REACH Data Sharing Explained: A Beginner’s Guide
Learn how companies registering the same substance share data, avoid duplicate testing, manage costs, and work together under EU REACH.
Data Sharing Under REACH — SIEF, Joint Registration & Costs
A Beginner-Friendly Guide to REACH Data Sharing
If you are new to EU REACH, you may wonder whether every company registering a chemical substance needs to generate all the required studies independently.
The answer is generally no.
REACH encourages companies registering the same substance to work together, share available information, avoid unnecessary testing, and share applicable costs.
This process is commonly referred to as data sharing under REACH.
Three important concepts to understand are:
SIEF
Joint Registration
Cost Sharing
Let's understand them in simple terms.
What Is Data Sharing Under REACH?
Data sharing under REACH means that companies registering the same substance cooperate to share relevant scientific information and, where applicable, the costs associated with that information.
For example, if five companies are registering the same chemical, there may be no need for each company to perform the same toxicity study separately.
Instead, the companies can investigate existing data and determine whether it can be shared.
Data sharing helps companies:
Avoid duplicate studies
Reduce unnecessary animal testing
Reduce registration costs
Identify data gaps
Improve regulatory efficiency
The basic principle is simple:
Same substance → Shared information → Less duplication
Why Is Data Sharing Important?
Chemical testing can be expensive and time-consuming. REACH therefore encourages companies to make use of existing information before conducting new studies.
Companies may consider:
Existing studies
Scientific literature
Read-across
QSAR
Weight-of-evidence approaches
Other scientifically appropriate information
This can help companies avoid unnecessary testing while still meeting their REACH information requirements.
What Is SIEF Under REACH?
SIEF stands for Substance Information Exchange Forum.
SIEFs were established under REACH to help companies dealing with the same substance exchange information and cooperate during the registration process.
SIEF participants could use the forum to:
Identify other companies registering the substance
Exchange existing studies
Identify data gaps
Discuss testing requirements
Share applicable costs
Is SIEF Still Relevant?
The formal SIEF system was associated with the earlier REACH registration process and registration deadlines.
However, the basic principle behind SIEF — cooperation and data sharing between companies registering the same substance — remains important.
Today, companies may use different arrangements, including data-sharing agreements, substance groups, and consortia, depending on their circumstances.
What Is Joint Registration Under REACH?
When several companies register the same substance, REACH generally requires them to work together to submit certain information jointly.
This is known as joint registration or joint submission.
The joint information may include:
Substance identity
Classification and labelling
Physicochemical data
Toxicological information
Ecotoxicological information
Study summaries
Other applicable registration information
However, companies may still have individual responsibilities.
For example, each company may need to provide information about its own:
Uses
Tonnage
Exposure
Company-specific activities
Lead Registrant and Member Registrants
Lead Registrant
The Lead Registrant (LR) coordinates the joint registration activities.
The Lead Registrant may coordinate:
Joint dossier preparation
Communication with other registrants
Data requirements
Testing activities
Communication with ECHA
Member Registrant
Other companies participating in the joint registration are generally referred to as Member Registrants.
Member Registrants participate in the joint registration while maintaining responsibility for their own applicable registration information.
Simply:
Lead Registrant = Coordinates
Member Registrants = Participate
How Does REACH Data Sharing Work?
A simplified data-sharing process looks like this:
1. Identify the substance
First, companies need to determine whether they are actually registering the same substance.
This may involve checking:
Chemical name
CAS number
EC number
Composition
Purity
Impurities
2. Identify other registrants
Companies then communicate with other companies registering the same substance.
3. Review existing data
Available toxicological, ecotoxicological, and physicochemical information is reviewed.
4. Identify data gaps
Companies compare the required REACH information with the information already available.
5. Agree on data access
If another company owns relevant data, appropriate access rights may need to be obtained.
6. Share applicable costs
Companies may share the costs of existing data or new studies according to the applicable cost-sharing arrangement.
7. Complete the joint registration
The relevant information is incorporated into the joint registration and submitted through the applicable REACH process.
What Is a Letter of Access (LoA)?
A Letter of Access (LoA) is commonly used in REACH data-sharing arrangements.
It can provide a company with specified rights to use relevant data for a particular regulatory purpose.
For example, if Company A owns a toxicological study and Company B needs to rely on that study for its REACH registration, Company B may need to obtain the appropriate rights to use the data.
An important point to remember is:
Access to data does not necessarily mean ownership of the study.
The exact rights and conditions depend on the relevant agreement.
How Much Does REACH Data Sharing Cost?
There is no fixed price for REACH data sharing.
Costs can vary depending on:
Number of available studies
Data ownership
Data-access arrangements
Testing requirements
Number of participating companies
Consortium or administrative costs
Registration requirements
Possible costs may include:
Data-access fees
Letter of Access fees
New study costs
Consortium fees
Administrative expenses
ECHA registration fees
For example, if five companies need to share the cost of a €100,000 study, they might contribute €20,000 each if an equal split has been agreed.
However, actual REACH cost-sharing arrangements may use different methodologies.
What Is a Data Gap Analysis?
A data gap analysis compares the information required under REACH with the information already available.
For example:
Information RequirementAvailable?Acute toxicityYesSkin irritationYesSkin sensitisationYesRepeated-dose toxicityNoAquatic toxicityYes
In this example, repeated-dose toxicity represents a potential data gap.
However, a data gap does not automatically mean that a new animal study is required.
Companies should first consider scientifically appropriate alternatives, where applicable.
What Are the Benefits of Data Sharing?
Effective data sharing can help companies:
Reduce Costs
Companies may avoid paying for duplicate studies.
Avoid Unnecessary Testing
Existing information can reduce the need for repeated studies.
Improve Registration Planning
Knowing what data already exists helps companies identify what is actually missing.
Improve Cooperation
Companies registering the same substance can coordinate their regulatory activities.
Support REACH Compliance
Sharing information helps companies meet their applicable registration obligations.
Common Challenges
REACH data sharing can also present challenges, particularly when several companies are involved.
Common issues include:
Confirming substance identity
Determining data ownership
Negotiating data-access costs
Identifying data gaps
Agreeing on cost-sharing methods
Coordinating multiple registrants
Clear communication and proper documentation can help reduce these challenges.
Conclusion
Data sharing under REACH is based on a simple idea: companies registering the same substance should cooperate, use existing information, avoid unnecessary testing, and share applicable costs fairly.
For companies preparing for REACH registration, understanding SIEF, joint registration, Lead Registrants, Member Registrants, Letters of Access, data gap analysis, and cost sharing is essential.
Before starting new studies, companies should first ask:
What data already exists?
Who else is registering the substance?
Can the existing data be used?
What information is missing?
How will the applicable costs be shared?
A good data-sharing strategy can help companies make their REACH registration process more efficient, cost-effective, and scientifically sound.
Key Takeaway
Identify the substance → Find existing data → Share information → Identify data gaps → Share applicable costs → Complete joint registration