Section 3 of the SDS

In the SDS, SECTION 3: Composition/information on ingredients comprises

  • either 3.1. Substances
  • or 3.2. Mixtures

Only section 3.1 or section 3.2 is expected, it is the only time when a heading may be legally omitted from the Safety Data Sheet.

3.1 Substances

For a substance, you are required to include the product identifiers and the CLP classification, and to include information on any impurities which affect the classification of the substance:

  • substance name
  • identification number(s)
  • % w/w of the substance

Impurity identification

  • substance name
  • identification number(s)
  • % w/w of the substance

Notes:  the substance identifiers (name and numbers) should match the information given in section 1.1 of the SDS (and these should match the REACH registration information if you, or your supplier, have registered the substance).

Classification information is not required here for a substance, as it has already been given in section 2.1 of the SDS, although some authors like to voluntarily include the classification information for both the pure substance and any impurities affecting the classification.

3.2 Mixtures

Substances contained in mixtures are required to be identified under Section 3.2 of the SDS, and the information required depends on whether the mixture is classified for CLP, or not.

Substances to be identified on mixture SDSs

If the mixture is classified for CLP, its component substances must be identified if they meet one or more of the following criteria, and if more than one criterion applies the lowest limit must be used:

  • substance is present at or above the generic cut off limits in the table below, or if there are other cut off limits for that substance (related to Specific Concentration Limits, or M-factors, see ECHA SDS guidance for more details at
  • if the substance is a sensitiser at EUH208 level (0.1 – 1% sensitiser class 1 or 1B, 0.01 – 0.1% sensitiser class 1A; or 10% of the specific concentration limit, if one exists for sensitisation )
  • if the substance holds a Workplace Exposure Limit (there is some debate about whether at cut-off limit of 1% applies, or whether this is at any concentration)
  • if a substance has been Authorised for specific uses, and is present at or above 0.1%.
  • substances which are on the SVHC candidate list, but which have not been authorised, and which are present at or above 0.1% in the mixture (note that the substance does not have to be identified as being on the SVHC candidate list, it just needs to be listed, although it is considered good practice to identify it as an SVHC)
  • substances which are PBT or vPvB and are present at or above 0.1% in the mixture

Generic limits for including a component substance on a CLP-classified mixture SDS (click image to enlarge).

This can also be downloaded as a pdf: Generic limits for including a component substance on a mixture SDS .  Note that mixtures subject to other regulations, e.g. the Detergents Regulation, may have stricter disclosure thresholds than CLP, so you need to check whether your mixture is affected by any other regulations.

If the mixture is not classified for CLP, its component substances must be identified if they meet one or more of the following criteria:

  • hazardous to health or the environment, at or above 1% w/w (or 0.2% v/v for gaseous mixtures)
  • substances with a Workplace Exposure Limit, at or above 1% w/w (or 0.2% v/v for gaseous mixtures)
  • substances which are  PBT or vPvB,at or above 0.1% w/w
  • substances which are on the SVHC candidate list, whether or not they have not been authorised,  present at or above 0.1% w/w

Note that UVCB substances, particularly fragrance oils, can potentially cause problems for identifying sensitisers, as if you identify the UVCB substance on the label (e.g. orange oil), this will not necessarily give information to people who are sensitive to an individual component in the UVCB.  In these circumstances, it is probably better to identify all of the UVCB component sensitisers (and other hazardous components) individually, rather than identify just the UVCB.

Should you identify every component substance, whether mandatory or not?

Some companies have gone down this route to ensure they give full disclosure.  However, for many other companies, this would be giving away their full formulation to their customers and competitors, so they do not identify components unless legally obliged to.  There are different rules for identifying component substances voluntarily, see the bottom of this page.

Information required for mandatory identified component substances

  • substance name
  • identification number(s)
  • CLP hazard classification of the substance
  • either the actual % w/w of the component, or a % w/w range (or, for gaseous mixtures, % v/v)
  • Its REACH registration number, if it has been registered (the last 4 digits may be omitted)
  • Its Authorisation number, if it has been Authorised
  • M-factor(s) for any substance classified Aquatic acute tox. 1 H400 and/or Aquatic chronic tox. 1 H410 (this is a “nice to have” rather than mandatory)

The CLP hazard classification of the substance is required to enable downstream formulators to calculate the effect of the substance in mixtures they make from the original mixture.  It is also possible that a substance may be classified more severely than a published classification (such as a Harmonised Classification or REACH registration classification) might indicate, e.g. due to impurities.

Percentage ranges are permitted under CLP

The use of percentage ranges is widespread in order to give a degree of confidentiality to commercially important formulations.

This is explained in a document from CEFIC: CEFIC-Industry-Position-Concentration-ranges-in-SDS-section3.2

However, where you are using percentage ranges, the overall classification of the mixture must reflect the maximum effects of the component(s).

For example, say you have a component in a mixture which is classified as Cat 2 H310, May be fatal in contact with skin, with no other components which are hazardous to health.  If you put a range of 20 – 30% on the SDS, you would have to classify the product as Cat 2 H310, as the threshold for classification is 25%.  If the actual figure is 22.8% w/w, and you want the mixture to be classified as Cat 3, H311, Toxic in contact with skin, you would have to change the range so that it stops at or below 24.9%, e.g. 15 – 24% w/w.

Percentage ranges in classification software

Some classification software packages do not use ranges, but allow you to input your own ranges.  When inputting the ranges for an SDS, you need to ensure that you have not exceeded a classification threshold accidentally.

However, other classification software packages use standard ranges, regardless of the hazards of the component mixture.   In this case, you have to check that your package has not accidentally exceeded a classification threshold, and you may need to manually input the range for that product, or for that hazard classification.  Inputting all of the classification thresholds into a software package can take some time, but it may be worthwhile to remove this potential ambiguity in your SDSs.

Confidential component substances in a mixture

Confidentiality can be claimed for substances which are classified with comparatively low-level hazards, for more details see .

Where confidentiality has been claimed for a component substance in a mixture, the alternative name should be used in Section 3.2, and there is no requirement to include any identification numbers or REACH registration number. (Note that an Authorised substance cannot be subject to a confidentiality claim).

However, the % w/w and CLP classification for the confidential component(s) must still be published, to enable any downstream user who makes a new mixture from the mixture to classify the new mixture accurately.

Including relevant notes on substances with a Harmonised Classification

In some circumstances, a substance (either alone, or as a component) may hold a Harmonised Classification which is conditional, that is it may not apply if certain criteria are met.

For example, Note N to the Harmonised Classifications states: “The classification as a carcinogen need not apply if the full refining history is known and it can be shown that the substance from which it is produced is not a carcinogen. This note applies only to certain complex oil-derived substances in Part 3.”

Notes J, K, L, M, P, Q and R are similarly conditional.

In these cases, if your substance, or component substance, is not classified as hazardous for the Harmonised hazard, it is good practice to include the details of the relevant Note in Section 3.1 or Section 3.2, as appropriate, to inform the reader that the classification for your product differs from the Harmonised Classification, and why.

Information required for voluntarily identified component substances

Briefly, if you identify a component substance voluntarily on the SDS, you do not need to provide any of the mandatory information, such as CAS or EC number, and you can even use text such as “proprietary” or “confidential” instead.  You can put in the exact quantity, or a percentage range, as you wish.  Also, if you wish to use a different chemical name, you do not need to make an application for a confidentiality claim.

From the point of view of clarity, we recommend that you put in “not classified for CLP”, so it is clear that the substance does not need to be identified by law, and you could even put a note underneath saying (substance x disclosed voluntarily).

This approach has been checked with the HSE Helpdesk in the UK, in the context of voluntarily disclosing 1% of a non-hazardous marker dye in a solvent (purely for commercial reasons, so the customer can see they are actually buying the marker dye and not just undyed solvent).  The full correspondence is given here for reference: Voluntary disclosure of component substances on an SDS .

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