The CE markings for engineered stone (agglomerate stone) as of the begining of 2010 are mandatory for modular tiles sold in the European Union. The JWG (Joint Working Group) n. 229/246 is responsible for setting standards for the agglomerate stone. The official designation of agglomerate stone represents all products which are manufactured by mixing mainly natural stone grit with a bonding agent. The natural stone grit may be of several sorts, marble, granite or other. The binder is said to be made of artificial components like unsaturated polyester resin or cement. The product group includes artificial stone and compacted marble.
The standards are not all complete, as the JWG is still working actively, however some standards have been approved and are actually already in use. The standards mentioned in the table relate to testing methods that are required for agglomerate stones. So basically when dealing with agglomerate stones, every laboratory should follow these procedures to guarantee comparability between agglomerate stones and the tolerance levels defined in the approved standards.
Until the end of 2010, 2 product standards have been approved and published, namely the UNI EN 15388 (voluntary standard) which specifies the requirements for kitchen and bathroom countertops, the other approved and mandatory standard is the UNI EN 15285 which defines the requirements for modular composite tiles. The UNI EN 15285 is effectively mandatory as of the 1st of January 2010, and includes tiles size up to 600 mm x 600 mm and with a maximum thickness of 20 mm destined to be applied on flooring and stares.
Currently the JWG (Joint Work Group) is working on two standards: one for agglomerate stone slabs and the other one for agglomerate stone tiles used as interior or exterior wall cladding.
So currently if you are selling agglomerate stone modular tiles for flooring and stairs in Europe, you must comply with the European standard EN 15285. Besides complying with specification in the factories at shop floor level and labeling, your product (agglomerate stone) must be tested by a certified laboratory according to the standard EN 14617. And of course, the labeling with the CE mark means that your product is within the tolerance levels defined by the standard, if not you should not label it as CE, which in the future may mean that you may not sell it in Europe.