As far as I know - it is 100% pure - no grass or dirt or bugs. Most psyllium used around the world is grown in India - it is cheap (a little over $1.00 per pound) BUT - I refuse to use it because I don't know how old it is nor how it has been harvested, stored or transported. This is why they can only guarantee an 85% for a lower grade and 95% for a higher grade.
I get mine from a man in North Carolina who has been growing it for years. I used to buy the whole seed heads, grind off the husks - soak and dry what seeds I needed and feed the rest of the seed to my cattle.
He got a milling machine some years back and now I just buy the pure husks with a few separate seeds. He is drying and storing his husks at 12% moisture and I hold it here at 12% until it is ground and used. The moisture content is KEY for effectiveness.
The age of psyllium is extremely important - over 2 years old and you can just toss it because it has lost all of its effectiveness. Who knows how long Indian psyllium has been sitting in storage waiting for the prices to go up.
The seeds have to be soaked - rinsed - soaked - rinsed - and soaked and rinsed again. Then they are dried and are ready to grind. The husk makes up the most part while the seeds make up a much smaller part.
Psyllium is hard to grow here in the US on a commercial basis. It is a weed - BUT - it has to be sown, grown, harvested and stored properly. It is just cheaper for the "big boys" to import it. I - am still a "little boy" in the game.