Tapware forms part of the European Construction Products Regulation (EU) No. 305/2011. This Regulation relates to all the products manufactured to become a permanent part of construction works. It is mandatory to affix the CE marking to the products covered by a harmonised standard. To be defined a harmonised standard, the European technical specification standard (EN) must be transposed at national level by all the member States and all the national conflicting rules must be abrogated. Unluckily technical standards regulating tapware are not harmonised and, therefore, we are not allowed to affix the CE marking.
Harmonised European standards are already available for ceramic products such as basins and WC units. The Official Journal of the European Union publishes the updated list of harmonised standards on a regular basis:

Products that are marketed in Europe and that are subject to mandatory marking must have the CE marking notwithstanding where they are physically manufactured (for instance in China or a EU Country such as Italy). In general, the Manufacturer is required to perform Initial Type Testing (ITT) and to implement a Factory Production Control System (FPC) pursuant to the harmonised reference standard, in order to verify that the technical performance complies with the essential requirements established by the European Construction Products Regulation. According to the system of Assessment and Verification of Constancy of Performance (AVCP), which is defined by six systems from 4 to 1+ depending on the impact of the product in terms of end Consumer/User safety, once in operation, in relation to the essential requirements set out by the Regulation, there are different Roles and Responsibilities of the manufacturer and the Notified Laboratory/Entity. At the end of this procedure, the Manufacturer can affix the CE marking to the product. “EN 997 Standard – Sanitary appliances – WC pans and WC suites” and “EN 14688 Standard – Sanitary appliances – Functional requirements and testing methods” in the above example describe in the Annex ZA of the Standard both the AVCP level and the other obligations relevant to the CE marking. It is important to notice the difference between a CE certification and a CE marking. In well-defined cases (according to the AVCP level) you must have a CE certification issued by a notified entity as evidence of the successful testing needed to obtain the CE marking. In the case of the simple marking, the manufacturer or the importer must however draw a self-declaration of conformity or Declaration of Performance (DoP) stating that all the legal requirements are met. Prior to the declaration, technical and acceptance tests must be carried out on the product in order to verify its safety and conformity with the European standards and a technical dossier must be drawn to collect all the documents evidencing the product conformity with the technical requirements.