This Technical Specification is used in the implementation of ISO 11238. This Technical Specification defines substances based on their scientific identity (i.e. what they are) rather than on their use or method of production.
ISO 11238 provides the conceptual framework for defining substances and specified substances and for assigning unique identifiers in the context of the ISO IDMP standards. ISO 11238 describes general concepts for defining and distinguishing substances and a high level model for the structuring of information for substances. This Technical Specification provides detailed explanations of each type or grouping of substance information, an element-byelement description for implementation of ISO 11238, and examples for a variety of substances and specified substances.
This first edition of the Technical Specification will only address substances, and Groups 1 to 3 of the specified substances as defined in ISO 11238 and Annexes A, B, C, and D. It is anticipated that specified substances Group 4, as defined in ISO 11238, will be addressed in a subsequent edition of this Technical Specification. Some information that would typically fall under specified substances Group 4 may be covered in the Annexes of this Technical Specification. This information, although not defining of either a substance or a specified substance Group 1, may be essential to distinguishing substances.

This Technical Specification addresses the following:
- Data elements necessary for defining substances and specified substances Groups 1 to 3;
- The logical use of data elements as defined in ISO 11238;
- Substances and specified substances Groups 1 to 3 business rules for determining necessary data elements, distinguishing and defining materials according to ISO 11238, triggering the assignment of identifiers.

This Technical Specification does not address the following:
- Business processes for data management;
- Implementation of a specific data information system (e.g. a relational database schema);
- Normative messaging standards for substances;
- The maintenance of controlled vocabularies;
- The specific global identifier system that should be used;
- Nomenclature standards for substances.