Also called nerve gasses (probably because they're distributed as a gas), these kill or disable their victims by inhibiting the body's ability to send nerve signals from one part to the other. They tend to cause quite violent deaths, making the muscles spasm all at once.

These have advantages over traditional poison gasses in that many of them can surpass a simple gas mask. The most potent nerve gasses can cause their effects by contact with any exposed skin, making fully sealed biohazard suits important for surviving them.