Atropine

Atropine was a chemical enzyme that can be used to prevent the effects of nerve gas.

-- Day 5 -- During Day 5 after the attack on the Sunrise Hills Shopping Mall, Jack Bauer demanded that the agents retrieve atropine for "a child under twelve" so that he could revive her from her exposure to VX-1 Nerve Gas. Later that day, after CTU had come under attack, Jack had responded to the remaining staff that the atropine was in the armory, which was in a contaminated zone and thus of no value to the staff.