Which symbol is used to indicate a toxic hazard?

The symbol that indicates a toxic hazard is the skull and crossbones. This symbol is recognized internationally as a warning about dangerous substances that can cause harm to health, particularly those that are fatal or harmful if inhaled, ingested, or come into contact with skin. It serves as a clear visual cue that alerts individuals to take caution and to exercise care when handling substances marked with this symbol.

In contrast, the other symbols provided represent different hazards. The flame symbol indicates flammability, the exclamation mark denotes a general hazard, often for irritants or less severe health risks, and the triangle typically represents other types of dangers but is not specifically linked to toxicity. Understanding these symbols is crucial for recognizing and mitigating risks associated with hazardous materials.