The purpose of authorisation, as envisaged in the REACH regulation, is to ensure that the "risks from substances of very high concern are properly controlled and that these substances are progressively replaced by suitable alternative substances or technologies, where these are economically and technically viable" (article 55).

The targeted substances are:

• substances that are carcinogenic, mutagenic or toxic for reproduction (CMR), category 1a or 1b,
• substances that are persistent, bioaccumulative (that can accumulate in the bodies) and toxic (PBT) or very persistent and very bioaccumulative (vPvB) in compliance with criteria listed in annex XIII of the regulation,
• substances that have been scientifically proven, on a case by case basis, as possibly having serious effect on human health or on the environment. These lead to a level of concern equivalent to that of the above substances, as the case may be, for example, endocrine disruptors (substances that may be harmful to human health or to the environment, by disturbing the hormonal systems).

The authorisation procedure is divided in four steps:

• identification of substances of very high concern: Member States of the European Union or the European Chemicals Agency (ECHA) identifies substances that have properties of very high concern. These substances are given in the "candidate list" (list of candidate substances for authorisation) that is published and regularly updated by the ECHA.

• Prioritisation of substances: the ECHA orders the candidate list substances in accordance of their priorities. These "priority" substances are voted upon in the committee to decide upon their inclusion in appendix XIV (list of substances subject to authorisation). After a deadline included in the Annex Authorisation, they can no longer be manufactured or marketed in Europe unless an authorisation is granted for specific uses.

Priority shall  normally be given to substances which are :
• persistent, bioaccumulative and toxic (PBT) or very persistent, very bioaccumulative (vPvB) or 
• with wide dispersive use or high tonnage.

ECHA submits its recommendations to the European Commission for the inclusion of substances in annex  XIV.

For more information about this procedure go to the website of ECHA.
• application for authorisation: once a substance is included in annex XIV, industries can submit their application for authorisation to ECHA. These are assessed by the Agency's scientific committees. ECHA gives its opinion on the application  for authorisation to the Commission.
• granting of authorisation: The European Commission will grant its authorisation based on one of the two options envisaged in the legislation:

o if it is proven that the risk associated with the use of the substance has been adequately controlled
o in case of substances for which no threshold (concentration limit) has been fixed, (as in the case of carcinogenic and genotoxic substances or substances having PBT or vPvB properties), authorisation may only be granted if it is demonstrated that socio-economic benefits outweigh the risks and that there is no suitable alternative substances or technologies.