Carbon dioxide

Carbon dioxide was a gas that humans expelled from their lungs during respiration. When she crashed her escape pod into a river on the planet Mokivj to avoid pursuit from the Batuu police in 19 BBY, Padmé Amidala took several large breaths to flush as much carbon dioxide as possible from her lungs before entering the water. The planet Dagobah was covered with thick clouds of water vapor and carbon dioxide.

Text and facts from the “Carbon dioxide” article on Wookieepedia, licensed under CC BY-SA 3.0. Modified for this site.