Philip and Paul look into fireworks and the chemicals that they use in their propellants such as Sulfur Carbon and Potassium Nitrate and the toxic chemicals like sulfur dioxide, nitrogen dioxide that they produce. They also look at the toxic chemicals that make the pretty colours. When these fireworks explode they leave behind microscopic particulates in the air. The largest of these called PM10 stay around for up to five days and the smallest stay around for several years in the air we breathe. Every year in every country where there are fireworks days after the events there is a rise in the number of hospital emissions with sufferers of Asthma and other breathing problems directly related to the firework displays. Some of the chemicals in the fireworks are toxic like copper and this can get into the topsoil and be taken up by plants and enter the food chain. So what are the alternatives - really there is no such thing as eco friendly fireworks - the ones labelled so just have slightly less nasties in them. Home fireworks are usually the worst culprits, so if is often best to go to a professional display but better still go and watch a laser display or a drone show.