Europe's highest court has ruled that a provision in the European Union's chemical regulation REACH, requiring monomers that have been reacted to form polymers to be registered, is valid.

The court found that the regulation's coverage of monomers, chemical building blocks that create polymers when they are reacted and linked together, should be considered to include the reacted monomers that have bound together to make a polymer.

The court was hearing a judicial reference from the U.K.'s High Court, which is considering challenges from several companies over the regulation's provisions on monomers and polymers.

The plaintiffs include French organic chemical firm S.P.C.M. SA, German chemical conglomerate C.H. Erbsloeh KG, U.K. chemical technical services specialist Lake Chemicals and Minerals Limited, and former U.S. chemical firm Hercules Inc., which was taken over in 2008 by Ashland, Inc. (ASH), another U.S. chemical firm.

The REACH Regulation requires the registration of all chemicals made or imported into the E.U. Polymers are excluded from the regulation but monomers aren't. In addition, monomers making up over 2% of the weight of a polymer must be registered if they weren't registered at an earlier stage in the manufacturing process and if the total amount of the monomer exceeds one metric tons a year.

The chemical companies argued reacted monomers shouldn't have to be registered, as they are chemical components of polymers, which aren't covered by the regulation.

-By Mike Gordon, Dow Jones Newswires; +352 691 180 766; mgordon.dowjones@gmail.com