What is the significance of signal words on chemical labels?

Signal words on chemical labels are significant because they serve as a quick reference to convey the level of danger associated with the substance. Specifically, these words highlight the severity of the hazards present. For instance, the signal words "Danger" and "Warning" indicate varying degrees of risk, with "Danger" typically signifying a more severe hazard than "Warning." This helps individuals handling the substance to immediately understand the potential risks and exercise appropriate caution.

The other options, while relevant to overall safety and handling practices, do not accurately reflect the primary purpose of signal words. For instance, the shelf life of a chemical is determined by different factors and is not indicated by signal words. Similarly, while personal protective equipment is vital for safe handling, it is usually specified elsewhere on the label rather than through signal words. Lastly, defining the chemical's usage goes beyond what signal words convey and would generally be included in other sections of the label. Thus, the focus on signal words is specifically about hazard severity, making the understanding of this feature crucial for safe chemical handling.