The plot of Call of Duty: Black Ops revolves around a Soviet plot to unleash a Nazi-made chemical weapon named Nova 6. Lore documents reveal it to contain at least neodymium, rhenium, and sulfur.
The Nova-6 Poison Cabinet Code in Call of Duty: Black Ops Cold War. To make a long story short, the code required to unlock the poison cabinet is 16-75-60. This cabinet can be found during the Desperate Measure mission.