The Germans did a lot of work on various nerve agents such as Sarin, Tabun, Soman, etc and plans for mass-production were well-advanced.

However, German Intelligence feared that the Allies also had plenty of production capability ( in fact, they didn't ) and also that the Allies ability to reach targets inside Germany would prove catastrophic in a 'tit-for-tat' scenario.

( So maybe the Bomber Offensive wasn't such a waste of effort after all.....)

__________________
"Stand by to pull me out of the seat if I get hit" - Guy Gibson