User blog comment:GeneralOwnage55/Delta's plasmids and weapons./@comment-1330314-20100113214748

Blue's right, the level Three upgrades to the elemental plasmids made the Chem Thrower obsolete.

Also, don't be mislead: when it says this weapon "replaces" that one, it means it has exactly the same function as its predecessor. In terms of weapon slots, though, the Hack Tool sort of replaces the Chemical Thrower.