Dilution is the solution to pollution.
Vinyl chloride burned off results in Hydrochloric Acid.
I had seen it reported that when vinyl chloride is burned is gives off phosgene gas. And it happened in East Palestine.
Phosgene was used extensively during World War I as a choking (pulmonary) agent. Among the chemicals used in the war, phosgene was responsible for the large majority of deaths.
Phosgene is not found naturally in the environment.
Phosgene is used in industry to produce many other chemicals such as pesticides.
Phosgene can be formed when chlorinated hydrocarbon compounds are exposed to high temperatures. Chlorinated hydrocarbon compounds are substances sometimes used or created in industry that contain the elements chlorine, hydrogen, and carbon.
The vapors of chlorinated solvents exposed to high temperatures have been known to produce phosgene.
Chlorinated solvents are chlorine-containing chemicals that are typically used in industrial processes to dissolve or clean other materials, such as in paint stripping, metal cleaning, and dry cleaning.
Phosgene gas is heavier than air, so it would be more likely found in low-lying areas.
https://emergency.cdc.gov/agent/phosgene/basics/facts.asp