[fy20]

As a European reading these comments I never would have expected fireworks in the US to regulated at all. In my country you can buy whatever you want. The most popular time to use them is at New Year, and even in supermarkets they have popup stalls selling then. If you go out at midnight you can see fireworks in every direction.

I live in a capital city thats surrounded by forest. I've never heard of any forest fires caused by them, but I guess it's because winter - we often have snow that time of year.

It definately has a big effect on air quality though, the smell of gunpowder lingers until the next day. We are far from the sea so there is little wind that time of year, and the cold temperatures cause the smoke to stay close to the ground (same issue with wood burning stoves which are common in older houses).