Final answer:
Placards are primarily used on individual packages to provide information about contents, handling, or warnings, especially for hazardous materials during shipping.
Step-by-step explanation:
Placards are signs that display information or instructions, and they have a variety of uses in different contexts. Based on the options provided: a) buildings, b) individual packages, c) storage lockers, d) storage papers, placards are commonly used on individual packages to convey information about the contents, handling instructions, or warnings in shipping and handling environments.
For example, in the context of shipping hazardous materials, placards are required by law to be placed on the outside of shipping containers to communicate the risk to handlers and emergency responders. Similarly, they may be used to label storage lockers for organizational or safety purposes. In everyday use, placards might not be commonly found on buildings or storage papers, but they could be used in specific instances, such as warning or informational signs on buildings or labels on large-scale document storage systems.
Items such as egg cartons, packing peanuts, disposable cups, plates, trays, and cutlery, and disposable take-away containers typically do not require placards, as they are not used to convey information in a shipping or storage capacity.