Polluted Oxygen

Polluted Oxygen is a breathable gas that appears throughout the asteroid as a byproduct of polluted materials and certain critters, and it is one of the main early sources of germs in the atmosphere. It is also a useful resource in its own right: Duplicants can clean it into regular Oxygen with Deodorizers, while some creatures and systems directly consume or generate it.

Polluted Dirt, Slime, and bottled Polluted Water all emit Polluted Oxygen when stored or left in an area with less than 1800 g of gas pressure. The gas released from these materials carries any germs present on the source substance into the surrounding air. Unbottled Polluted Water also releases germy Polluted Oxygen in low-pressure environments, and its output rate is random. If Polluted Dirt is submerged in a liquid or stored under at least 1.8 kg/tile of gas pressure, it will not off-gas. In Storage Bins, the same pressure rule applies, so keeping polluted materials sealed is an effective way to prevent unwanted gas buildup.

Morbs produce Polluted Oxygen without any input when the surrounding pressure is below 1000 g, and they also release Polluted Oxygen when they die. Pufts and Puft Princes can breathe Polluted Oxygen and convert it into Slime, making polluted atmospheres useful for keeping these critters alive and productive. Two types of geysers also generate this gas: the Hot Polluted Oxygen Vent and the Infectious Polluted Oxygen Vent. Both produce about 95 g/s and become stifled at 5 kg of air pressure, but the Infectious version also spreads Slimelung. Their output is enough to support roughly five wild Pufts or one to two tame Pufts, though the hotter vent must be cooled before it can safely support critters and may be useful for feeding Steam Turbines.

Polluted Oxygen can also be obtained from industrial and exploration sources. The Sublimation Station converts 1000 g/s of Polluted Dirt into 660 g/s of Polluted Oxygen. On rocket missions, it can be harvested from renewable Space POIs, including the Oxygen Rich Asteroid Field and the Organic Mass Field, where it appears in different cycle yields.

A few practical notes make it easier to handle:

• Deodorizers convert Polluted Oxygen into Oxygen and Clay using a Filtration Medium.
• Because off-gassing depends on pressure and exposed mass, large stockpiles of Polluted Dirt can create substantial gas output if left uncovered.
• In the Spaced Out DLC, the off-gassing rate of Polluted Dirt is reduced by a factor of 10.
• Polluted Oxygen can be cooled to its condensation point and then reheated as part of a process to convert it into Liquid Oxygen.
• Its former name was Contaminated Oxygen.