As we currently know it, the three-bladed radiation warning symbol was allegedly created at the University of California Radiation Laboratory in Berkeley around 1946.
What we’ve been able to find out is that the world-recognised symbol of the Nazi SS (Schutzstaffel) was first worn by the Leibstandarte in 1933. It originated from the “Sig” or “Sigel” or even “Siegel” rune and was part of Hitler’s widespread use of occult symbols.
The Biohazard symbol was originally developed by the Dow Chemical Company in 1966. An engineer by the name of Charles Baldwin claims to have been directly involved in its creation. According to his account they were concerned by the lack of standardisation and prepared several possible designs that were market-tested before selecting the one that is currently accepted as the standard.