RXMARINE CHEMICAL TAG::
Tannic acid is a light yellow to tan solid with a faint odor. Sinks and mixes with water. ( USCG, 1999) CAMEO Chemicals. Polyphenolic compounds with molecular weights of around 500-3000 daltons and containing enough hydroxyl groups (1-2 per 100 MW) for effective cross linking of other compounds (ASTRINGENTS).
Tannic Acid provides, in addition to common physical constants, a general description including typical appearance, applications, and aqueous solubility. The monograph also details the following specifications and corresponding tests for verifying that a substance meets ACS Reagent Grade specifications including: Identification, Loss on Drying, Residue after Ignition, Heavy Metals, Zinc, and Sugars, Dextrin.
In foods and beverages, tannic acid is used as a flavoring agent. In manufacturing, tannic acid is used in ointments and suppositories; for tanning hides and manufacturing ink; and to kill dust mites on furniture.
No more than 2 daily cups of tea that are very tannic (like black tea), and you'll be alright.