I'm curious on my weed pgr ?

I did not mean to promote the use of these products.
I think Chlormequat chloride was found to produce nasty chemicals in the smoke stream.

“Not combustible. Gives off irritating or toxic fumes (or gases) in a fire including nitrogen oxides, hydrogen chloride.

https://www.inchem.org/documents/icsc/icsc/eics0781.htm