Hi Barry, Sorry to have missed this one. There is a reference in Fire June 1994 'Video tapes fed fatal fire' FRS/BRE did some calorimetry for Kent Fire Brigade following a fatal fire in February of that year. Briefly, you get abot 1MW from 20-25 video cassettes, depending on whether they are in cardboard or library covers. roughly equivalent to a standard foam filled armchair (ie not FR treated). The videos were on shelves the same depth as the cassettes. In the fatal fire, clothes were ignited on a fire guard and the flames from this source are believed to have ignited the first of 300 cassettes stored on shelving in the sitting-room. They need a sustained heat source to get going but do not produce a pool fire as you might expect - the body of a cassette was polypropylene at that time - suspect it may not have changed very much. (ABS was used for professional use). If cassettes are stored in drawers or cupboards they will be difficult to involve in a fire.