Nerve gases (also known as nerve agents) are a class of chemical weapons. During Day 5, the terrorist group known as the Dawn Brigade (led by Vladimir Bierko) used a stolen nerve gas called Sentox to threaten America.

Before Head Shot Edit

The Aum Shunrikyo cult released sarin nerve gas bombs into the Tokyo subway system "some years" before Head Shot.

Before Day 5 Edit

According to Bill Buchanan, the American military had destroyed stockpiles of nerve gas years before Day 5.("Day 5: 11:00am-12:00pm")

Day 5 Edit

The Sentox nerve agent was created by the Sentox Project and compressed in canisters, from which they could be dispersed in a gaseous form. Upon release, the nerve gas looked like vapor, but it quickly became invisible and apparently odorless, killing unsuspecting civilians in the Sunrise Hills Shopping Mall, intelligence agents at CTU Los Angeles, and servicemen on the Natalia when utilized by the terrorists. The victims in each case struggled horribly to breathe, drooled, and wretched. The military-grade Sentox quickly killed those exposed.

Penetration through the skin, not only via inhalation, was also a distinct danger: Jack Bauer, while briefly exposed to the gas, tightly covered himself with his hooded sweater to prevent the gas from seeping into his body through the skin.

When the Dawn Brigade operative Ostroff gassed CTU Los Angeles, the substance proved its lethal effects. Many CTU agents died from exposure, including Lynn McGill, Edgar Stiles and a guard named Harry Swinton. Estimates later that night revealed that 40% of CTU's staff was eliminated in this attack.

Background information and notes Edit

• Sentox is a fictional variant of the real nerve gas known as VX.

• Nerve gasses are clear and colorless, and they can be odorless or have a slightly sweet smell. They enter the body through the air or on contact with the skin. Though these chemicals are liquid at room temperature, nerve gases can be released using spray tanks, bombs, missiles or land mines. Nerve agents have more density than air, making them dangerous to people in low lying areas.

• Nerve gases attack the nervous system of the body by interrupting the breakdown of neurotransmitters that signal muscles to contract. The gases inactivate the enzyme cholinesterase, which normally controls the transmission of nerve impulses. The impulses continue uncontrolled and cause respiratory breakdown.

• Nerve gases generally cause death by asphyxiation. The symptoms preceding this include blurred vision, runny nose, tightness in the chest and constriction of the pupils. The victim will next have difficulty breathing, and will experience nausea and drooling. This phase is followed by twitching and jerking, and the victim will lapse into a coma and suffocate as a consequence of convulsive spasms, symptoms mirrored on the show.

• Certain types of nerve gas can penetrate the skin, including VX, tabun and sarin. While it may take longer to absorb this way, these types can still lethally poison if the gas touches the skin, which is why Jack wrapped himself tightly when he entered an exposed area.