None at all.
There are standards for importing whole bikes and probably standards for components. They are to do with safety. contact Intertek - I know they do testing for imported Taiwanese bikes - I used to work for them!
The four different CEN standards that were published in the EU Official Journal are:
EN 14764 for City and Trekking bicycles
EN 14766 for Mountain bicycles
EN 14781 for Racing bicycles
EN 14872 for Bicycles – Accessories for bicycles – Luggage carriers.
EN 14765 for childrens bikes has not yet been published.