The Ionising Radiations Regulations 1999 (IRR99) apply to any organisation carrying out work with radioactive substances or X-ray sets. The IRR99 can also apply to organisations working with materials that contain natural radioactivity, such as mineral sands.

In most cases the regulations require organisations working with ionising radiation to consult with a 'suitable' Radiation Protection Adviser (RPA) as to what they need to do to comply with the law. A suitable RPA:

• is an individual or body that meets the HSE criteria of competence
• has the necessary experience and expertise to advise on the organisation's uses of radiation
• has been formally appointed in writing

The IRR99 require that all RPA advice must be provided by individually certificated RPAs or RPA Bodies who meet the HSE criteria of competence. The RPA can be either an employee or an external consultant.