scope:

The system Standard, of which this is Part 3, specifies the requirements for a multilayer piping system.
The multilayer piping system is intended to be used for hot and cold water installations inside buildings.
In respect of potential adverse effects on the quality of water intended for human consumption, caused by the product covered by ISO 21003:
This Standard provides no information as to whether the product may be used without restriction in any of the Member States of the EU or EFTA;
It should be noted that, while awaiting the adoption of verifiable European criteria, existing national regulations concerning the use and/or the characteristics of this product stay in force.
Requirements and test methods for components of the multilayer piping systems are specified in Part 1 and Part 3 of ISO 21003. Characteristics for fitness for purpose (mainly for joints) are covered in Part 5.
This part of ISO 21003 specifies the characteristics of fittings.