requirement to comply with the IRR99, despite some of the requirements of the HASS Directive duplicating to some extent requirements of the IRR99. Users must comply with both sets of legislation and HSE and the Environment Agencies will work closely to ensure a consistent and comprehensive regulatory approach.

Article 8(1) of the HASS Directive (appropriate training of, and adequate information to be given to, employees and other persons concerning ionising radiation), as stated by regulation 19 of the HASS Regulations, is implemented by regulation 14 of the IRR99 and regulation 14 of the Ionising Radiations Regulations (Northern Ireland) 2000 (IRR(NI)2000). This means that in relation to HASS, the appropriate training and adequate information (which must be repeated at regular intervals and documented) required by IRR99 / IRR (NI) 2000 shall include:

Medical exposure

The Department of Health take the lead on The Ionising Radiations (Medical Exposure) Regulations 2000.


Justification is one of the key principles of radiological protection established by the International Commission on Radiological Protection on which the radiological framework of the UK is based. The principle of justification is that no practice involving exposures to radiation should be adopted unless it produces sufficient benefit to the exposed individuals or to society to offset the radiation detriment it causes. The Department of Environment, Food and Rural Affairs take the lead on the Justification of Practices Involving Ionising Radiation Regulations 2004.

Revision of the European Basic Safety Standards

In 2007, the EC began the process of revising the 1996 Basic Safety Standards Directive (96/29/Euratom) referred to above with the intention of recasting (consolidating) a series of radiation (EURATOM) Directives into one new Basic Safety Standards Directive.

Updated 2017-10-25