As of the 1st July 2014 it became compulsory that all structural steelwork was CE marked. This means that anyone manufacturing or designing steel framed buildings or components of steel within the European market must comply with this law. After this date it is now illegal to sell any structural steel without being CE marked, failure to do so causes serious consequences potentially leading to imprisonment.
Under the Construction Products Regulations (CPR) there are new legal obligations that have been introduced to producers and steel manufacturers within the EU. This applies to constituent products (beams, etc) and not only that but to the fabricated elements.
The standard that overlooks the fabricated structural steelwork is BS EN 1090: Execution of steel structures and aluminium structures.