This reference for a preliminary ruling concerns the interpretation and validity of certain provisions of the REACH Regulation. In light of the fact that the registration requirements in Title II of the REACH Regulation do not apply to polymers,the England & Wales, Queen’s Bench Division Administrative Court, sought clarification of the concept of ‘monomer substance’, as used in article 6(3) of the REACH Regulation. The referring Court asked whether ‘monomer substances’ were to mean ‘reacted monomers’, namely monomers which have reacted together in such away that they are bound in the polymers of which they are components, ‘unreacted monomers’ which are residual to the polymerisation process and which retain their own chemical identities and properties separate from the polymer after that process is complete, or both ‘reacted’ and ‘unreacted monomers’. The ECJ concluded that the concept of ‘monomer substances’ in article 6(3) of the REACH Regulation relates only to ‘reacted monomers’ which are incorporated in polymers and that the obligation to register ‘reacted monomers’ is an appropriate means by which to realise the objectives of the REACH Regulation.