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On a chemical label, what does the skull and crossbones pictogram mean?

Acute toxicity, fatal or toxic, even in small amounts.

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  1. The chemical burns skin and metal
  2. The chemical can catch fire
  3. Acute toxicity that can be fatal or toxic ✔

Why: Skull and crossbones marks the most severe acute toxicity. Milder acute toxicity, called harmful, gets the exclamation mark instead.

Huh, didn't know that: If the skull and crossbones is on a label, the exclamation mark is not used for acute toxicity.

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References

Answer: Acute toxicity that can be fatal or toxic. Skull and crossbones marks the most severe acute toxicity. Milder acute toxicity, called harmful, gets the exclamation mark instead.

  1. OSHA Quick Card: Hazard Communication Standard Pictogram (osha.gov) www.osha.gov/sites/default/files/publications/OSHA3491QuickCardPictogram.pdf
    Skull and Crossbones: Acute Toxicity (fatal or toxic)
    Checked 2026-10-10.
  2. 29 CFR 1910.1200 Hazard Communication (eCFR), Appendix C www.ecfr.gov/current/title-29/section-1910.1200
    If the skull and crossbones pictogram is included, the exclamation mark pictogram shall not appear where it is used for acute toxicity
    Checked 2026-10-10.

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