Even if they DID use “harsh chemicals”, growers strive to flush the plants at the end of the growing cycle so as to use up any remaining nutrients.
Chemicals affect flavor. Any grower leaving chemicals in the plant will have an inferior product.
The vast majority of growers are criminals. They do not care about the quality. It isn’t like going to Chez Panisse or buying a bottle of Domain Leflaive. They grow in crap conditions and sell crap. The sites they grow at would be labeled a hazardous chemical site by any other industry standard.
My knowledge of this comes from the people I know in law enforcement who raid the places, and Fish and Game who are involved in the cleanup and my own experience working for ranchers who have to deal with these idiots.
Bottom line, you are gambling being around this business.
Chemicals like carbon dioxide and cellulose?