Which hazard category requires the label of "Warning"?

The hazard category that requires the label of "Warning" corresponds to moderate toxicity. This classification is used to indicate substances that can cause effects that are harmful but are not immediately life-threatening. The "Warning" label serves as a precautionary measure to alert users about potential dangers associated with these substances, thereby promoting safe handling and use practices.

Moderate toxicity often signifies that exposure could lead to noticeable adverse effects on health, although the severity may not reach as critical a level as those categorized with a higher label, such as "Danger," which is designated for substances of high toxicity. Understanding these categories and their associated labels is crucial for ensuring safety in environments where chemicals are present.