Requires Factorio 2.1.23 or later in the 2.1 series.

Phosphorus FAQ

Do I need Space Age?
You need to own it: spoiling is a Space Age feature. It does not have to be enabled; Phosphorus works in vanilla.

Where does phosphorus come from on Vulcanus?
Big and huge volcanic rocks drop phosphate rock next to their tungsten ore, enough for the lubricant of the first foundries and turbo belts. Once a foundry runs, basic slag turns 500 lava and 2 calcite into 250 molten iron, 5 stone and 4 phosphate rock.

What about Fulgora, Gleba, platforms and Aquilo?
Fulgora leaches 20 scrap, 20 sulfuric acid and 50 water into 30 phosphoric acid for local batteries. Gleba ashes 30 spoilage in a biochamber for one phosphorus ash, used for acid and fertilized iron or copper bacteria. Both planets make their own white phosphorus from that acid: a phosphorus furnace reduces 60 phosphoric acid with one solid fuel (Fulgora) or two carbon (Gleba, from burnt spoilage) into four white phosphorus. It costs more phosphate than rock and takes no productivity, but it covers lubricant, red phosphorus and heat pipes without imports. A crusher gets phosphate rock and carbon from carbonic asteroids; a carbon-fed phosphorus furnace works without coal. Drop phosphate and carbon to Fulgora or Gleba. A platform furnace still needs imported stone flux. Aquilo remains import-based: ship red phosphorus, ash, doped silicon and finished parts.

Which planet mods does it support?

• Arig: Sand sifting has a 2% chance to yield one phosphate rock, unlocked with its sifting research.
• Muluna: Regolith digging has a 2.5% chance to yield one phosphate rock, unlocked with its digging research. White phosphorus spoils without fire; conversion kilns need another heat source.
• apia: Phosphoric acid works in both mods' recipes.
• Muria: Acidthrowers use phosphoric acid.
• Maraxsis: White phosphorus spoils without fire underwater.
• Rubia: Crapapults can't take white phosphorus.
• Paracelsin: Macerators can't take white phosphorus.
• Panglia: Crushers can't take white phosphorus.

Flare Stack's incinerators can't take white phosphorus either.

What is black phosphorus for?
A foundry at Vulcanus pressure turns ten red phosphorus into eight stable black phosphorus. Ship it to Fulgora: two black phosphorus replace one of the two holmium plates in a supercapacitor, retaining the other ingredients. Research needs metallurgic and electromagnetic science. The foundry's productivity bonus applies; black phosphorus has no route back to red or white.

Can Space Age machines and research improve production?
Cryogenic plants also run phosphorus chemistry; electromagnetic plants run doped silicon. Washing cannot gain productivity, so the red/white round trip stays a loss. Infinite phosphorus productivity uses red, green, blue, space and metallurgic science, adding 10% per level to every arc-furnace route, including carbon and cadmium dust recovery. Krastorio's science-tier rules still apply.

My chest caught fire. Why?
White phosphorus that waits 15 minutes anywhere ignites (startup setting "White phosphorus ignites after": 2 to 120 minutes). Keep it moving, keep buffers small, burn the surplus in a combustion tower, or ship and store it as red phosphorus.

How do I stop a fire from spreading?
Walls keep their full fire resistance and stop it; so do gaps of a few tiles. Wooden buildings burn better and can carry the fire a few hops.

Is anything safe from it?
In space (Space Age platforms, SE orbits and asteroid fields), on thin-air worlds below 10 pressure, and under water, white phosphorus still turns to ash without fire. The combustion tower's fuel slot never spoils.

Can I store fresh white phosphorus later in the game?
Yes. Production and utility science unlock the preservation cabinet: one input slot, one output slot, and a separate ash-removal slot. It accepts only white phosphorus. Five items become five fresh items in five seconds, retaining their quality. A supplied cabinet keeps its contents fresh even when the output is full. It draws 250 kW continuously, including while empty, and uses one water per second while occupied. The window has moving water and bubbles; amber means conditioning or idle, green means preservation, and red means missing water or power.

What happens if the cabinet stops?
Ageing resumes when water or power runs out, or when the circuit disables it. Spoiled phosphorus becomes ash; expired batches cannot be restored. An inserter can empty the separate ash slot. If that slot is full, ash stays in the process slots rather than disappearing. Connect water to the pipe input at the back.

Which materials does the cabinet use?
Twenty steel, twenty stone bricks, ten processing units, two pumps and five plastic. With Molybdenum, the twenty steel are molybdenum steel. With Magnesium, twenty magnesia replace the bricks as insulation. With Cadmium, add five cadmium-plated hardware for the wet-service fittings. With Antimony, add two antimony trioxide for flame-retardant components. The corresponding material research is also required; these mods are optional.

Can research make phosphorus safer or more damaging?
Both lines start at production and utility science. Weapon research also uses military science and raises hostile phosphorus burn damage by 20%, 40%, then 60%; infinite space-science research adds another 20 percentage points per level. Accidents and friendly burns are unchanged. Building protection reduces phosphorus damage by 25%, 50%, then 75%, followed by space-science tiers for 90%, 95%, and 99%. The final finite tier costs 20,000 of each required science pack. Protection applies after existing resistances to stationary buildings, excluding characters, vehicles, trains and robots. It leaves 1% damage and does not stop contents spoiling or fire spreading.

Why won't my kiln run?
It needs heat of at least 300 °C through heat pipes, such as a combustion tower's. Place it directly against a tower: long heat-pipe runs take minutes to warm up. Without heat it stops, and its batch will burn.

Does an unused combustion tower cool down?
Yes. It loses 1 °C each second while not actively burning, down to 15 °C. An isolated tower falls from 500 °C to the kiln's 300 °C threshold in 3 minutes 20 seconds. Connected heat pipes and machines store heat and can keep it warm longer. Burning still supplies the full 2 MW. A full ash slot also stops combustion and lets the tower cool.

What changed for kiln and retort construction?
With reachable early Magnesium, magnesia replaces their stone bricks. Antimony adds two antimony metal to the kiln's external drive bearings, or two Babbitt alloy with supported early BZ tin. Retorts add five tellurium copper for condenser fittings when reachable at red/green science, otherwise five copper plates, plus four pipes. Retort construction and reactivation now have a small separate 50-unit red/green research after Phosphorus processing and eligible Tellurium processing. The kiln remains earlier. Existing saves that researched Phosphorus processing keep retort access automatically; existing factories need the new construction materials.

How long does my glow marker have left?
Point at it: the time left appears above it. In your inventory the item's spoil bar shows it. A marker dims for its last 8 hours.

What changes for land mines?
The standard batch is one steel, two explosives and one red phosphorus for four mines in five seconds. Red phosphorus represents primer components. Land-mine research requires Phosphorus processing at the same science tier; earlier overhaul recipes and research cycles are skipped. Damage, trigger behavior and placed mines are unchanged. Existing assemblers keep their recipes but need red phosphorus; research Phosphorus processing if it is not yet available. Disable the startup setting or bypass land-mine to keep the host recipe.

What changed for explosives?
The normal explosives recipe needs one phosphorus ash per four explosives. In vanilla, two coal, two sulfur, 20 water and one ash make four explosives in eight seconds. The separate ash-dried recipe is removed, and existing plants using it switch to the normal recipe when you update. Existing explosives and combat effects stay the same. Explosives research follows Phosphorus processing at the same science tier. Burn white phosphorus in a combustion tower for a steady ash supply. Disable the startup setting or bypass a recipe to keep its host ingredients.

What do I do with all the ash?
Make explosives, dissolve it into phosphoric acid (batteries, phosphate concrete), fill land with it (20 ash + 20 stone), ship it to Gleba as fertilizer, or, with SE and similar mods, put it into heat shielding.

Why are my plastic, lubricant, processing unit, battery or heat pipe recipes different?
They need phosphorus (heat shielding too, where a mod adds it). Each change can be switched off in the startup settings.

Can I void white phosphorus in an incinerator or crusher?
No. Phosphorus removes such recipes from other mods so that nothing destroys white phosphorus without dealing with it. Burn it in a combustion tower instead: you get heat and ash for phosphoric acid.

Does it cost UPS?
Hazard logic reacts to spoilage and phosphorus damage. Glow markers and combustion towers are processed in small slices, and cabinets check their supplies four times a second and animate active water at 20 updates per second. Large numbers of active cabinets add work; keep buffers sized for the factory rather than building unused banks of storage.

What do the material-pack integrations add?

External material packs add prepared furnace charges, phosphate leach slurry, chlorinated solvent feed and iron-phosphate cathodes. Native filters, reagents and machine parts connect the buildings and chemistry to the rest of the factory. Existing electronic, polymer and explosives recipes use phosphorus at the appropriate stage.

Will this change my Fluffy-only factory?

Fluffy-only games keep their existing recipes, machines and progression, with or without Space Age. The extra requirements activate only with the relevant external material providers. They do not add machinery requirements to a normal Fluffy-only game.

How should I update a factory that uses material packs?

Back up your save and update the Fluffy material mods you already use together. You do not need to install additional siblings. Existing external production lines may need new ingredient feeds, intermediate transfers or a different crafting machine. Saved materials and recipe references are preserved; check around machines for returned stock after upgrading.

The matching versions are listed in the Caesium FAQ. The companion mods remain optional.

Provider conflicts still apply. BZ + Trikop is supported; Manganese on its own has an upstream steel-furnace limitation that can block progression. Space Exploration and Space Age are separate configurations.