5. Reporting a material change after consent has been granted

An employer must immediately notify HSE of any material change to the work practice which would affect the particulars provided with the application for consent.

Material change in this context means a significant change to the safety assessment submitted with the application and referenced in the certificate of consent.

You should consider the possible effects of any proposed modification to your work practice or facilities and to the working practices undertaken to determine whether these could cause a material change. Where you consider this to be the case, you must:

  1. revise the safety assessment to ensure it continues to accurately reflect the risks from the work practice
  2. submit the new or modified safety assessment to HSE

You should have written arrangements by which the effects of any modifications to your installations, facilities, working arrangements, operating parameters or external impacts are identified and considered.

You should consider a ‘material change’ as a change in the way in which the work practice is performed and consequent changes to the safety assessment which have the potential to change the nature or scope of the hazards and risks associated with the work.

Examples of a material change

This would include but is not limited to:

  • significant increases in the quantities of radioactive substances or numbers of radiation generators used in the practice - in this context significant means at least double the quantities or numbers detailed in the original application
  • changes in the type or nature of radioactive substances used in the work practice
  • changes in the type or the output energies of the radiation generators used in the work practice
  • changes to the engineering controls, design features, safety features and warning devices which restrict exposures to persons
  • major modifications to existing plant or technologies
  • a significant increase in the number of premises at which the work practice is performed - in this context significant means at least double the number of premises detailed in the original application
  • changes in in the types of personal dosimetry used - this would include the introduction of new types of personal dosimetry or the cessation of that detailed in the original application
  • the identification of additional reasonably foreseeable radiation accidents or changes to those already identified
  • significant changes to local rules or contingency plans
  • significant changes in radiation safety management or safety-critical administrative procedures
  • identification of new radiation hazards to those previously identified and referenced in the safety assessment
  • the work practice can no longer be carried out in accordance with the conditions of consent

If you’re unsure whether a change to the work practice or safety assessment is a material change, contact HSE.

How to report a material change

To report changes, use the ionising radiation contact form.

What HSE will do

Where we have been notified of a material change, we will carry out an initial review of that material change within 1 month of the notification. If the initial review reveals that a more thorough review or reassessment of the practice is necessary, this will take up to 3 months. The employer will be charged for the time taken to conduct that review or reassessment.

If the thorough review or assessment is successful, we will issue a new certificate of consent which will supersede the previous consent certificate.

The new consent certificate will be valid for 5 years from the date of issue.

If the notified material change is unacceptable we may ask you to reverse the material change or, if necessary, revoke the consent.


You are required to report a material change under regulation 7(5) of the Ionising Radiations Regulations 2017 (IRR17) (on legislation.gov.uk).

Is this page useful?

Updated 2024-06-04