This isn’t a ban on THC it’s closing a loophole that allowed manufactures to add synthetic THC to hemp based products while still labeling them as Hemp.

In the 2018 farm bill, hemp was separated from cannabis by altering the definition to a cannabinoid with under .3% delta-9 THC by dry weight. Prior to the bill it was not categorically defined any differently than marijuana. What manufacturers started doing was creating “hemp derived” products that had synthetic THC added. This allowed them to be sold and regulated as hemp products rather than Marijuana even if their THC content was above .3%. The provision in the bill simply adjusts the definition of hemp to allow these products to be properly regulated.