GS mark is the voluntary safety mark of Germany. It holds high recognition by consumers. Many products, including electric tools, IT equipments and household appliance, etc. are difficult to sell in and around Germany with GS mark.

Product evaluation, certification, and pre-license inspection
Product evaluation is on the basic of harmonized European Standard, and refers to the Low-voltage directive, EMC directive and Machinery directive. If the GS required product does not have the related European standard, it would issue the IEC standard certificate. The use-life of the certificate is five years.
Pre-license inspection is the necessary requirement. After this, it is the annual factory inspection.
Besides in accords with European harmonized standard and German National Deviations, product evaluation should also refer to ZEK document issued by ZEK, and documentation established by Exchange of Experience Forum 1 (EK1). Some products also need Ergonomic testing.
According to ZEK 01-08, from April 1 2008 on, products applied for GS certification should has the PAHs evaluation, thus to complied with the regulation and avoid health hazard. This compulsory requirement adapts to all the possible PAHs materials that can be touched by human being or put into mouth in ordinary use or reasonable anticipative misusing. Products accessed GS certificate before April 1 2008 should accomplished the PAHs evaluation before March 31 2009.
Revised edition ZEK 01.1-08 of ZEK 01-08 has been published on June 25 2008.
Ergonomic testing required by GS mark containing multi-sorts of IT products, including LCD/CRT display services, computers, laptops, and other computer peripheral equipment (such as keyboards, mices, printers, scanners, etc.), must be complied with the related ergonomics standard within EK1-ITB 2000.