Industrial radiography is the use of ionising radiation in non destructive testing (NDT). NDT is a process where an article is "tested", and in the case of industrial radiography uses ionising radiation (via a radioactive source, x-ray tube or accelerator) to form an image on radiation sensitive film or real time imaging systems, to detect potential or actual defects. Examples of this would include testing for a crack in a gas pipe, a defective pipe weld, integrity of a pressure vessel or similar. The UK IRR17 defines this exactly as follows 'means the use of ionising radiation for non-destructive testing purposes where an image of the item under test is formed (but excluding any such testing which is carried out in a cabinet which a person cannot enter)' (Reg 2-1). Note here the word "test" (of an item). It follows that Industrial Radiography does not include any of the following:

• X-ray screening for security purposes (e.g. in cargo and freight etc)
• X-ray diagnostic imaging or patients (this is a medical exposure - diagnostic radiology).
• X-ray imaging of a painting, museum specimen or similar.
• X-ray of animals (e.g. veterinary x-ray) - note this is not diagnostic radiology as that only applies to medical x-rays of humans.

Note that 'excluding any such testing which is carried out in a cabinet which a person cannot enter' has created some discussion between RPAs, users and the regulators during 2024. 'Where a person cannot enter' is not defined in IRR17 with respect to 'reasonably practicable' (to enter), so could mean 'wherever is possible' (regardless of practicability). More recent discussion with the regulator (HSE) has clarified that this means where 'a cabinet cannot be entered without climbing in to, contorting to access' (and similar). Therefore, whilst IRR17 has not been amended, it is reasonable to assume that 'which a person cannot enter' can be tested by application of reasonably practicable. Therefore, 'testing' in a small cabinet (which cannot be reasonably practicably entered) would not be defined as NDT (IRR17) and would not need a consent. 

For a detailed discussion of industrial radiography, check out the following link (December 2023): Potential occupational, non-occupational and accidental radiation exposures in industrial radiography using radioactive sources.