This article investigates health and safety risks at a biogas station, in particular the activities in the condensation shaft. There were selected three scenarios in total, which can lead to a fatal accident during the maintenance and servicing of equipment located in the condensation shafts. These are the following scenarios: (1) the worker descends to the condensation shaft and in the subsequent service activities consumes oxygen contained in shaft, falls into unconsciousness and dies. (2) There is such a gas concentration in the condensate shaft that intoxication occurs (but even direct asphyxiation is possible-e.g., methane, carbon dioxide) thereafter subsequent death. (3) The worker suffers fatal injuries due to a fall from a height. The individual scenarios are discussed in the article, including whether and under what circumstances these may occur. To support the authors claims, measurements of selected gases concentrations were made in condensation shafts at eight biogas plants. The aim of this article is to highlight the risks that can be encountered when working in condensing shafts and how they can be prevented. (C) 2017 American Institute of Chemical Engineers