Now benzene and formaldehyde are being created in the atmosphere from the smoke + UV radiation which happen to smell like plastic but are toxic and can have very adverse effects on human/animal health ( https://www.theweathernetwork.com/en/news/weather/severe/smelling-plastic-millions-are-in-the-path-of-toxic-smoke-plumes ). H/T: @lisa_iannattone
You can learn more about formaldehyde here ( https://www.epa.gov/indoor-air-quality-iaq/what-should-i-know-about-formaldehyde-and-indoor-air-quality ) and benzene here ( https://emergency.cdc.gov/agent/benzene/basics/facts.asp ).4/