Products that are, or contain, polymers require registration prior to importation or sale in Canada.
Polymers are materials made of long, repeating chains of molecules. These materials have unique properties, depending on the type of molecules being bonded and how they are bonded.
The definition of a “supplement” has been recently reviewed by the CFIA. As a result, it was determined that the scope of the definition extends beyond materials that directly affect plant growth, crop yield, or that directly amend the physical properties of the soil.
Source : Fertilizer Canada