A quick follow-up note:
Ms Moon was wondering how many deaths Dow Chemicals caused--they manufactured Agent Orange as well as napalm.
I went looking. The answer is "x", where "x" = a lot.
I found this brief Stephen King–like report on 5 Dow factory workers' deaths from exposure to 2,4-D, an ingredient in herbicide:
https://www.cdc.gov/mmwr/preview/mmwrhtml/mm4923a3.htm
Why am I sharing it? I guess because five individual deaths are imaginable.
Also, if I were going to write a horror story, I would borrow from this report--even this sentence about how the chemical works is gruesome:
"Uncoupling oxidative phosphorylation at the mitochondrial level leads to profound disturbance of energy production and may have caused the rapid deaths described in this report."