The chemicals used in most fireworks are the same ones found in explosives.

The source of the August 2020 Beirut explosion was dozens of bags of fireworks.

The random explosion of fireworks can trigger a startle response in people who have post-traumatic stress disorder (PTSD).

For individuals who have witnessed gun violence or who have served in the military, fireworks may trigger their PTSD.

Airborne particles from fireworks have been found to deplete lung defenses far more than pollution from traffic sources.

Fireworks represent a danger both to animals who live in areas where they explode, or in relatively distant locations when the wind transports the harmful particles released on explosion.

Particle pollution in the air has been found to eventually deposit on the ground and get washed into lakes and rivers.

Many birds who flee from their nests due to the sounds of fireworks do not know how to return to their nests once the noise ends, which leaves many of their young helpless.

Even 'safe' fireworks can be a hazard in drought-stricken areas at risk from bushfires. 

Because of light pollution, most people on Earth never see a naturally dark night sky, and this also affects migrating birds, insects and other animals by disrupting the light-dark cycle they are tuned into.