Article 15 and Annex IV of Regulation (EU) 10/2011 require a written declaration for plastic materials and articles; it is issued by the business operator and must allow the material to be identified easily. Compare the declaration with what you bought, line by line:

In the declarationYour check
Material and article identityDoes it match your container, lid and gasket
Issuing and manufacturing businessAre name and address given
DateRecord the date and version of the declaration
Food types it may contactDoes it cover your product
Contact time and temperatureDoes it cover your filling, storage and washing conditions
Surface-to-volume ratioDoes it suit the volume you use

Where a multi-layer material relies on a functional barrier, the declaration confirms that separately. It has to be renewed when a substantial change in composition or production alters migration, or when new scientific data become available (Article 15(3)), so an old declaration is read for whether it is still current. The test and calculation records behind it are held by the issuing business and made available to the authorities on request (Article 16).