If I can locate the thread, I will post it - but the CT PG is about the lowest grade of PG you can buy.
That would be good, but this thread is about TS's USP PG.
Since it is pure enough to be legally labelled as USP=pharma it is totally fine if it is also marketed as a less pure Food grade, or an even less pure Ag grade, or a much less pure industrial grade. In this case, TS, has a USP PG that is mainly marketed to the Ag use because that is what the store caters to in general.
Remember our primary concern is if the PG & VG is pure enough to use the USP labeling and the secondary concern, for taste at least, is how far above that level of purity it goes, but our minimum is USP which TS's PG is clearly labeled as such.