|Nerve gas grenade|
The Nerve Gas Grenade can be used in Rhoemer's Base and Missile Silo. It is great for taking down groups of enemies quickly and stealthily. It is also required to kill Rhoemer in the last level.
Syphon Filter 2
This weapon is found in only one mission, I-70 Mountain Bridge. As with the first game, it is required to proceed through the mission without failing it; in this case, Gabe must use it to take down a bridge bombing commander (although any suppressed weapon would technically work as well).
The nerve gas is also used by The Agency, who attempts to carpet bomb the Colorado Mountains to kill CBDC agents who might have escaped from the C-130 Hercules alive, including Gabe Logan, Jason Chance, John Ramirez and other survivors. As expected any animals and plants that were in the vicinity would also die. Lian Xing sabotages the F-22 Raptors which carried the payload while in McKenzie Air Force Base, stopping the antagonists from carrying out their dastardly scheme.
Syphon Filter 3
This weapon is seen in the Pugari Gold Mine and Pugari Complex. It is not compulsory to complete the mission anymore, making it an optional weapon.
Syphon Filter: The Omega Strain
"Sarin, Isoproposymethylphosphonyl fluoride, is a colourless, odourless gas intended for chemical warfare. It is 26 times more powerful than cyanide and has a lethal dose of only 0.5 milligrams. It is absorbed into the body via the lungs or through the skin and attaches Acethlocholine Receptors, which are responsible for stimulating muscle contractions and respiration. First the victim experiences tightness in the chest, followed by bronchospasm, convulsions, and eventually respiratory failure that causes death. It is commonly known that Saddam Hussein produced mass quantities of Sarin gas and used it on his own people in the 1980's. The US Government classified Sarin as a Weapon of Mass Destruction and used the claim that Iraq still has large quantities as part of their justification for invading Iraq in 2003."
-Weapon description from Syphon Filter: The Omega Strain
The Nerve gas grenades are called the "Sarin nerve agent" and are unlocked by achieving the Expert Tactical Explosive Specialist rating. Because it lingers in the air for a long time, dissipating slower than the DormaGen gas grenades, they are great for killing groups of enemies and bosses without proper protection against the gas.
- In Syphon Filter: The Omega Strain, this weapon was renamed "Sarin nerve agent" to more accurately represent the weapon. In real life, this type of gas grenade would be banned under the Geneva Convention and classified as a weapon of mass destruction, giving it the distinction of being the only weapon in Syphon Filter to exist but not to be allowed for use in the real world.
- It is generally common knowledge that Saddam Hussein manufactured massive amounts of Sarin and used it against his own people in the 1980's. Subsequently, the USA used the reasoning that Iraq still has significant quantities as part of their justification for invading that country in 2003.
- In Dark Mirror and Logan's Shadow, it is generally rare to find nerve gas grenades, but the MB-150's X34 gas darts have a similar effect.
- In Syphon Filter 2, it is used in only one mission, while in Syphon Filter and Syphon Filter 3, it is seen in two missions but nowhere else.
- Sarin is very lethal even in low concentrations; in fact, it is 26 times more powerful than cyanide. With a lethal dose of only 0.5 milligrams, death can occur from one to ten minutes following direct inhalation of a lethal dose from suffocation, which happens due to lung muscle paralysis, unless some antidotes are instantly administered. Even victims who absorb a non-lethal dosage but fail to receive immediate medical treatment may suffer from permanent neurological damage.
- It is rather ironic that the reformed Agency would possess such a weapon, given that their main purpose is to stop the spread of these devices.