"[Code of Federal Regulations] [Title 21, Volume 3] [Revised as of April 1, 2017] [CITE: 21CFR184.1155]
TITLE 21--FOOD AND DRUGS CHAPTER I--FOOD AND DRUG ADMINISTRATION DEPARTMENT OF HEALTH AND HUMAN SERVICES SUBCHAPTER B--FOOD FOR HUMAN CONSUMPTION (CONTINUED) PART 184 -- DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE
Subpart B--Listing of Specific Substances Affirmed as GRAS
Sec. 184.1155 Bentonite. (a) Bentonite (Al2O34SiO2nH2O, CAS Reg. No. 1302-78-9) is principally a colloidal hydrated aluminum silicate. Bentonite contains varying quantities of iron, alkalies, and alkaline earths in the commercial products. Depending on the cations present, natural deposits of bentonite range in color from white to gray, yellow, green, or blue. Bentonite's fine particles provide large total surface area and, hence, pronounced adsorptive capability.
(b) The ingredient must be of a purity suitable for its intended use.
(c) In accordance with 184.1(b)(1), the ingredient is used in food with no limitation other than current good manufacturing practice. The affirmation of this ingredient as generally recognized as safe (GRAS) as a direct human food ingredient is based upon the following current good manufacturing practice conditions of use:
(1) The ingredient is used as a processing aid as defined in 170.3(o)(24) of this chapter.
(2) The ingredient is used in food at levels not to exceed current good manufacturing practice. Current good manufacturing practice results in no significant residue in foods.
(d) Prior sanctions for this ingredient different from the uses established in this section do not exist or have been waived.
[47 FR 43367, Oct. 1, 1982, as amended at 73 FR 8606, Feb. 14, 2008; 76 FR 59249, Sept. 26, 2011] "
WARNING: For all those that have koi or garden ponds do not use just any bentonite clay in your water. This page list many of the uses of bentonite and not all sources are created equal. So please do not put any of the kitty liter or oil dry products in your ponds. Point in fact; at the turn of the century a man in Malaysia used kitty liter in his koi pond. The next morning, he discovered his pump had stopped and all his koi were dead. The kitty liter had gotten into the pump, swelled and caused it to seize up.
Bentonite clay was formed by the alteration of minute glass particles derived from volcanic ash. Bentonite occurs in rocks that were deposited in the Ordovician to Neogene periods (about 488.3 to 2.6 million years ago).
Bentonite was first named taylorite, after William Taylor, who studied clay deposits in the United States. The use of the name taylorite stopped when this class of minerals was split up into separate groupings. In 1898, W C Knight used the name bentonite to refer to this specific type of clay because the first site discovered was near Fort Benton in the Wyoming / Montana region of the United States. Bentonite clay is an aluminum phyllosilicate, which consists mostly of the mineral montmorillonite (montmorillonite is a very soft phyllosilicate group of minerals that form when they precipitate from a water solution as microscopic crystals, known as clay. It is named after Montmorillon in France).
Bentonite is part of the smectite class of clays. Smectites are clay minerals which are approximately less than 2 micrometres in dimension. Although they are rare in large quantities, smectites are common in most earth surface sediments. The formation of large deposits of smectite (i.e., bentonite) requires rather special geologic conditions.
Bentonite is a material derived from the alteration, over geological time periods, of glassy material emitted from volcanoes (tuff or ash), or from the alteration of silica bearing rocks such as granite and basalt. Bentonite only forms in the presence of water. Depending on the nature of formation, bentonite can have a variety of accessory minerals in addition to its constituent mineral montmorillonite. These minerals may include attapulgite, kaolin, mica, and illite as well as minerals like quartz, feldspar, calcite and gypsum. The presence of these minerals may affect the value of a deposit.
There are two types of bentonite, calcium bentonite (non-swelling) and sodium bentonitethe (swelling). The uses of each are dependent upon specific physical properties.
SOME USES OF BENTONITE:
Toxic waste cleanup
Water purification systems
Clarifying agent for wine, vinegar, fruit juice, beer, oils
Iron ore pelletizing
Sealants (reservoirs and landfills)
Moulding sand binder
Used in cements and concrete
AND MANY MORE
United States, Japan, Greece, Italy, Brazil, Romania, Germany, Mexico, Argentina, Spain, India, Hungary, Poland, Canada, Turkey, Cyprus
CLAY: SOURCE OF LIFE
Below is an interesting article from a Science journal I found way back.
Clay's matchmaking could have sparked life: Two of the crucial components for the origin of life - genetic material and cell membranes - could have been introduced to one another by a lump of clay, new experiments have shown.
The study of montmorillonite clay, by Martin Hanczyc, Shelly Fujikawa and Jack Szostak at the Massachusetts General Hospital in Boston, revealed it can sharply accelerate the formation of membranous fluid-filled sacs.
These vesicles also grow and undergo a simple form of division, giving them the properties of primitive cells. Previous work has shown that the same simple mineral can help assemble the genetic material RNA from simpler chemicals. "Interestingly, the clay also gets internalised in the vesicles," says Leslie Orgel, an origin of life expert at the Salk Institute for Biological Sciences in San Diego, California. "So this work is quite nice in that it finds a connection between the mechanism that creates RNA and encloses it in a membrane."
Inherit, mutate, evolve The genesis of genetic material and the emergence of cell structure are hot areas of research, but until now the two had not connected. The birth of genetic material was clearly crucial for life to take on its unique abilities to inherit, mutate and evolve.
And membranes were key to the physiology of cells because they protect their contents, concentrate chemicals to promote reactions and isolate successful genes from unsuccessful ones. "It's clear you really need both these elements to get evolution off the ground and running," says Szostak.
Research has already shown that some of building blocks for RNA-like molecules and membranes are spontaneously created by chemical reactions in outer space and in conditions that may have existed on the primordial Earth. But how these subunits were then assembled is still debated.
For RNA, one popular theory revolves around the unusual properties of montmorillonite clay. The negatively charged layers of its crystals create a sandwich of positive charge between them. This turns out to be a highly attractive environment for RNA subunits to concentrate and join together into long chains.
Szostak wondered whether montmorillonite could also help the assembly of vesicles from simple fatty acid precursors. He remembers the day his colleagues Hanczyc and Fujikawa ran into his office to show him their first results: the clay caused a 100-fold acceleration of vesicle formation.
"It was pretty amazing," he says. Once formed, the vesicles often incorporated bit of clay and were able to grow by absorbing more fatty acid subunits.
His team also showed the clay could hold RNA and form vesicles at the same time. Fluorescently-labelled RNA attached to the clay ended up assembled into vesicles after the reaction. And the researchers were able to get these "protocells" to divide by forcing them through small holes. This caused them to split into smaller vesicles, with minimal loss of their contents.
Szostak admits that in a natural setting the vesicles would rarely be forced to divide in this way. So now his group is searching for different mixtures of membrane-forming molecules that might divide spontaneously when they reach a certain size.
Journal reference: Science (vol 302, p 618)