Zyklon B was not developed for killing people. The most common usage was for killing lice in clothes.
(To make it very clear: It was also used for killing people in Vernichtungslagern).
Zyklon B might not have been developed as a chemical weapon, but Haber was instrumental in developing and advocating for the use of chemical weapons explicitly on humans for Germany and Spain both during and after WWI (source)
Zyklon B was not developed for killing people. The most common usage was for killing lice in clothes. (To make it very clear: It was also used for killing people in Vernichtungslagern).
Zyklon B might not have been developed as a chemical weapon, but Haber was instrumental in developing and advocating for the use of chemical weapons explicitly on humans for Germany and Spain both during and after WWI (source)