Both!!!! As a boy I used to make bombs – but I can’t tell you the ingredients and, anyway, the important one isn’t available over the counter any more. Then I had two accidents in the laboratory, one where a flask of hydrazine (a constituent of rocket fuel) caught fire and actually burnt through the clay tile it was standing on and the other was a hydrogen explosion. Fortunately I was wearing protective clothing and eye protection on both occasions. Explosions in laboratories are bad news but, fortunately I still have all my fingers!!!!