A homogeneous material with a definite composition. A homogeneous material with a definite composition. If the element is present, it must have either a @value, an @id, or extensions Unique identifier for the substance, often an identifier associated with the package/container of the substance instance (usually a label affixed directly). A code to indicate if the substance is actively used. A code that classifies the general type of substance. This is used for searching, sorting and display purposes. A code (or set of codes) that identify this substance. A description of the substance - its appearance, handling requirements, and other usage notes. When the substance is no longer valid to use. For some substances, a single arbitrary date is used for expiry. The amount of the substance. Active Inactive Entered in Error If the element is present, it must have either a @value, an @id, or extensions