What is indicated by the Skull and Crossbones symbol in hazard communication?

The Skull and Crossbones symbol in hazard communication specifically indicates acute toxicity. This symbol is a clear warning that a substance can cause serious health effects, including death, when it enters the body through various routes such as ingestion, inhalation, or skin contact. Acute toxicity refers to the harmful effects that occur following exposure to a high dose of a substance over a short period of time. The presence of this symbol on a chemical's labeling signals to users the need for immediate caution and protective measures, emphasizing the potentially life-threatening nature of the chemical in question. It draws attention to the urgent need for proper handling procedures to avoid dangerous exposures.