Any manufacturer, retailer or importer of chemical products must declare certain products to an approved body such as the INRS (French National Institute for Research and Safety). A chemical product is a substance created by assembling various chemical substances. It will have different properties (colour, odour, boiling point etc.) from those of its components.
Manufacturers and retailers of e-liquids are subject to this declaration, as the chemical products contained in e-liquids are among those that should be declared: PG, VG, nicotine, flavouring, ethanol etc.