Which signal word indicates severe corrosive properties in hazard class I?

The signal word that indicates severe corrosive properties in hazard class I is "Danger." This term is used in hazard communication to convey that the material poses a high level of risk, indicating that exposure can lead to serious injury or irreversible damage. In the context of corrosive materials, "Danger" alerts individuals to the potential for severe chemical burns or other life-threatening effects if the substance comes into contact with skin or eyes, or if it is ingested or inhaled.

While "Caution," "Warning," and "Toxic" are also important in communicating hazards, they denote less severe risks compared to "Danger." "Caution" is typically reserved for situations that are less hazardous, "Warning" indicates a moderate level of hazard, and "Toxic" specifically refers to substances that can cause harm through exposure but does not inherently imply corrosiveness. Thus, "Danger" is the most appropriate signal word for materials that are classified as having severe corrosive properties.