This technique combines ninjutsu, chemistry, and medical knowledge, thus requiring fine chakra control and advanced ability in medical ninjutsu. The user converts chakra in their body into a special chemical that they then exhale from their mouth. When the chemical comes into contact with the air, it becomes a cloud of poison. Breathing in even a small amount of the poison will cause immediate death.
The Poison Mist used by Ibuse differs from that used by Shizune. Rather than kill those that inhale it, Ibuse's causes victims to become paralyzed after only a few seconds, allowing Hanzō to attack them at his leisure with his kusarigama. Ibuse must first generate and store the poison within his body for five minutes before he can use it.