Oxygen Not Included Wiki

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Oxygen Not Included Wiki
This article has not been revised for the current version (U40-494396). It was last updated for AP-398142. It may contain inaccuracies.
This article has not been revised for the current version (U40-494396). It was last updated for AP-398142. It may contain inaccuracies.

Slime is one of the Resources in Oxygen Not Included. It is found mostly in the Swamp Biome, and in maps with the Slime Molds World Trait.


Slime turns into Dirt when heated to above 125°C. If Slime in the form of debris reaches this temperature, it forms a natural tile of Dirt.

It emits Polluted Oxygen once dug up, losing mass in the process, even when in a Storage Bin. This can be prevented by storing it submerged in a Liquid or under a Gas pressure of at least 1.8kg/tile.

  • The Liquid method is much more reliable and manageable, but poses a problem in layout planning, especially when the layout has to be changed.

Slime storage.jpg


Algae Distiller can produce Algae from Slime. 600 g/s Slime = 200 g/s Algae + 400 g/s Polluted Water.

Dusk Cap domestic growth requires 4 kg/cycle Slime. It reduces Dusk Cap growth length from 30 to 7.5 cycles.

Sage Hatches can eat Slime and excrete Coal.

Slime can be used as bait in Airborne Critter Bait to attract Pufts and Puft Princes.

If heated, it can be converted into Dirt


Slime exists in the Swamp Biome and also in ruins. Random placed Slime balls can be found in maps with Slime Molds World Trait.

Pufts and Puft Princes breathe Polluted Oxygen and excrete Slime.

Spaced Out Logo.png It can be harvested on rocket missions to renewable Space POIs:

  • In Organic Mass Fields at a rate of 162 – 486 kg per cycle.

Excavating and Decontaminating Infected Slime[]

Slime generally is contaminated with Slimelung Germs and emits lots of Polluted Oxygen after being dug up. The Germs will then be present on the Polluted Oxygen and will rapidly multiply. Deodorizers can help clean up the Polluted Oxygen. They won't, however, kill Slimelung Germs. Instead, the Germs will slowly die off in regular Oxygen. Hence, having Deodorizers around before operations to excavate the Slime in a Swamp Biome is important, especially if the technique used doesn't kill the germs before excavation.

More convenient methods consider the Thermal Conductivity of the Slime; it is considerable. Expect Slime tiles that are adjacent to each other to exchange heat quickly.

Temporary Storage in Chlorine[]

Restricting access and having Duplicants move through Sinks will be important when excavating infected Slime.

Storing Slime in a Chlorine atmosphere can kill all Slimelung after a full cycle.

  • However, this means that Duplicants have to come into contact with the infected Slime, which means that they will get it over themselves.
    • Although they cannot infect themselves from skin contact, they can contaminate any bottled Polluted Oxygen and Slime that they come into contact with, including the Slime that you are using to grow Mushrooms.
  • This is also an inefficient use of the Duplicants' time, due to the need to limit their access and have them clean up themselves.
  • The Deodorizers also need to be cleaned up afterwards; they often contain infected Polluted Oxygen, so they may need to be deconstructed in phases so that Deodorizers that have yet to be deconstructed can sponge up the Polluted Oxygen released by those that have been deconstructed.
  • The Clay that the Deodorizers have made from the Sand that has been loaded in them also has germs. If there is a Kiln that is making Ceramic, the Duplicants will be eager to get that Clay somewhere else - and spread germs all over as a result. This may result in the need to store the Clay in Chlorine as well.
  • The Duplicants will drop Slime they are carrying if their shift ends in the middle of their task

In the early game this is the only method available. Later on the danger and inconvenience to Duplicants can be eliminated with Atmo Suits. The disinfection of Slime can be automated with the use of Conveyor rails and sensors. Disinfecting Slime can also be combined with disinfecting Polluted Water from toilets. However cleaning out a Slime biome still involves a considerable amount of labor.

Flood/Contact with Chilled Water or other Liquids[]

An insulated cavity has to be made around the slime before filling the gaps with chilled water.

This is a method that can be carried after gaining the means to chill liquids with Thermo Aquatuners and Steam Turbines. However, the slime has to be surrounded by an insulated cavity, which can be tricky to build if the seam of slime has awkward shapes.

The disadvantage of this method is the containment of the Liquid and its disposal. See the screenshot to notice the problems:

  • Firstly, the liquid has to be chilled. Thermo Aquatuners and Steam Turbines can only do this up to above the freezing temperature of the liquid; any further attempt at chilling the water would cause the water to freeze, thus damaging the pipes.
  • The liquid then has to be channeled and spilled into the cavity. This can take a while.
    • This should be done before the cavity is sealed; doing this after the cavity has been sealed may cause any trapped gases to be pressurized, which in turn might pressurize the liquid that is poured in.
      • The trapped gases linger at the vent, meaning that the vent will keep releasing liquid and will not be flooded itself; this causes the abovementioned pressurization of the liquid.
  • The walls of the cavity can be stressed by the liquid that they are containing in; in the case of the abovementioned pressurized liquid, this risk is much more significant. See Liquid: Pressure Damage.
  • The liquid has to be re-chilled afterwards, making this already slow method even slower.

The most welcome advantage of this method is that after the Slime has been chilled, excavating it and having it drop into the liquid prevents its sublimation.

Multiple bridges require greater reserves of material, especially that for the insulated tiles.

Insulated Heat Sink Bridge from Cold Biomes[]

This is the most easily deployed method. A contiguous stretch of Metal Tiles, in contact with a cold biome (preferably with a rock tile made of material with considerable Thermal Conductivity) is made all the way to come into contact with Slime seams, with the sides bounded by Insulated Tiles.

Metal Tiles are recommended above other things that can be made with Refined Metal; they displace gases and liquids, thus maximizing heat conduction through themselves.

The disadvantage is obvious; this takes a lot of materials, both for the bridge and the ladders that are needed for the scaffold. This requires the player to have considerable reserves of materials in the first place.

  • The amount of space needed becomes a serious impediment if the Slime seams are located in places with dense pockets of Polluted Oxygen that are infected with Slimelung.

Furthermore, the further away the cold biome is, the less effective this method would be. This is the main setback of the method; after about fifteen tiles away, this method is no longer effective, even with conductive materials.

  • Spending the effort and time to make so much Refined Metal would be terribly unwise too.

(In addition to the Thermal Conductivity, the player should consider specific heat capacity of the material too.)

Insulated Chilled Liquid Channel from Cold Biome and Metal Tile Heat Exchanger[]

This method is as complicated as this combined screenshot would suggest.

This method is the most reliable - but it is easy to mess up, especially with regard to the layout of the piping at the heat-sink end and the chilling end.

The heat sink end is the edge of a cold biome, or whichever cold location in the biome. For moderated heat sinking, just two segments of Radiant Liquid Pipe made of Aluminum that are adjacent to something cold and solid is enough.

As for the chilling end, two segments of the same piping should be adjacent to the seam of Slime; then the piping is encased in Metal Tiles of either Aluminium or Gold (either is good; Gold has the advantage of having much lower specific heat capacity, and being more common than the former). Then, surround the Metal Tiles (and the Slime seam, if possible) with Insulated Tiles.

  • The segments of piping near and at the chilling end should be joined together with Liquid Bridges, so as to make changes to the direction of the piping easier later. (The Liquid Overlay will show a mess of input and output ports however.)

For the least fuss at re-channelling the pipes later, a Liquid Reservoir should be used to store the Liquid when they are not being circulated around. In particular, when chilling is not being done, all of the Liquid should return to the Reservoir - including the Liquid at the heat sink end.

To achieve this, the heat sink end should occur along the line that goes into the Intake port of the Reservoir. Therefore, whenever the player wants to stop the circulation of the Liquid, the player can remove one of the Bridges that occur between the Output port of the Reservoir and the chilling end. Any liquid that is out of the reservoir should occur after the Output port, and away from the heat sink end.

  • This is to avoid any freezing of the Liquid and breaking of the pipes; most cold biomes are cold enough to freeze most readily available Liquids.

Compared to the method of the Heat Sink Bridge (as shown previously), this method won't be chilling the slime as fast; this is due to the chilling being provided by packets of 10 kg of Liquid instead of contiguous lines of 100 kg Solids.


  • Storing Slime in multiple weight-limited Storage Bins with Deodorizers right above them can give you low power Oxygen without needing Algae Terrariums or Algae Distillers. However, Slime converts to Polluted Oxygen at a low rate (thus you need more Compactors) and at the Slime's original temperature (swamp biomes are at least 30+°C, you'll need a Wheezewort or two). Deodorizing Polluted Oxygen will result in 10% less Oxygen (more efficient than Deoxiders) and still infected with Slimelung (though the germs will eventually die off in pure Oxygen), and you'll lose out on the Polluted Water from the distillers.
    • There is also the matter of over-pressurization. The sublimating Slime is very difficult to control.
  • The Slime tiles that are part of Ruins do not have Slimelung.

See also[]