What does H331 mean?

Categories and label elements

CLP abbreviation	Pictogram	Signal word
Acute Tox. 3	GHS06Skull and crossbones	Danger

Related precautionary statements (P codes)

The precautionary statements that CLP Annex IV assigns to this class. Not all of them go on the label: under CLP Article 28(3), no more than six precautionary statements appear on the label unless the nature and severity of the hazard require more; the selection depends on the product and its users.

When does a mixture need H331?

Whether a mixture needs H331 is calculated from the classes and concentrations of its components. The values in the rule file for this code are:

• A component of this class is taken into account in a mixture only at a concentration of ≥ 0.1 %. (CLP Annex I Table 1.1)
• The category of the mixture is calculated from the ATE values of the components (route: inhalation) with the additivity formula 100/ATEmix = Σ(Ci/ATEi).

For a step-by-step worked example see classifying a mixture under CLP.

Where is H331 written in the SDS?

H331 is tracked in three places of the SDS: the classification line in Section 2.1 ("Acute Tox. 3"), the label elements in Section 2.2 and the component list in Section 3. Section 16 repeats the explanation of the code. In addition, it is justified in Section 11 (toxicological information) under the relevant effect heading.

How does H331 appear on the label?

The label elements for H331 are: pictogram GHS06 (skull and crossbones); it is written with the signal word "Danger". In the Chemoris template Section 2.2 carries at most 8 H statements; if the limit is exceeded the least severe ones are dropped and a warning is shown. For the bottom of the label, 8 P statements are candidates for this class in CLP Annex IV; under CLP Article 28 at most 6 of them are selected.

Where does it appear in the safety data sheet?

• Section 2.1: classification; the class abbreviation and H331 are given together.
• Section 2.2: label elements; H331 with its full text, pictogram and signal word.
• Section 3: composition table; in the row of every component that has this class.
• Section 16: the full text of the H statements cited as codes in earlier sections.

Class criteria and thresholds for H331

The values below come from the Chemoris rule file (CLP Annex I). They show the condition under which H331 arises in a mixture. For physical hazards and other classes that depend on test data, the result comes from the mixture's own measurement, not from component percentages.

H331 compared with H330 and H332

The table below puts H331 next to its closest neighbouring statements; the values are read from the rule data.

H331 and H330 carry the same signal word (Danger). Both are shown with the same pictogram (GHS06). The signal word differs: Danger for H331, Warning for H332. The pictogram differs: GHS06 for H331, GHS07 for H332.

H330 H332

In which SDS sections does H331 appear?

H331 does not stay only in the label section of an SDS; the class itself and the precautionary statements assigned to it shape the content of other sections too. The counts are calculated from the P statements that Annex IV assigns to this class.

Statements that appear on the label together with H331

H331 is never printed alone on a label; it sits next to the pictogram and the signal word. The Chemoris selection method (response, prevention, storage, disposal in that order; core statements first) gives these first 5 candidates for this class:

The GHS06 pictogram and “Danger” are printed together. This ranking applies because a label usually carries at most 6 statements; when a combined statement is selected, its parts are not printed again.

Official EU wording of H331 in other languages

When a product is exported to the EU, the SDS and label are expected in the official language of the Member State where it is placed on the market (REACH Article 31(5)). The table gives the official wording of H331 from the CLP Annex III/IV language versions published in the Official Journal of the European Union. Source: EUR-Lex CELEX 02008R1272-20260701.

Common mistakes with H331

• Mixing up exposure routes: H331 concerns only the inhalation (vapour) route; ATE is calculated separately for each route (CLP Annex I 3.1.3.6.1 (formula), Table 3.1.1 (category ranges), Table 3.1.2 (converted ATE)).
• Pouring every P candidate onto the label: there are 8 candidates, but CLP Article 28(3) limits a label to 6 precautionary statements (up to 8 when needed).
• Writing unlimited H statements for a multi-class product: in the Chemoris template, Section 2.2 holds at most 8 H statements.

Next steps

To read a statement like H331 correctly on a label and in an SDS, see the guide How to read H and P codes; to pick the class and prepare the label automatically, use the free label tool.

Related hazard statements

Other H statements in the same hazard family as H331 (Acute Tox.). The difference between categories mostly comes from the degree of severity.

• H300Fatal if swallowed.
• H301Toxic if swallowed.
• H302Harmful if swallowed.
• H310Fatal in contact with skin.
• H311Toxic in contact with skin.
• H312Harmful in contact with skin.
• H330Fatal if inhaled.
• H332Harmful if inhaled.

Frequently asked questions