The BPA is concerned that companies are increasing being asked to address the environmental effects of fireworks, and have prepared this brief guide to assist members.
Fireworks are explosives and function by self-sustaining exothermic chemical reactions involving primarily an oxidant and a fuel. To this basic mix are added components to create colours or effects, or to assist in the manufacturing processes. Many fireworks have a significant proportion of blackpowder (gunpowder) acting as a propellant.
The chemistry of combustion of fireworks in general is not very well documented, but the combustion chemistry of blackpowder is well known. Therefore the following conclusions can be drawn from studies carried out by consultants from sites, such as Theme parks where displays are fired all year round.
Gaseous products from fireworks combustion include Carbon Dioxide, Carbon Monoxide, Sulphur Dioxide, Nitrogen oxides, water vapour and nitrogen. In a typical firework display where we have approximately 250Kg of blackpowder is fired over 10 minutes, the rates of production of these gasses is approximately.
- Carbon Dioxide – 68 g/s
- Carbon Monoxide – 29 g/s
- Sulphur Dioxide – 2 g/s
- Nitrogen oxides – 7 g/s
- Nitrogen – 22 g/s
Given that these are formed in a large volume of air and are subject to immediate dilution by wind the potential human health or environmental effects are very low.
By way of comparison these figures (for a 10 minute display) equate roughly to
- 5000 person- kilometres of travel by bus
- 5000 person- kilometres of travel by plane
- 8000 person- kilometres of travel by car
- 26000 person- kilometres of travel by high speed train
So, for instance, if 10,000 people come to specifically see the display and travelled by car or bus at some point in their journey, travelling an average of 50km round trip each, the atmospheric pollution caused by the display is approximately 1.5% of the pollution caused by people travelling to the display.