Chemical weapons
Hitler was victim by a mustard gas attack in WW One !
http://en.wikipedia.org/wiki/Adolf_Hitler#World_War_I
he refuse to use Chemical weapons in WW Two
Bioweapons
The "Drittes Reich" had a very smal bioweapon program
the Wehrmach is not interested of biological warfare
because they consider them to be considered inefficient and unpredictable.
then in 1942 Hitler banned any biological war research in the Reich.
Ironically, he was the ONLY state leader of the major powers during WW2,
how respect the Geneva Protocol concerning the biological war
Nuclear weapons
several groups work on Bomb from 1933 to 1942
Reichswehrministerium (Reich Ministry of Military)
Reichserziehungsministerium (Reich Ministry of Education) !
Heereswaffenamt (Army Ordnance Office)
all those groups intrigue against each other, or had other ideas how to build the bomb
after 1942 until 1944 came under
Reichsministerium für Bewaffnung und Munition (RMBM, Reich Ministry for Armament and Ammunition)
in hands of Reich Marshal Hermann Göring later under Albert Speer
in 1944 it came program in hand of the SS but nothing of this was combat ready as War ended
yes there are rumours of nuclear testing in 1945
but the only evidence is that a primtiv breeder reactor ran for some minute in 1943
(called Uranmaschine build by Kurt Diebner )
there still uran isotopes waste on reactor site at Gottow facility, near Berlin.
source on Nazi nuclear program TV doku "ZDF History Was ist dran an Hitler Bombe ?"