How many specific words can be used as signal words on a label?

Signal words on a label serve to quickly communicate the hazard level of a substance or situation, providing crucial information for safety. When referring to how many specific words can be used as signal words, it is accurate to say that two distinct words are commonly employed. These are "Warning" and "Danger." The use of these words corresponds to different levels of hazard; "Danger" indicates more severe risks, while "Warning" implies a lesser degree of hazard. This system allows individuals to immediately grasp the potential dangers associated with a product, which is vital for ensuring safety in environments where such products are used.

In contrast, the other options don't accurately reflect the established naming conventions in safety labeling. It is important for individuals to recognize these signal words, as they are essential for understanding the seriousness of hazards and ensuring proper precautions are taken.