Companies that manufacturer or import chemical substances in quantities above 1 tonne are responsible for demonstrating how substances can be used safely. To this end, they must collect information regarding the physical chemical properties, hazard profile and uses of their substances. If a substance is identified to be hazardous, a Chemical Safety Assessment (CSA) must be performed where it is manufactured or imported in a volume above 10 tonnes per year. The collected information must be compiled in a substance registration dossier using the specialised software program IUCLID, and submitted to ECHA through REACH-IT. Further, manufacturers and importers must provide their customers with a Safety Data Sheet (SDS).

REACH registration applies to substances on their own, substances in mixtures and –in certain cases – to substances in articles. Chemical substances that are already regulated by other legislations such as medicines, or radioactive substances are partially or completely exempted from REACH requirements.

Registration is based on the “one substance, one registration” (OSOR) principle. This means that manufacturers and importers of the same substance have to join together in a so-called Substance Information Exchange Forum (SIEF). The purpose of the SIEF is to facilitate data-sharing and agreement on the classification and labelling of the substances concerned. SIEF members must either:

• give their assent to one (lead) registrant who will first submit joint parts of the dossier, or
• jointly (as a consortium) submit the information on the intrinsic properties of the substance in their registration dossier

REACH requires registrants to make every effort to reach an agreement on sharing the required data and ensure that the cost of sharing the information required for registration are determined in a fair, transparent and non-discriminatory way.