SDS Section 2: Hazard identification

What OSHA requires in Section 2

OSHA enforces the content of Section 2 under the Hazard Communication Standard.

Appendix D requires Section 2 to include:

• The classification of the chemical in accordance with paragraph (d) of 1910.1200, meaning the hazard classes and categories the product meets (for example Flammable liquid, Category 2).
• Signal word: "Danger" for the more severe hazard categories, "Warning" for the less severe. Only one signal word appears.
• Hazard statement(s) for each hazard class and category.
• Pictogram(s), which may be shown as a black-and-white graphic or simply named.
• Precautionary statement(s), the recommended measures to prevent or limit exposure.
• Hazards not otherwise classified (HNOC) or hazards not covered by the GHS, for example a dust explosion hazard or simple asphyxiant.
• For a mixture, a statement of the percentage of the mixture consisting of ingredients of unknown acute toxicity when such an ingredient is used at 1% or more and the mixture has not been classified by testing as a whole.

Section 2 is the content that has to agree with the label. OSHA expects the same classification-driven information on both.

GHS Annex 4 and international differences

GHS Annex 4 describes the same elements: the substance or mixture classification, the label elements (pictogram, signal word, hazard statement and precautionary statement), and other hazards that do not result in classification. The standard wording of hazard statements and precautionary statements comes from the UN GHS; on this site you can look up the text of any code in the hazard statement reference and the precautionary statement reference, and see all symbols on the pictogram page.

Classification systems differ between jurisdictions. A country can adopt only some GHS hazard classes or categories, which is why the same product can carry different classifications in the US, the EU and elsewhere. For instance, OSHA does not adopt the GHS aquatic hazard classes, so a US sheet may omit them while an EU sheet includes them. Read our OSHA HazCom overview and the EU CLP page for the main differences.

What to look for and red flags

What to look for

• The signal word and pictograms tell you the severity at a glance. Learn the nine GHS pictograms.
• The hazard statements are the precise wording. "H225 Highly flammable liquid and vapour" is much more informative than the flame symbol alone.
• The precautionary statements are grouped into prevention, response, storage and disposal. Use them to build handling rules.
• Any additional hazards that classification does not capture, such as dust-explosion potential.

Red flags

• "Not classified" for a product that Section 3 shows contains a well-known hazardous ingredient. Check whether the concentration is below the classification cut-off.
• A pictogram set that does not match the hazard statements (for example a flammable-liquid statement but no flame).
• A sheet with no hazard information at all and no explanation. This usually means the supplier did not classify the product, not that the product is safe.
• Old "R-phrases" or "Risk phrases" and the orange hazard symbols. These belong to the pre-GHS system and indicate an out-of-date sheet.

Worked example: typical fields

An illustrative layout. The real classification of any substance depends on the supplier and concentration, so see the hazard section of the methanol page for a sourced example with pictograms and statements.

Classification

List of hazard classes and categories, such as "Flammable liquid, Category 2" and "Acute toxicity (oral), Category 3"

Signal word

Danger or Warning

Pictograms

GHS codes such as GHS02 (flame) and GHS06 (skull and crossbones)

Hazard statements

H-codes with their full wording

Precautionary statements

P-codes grouped under prevention, response, storage and disposal

Other hazards

Hazards not otherwise classified, such as combustible dust, if relevant

See how this looks on a real page: methanol safety data, hazard identification section. Every chemical page uses these 16 sections with the same anchors, so you can compare any substance.

Common mistakes

• Reading the pictogram and skipping the words. The pictogram is a summary; the hazard statements carry the details and categories.
• Treating "Warning" as "safe". The signal word reflects severity category, not whether the product is harmless. Warning-level products still injure people when misused.
• Copying the classification of a pure substance onto a mixture. A mixture is classified on its own composition. The rules for mixtures differ from those for pure substances.
• Confusing GHS pictograms with transport placards. The red-bordered diamond on a label and the DOT hazard class diamond on a vehicle are related but separate systems; see DOT hazard classes.
• Ignoring the precautionary statements when writing a procedure. They are not boilerplate. They are the supplier's baseline for safe use.

How Section 2 relates to other sections

Section 2 is the summary of the hazards that the rest of the sheet explains in depth. The reasons behind health classifications appear in Section 11, physical hazard data in Section 9 and Section 10, and environmental classification in Section 12. The precautionary statements here are expanded into practical advice in Section 7 and Section 8. If the classification depends on ingredients, Section 3 shows which ones drive it.

Frequently asked questions