this morning. I decided to sit down on a bench in town while my wife and daughter raided the clothes shops. Before I sat, I noticed the man who had sat there before me had been smoking. I placed my plastic carrier bag containing some shopping on the ground in front of me. I began reading my newspaper, and suddenly my shopping bag erupted in flames. After frantically stamping out the flames, I had a look to see what could have caused such a sudden eruption. I had bought some steak that was packed in a tray sealed with cellophane. The tray had burned away almost half way along its length. After having worked as an engineer in a meat packing plant I know the tray is filled with a mixture of 75% oxygen and 25% carbon dioxide. So I think I must have placed my carrier bag on a still lit cigarette end which burned a hole in the bag then the tray, releasing the oxygen rich mixture, accelerating the burning.It cerainly added a bit of excitment to my day, but ruined my steak!