I have had a pressure cooker blow up on me. Literally. I was raised around them and was cooking beef stew. I had put whole frozen tomatoes in it. I have always cooked on really low heat. The pot had cooked the amount of time it needed to and I had turned it off and waited for it to cool some. I touched the "dinger" with a long knife to see if there was any steam left in. NO hiss. I started turning the handle and it blew all over me. I had instant blisters on my upper body where food landed and steam burns on my hands & lower arms.. DH inspected the lid and there was a tomato seed stuck in the exhaust spout. Thank God I had made the kids leave the kitchen or they would have been burned also. I still use one but am very cautious and it will sit for hours to cool before I will open it. I make sure everything is de-seeded before I put it in the pot.