挥发物或“H2”是一种可燃气体存在的氧气和呼吸气体的Zrilian物种。大多数行星上挥发物的主要来源是冰（氢气），可以在表面开采。挥发物在氧气存在的情况下会在300摄氏度或以上自燃，在一氧化二氮存在的情况下会在50摄氏度或以上自燃。

它是一种由氢、氯和碳氢化合物组成的均质化合物。这意味着它是有毒的，因为氯，但也可燃的，因为氢气和甲烷的部分，可以转化为水与氧气在H2燃烧室，有一个独立的催化剂，帮助释放氢原子。

可能的化合物:CH3Cl(一氯甲烷)

挥发物是一种极具活性的复杂有机分子，可与氧结合用作可燃燃料。它是由冰(挥发物)精制而成。

由于模糊和基本上被遗忘的ODA法规，挥发物有时被各种技术项目标记为“H2”。然而，尽管它们与氢相似，但它们并不是“真正的”氢。在没有催化剂的情况下，挥发物不会产生水(参见H2燃烧室)。单独而言，当它们按以下比例燃烧时，会产生污染物和二氧化碳:

Different ratios of Volatiles and Oxygen will produce different temperatures and pressures during combustion. Combustion will create a large amount of Heat, pressure, and Carbon Dioxide. This reaction is useful inside a Furnace for smelting ores and creating alloys, but can be catastrophic when inside a Canister or a room. Currently as of version v0.1.1089.5513, it is labeled in the atmospheric analyzer as H2, but it is not Hydrogen.[1]. When burned, it produces heat, Pollutants, and Carbon Dioxide in the following reaction:

2 [Volatiles] + 1 O2 → 3 X + 6 CO2 + Heat

This reaction is inconsistent with volatiles being simple hydrocarbons (too much CO2 is produced), but it may be consistent with more complex organic molecules. The reaction appears to only take place with specific quantities of gas, so Oxygen is often left over even when there is an excess of volatiles.

Volatiles have a specific heat of 20.4 Joule / mol.

The Specific heat of 20 g/mol is in-between the specific heat of Hydrogen and Methane. The actual Autoignition temperature of Chloromethane in Oxygen is 625 °C (1,157 °F; 898 K), the game grossly underestimated the iginition temperature by about 11 times.

You can collect Hydrogen from the following sources:

Source Amount Ice (Volatiles) 22 mol Can be also obtainable by trading.

Seems that a concentration of H2 greater than 6% in an atmosphere it is lethal to plants, keep attention on that designing a greenhouse, because Advanced Composter will release H2 during the process.