Can tannic acid be used safely on fabric, tile & grouting and skin?

Question:Tannic acid is contained in tea. I spilled some tea on the tile floor and it seemed to clean the tile.

Answers:
I hate when that happens. I make a clean spot by spilling something, then I have to go and clean the hole darn floor.

Yes, it can clean. It is astringent and has a pH of about 10. So it's a little stronger than your average soap. As a matter of fact, I remember my dad using it in his dry cleaning business for specific types of stains. Not tea, tannic acid. Maybe wine stains? I think there was another step to completely remove the stain after that.