Nerve Gas in the Nuclear warhead storage building (Metal Gear Solid The Twin Snakes)

Nerve gas is released into the Shadow Moses nuclear warhead storage building.

Poison gas, in military use, is a weaponized chemical agent designed to injure or incapacitate an enemy force, or deny unhindered use of a particular area of terrain. It has often been used as a deterrent against intruders in high security facilities. Usage of poison gas against a group of people is sometimes referred to as "gassing." In addition to standard poison gas, high concentrations of anesthetic gases can also be used for the same effect.


Outer Heaven Uprising

Main article: Outer Heaven Uprising

The fortress of Outer Heaven contained several gassed areas as a security measure against infiltrators, including Building 1's third floor, and Building 2's basement floor. In addition, several areas of Building 3's 100th floor basement were filled with poison gas to prevent any intruders from reaching TX-55 Metal Gear.

During Operation Intrude N313, FOXHOUND agent Solid Snake was forced to locate a gas mask in order to bypass the gassed areas within the fortress.

Zanzibar Land Disturbance

Main article: Zanzibar Land Disturbance

Like Outer Heaven before it, the fortress of Zanzibar Land also made use of poison gas, specifically nerve gas. The third floor of the Zanzibar Building was gassed in certain areas, where various types of research were being conducted there. In addition, the swamp armory and the biological research lab also released nerve gas if an alert was triggered by an intruder. Due to this, Zanzibar Land researchers and personnel would wear gas masks while operating in these areas.

Infiltrating the fortress in 1999, Solid Snake again procured a mask to protect himself in gassed areas, during Operation Intrude F014. After Snake reached the armory in the swamp, the mercenary Running Man released nerve gas throughout the building, hoping to evade Snake and force him to run out of air during their battle.

Shadow Moses Incident

Main article: Shadow Moses Incident

During the Shadow Moses Incident, FOXHOUND and the Next-Generation Special Forces, upon taking over control of Shadow Moses Island, released organophosphates (such as Soman) into the western labs in order to prevent Dr. Hal Emmerich from escaping. In addition, the supply tunnel leading north from the tank hangar was set up with self-sealing doors and infrared sensors, where gas would be released upon detection of an intruder. The control room in the underground maintenance base was also equipped with nerve gas release valves if the intruder was detected as having infiltrated by one of the cameras.

These gas releases could also be activated remotely, as evidenced by their activation shortly after Liquid Snake revealed his ruse as Master Miller when Metal Gear REX was unwittingly activated by Solid Snake. The nuclear warhead storage buildings would also release gas when an intruder was detected, and it was for this reason why the NBC unit of the Next-Generation Special Forces often donned gas masks, as they can't risk using their heavy weapons in the area. Solid Snake managed to evade them by avoiding tripping the infrared sensors in the tank hangar as well as being spotted, and also donned a gas mask in the event that he did have to go through them. In addition, Otacon unlocked the door to release Snake after Liquid activated the gas, also resulting in the gas dissipating. Because of the Soman being naturally colorless in composition while in its pure form, the Sons of Big Boss had colored the gas yellow to make detecting a leak easier.

World Marshal Incidents

See also: Raid at World Marshal, Ambush in Africa, Abkhazian Coup, Investigation in Guadalajara, Raid in Denver, and Operation Tecumseh
Warning: The following information is from outside Hideo Kojima's core "Metal Gear Saga." It has some level of canonicity within the continuity, but reader discretion is advised.[?]

During the mission in Mexico, several kids were exposed to high doses of chloroform gas, with the chief scientist also forcing Raiden to not rescue them by holding George hostage. Ultimately, Raiden managed to save the kids, as well as George, after killing the scientist (and nearly George in the process, due to the scientist holding George as a human shield), with the effects having faded by the time Raiden arrived in Denver. Raiden, when inquiring the status of the kids he saved, also expressed some surprise that the lab used chloroform, since its status as an anesthetic was rendered obsolete in favor of servoflurane and isoflurane, although Doktor speculated that it may have been used as an organic solvent, the chemical synthesis for medication, or an ingredient for cryopreservers.

Non-"Metal Gear Saga" information ends here.

Unconfirmed usage

The following information has been detailed in official Konami-licensed media, written by various external authors. Its status in the Metal Gear canon is unconfirmed.[?]

An assassin managed to leak nerve gas into Master Miller's home in Alaska, which Miller attempted to escape from by donning gear in his ice cave. However, he succumbed to the gas before he could save himself. When first noticing the gas, Miller speculated it was servoflurane.

Behind the scenes

Poison gas is a recurring environmental hazard in the Metal Gear series that the player character must navigate through. In the original Metal Gear, gassed rooms were depicted with puffs of smoke emerging from the ground. Metal Gear 2: Solid Snake and Metal Gear Solid depicted the gas as having flashes of color (red and yellow, respectively), accompanied by a hissing noise.

In the timeline included in Metal Gear 2's user manual, it was stated that nerve gas and other chemical agents were banned worldwide by 1998. However, it was retconned slightly in Metal Gear Solid, where it was stated that, although there were indeed plans to get rid of chemical weapons worldwide by that year, the United States refused to do so and the talks fell apart, the reason being speculated to be related to America not wanting to give up its stance as the world's sole superpower.

According to the Art of Metal Gear Solid 4, the Gekko were to carry cylindrical containers that contained poison gas. This was eventually implemented during their appearance in the event The Encounter - 2014 for Metal Gear Survive.


Notes and references

Community content is available under CC-BY-SA unless otherwise noted.