GEA is the first European manufacturer to offer semi-hermetic compressors certified according to ATEX machine category 2 (zone 1+2). In 2014, GEA also included compressors certified according to ATEX machine category 3 (zone 2) in its program. Within the European Union, electrical and mechanical machinery operated in explosive atmospheres must comply with the so-called ATEX (ATmospheres EXplosibles) conditions. All ATEX compressors are also approved for operation with the current hydrocarbons. The models in the HG Series are the basic compressors for ATEX versions.