In-situ burning (ISB) is the controlled combustion or burning of hydrocarbon vapours from spilled oil. ISB can rapidly remove oil from a land, snow, ice or water surface, and combusts it to mostly Carbon Dioxide and water. ISB can rapidly reduce the volume of spilled oil, and thus greatly reduces the need to collect, store, transport and dispose of recovered oil. ISB can also shorten the overall response time, thus aiding environmental recovery. This guide contains information about the in- situ burning of oil spills, including both the scientific aspects of the burning process and its effects. It also presents practical information on the procedures and equipment required for ISB operations.