IUCLID – tool for Registration

IUCLID – International Registration Data input system


The International Uniform Chemica Information Database (IUCLID) is EU developed software to allow data entry for Registration under different regulatory regimes, including EU and UK REACH, Biocides, Plant Protection, Poison Centre Notification and a range of similar regulatory frameworks in Japan, New Zealand and Australia. 

Although many global ‘REACH’ processes link in to the EU format for Registration, the UK is experimenting with its own format and as of mid-2023 a trial UK ‘working context’ has been listed. The concept of the ‘working context’ allows a data base to be reorganised into the necessary format for different types of dossier.

As a general rule, the software is easy to use once familiar with it – getting familiar can be frustrating as some steps are not intuitive and help is poor. Knowledge is needed to select the correct working context and also if creating lead-dossiers, knowledge of technical terms for data input is essential (for example, understanding different types of mutagenicity tests).

First steps are setting up libraries to include repeating fields such as Legal Entities, Reference Substances, Contacts, Sites and Test Substances. References can also be tiresome to input, but once libraries are set up, it becomes easier to link everything together.

Which version of IUCLID?

Three options are available for the use of IUCLID, including a Cloud version, Desktop and Network.  Each has advantages and disadvantages. In all cases, a valid EU REACH IT account is needed; can be ‘EU Account’ for EU legal entities or ‘ECHA Account’ which accepts ‘foreign users’.

Creating an ECHA Account is simple, with contact details needed, including e mail; recommended to set up with a generic e mail that is monitored across your organisation (in case you retire or get a better job elsewhere).

Your final choice may due to personal preferences.

Type of IUCLID

Feature  CloudDesktop downloadNetwork download
Set upEasy to get started. Must be linked to EU REACH IT accountDownload onto a single device; allow 20 minutes plus for everything to get going.Expect your IT colleagues to be annoyed with you and complain it is not compatible with your network.
Important!If acting as Only Representative, you need a Cloud set up for each company being represented.  If working for different organisations (including as OR), use ‘advanced options’ and select option to allow multiple Legal Entities.
AdvantageEasy to get started and by sharing log-in, useful share withing organisation.  Everything on your device without down-time. No-one else messing about with your files.Good to share within organisation to allow multiple users
DisadvantageCan be slow and difficult to access if ECHA server down. Care needed if working for multiple organisations Has had reduced functionality Can be difficult to link to Chesar software for CSR  All on one machine, so important to backup as ‘export’ files in your device in case of catastrophic failure.Can be slow and especially annoying if others start to mess about with your data sets.
IT concerns  Even though on Cloud, export files are imported and brought into device / network.For the over-cautious IT manager, having a stand-alone PC not on company network is safest optionEarlier versions of IUCLID had compatibility issues with some network systems.
File sharingCan export file or share log-in detailsExport files neededShared within network or export files for others to work on or view
Dossier upload  Direct upload for EU REACH, but otherwise create export dossier filesExport dossier filesExport dossier files

As indicated in the table above, a major practical issue is when cautious IT colleagues worry that the software does not have all the security certificates they may want to see and this may include access to Cloud version.  Even with the Cloud, files imported carry a specific file extension (.i6z) which can upset internal security systems. The .i6z files can only be opened in IUCLID.


The Chemical Safety Assessment and Reporting tool (CHESAR) can also be downloaded free of charge from the same parts of the ECHA web-site.  Again the software is easy to use once basics are understood and links closely with IUCLID to extract key data and then upload uses into IUCLID.

Although there is no obligation to use the Chesar tool (and other models for estimated the risk characterisation of substances are available), ECHA have made it almost essential to use by checking that the CSR (attached as pdf file) is identical to uses described in Section 3.5 of IUCLID. It is technically possible to manually input Section 3.5 to match the CSR, but as it is a computer check and not human, even slight difference in how information nis presented can flag up as a validation failure – and annoyingly, these are not picked up by the IUCLID validation tool.

There have been problems linking Chesar to IUCLID Cloud files, so if expecting to be Lead Registrant and needing to prepare a CSR, a download version of IUCLID is strongly recommended.