Neurotoxin



Neurotoxin, comically referred to as Deadly Neurotoxin by GLaDOS, is a gaseous chemical agent that appears in Portal and in Portal 2's single-player campaign. Manufactured in the Neurotoxin Production Facility, can be ventiled into any part of Aperture Science Enrichment Center and is pumped through a series of emitters.

Overview
Neurotoxin is not an environmental hazard in the traditional sense of gameplay, as it only appears during specific, scripted events in the Portal series, mostly at the game's climax. In the Lab Rat comic, it is confirmed that GLaDOS ventilated neurotoxin as a means of killing all Aperture Science personnel prior to Chell's awakening in Portal, and is frequently as an attempt to kill her.

The entirety of these gases are stored and manufactured in a reinforced tank, located in the bowels of the Enrichment Center. Eight main hoses allow the gas to be transferred to any location within the facility.

The variety of neurotoxin used within the Aperture Science facilty is unusual in that a certain concentration is required before it becomes lethal. Until the saturation level has been reached, the gas is not lethal and is presumed to be merely toxic. It is this delay that provides Chell with the opportunity to defeat GLaDOS in Portal.