When preparing a Safety Data Sheet (SDS), one of the most important stages is assessing the composition of the product and properly compiling the information required in Section 3 of the SDS (3.1 for substances and 3.2 for mixtures, respectively).

From this section, users obtain information about the product’s composition, which allows them to assess hazards in conjunction with the details in Section 2 of the document. It is also the section that typically raises the most concerns for companies due to the extent of data that must be disclosed.

Section 3 of the SDS – Which Substances Must Be Listed?

For pure single-component substances, the situation is relatively straightforward. Here, there is no option to conceal information in the SDS – the product must be properly identified using the chemical name and the relevant numbers (CAS, EC, and index number). Exceptions may apply to substances in the R&D phase, in line with exemptions under the REACH and CLP regulations.

SDSs for mixtures are a more complex issue because the listing of components in Section 3 is governed by the rules set out in Annex II of the REACH Regulation, as amended by Regulation (EU) 2020/878.

In short, the SDS must disclose substances that:

• Are classified as hazardous under the CLP Regulation and are present in the mixture at concentrations exceeding the thresholds defined in Regulation 2020/878/EU;

• Have occupational exposure limit values (OELs) established at the EU level;

• Are classified as vPvB, PBT, or endocrine disruptors (ED).

Additionally, substances with national OELs must be listed with reference to Section 8, where national limit values must be included accordingly.

As a result, SDSs for mixtures can vary significantly in terms of how much information is provided in Section 3.2, depending on the product composition and the hazards posed by its components. Sometimes this section includes only a small fraction of the formulation (e.g., low-hazard aqueous solutions), while in other cases, it may require listing most or all components (e.g., mixtures of organic solvents, where many substances have OELs).

This leads to the key question – does the Safety Data Sheet allow for the protection of a company’s trade secrets?

SDS and the Use of an Alternative Chemical Name

As a rule, all information required under Regulation 2020/878/EU must be included in the SDS in order for it to be considered compliant.

The SDS guidance states clearly:

“Information required to be included in the safety data sheet may not be claimed as confidential.”

EU legislation is strict in this regard, and in principle, no exemptions are allowed. However, there is a mechanism provided in the CLP Regulation that theoretically allows for "masking" the identity of a substance – this is outlined in Article 24 of the CLP Regulation. The purpose of the alternative chemical name is to protect confidential business information, particularly intellectual property rights.

An alternative chemical name is a specific identifier that replaces the chemical name of a substance in communications (including SDSs) and removes the obligation to disclose the CAS or EC number. However, it is not a universal solution – its use is limited to specific cases:

• It is only applicable to substances in mixtures (it cannot be requested for pure substances);

• It is limited to the mixtures covered by the application;

• Most importantly: it may only be granted for substances that meet the criteria set out in Part 1 of Annex I to the CLP Regulation.

Therefore, such an application can only be made for substances with a low hazard profile. Corrosive substances, environmentally hazardous substances, or CMRs cannot be covered by an alternative name. Additionally, the applicant must demonstrate that the use of an alternative name meets the requirement to provide sufficient information for implementing the necessary occupational health and safety precautions and that risks associated with the use of the mixture are adequately controlled.

In practice, the use of this confidentiality mechanism is very limited and rarely applied by suppliers of substances and mixtures, as it comes with additional administrative obligations (filing the application, monitoring for changes in the data submitted) and costs (application fees depending on the number of mixtures involved).

SDSs in Other Jurisdictions

Not all jurisdictions treat trade secret protection as strictly as the EU. For example, in the United States, SDSs can include confidentiality claims in a much more flexible manner, although there are also limitations.

The possibility of masking information must be assessed individually for each product and jurisdiction, as requirements will differ depending on the country and the substances involved.

SDS – What Should I Do Next?

Given the limited possibilities under EU law for treating compositional data as a company trade secret, Section 3 of the SDS should be developed with analytical precision and attention to detail to ensure that only the absolutely necessary information is included. Additionally, it is possible to provide concentration ranges instead of exact values – but one must ensure these ranges are applied appropriately and do not compromise the overall integrity of the document.