Ionising Radiation Regulations 1999 - free guide to IRR99 IRR99-ionising-radiation-regulations
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Ionising Radiations Regulations 1999

A Guide for Radiation Protection Supervisors

Designed for RPSs, radiation workers & employers, our Guide to the IRR99 provides a background to the legislation & changes introduced in 1999, along with guidance notes for all 41 regulations.

Interpretation and General
General Principles and Procedures
Arrangements for Management of Radiation Protection
Designated Areas
Classification and Monitoring of Persons
Control of Radioactive Substances, Articles and Equipment
Duties of Employees and Miscellaneous

The Complete IRR99 Regulations

Reg 1 : Citation & commencement
Reg 2 : Interpretation
Reg 3 : Application
Reg 4 : Duties under the Regs
Reg 5 : Authorisation of specified practices
Reg 6 : Notification of specified work
Reg 7: Prior risk assessment
Reg 8: Restriction of exposure
Reg 9: Personal protective equipment
Reg 10: Maintenance and examination of engineering controls etc. and PPE
Reg 11: Dose limitation
Reg 12 : Contingency plans
Reg 13 : Radiation Protection Advisers
Reg 14 : Information, instruction and training
Reg 15 : Co-operation between employers
Reg 16 : Controlled and supervised areas
Reg 17 : Local rules and Radiation Protection Supervisors
Reg 18 : Additional requirements for designated areas
Reg 19 : Monitoring of designated areas
Reg 20 : Designation of classified persons
Reg 21 : Dose assessment and recording for classified persons
Reg 22 : Estimated doses and special entries
Reg 23 : Dosimetry for accidents, etc
Reg 24 : Medical surveillance
Reg 25 : Investigation and notification of overexposure
Reg 26 : Dose limitation for overexposed employees
Reg 27 : Sealed sources and articles containing radioactive substances
Reg 28 : Accounting for radioactive substances
Reg 29 : Keeping and moving of radioactive substances
Reg 30 : Notification of certain occurrences
Reg 31 : Duties of manufacturers etc. of articles for use in work with radiation
Reg 32 : Equipment used for medical exposure
Reg 33 : Misuse or interference with sources of radiation
Reg 34 : Duties of employee
Reg 35 : Approval of dosimetry services
Reg 36 : Defence on contravention
Reg 37 : Exemption certificates
Reg 38 : Extension outside Great Britain
Reg 39 : Transitional provisions
Reg 40 : Modifications relating to the Ministry of Defence etc
Reg 41 : Modification, revocation and saving


Part I

Interpretation and General

Covering IRR99 Regulations 1 - 4

IRR99 Reg 1: Citation and commencement

All of the Radiation Regulations came into effect on 1 January 2000, except for Regulation 5 (Authorisation of specified practices) which came into force on 13 May 2000.

IRR99 Reg 2: Interpretation

A glossary is provided of various terms used. - a few key definitions are given in Appendix I to this guide for those terms set in quotation marks in the text.

IRR99 Reg 3: Application

The three basic types of work to which the Radiation Regulations apply are:

  • Any 'practice'
  • Any work in an atmosphere of natural radon gas at concentration > 400 Bq/m3 averaged over 24 hours
  • Any work with any 'radioactive substance' containing naturally occurring radionuclides

Reg 3(2)

A number of the Radiation Regulations are excluded if the work involves radon gas only.

Reg 3(3) & (4)

Several of the Regulations do not apply to persons undergoing medical exposures or a person who acts as a comforter and carer.

IRR99 Reg 4: Duties under the Regulations

Reg 4(1)

Any duty imposed on an employer to satisfy the Regulations in respect of persons other than his employees, is only relevant where such persons are exposed as a result of the work conducted by that employer.

Reg 4(2)

The term 'employer' includes the manager of a mine, the operator of a quarry and the holder of a nuclear site licence issued under the Nuclear Installations Act 1965.


Part II

General Principles and Procedures

Covering IRR99 Regulations 5 - 12

IRR99 Regulation 5: Authorisation of specified practices

Reg 5(1)

Prior written authorisation from the HSE is required for the use of accelerators (except electron microscopes) and for work with X-rays in:

  • Industrial radiography
  • The processing of products
  • Research
  • Exposures for medical treatment.

The HSE has issued generic authorisations for some practices, whereby individual application for authorisation will not be necessary, provided certain conditions ensuring very low radiation exposures can be met. Note that such practices may still need to be notified to the HSE.

Reg 5(3) & (4)

The authorisation may be subject to conditions and may be time limited. Any change in circumstances relevant to an authorisation needs to be notified to the HSE.

IRR99 Regulation 6: Notification of specified work

First time work with radiation must be notified to the HSE by the employer at least 28 days before commencing work. Such notification must include the particulars specified in Schedule 2. However, work specified in Schedule 1 or at a nuclear licensed site is excluded.

Work not required to be notified (Sch 1)

The following exemptions apply to work being conducted on a single premises or site:

  • The operation of cathode ray tubes in VDU's or any other equipment with an operating potential not exceeding 30 kV, provided that the dose-rate at 10 cm from any accessible surface does not exceed 1 Sv/h;
  • The operation of any other equipment provided that the dose-rate at 10 cm from any accessible surface does not exceed 1 Sv/h and the equipment is of a type which is approved by the HSE
  • Where the concentration and activity levels in Table 1 below are exceeded, but the radioactive material is in the form of a sealed source installed in equipment which is of a type approved by the HSE and the dose-rate at 10 cm from any accessible surface does not exceed 1 Sv/h;
  • Where the concentration of activity (Bq/g) does not exceed a specified level;
  • Where the quantity of radioactivity (Bq) does not exceed a specified level.

Radiation work is to be notified when both the concentration and activity are exceeded. Such values for the common range of radionuclides used in industry and research are given in below.

Notification values for commonly used radionuclides (Sch 8*)

Radionuclide Concentration*
3H 1 x 106 1 x 109 Elemental and cmpds.
14C 1 x 104 1 x 107 Excluding 14CO & 14CO2
14C 1 x 107 1 x 1011 As 14CO2
32P 1 x 103 1 x 105  
33P 1 x 105 1 x 108  
35S 1 x 105 1 x 108 Excluding organic or vapour
45Ca 1 x 104 1 x 107  
51Cr 1 x 103 1 x 107  
60Co 1 x 101 1 x 105  
125I 1 x 103 1 x 106  
137Cs 1 x 101 1 x 105  
226Ra 1 x 101 1 x 104 In equilibrium with daughters
241Am 1 x 100 1 x 104  

IRR99 Regulation 7: Prior Risk Assessment

Reg 7(1)

Before any new activity involving work with radiation can proceed the employer must make an assessment of the risk to employees and others in order to identify the measures to be taken to restrict exposures.

Reg 7(2)

Before any use of radiation can proceed the employer needs to ensure that an assessment has been undertaken (in line with the 'MHSWR') which identifies all hazards with the potential for causing a radiation accident, and the nature and the magnitude of the risks to employees and others arising from these hazards.

A risk assessment must be suitable and sufficient. In particular the assessment should show that:

  • The hazard is clearly identified, e.g. whole-body exposure to neutrons, exposure of the fingers to a collimated X-ray beam, direct contact with radioactive material
  • Those persons potentially affected are identified, e.g. operational staff, maintenance personnel, stores persons, cleaners
  • The risk is evaluated, by considering both probability and consequence, to arrive at a risk rating (e.g. low, medium or high)
  • Decisions are taken on whether the existing precautions (guarding, interlocks, safety screens, etc) are adequate or whether more should be done to reduce exposures to as low as reasonably practicable (ALARP)
  • Record the findings under the title Risk Assessment in the Local Rules by way of summary or reference, and set a date for periodic review.

Reg 7(3)

Where an accidental risk of exposure is identified, every effort is required to:

  • Prevent the accident occurring
  • Limit the consequences should it occur
  • Provide employees with information, instruction, training and equipment necessary to restrict exposures

For further precautions the employer should consider the need to designate certain working areas as Controlled or Supervised Areas and to take steps to prevent the possible spread of contamination.

IRR99 Regulation 8: Restriction of Exposure

Reg 8(1)

All radiation exposures are to be restricted as low as is reasonably practicable (ALARP). For the majority of cases this means a combination of physical protection and written procedures.

Foremost in any work with radiation the employer should take action to control doses by engineered means. Only after these have been applied should consideration be given to the use of supporting written procedures. Lastly, employers should provide personal protective equipment (PPE).

Reg 8(2)

Protection by physical means

Engineered controls and design features - these may be physical controls which are intrinsic to the device or specially fitted to restrict exposure. Examples include housings, enclosures, shielding and beam collimation for radiation sources and X-rays and containment of radioactive materials to prevent the spread of contamination.

Shielding will normally be adequate if designed to reduce accessible dose-rates below 7.5 Sv/h in areas where persons will be working. If there is unrestricted access to the device then the dose-rate should be the lowest that is reasonably practicable.

Safety features and warning devices - these are designed to prevent unintended exposure and indicate the status of the equipment in normal operation. Examples include interlocks on doors and exposure controls coupled to pre-exposure and exposure signals.

Where possible, interlocks or trapped key systems should be provided to:

  • Prevent the exposure commencing whilst the access panel or barrier is open
  • Interrupt the exposure if the access panel or barrier is opened
  • Prevent the exposure recommencing merely by closing the access panel or barrier

Sources of radiation which can give rise to significant exposure in a very short time should be fitted with visible and audible warning devices which:

  • Indicate the position of the radioactive source or whether the shutter is open or closed
  • Indicate the state of readiness of an X-ray generator to emit radiation and give a signal when the useful beam is about to be emitted
  • Are designed to be automatic and fail-safe.

Personal protective equipment - suitable PPE (in compliance with PPE Regs 1992) may be provided to further assist protection unless this is not warranted by the particular circumstances.

Protection by written procedures

A written System of Work may be necessary where the risk assessment indicates that specific procedures would improve radiation protection still further. This takes the form of a set of operational precautions which will help minimise the risk of exposure and is particularly relevant for work with or around the source of radiation which is beyond the scope of normal operations.

In circumstances where a person could receive an overexposure in a period of minutes or less, the System of Work may be more complex and require the issue of a Permit to Work, which specifies the tasks to be performed for the job and the level of supervision required.

Reg 8(3) - Dose constraints

Where it is appropriate, 'dose constraints' should be used at the planning stage of radiation protection to assist in restricting exposures as far as reasonably practicable.

In general, the value assigned to any dose constraint is intended to represent a level of dose which ought to be achieved in a well-managed practice.

Reg 8(5) & (6) - Pregnancy

Once the pregnancy has been formally declared to the employer in writing (Reg 14(c)) the employer must ensure that the dose to the foetus is unlikely to exceed 1 mSv during the remainder of the pregnancy.

This may be practically interpreted as an external dose limit of 2 mSv to the woman's abdomen given that the abdominal wall shields a half of the exposure. In most cases an assessment will show that such an external dose is unlikely in the remainder of term so no action is required.

Note that the 'MHSWR' require the risk assessment under Reg 3 to be extended to women of childbearing age or to new or expectant mothers where they may be exposed to any hazard which may adversely affect their health and safety or that of their baby.

Reg 8(7) - Investigation Level

An investigation is required when an individual's effective dose exceeds 15 mSv for the first time in any calendar year. However, employers are encouraged to set a lower investigation level, as appropriate to the work, which must be included in the Local Rules (if these are required by Reg 17) or referred to by other suitable means.

IRR99 Regulation 9: Personal protective equipment

Reg 9(1) & (2)

Any PPE provided must comply with the requirements of the PPE Regulations 1992 (SI 3139), apart from some respiratory protective equipment which must have been approved by the HSE.

Reg 9(3)

When not in use, PPE must be stored in such a manner as to keep it in good working condition.

IRR99 Regulation 10: Maintenance and examination of engineering controls etc. and PPE

Reg 10(1)

All engineering controls, warning devices, design and safety features must be properly maintained and periodically examined and tested.

Reg 10(2)

All PPE must be maintained and periodically examined. In the case of respiratory protective equipment a record of its state must be kept for 2 years.

IRR99 Regulation 11: Dose Limitation

Reg 11 (Schedule 4 - Part I)

The employer must ensure that the following dose limits (prescribed in Schedule 4) are not exceeded in any calendar year:

Annual dose limits for employees and members of the public

Dose Employees
(age 18+)
(age <18)
Members of Public
Effective dose 20 mSv 6 mSv 1 mSv**
Equivalent dose for eye 150 mSv 50 mSv 15 mSv
Equivalent dose for skin*** 500 mSv 150 mSv 50 mSv
Equivalent dose for the hands, forearms, feet and ankles 500 mSv 150 mSv 50 mSv

* A trainee is an employee aged 16-18 (including a student) who is undergoing instruction in work with radiation
** For exposure to radiation resulting from medical exposure of someone else the limit is 5 mSv in any 5 consecutive calendar years
*** Averaged over 1 cm2 regardless of area exposed

Dose limits apply to any calendar year.

Women of reproductive capacity

An equivalent dose limit applies to the abdomen of women of reproductive capacity for exposure to external radiation, being 13 mSv in any consecutive period of three months.

Reg 11 (Schedule 4 - Part II) - Special circumstances

Where an employer is able to show that the occupational dose limits set out in Table 2 are impracticable due to the nature of the work being undertaken, the effective dose to employees aged 18 or over may be limited to 100 mSv in 5 consecutive calendar years with a maximum in any single year of 50 mSv. In such a case the equivalent dose limits shall remain unchanged.

The following conditions apply to the use of this higher effective dose limit:

  • The RPA and affected employees are to be consulted
  • The reasons for the decision are to be provided in writing to both the affected employees and the 'approved dosimetry service'
  • The HSE is to be notified (usually within 28 days) giving reasons for the decision
  • A copy of the reasons for the decision is to be retained by the employer for 50 years thereafter

IRR99 Regulation 12: Contingency Plans

Reg 12(1) & (2)

Where the risk assessment made in accordance with Reg 7 shows that a radiation accident is reasonably foreseeable, the employer must prepare a contingency plan to ensure that doses to those affected are restricted to a minimum.

A suitable emergency plan is to be detailed for each accident scenario identified and must be incorporated into the Local Rules by way of summary or reference.

Appropriate instructions are to be given to all those who may be involved in the plan and, where appropriate, rehearsals of the plan are to be conducted at suitable intervals.


Part III

Arrangements for the Management of Radiation Protection

Covering IRR99 Regulations 13 - 15

IRR99 Regulation 13: Radiation Protection Advisers

Reg 13(1)

Whenever work with ionising radiations requires notification to the HSE an employer needing advice on compliance with the Regulations must consult a radiation protection adviser (RPA).

Reg 13(2)

If the employer requires specific advice on the following matters, the RPA must be appointed in writing and such formal appointment shall include the scope of advice to be given.

Reg 13 (Schedule 5)

Matters for which an RPA must be appointed in writing:

  • Implementation of requirements for Controlled and Supervised Areas
  • Prior examination of plans for installation and commissioning of new or modified sources of radiation in relation to engineering controls, design features, safety features and warning devices provided to restrict exposure
  • Application, calibration and maintenance of instruments used for monitoring both radiation and contamination
  • Periodic examination and testing of engineering controls, design features, safety features and warning devices with regular checks on Systems of Work for restricting radiation exposure

It is the employer's responsibility to ensure that the appointed RPA is suitable to the appointment. To be suitable, an RPA will need to possess the knowledge, experience and competence required for the relevant field of radiation protection. Individuals and organisations wishing to act as RPAs must satisfy HSE criteria of competence and become accredited by either:

  • Achieving a National or Scottish Vocational Qualification Level 4 in Occupational Health and Safety with the appropriate radiation protection modules, or
  • Having been awarded a Certificate of Competence by an HSE recognised Assessing Body.
    [The first organisation to become recognised by the HSE as an Assessing Body is called RPA 2000 Ltd which was formed jointly by the Society for Radiological Protection (SRP), the Association of University Radiation Protection Officers (AURPO), the Institute of Radiation Protection (IRP) and the Institute of Physics and Engineering in Medicine (IPEM).]

IRR99 Regulation 14: Information, Instruction and Training

All employees who are engaged in work with radiation are to be given appropriate training in radiation protection and receive sufficient instruction for them to appreciate the risks to health caused by exposure to radiation, the precautions to be taken and the importance of complying fully with the Regulations.

The level of information given depends on whether the individual concerned is involved in the management of radiation protection and whether he is directly or indirectly involved with the radiation work.

The Radiation Protection Supervisor (RPS) should receive formal training appropriate to the radiation source under his supervision (sealed sources, X-rays, radiochemicals, etc). This should include radiation protection principles and procedures, the regulations which apply to the work, the relevant equipment and working conditions to enable them to supervise the work safely.

Plant operators, laboratory staff, and others who work directly with the radiation, should receive specific instruction from the RPS in the nature of the hazard, the associated risks, precautions to be adopted and what to do in emergency. It is the duty of those working closely with the radiation to inform others in proximity (whether other staff, maintenance personnel, visitors, etc.) of the presence and nature of the radiation hazard for their own reassurance.

Employers should consult their RPA when planning the extent of instruction and training.

Female employees must be informed by their employer of:

  • The possible risk arising from exposure to the foetus and to a nursing infant
  • The importance of informing their employer in writing as soon as possible after becoming aware of their pregnancy, or if they are breastfeeding

IRR99 Regulation 15: Co-operation between employers

Where the employees of one organisation are potentially at risk of radiation exposure from the operations of another organisation, there must be cooperation by exchange of information to ensure that the work is in full compliance with the Regulations.

In particular, decisions will need to be taken concerning the RPS appointment, the arrangements for monitoring around radiation sources, the arrangements for assessing personal doses, and the Local Rules which both employers are required to adopt. The amount of detail exchanged will depend on the complexity and direction of the work.


Part IV

Designated Areas

Covering IRR99 Regulations 16 - 19

IRR99 Regulation 16: Controlled and Supervised Areas

In order to restrict employee doses to a minimum, controls are placed on areas with enhanced radiation exposure or a significant presence of radioactive material. Such controls may range from routine monitoring of the radiation to restriction of access to certain authorised employees. In all cases the employer must have control over the area in question.

Reg 16(1)

A Controlled Area must be designated by the employer where:

  • A risk assessment (Reg 7) indicates the need for special procedures to be followed, so as to restrict exposure during normal operations or limit the probability of an accident involving the source of radiation.
  • The dose to an employee (aged 18 or over) working in the area is likely to exceed any of the values in column 2 of the following Table.

Likely employee annual doses for designation of areas

Dose Controlled Area Supervised Area
Effective dose 6 mSv 1 mSv
Equivalent dose for eye 45 mSv 15 mSv
Equivalent dose for skin 150 mSv 50 mSv
Equivalent dose for the hands, forearms, feet and ankles 150 mSv 50 mSv

A Controlled Area is most likely to be required if:

  • There is foreseeable access to the area for people whose work does not normally involve radiation.
  • Dose-rates from external radiation and potential levels of contamination from radioactive materials during normal work are likely to be significant.
  • Substantial external dose-rates or high levels of contamination (surface or airborne) can be expected in the event of a failure of control measures.
  • Normal control measures for an area have to be suspended for work such as maintenance or source changing.

In certain circumstances it is generally accepted that special procedures will always be necessary to restrict the possibility of significant exposure and therefore a Controlled Area is required.

Such circumstances occur where:

  • The external dose-rate in the area exceeds 7.5 Sv/h when averaged over the working day. [This figure relates to the statutory invstigation level of 15 mSv in a 2000-hour working year]
  • The hands can enter the area and the 8-hour time averaged dose-rate in that area exceeds 75 Sv/h
  • There is significant risk of spreading contamination outside the area
  • It is necessary to prevent, or closely supervise, access to the area by employees who are unconnected with the work with radiation.

The following diagram summarises the considerations that are important for deciding on the need for a Controlled Area.

Controlled Area Decision Tree

Reg 16(3)

A Supervised Area is required to be designated by the employer where:

  • It is necessary to keep conditions in the area under review in case redesignation as a Controlled Area is required
  • The dose to an employee (aged 18 or over) working in the area is likely to exceed any of the values in column 3 in the Table above.

The level of supervision extended to a Supervised Area requires the RPS to be aware of the persons working in that area and to conduct periodic monitoring to check radiation dose-rates or the presence of radioactive contamination.

In laboratories there will be general requirements for preventing spillages and for cleaning up any contamination arising from a forseeable accident. At least a part of the laboratory, therefore, should be designated as a Supervised Area to routinely check for the build-up of surface contamination resulting from poor work practices.

IRR99 Regulation 17: Local Rules and Radiation Protection Supervisors

Reg 17(1) - Local Rules

Written procedures in the form of Local Rules must be produced for any Controlled Area and, depending on the nature of the work, any Supervised Area.

The purpose of the Rules is to assist the RPS in instructing workers in radiation protection and, in the event of an accident, to provide a clear reference to prepared contingency plans. They should be relevant and concise and, whilst a generic set is applicable for similar work areas, they must as a minimum contain:

  • The name of the RPS
  • A description of the Controlled and Supervised Areas
  • A risk assessment
  • A contingency plan (being, at the least, emergency contact details).

Reg 17(4) - Radiation Protection Supervisors

Wherever work is governed by Local Rules the employer must appoint in writing at least one RPS to supervise adherence to the Rules. He has the duty of ensuring the company complies fully with the applicable regulations. However, responsibility ultimately rests with the employer and this cannot be delegated.

IRR99 Regulation 18: Additional requirements for designated areas

Reg 18(1) - Designation of Controlled & Supervised Areas

The boundary of a Controlled Area must, where practicable, be physically demarcated. Alternatively, it may be delineated by other suitable means.

As an example, the use of mobile gauging equipment at multiple test locations involves the designation of temporary Controlled Areas, which makes the use of warning tape or other physical barrier impracticable.

In such circumstances, the Controlled Area is maintained by constant supervision by the operator who verbally informs persons approaching the gauge of the need to keep at a certain distance, as described for the Controlled Area in the Local Rules.

Reg 18(1) - Warning signs

Regardless of how the Controlled Area is maintained, there is a requirement for a warning sign, located in a suitable position, to indicate all of the following:

  • The designation of the Area
  • The nature of the radiation source
  • The risks arising

For Supervised Areas, signs warning of the designation of the area are required, only where appropriate. If used, however, they must also indicate the three points above.

Reg 18(2) - Restrictions on access

No person is permitted access to any Controlled Area unless he is one of the following:

  1. A classified person
  2. A non-classified person entering in accordance with written procedures such that
    • For an employee aged 18 or over, his annual exposure is below the level which requires him to be classified (i.e. 6 mSv effective dose), and
    • For any other person his exposure does not exceed any relevant annual dose limit (e.g. 1 mSv effective dose for members of the public);
  3. An 'outside worker' (being a classified person) in respect of whom the employer has ensured that he:
    • Is subject to formal dose assessment (Reg 21)
    • Has been provided with and trained in the use of any personal protective equipment that may be necessary (Reg 8(2))
    • Has received any specific training that may be required (Reg 14)
    • Has been certified fit for the radiation work which he is about to carry out (Reg 24).

Reg 18(3) - Dose assessment for non-classified persons

For a non-classified person entering a Controlled Area in accordance with written procedures, the employer must be able to demonstrate that his exposures do not exceed the relevant annual dose limits, i.e. 6 mSv effective dose for employees and 1 mSv effective dose for other persons.

Such dose assessment may be achieved by either issuing a personal dosimetry badge, or other suitable means, e.g. recording the time spent in the area and the measured dose-rate using a portable survey meter.

The product of the two provides an assessment of the dose received.

Reg 18(4) - Dose estimation for outside workers

The employer who has designated the Controlled Area in which the outside worker is employed must ensure that:

  • The dose received by the worker is estimated for the time spent in the area
  • On completion of the work, an estimate of the dose received is entered into the worker's radiation passbook (Reg 21(3)(h)).

Reg 18 (5) - Dose records for non-classified workers

Records of all dose assessments must be kept for 2 years from the dates of recording and, if requested, the employer must make them available to the individual concerned.

Reg 18(6) & (7) - Radioactive contamination

If there is a significant risk of the spread of contamination from a Controlled or Supervised Area, the employer must make adequate arrangements to restrict such occurrence.

Where appropriate, these arrangements must include:

  • Provision of suitable washing and changing facilities for use on entry into and exit from the Area, and the proper maintenance of these facilities
  • Prohibition of eating, drinking and smoking
  • A means of monitoring for contamination any person or item leaving the Area

IRR99 Regulation 19: Monitoring of Designated Areas

Reg 19(1)

Levels of radiation must be routinely monitored both within and around all Controlled and Supervised Areas to confirm the correct designation of the area and to keep working conditions under review.

In particular, checks should be made for any of the following:

  • The presence of enhanced levels of radiation exposure within and beyond the confines of the Area
  • Leakage beams emerging from such items as gauging devices, source housings, X-ray tubes or cabinets, waste storage containers, etc.
  • The presence of contamination on surfaces from the spread of unsealed radioactive material
  • The presence of airborne contamination resulting from the release of gaseous materials or the resuspension of surface contamination.

When considering the adequacy of the monitoring regime the employer will need to consider in particular:

  • What kinds of measurements are to be made
  • What method of measurement; - direct monitoring with an instrument, collection of air samples, use of wipe samples
  • Where the measurements should be made; - note that in order to check the continued correct designation of areas, monitoring is necessary both inside and outside the boundaries of the designated areas
  • How frequently the monitoring should be carried out
  • Who should conduct the monitoring
  • How the records should be kept
  • Reference levels and action levels.

Reg 19(2) & (3) - Tests on instruments

The monitoring instruments used must be appropriate to the task and properly maintained. In addition, each instrument must have undergone performance tests before use and periodically at least once every year.

These tests are to be carried out by or under the supervision of a qualified person who has access to facilities and has the necessary expertise for conducting the tests.

Reg 19(4) - Records

Records of monitoring and checks on instruments must be kept by the employer for at least 2 years.


Part V

Classification and Monitoring of Persons

Covering IRR99 Regulations 20 - 26

IRR99 Regulation 20: Designation of Classified Persons

Reg 20(1) & (2)

All employees aged 18 or over who are likely to receive an annual effective dose greater than 6 mSv or an equivalent dose greater than 45 mSv (eye), 150 mSv (skin) or 150 mSv (hands, forearms, feet and ankles) must be designated as classified persons and informed of such.

The fact that an employee works within a Controlled Area is not in itself reason enough for their classification, particularly where the work is intermittent or takes place in one small part of the area.

Reg 20(2)

Prior to the classification of any person they must first be certified fit in a health record by either an 'appointed doctor' or employment medical adviser.

Reg 20(3) - De-classification

Employees may only be de-classified at the end of a calendar year, except when either:

  1. An appointed doctor or employment medical adviser so requires, or
  2. They are no longer employed by the same employer in a capacity which is likely to result in significant radiation exposure during the remainder of the calendar year

Exposure should be regarded as significant if the employee is likely to receive an effective dose of more than 1 mSv in that calendar year.

Reg 20(3)

When a classified person ceases employment with his current employer, the employer must request the 'approved dosimetry service' to produce a 'termination record' for that individual, which summarises his dose received during that employment.

The ADS is required to send a copy to the HSE and the employer must provide a copy to the individual concerned.

IRR99 Regulation 21: Dose Assessment and Recording for Classified Persons

Reg 21 (1)&(2)

The employer must ensure that all personal doses received by classified persons are assessed and recorded. The assessment is to be undertaken by an 'approved dosimetry service', which would normally provide personal dosimeters to be carried by the classified persons for a given period before return to the ADS for processing.

Reg 21 (3) - Arrangements to be made with an ADS for Classified Persons

The employer must arrange for an ADS to undertake all of the following:

  • Keep the dose records for 50 years from when they were made
  • Provide the employer with dose summaries at suitable intervals
  • Provide individual dose records at the request of the employer
  • Provide a 'termination record' to the HSE for any classified person leaving his current employer, and provide a copy to that employer
  • Provide the HSE with annual dose summaries within three months of the end of the calendar year.

Outside workers

Reg 21 (3)

Where the employer employs an 'outside worker', the 'approved dosimetry service' must provide the worker with a valid 'radiation passbook'. The passbook shall contain the details given in Schedule 6, which shall be kept up-to-date during his employment with that employer, and is not transferable to any other worker.

Reg 34 (3)

It is the duty of the outside worker not to misuse his radiation passbook or attempt to falsify any of the information in it.

Reg 21(6) & (7) - Dose records for classified persons

The employer must make available copies of recent dose summaries and dose records to classified persons at their request. Dose summaries are to be kept by the employer for at least 2 years. When a classified worker decides to leave his employment the employer must provide him with a 'termination record'.

IRR99 Regulation 22: Estimated Doses and Special Entries

Reg 22(1)

If any device used to assess the personal dose to a classified person is lost, damaged or destroyed, the employer must investigate the circumstances in an attempt to estimate the dose received by the individual.

Reg 22(1) & (2) - Estimated doses

Where there is adequate information to assess the dose, a summary should be sent to the approved dosimetry service which should then be in a position to enter the estimated dose in the individual's dose record. He must be kept informed of this process and a copy of the summary must be given to him on request.

Where there is inadequate information to estimate the dose, the employer shall arrange for the ADS to enter a notional dose in the individual's dose record, which shall be the proportion of the annual dose limit for the relevant period.

Reg 22(3) & (4) - Special Entries

If the employer suspects that the dose received by a classified person is much greater or much less than that recorded in the dose record, he shall investigate the circumstances and, where there is adequate information, send a summary copy of the information used to estimate the dose to the ADS.

The ADS should then amend the dose record with the estimated dose and identify it as a 'special entry'. The classified person must be kept informed of this process and a copy of the investigation report is to be kept by the employer for at least 2 years.

Reg 22(5)

Application for a special entry may only be made if less than 12 months has passed since the date of the original entry made in the dose record for classified persons, or less than 5 years has passed in the case of any other person.

Reg 22(6)

If the classified person is aggrieved by the decision to replace a recorded dose with a special entry dose in his dose record, he may apply to the HSE for a review of that decision provided no more than 3 months has passed since he was notified of the decision.

Reg 22(7)

Where the HSE concludes that the investigation in support of a special entry application was inadequate, or that the estimated dose was unreasonable, they may direct the employer to reinstate the original entry.

Reg 22(8)

Estimated doses which cause the effective dose limit of 20 mSv per year, or any equivalent dose limit, to be exceeded, shall first be approved by the HSE before being entered into the dose record.

IRR99 Regulation 23: Dosimetry for accidents, etc

Reg 23(1)

Whenever it is thought that an individual may have received an effective dose greater than 6 mSv, or an equivalent dose exceeding three-tenths of the relevant dose limit, the employer must arrange for the dosimetry device to be examined and to assess his dose as soon as possible.

If no such device is available, the dose should be assessed by some other means, in consultation with the RPA.

Reg 23(2)

The individual concerned must be informed of the result of the dose assessment and the employer must keep a record of the result for 50 years after the date of the occurrence.

IRR99 Regulation 24: Medical Surveillance

Reg 24(1) & (2)

The following employees are required to be under medical surveillance by an 'appointed doctor' or employment medical adviser:

  • Those persons about to be classified; [initial medical]
  • Classified persons; [periodic medical to demonstrate continued fitness for radiation work]
  • Non-classified persons who have received an 'overexposure'
  • Employees working according to conditions imposed by an approved dosimetry service (ADS) or employment medical adviser (EMA)

Reg 24(3)

The employer shall ensure that a health record is made for each classified person (and others to whom this Regulation applies) and maintained for at least 50 years from the date of the last entry. The particulars to be included in the health record are given in Schedule 7.

Reg 24(4)

An entry must be made in the individual's health record by either an AD or EMA and remains valid for 12 months.

Reg 24(6)

The doctor may certify that in his professional opinion the employee concerned should not be engaged in work with radiation or that his work should continue only in accordance with conditions that he may specify.

Reg 24(9)

Where an employee is aggrieved by a decision recorded in the health record he may apply to the HSE for a review of that decision, provided the application is made within 3 months of the date on which he was notified of the decision.

Reg 34(5)

It is the duty of employees to make themselves available for medical surveillance during working hours, if required by the employer, and to provide the doctor with such health information as he may require.

IRR99 Regulation 25: Investigation and notification of overexposure

Reg 25(1) & (2)

Where the employer suspects that an individual has received an 'overexposure', such that a relevant dose limit may have been exceeded, he is required to carry out an immediate investigation into the circumstances and keep a copy of such investigation report for at least 2 years.

If the investigation shows that an overexposure is likely to have occurred, the employer shall as soon as practicable notify the suspected overexposure to:

  • The individual concerned
  • The HSE
  • The AD or EMA (if his own employee)
  • The relevant employer (if employed by another)

Following such notification the employer shall investigate the circumstances of the exposure and assess the dose received in order to prevent a recurrence of the 'overexposure'.

A copy of this follow-up investigation report and dose assessment must be provided to all those listed above. A copy of the follow-up investigation report is required to be kept for at least 50 years.

Reg 25(3)

If the employee has a dose record, the estimated exposure is to be entered into it.

IRR99 Regulation 26: Dose Limitation for Overexposed Employees

Reg 26 (1)&(2)

Where an employee who has received an 'overexposure' is to continue radiation work, his applicable dose limit shall be the proportion of the annual limit in the time period remaining.


Part VI

Arrangements for the Control of Radioactive Substances, Articles and Equipment

Covering IRR99 Regulations 27 - 33

IRR99 Regulation 27: Sealed Sources and Articles Containing Radioactive Substances

Reg 27(1)

Wherever practically possible, all radioactive materials utilised for their radiation properties should be in the form of a sealed source.

Reg 27(2)

Sealed sources are required to be designed, constructed and maintained so as to prevent the leakage of any of the radioactive material.

Reg 27(3)

Sealed sources must be tested for leakage at least every 2 years and a record of the test kept for at least that period, or until a subsequent test. The purpose of the test is to demonstrate the continued integrity of the primary source containment.

If, however, the source is employed in equipment which is located in a hostile environment (e.g. it may be at risk from chemical attack, heat or physical damage) the frequency of testing should be increased accordingly to detect any breakdown in the source containment.

Where the source capsule is not accessible, an indirect test is normally sufficient provided the area wiped can reasonably be expected to reveal leakage. The necessity for a leak test is to be decided by the employer based on the likelihood of leakage and the type of source; tests may not be appropriate on sources which have no dimension greater than 5mm, such as microspheres.

IRR99 Regulation 28: Accounting for radioactive substances

Records must be maintained of the quantity, activity and location of all sealed or unsealed radioactive substances for at least 2 years from their date of origination or from the date of disposal.

IRR99 Regulation 29: Keeping and moving of radioactive substances

Reg 29 (1)

When not being used, moved, transported or disposed of, all radioactive sources must be kept in a suitable receptacle in a suitable store, i.e. to prevent access by unauthorised persons.

The principal controls placed on secure storage are stipulated as conditions attached to a source Registration licence issued by the Environment Agency under the Radioactive Substances Act 1993. These relate to the prevention of loss or escape of radioactive materials which could result in contamination of the environment. If no such licence is required, the relevant Exemption Orders prescribe conditions relating to secure storage.

Reg 29 (1)

Whilst being moved on the premises or site a source must be kept in a suitable and labelled receptacle.

Transportation involving carriage of radioactive sources on the roads is subject to the requirements of the Radioactive Material (Road Transport) Regulations 2002.

IRR99 Regulation 30: Notification of certain occurrences

Reg 30(1) - Accidental release

The accidental release of radioactive material is required to be notified to the HSE whenever the activities involved exceed the values given in column 4 of Schedule 8.

Accidental release refers to the release of radioactive material into the atmosphere as gas, aerosol or dust, by spillage or other release giving rise to significant contamination.

Such notification values for the common inventory of radionuclides in research use are given below:

Notification levels for accidental release

Radionuclide Quantity (Bq)
3H 1 x 1012
14C (Excluding 14CO & 14CO2) 1 x 1011
32P 1 x 1010
33P 1 x 1011
35S (Excluding organic or vapour) 1 x 1011
45Ca 1 x 1010
51Cr 1 x 1012
125I 1 x 1010

Reg 30(2)

This notification is not required where the release is in accordance with an Authorisation licence issued under the Radioactive Substances Act 1993.

Reg 30 (3) - Loss or Theft

Loss or theft of radioactive materials which exceed the quantity values given in column 5 of Schedule 8 must be notified to the HSE.

Such notification values for the common range of radionuclides in industrial or research use as sealed sources are given below:

Notification levels for loss or theft

Radionuclide Quantity (Bq)
60Co 1 x 106
63Ni 1 x 109
85Kr 1 x 1012
133Ba 1 x 107
137Cs 1 x 105
226Ra 1 x 105
238U 1 x 105
241Am 1 x 105

Reg 30 (4)

Where the employer suspects that a notifiable release, loss or theft may have occurred, he must carry out an immediate investigation to confirm the occurrence or otherwise.

Reg 30(5)

A report of any investigation which confirms accidental release, loss or theft must be kept on record for at least 50 years. If it is shown that no such incident occurred, the investigation report is required to be kept for 2 years.

IRR99 Regulation 31: Duties of manufacturers etc. of articles for use in work with radiation

Reg 31(1)

A general duty is placed on manufacturers of items which generate radiation or contain radioactive sources to ensure that they are designed and constructed so as to restrict radiation exposures as far as reasonably practicable.

Reg 31 (2) - Critical examination

A person who erects or instals any item which emits radiation at a workplace is required to:

  • Undertake a critical examination of the proper operation of safety features and warning devices and to ensure that there is sufficient protection from radiation
  • Consult with either his own RPA or the RPA appointed by the employer on the nature of the examination and the results obtained
  • Provide the employer with information about proper use, testing and maintenance of the equipment

The duty to ensure that the critical examination is carried out rests with the employer or installer who erects the article, not the user. The examination may be carried out during erection or installation, commissioning, or trials prior to use and will normally require co-operation between employers.

Although an RPA is required to be consulted, he need not be present when the examination is carried out.

IRR99 Regulation 32: Equipment used for medical exposure

Reg 32(1)

The employer must ensure that all equipment used in connection with medical radiation exposures is designed, constructed, installed and maintained so as to restrict as far as reasonably practicable the exposures received by patients, and to be compatible with the clinical or research objective.

Reg 32(2)

Diagnostic equipment which is installed after the coming into force of these Regulations must be provided with a means of informing the operator of the quantity of the radiation delivered during the procedure.

Reg 32(3) & (4)

The above is to be achieved by making use of a suitable quality assurance programme which shall require the following to be carried out:

  • Testing prior to use of a new installation
  • Performance testing periodically and after any major maintenance
  • Where appropriate, periodic measurements of the doses delivered to those undergoing the exposures

Reg 32(6)

Where it is suspected that a person has received a much greater exposure than intended whilst undergoing a medical procedure, the employer must make an immediate investigation and, if the exposure is confirmed, inform the HSE and arrange for a more detailed investigation of the particular circumstances and the dose received by the patient.

Reg 32(7)

The immediate investigation report must be kept for 2 years and the detailed investigation report kept for 50 years.

IRR99 Regulation 33: Misuse or interference with sources of radiation

It is an offence, without reasonable cause, to intentionally misuse or interfere with any radioactive substance or electrical equipment which is subject to the Regulations.


Part VII

Duties of Employees and Miscellaneous

Covering IRR99 Regulations 34 - 41

IRR99 Regulation 34: Duties of employee

Reg 34(1)

Employees must not knowingly expose themselves or any other person to radiation to an extent greater than that which is necessary for the work being undertaken and all work is to be carried out with reasonable care.

Reg 34(2)

Where personal protective equipment is provided for an employee's benefit, he must make full and proper use of it, report any defects to the employer and, as far as possible, return it to its proper storage place when not in use.

Reg 34(3)

It is the duty of every outside worker not to misuse his radiation passbook or attempt to falsify any of the information in it.

Reg 34(5)

All employees appointed as classified persons must make themselves available for annual medical examinations during work time and shall provide the doctor with such health information that is asked for.

IRR99 Regulation 35: Approval of dosimetry services

Reg 35(1) & (2)

On approval of a dosimetry service the HSE issues a certificate of approval for specified areas of dosimetry which may be subject to conditions and may be revoked at any time.

IRR99 Regulation 36: Defence on contravention

Various defences are provided in respect of the following Regulations:

Reg 36(1)

Reg 6(2) 28 days advance notification to the HSE of intent to begin radiation work

Reg 36 (2)

Reg 7 Prior risk assessment. [defence relates to the initial ignorance of the requirements of the Regulation quickly followed by compliance ]

Reg 36 (3)

Reg 27(2) Prevention of leakage from a container holding radioactive material. [defence relates to reliance on written assurance provided by the supplier that the article complied fully with the Regulation ]

IRR99 Regulation 37: Exemption certificates

Reg 37 (1)&(2)

In recognition that the Regulations may not be appropriate in certain cases, the HSE may grant a certificate exempting persons, premises or equipment from the limiting effect of the Regulations. Special conditions may be applied to the exemption, but the overriding consideration will be not to prejudice the health and safety of those involved.

IRR99 Regulation 38: Extension outside Great Britain

Reg 38(1) & (2)

Specified sections of the Health & Safety at Work etc. Act 1974, and the consequent Application outside GB Order 1995 (SI 263) ensure that in certain circumstances these Regulations can be enforced for work conducted outside Great Britain.

Exemption to this may be granted for work carried out by appointed medical authorities or approved dosimetry services, providing an equal standard of protection is afforded.

IRR99 Regulation 39: Transitional provisions

A series of provisions enable smooth transition from IRR85 to IRR99. Dates are given by which time compliance with particular Regulations must be achieved.

IRR99 Regulation 40: Modifications relating to the Ministry of Defence etc

For specific guidance please contact Radman

IRR99 Regulation 41: Modification, revocation and saving

For specific guidance please contact Radman


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