The substance information exchange forum (SIEF) has been in use since the start of REACH registration. Their purpose is to help information exchange to avoid duplication of tests, prepare joint registration dossiers and decide the classification and labelling of substances.

As registration is based on the principle of ‘one substance, one registration’. Each substance has one Sief, with members producing or importing at different tonnages.

1. If no registration has yet been submitted, you need to get organised with other potential co-registrants and prepare the joint registration. If you are the only registrant for a substance, you need to proceed on your own.
   SIEF members must share available scientific data and decide how to fill data gaps. You need to discuss the relevance, reliability and adequacy of the data available and you need to agree on cost sharing.
2. If a joint registration already exists, you need to contact the registrants and agree to join them.

The REACH Regulation says that Siefs will cease to exist on 1 June, the day after the last registration of substances but Syensqo express for a "continuation of a collaboration platform to take care of the post-registration duties" (see SIEF agreement post June 2018 and communication within SIEF below).

Share information about the substances is a fundamental aspect of REACH. By doing this, registrants of the same substance can reduce registration costs and avoid unnecessary testing, especially on vertebrate animals.

All data sharing agreements have to include detailed costs information on the data to be shared. The aim is that registrants and/or potential registrants make every effort to ensure that the cost of data sharing for registration purposes is fair, transparent and non-discriminatory.

A data sharing agreement must :

1. itemize the data to be shared. This must include the cost of each data item, and explain how it meets the REACH information requirements;
2. itemize and justify any relevant management costs associated with the data sharing agreement and/or registration; and
3. have a cost sharing model which includes a reimbursement mechanism.

The reimbursement mechanism should take into account the possibility of future registrants joining the data sharing agreement at a later stage, through a method of proportional reimbursement.

Where registrants have shared information and submitted it jointly, any further costs in relation to the operation of the data sharing agreement should be documented annually.

Syensqo has written a guidance (to be updated - Syensqo's rules and template) (IND-HSE-PRAS-08-GUI) giving some advices and rules to be applied for data and cost sharing.
In addition, a calculation tool (to be updated - Syensqo's rules and template) has been developed to support GBU product stewards to define the costs of data and letter of access.

The workflow below explain the different processes when Syensqo is lead registrant or data owner