Alginic acid is a substance that comes from algae, which are plants that grow in the water. It is used in many products, like medicine, food, and cosmetics, because it can thicken or stabilize them. Full definition
Kelp contains alginic acid which binds with toxins in the intestines and then carries them out of the body (best-natural-health-supplements.com)
This is, in part, due to the substance called alginic acid which transforms heavy metals into harmless salts. (store.newwayherbs.com)
Humans can also harvest kelp directly to feed aquaculture species such as abalone and to extract the compound alginic acid, which is used in products like toothpaste and antacids. (en.wikipedia.org)