(105)In order to ensure that there are no barriers to trade on the internal market, requirements on packaging sustainability, including on substances of concern in packaging, compostable packaging, packaging minimisation, reusable packaging and re-use systems, should be harmonised at Union level. In order to facilitate conformity assessment as regards such requirements, including methods for tests, measurements or calculations, it is necessary to provide for a presumption of conformity for packaging and packaged products which are in conformity with harmonised standards that are adopted in accordance with Regulation (EU) No 1025/2012 for the purpose of expressing detailed technical specifications of those requirements.