The main objective of this paper is to present and discuss a set of scenarios that may lead to hydrocarbon releases on offshore oil and gas production platforms. Each release scenario is described by an initiating event (i.e., a deviation), the barrier functions introduced to prevent the initiating event from developing into a release, and how the barrier functions are implemented in terms of barrier systems. Both technical and human/operational safety barriers are considered. The initiating events are divided into five main categories: (1) human and operational errors, (2) technical failures, (3) process upsets, (4) external events or loads, and (5) latent failures from design. The release scenarios may be used as basis for analyses of. (a) the performance of safety barriers introduced to prevent hydrocarbon releases on specific platforms, (b) the platform specific hydrocarbon release frequencies in future quantitative risk analyses, (c) the effect on the total hydrocarbon release frequency of the safety barriers and risk reducing measures (or risk increasing changes). (C) 2005 Elsevier Ltd. All rights reserved.