The inventory "will significantly improve safety by providing up-to-date information on all the hazardous substances that are on the EU market today," said Geert Dancet, executive director of the European Chemicals Agency (ECHA).
The inventory will be drawn from data submitted by manufacturers and importers under the EU's classification, labelling and packaging (CLP) regulation, in force since 20 January 2009.
Just over 3.1 million notifications of 24,529 different substances in use on the EU market were submitted to the agency by this week's deadline.
The high number of substances notified is a result of the fact that companies were required to send bulletins for all chemicals classified as hazardous regardless of volume – even for substances for which no registration is required under new EU chemicals regulation REACH or which only have to be registered under it in 2013 or 2018.
The agency hopes to have the classification and labelling database ready by May this year.
The full inventory will be accessible to EU-27 competent authorities and any non-confidential information will be made public in an inventory on the ECHA's website.
The CLP is about "how to identify and classify the hazards of chemicals and how to communicate them to consumers, workers and the wider public," said Dancet.
EU Environment Commissioner Janez Potočnik said the exercise "will improve safety for all those handling chemicals and will enable downstream users and consumers to select less hazardous chemicals for their needs".
New warning pictograms
Many EU manufacturers and importers will also need to prepare new labels in accordance with the CLP regulation, which introduces new warning pictograms for physical, health and environmental hazards of chemicals.
The current EU pictogram - a black symbol on an orange background - is being replaced by the UN's globally standard for hazard pictograms - a black symbol on a white background inside a red frame - for chemicals used at the workplace and for consumer products such as detergents or house cleaning substances.
The new labelling provisions also take on board signal, hazard and precautionary statements provided for by the UN scheme.
Under the CLP regulation, re-labelling and re-packaging of substances and mixtures which were placed on the market before December 2010 (for substances) and June 2015 (for mixtures) may be postponed until December 2012 and June 2017 respectively.