Stop being facetious.
An unintended side effect - however horrific it was - is very different to the intentional use of chemical agents designed to kill a civilian population.
What you are doing is like accusing the Russians of nuclear attacks on Europe because of the Chernobyl fallout cloud.
Just because people are dead either way does not make the crimes equivalent, since intent does matter. When manufacturing defects kill people, the crime is typically negligence or at worst manslaughter. It is not murder.
Though to play devils advocate, the idea that the US could starve out the Viet Cong with herbicides was pretty awful, since civilians would (and did) suffer from starvation much more than enemy soldiers.
We definitely meant to kill some people and innocent casualties are always a possibility. So it's not the same thing as a malfunction in an energy facility. It's more like when we also illegally try to kill armed militants from drones and then end up bombing a wedding or something.