Substances of very high concern are substances that have hazards with severe consequences. Substances meeting the criteria may be placed on a list. The list of SVHCs was first published on 28 October 2008 and was last updated on 30th March 2010. This list is known as the Candidate List and all substances are added by the European Chemicals Agency (ECHA). SVHC may have very serious, or in some cases, irreversible affects on both people and the environment, hence the reason for their authorisation.