Gas chromatograph analysis of sealed goaf areas at Mandalong Mine show that ethane concentrations of 30 ppm are present in older areas and up to 225 ppm have been recorded in more recent areas. Such high levels of ethane would normally be considered an indication of spontaneous combustion for many mines. However, at Mandalong Mine despite these high ethane levels, no significant carbon monoxide is recorded, indicating that the ethane being measured is a result of gas desorption from the coal over time. Generally, there is a sympathetic evolution pattern between ethane and methane, with some areas of the mine being richer in ethane than others. This paper presents results from the mine showing trends in ethane emissions from the sealed longwall panels that have been extracted to date and discusses the implications of the historical goaf seal data for reviewing the existing TARP.