HSK GmbH has five shareholders. The largest share is held by SRH Verwaltungsgesellschaft mbH, whose sole shareholder is Stadtreinigung Hamburg – an institution under public law.

Hanseatisches Schlackenkontor GmbH (HSK GmbH) supports Hanseatisches Schlackenkontor ARGE Distribution (HSK ARGE Vertrieb) and its retailers in marketing and sales. It guarantees the take-back of emvau building materials during dismantling measures and has the mission to develop new building material products based on household waste incineration ash (emvau-schlacke) and to expand the application possibilities of this building material.