In addition to new diseases affecting explorers and colonies, Nature had other surprises in store for Humans moving outward.
Simple, hardy forms of life proved more common across the stars than ever dreamed before.
Some of these life forms contain or exude poisonous substances which can harm or kill the unwary exposed to them.
New technological compounds may also poison those who come into careless or casual contact with them.
Alliance regulations try to maintain strict controls over exposure to known hazardous chemicals, but only have delayed effect.
As colonies expand and more expeditions explore xeno-archeological ruins or derelicts, they may encounter new, uncatalogued poisons.