18 April 2017

BASF Opts for Voluntary Product Certification for Styrodur Insulation Boards

  • KEYMARK replaces the Ü mark
  • “DIN-Geprüft” (DIN-Tested) application in accordance with 4108-10

In October 2016, the familiar Ü mark for harmonised building products was dropped (Judgement of the Court (Tenth Chamber) of 16 October 2014—European Commission v Federal Republic of Germany (Case C-100/13) (1)). In order for end users to obtain proof of high quality after the termination of the Ü mark, BASF has decided to use the KEYMARK as a voluntary product certification for insulation boards made of Styrodur® (XPS: extruded polystyrene). In the past, the Ü mark—alongside the CE mark—was the only verification that a building product was approved for use in Germany. The CE mark on its own, however, does not provide proof of quality, because no independent quality testing is carried out.

KEYMARK and DIN—documented rigorous testing
In the process of KEYMARK certification, an accredited laboratory gathers samples from production sites and warehouses and carries out a rigorous examination of all the properties listed in the DoP (Declaration of Performance). The high quality standard of BASF’s green Styrodur® insulation boards remains unchanged and can now be identified by the KEYMARK symbol on the label. In addition to the KEYMARK logo, which verifies the product’s conformity with the European standard EN 13164, BASF also has its green insulation boards tested in accordance with the German standard DIN 4108-10. This standard determines the suitability of XPS for the relevant applications, which can be identified by means of the “DIN-Geprüft” (DIN-Tested) logo next to the KEYMARK symbol on the label.

KEYMARK is a voluntary product certification awarded by DIN CERTCO, a TÜV Rheinland company in cooperation with the German Institute for Standardization (DIN).


About BASF
At BASF, we create chemistry for a sustainable future. We combine economic success with environmental protection and social responsibility. The approximately 114,000 employees in the BASF Group work on contributing to the success of our customers in nearly all sectors and almost every country in the world. Our portfolio is organized into five segments: Chemicals, Performance Products, Functional Materials & Solutions, Agricultural Solutions and Oil & Gas. BASF generated sales of about €58 billion in 2016. BASF shares are traded on the stock exchanges in Frankfurt (BAS), London (BFA) and Zurich (BAS). Further information at

About Styrodur®
The compression-proof, water-repellent, and rot-proof Styrodur has protected homes from heat, cold, and moisture for more than 50 years. The green XPS is characterised by its reliable product quality as well as the continuous efforts to gain approvals. Today, Styrodur is the insulation material with the greatest number of officially approved uses in the German XPS market. Insulation with Styrodur prolongs the lifespan of buildings, increases their value, and improves the living environment. The various Styrodur types, which contain air as the cell gas, differ mainly in their compressive strength.

You can find more information on Styrodur® on the homepage (

Last Update 18 April 2017