Given the task definition and input, reply with output. In this task, we ask you to elaborate the sentence without changing its general meaning. You can do so by explaining further the input sentence, using more precise wording, adding qualifiers and auxiliary information etc.

The Convention also says that any toxic chemical is a chemical weapon unless it is used for legal reasons .

Under this Convention , any toxic chemical , regardless of its origin , is considered a chemical weapon unless it is used for purposes that are not prohibited ( an important legal definition known as the General Purpose Criterion ) .