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Colloidal silver refers to microscopic particles of silver that are held in a liquid suspension. A colloid is technically defined as particles which remain suspended without forming an ionic, or dissolved solution. The broader commercial definition of colloidal silver includes products that contain various concentrations of ionic silver, silver colloids, ionic silver compounds or mild silver proteins in purified water. Colloidal silver with concentrations of 30 parts per million (ppm) or less are typically (but not always) manufactured using an electrolyte process, whereas colloidal silver with higher concentrations of 50 ppm or more are usually (but not always) either silver compounds such as silver chloride and silver iodide or are solutions that have been bound with a protein to disperse the particles.

History and Applications

Prior to 1938, colloidal silver was widely used by physicians as a mainstream antibiotic.^[1] It was produced by pharmaceutical companies under various names, including Protargol. But the electro-colloidal production process was costly and the pharmaceutical industry developed fast-acting, less-expensive sulfa drugs and penicillin. Silver nitrate solutions are still used in neonatal units to protect newborn infant's eyes from infection.^[2] Silver-based cremes have been used in burn centers for more than 100 years.^[3] Colloidal silver can be used to keep drinkable water potable over a long period.^{[citation needed]} Concentrations of colloidal silver at 5 parts per million or higher have been found to kill numerous infectious bacteria.^[4] Colloidal silver has been approved by the EPA as a disinfectant for hospitals and medical centers.^[5]

Method of Action

Colloidal silver kills bacteria by inhibiting the expression of enzymes and other proteins essential to ATP production. ^[6]

Controversies

Argyria

Long-term intake of high doses of certain silver products may result in an extremely rare condition known as argyria, which is a blue or gray discoloration of the skin. It occurs when sunlight interacts with silver deposited in the skin, in the same way that silver particles in photographic film darken when exposed to sunlight. It can occur both via ingestion of silver, or through topical application of silver to the skin.^{[citation needed]} While generally considered permanent, some have claimed to have reversed it.^[7] Argyria is non-fatal^[8] , but at high doses, some cases of kidney damage, stomach distress, and headaches have been reported, and a few rare cases of brain and nerve damage.^[9] An FDA “Talk Paper” references silver ingredients and silver salts that includes silver proteins, silver chloride and silver iodide. They claim that the use of these “gelatinous” silver solutions has resulted in rare cases of argyria.^[10] Advocates don't dispute the fact that almost all known cases of argyria resulted from use of highly concentrated silver compounds such as silver oxide, silver nitrate or silver chloride and not the electrolyte-manufactured solutions, which contain only ionic and colloidal silver and typically comprise silver concentrations of 30 ppm or less.

Advocates assert that, under careful use of properly produced colloidal silver, argyria is virtually impossible,^[11] though these claims are anecdotal and have not been confirmed by scientific study.^[who?] Advocates also claim that very few if any current cases are known to exist. They view the entire controversy as an orchestrated scare tactic by special interests who they say deliberately exaggerate and mislead people away from colloidal silver products. However, occasional verified cases of argyria continue to be reported and proven, sometimes making the television news programs.^[12][13][14]

Government reactions

The U.S. Food and Drug Administration (FDA) banned over-the-counter sales in the U.S. of any product claiming to have therapeutic value, health benefits, or making any medical claims, unless it has undergone the rigorous safety and efficacy testing required of pharmaceuticals. As such testing has not been conducted with colloidal silver, the product now has the status of a dietary supplement in the US (dietary supplements cannot claim to cure diseases, only that they "support healthy functioning").^[15] The FDA has issued warnings to Internet sites selling or promoting colloidal silver as an antibiotic or for other medical purposes.^[16] If no medical benefits are claimed, colloidal silver is sold as a supplement, and as long as the products comply with all other FDA regulations, its sale is considered legal.^[17] In 2002, the Australian Therapeutic Goods Administration made a similar ruling.^[18]

Differing preparations

The term, "colloidal silver", has been used inaccurately by some to advertise products which are mostly silver compounds or proteins bound with silver^{[citation needed]}. This has contributed to over-all confusion about the term "colloidal silver" in the market. In order for a mixture to be a true silver colloid, the silver atoms must be tiny metallic particles suspended in solution. Confusion around colloidal silver is increased by the fact that there is more than one manufacturing process, and that these lead to a number of significantly different products that have differing properties, all of which go by the name "colloidal silver".

Preparations called 'colloidal silver' include:

• Electrolytic silver (most common method used today)
• Ground silver (standard form of colloidal silver pre-World War II)
• Electrolysis of salt solution (produces a yellow product)

References

See also

• Colloidal gold
• Argyria

External links

• Wadhera, Akhil (2005). "Systemic argyria associated with ingestion of colloidal silver". Dermatology Online Journal. 11 (1): 12. Retrieved 2006-02-25. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help) A report on one of the few known cases of argyria caused by colloidal silver.
• Rosemary's Story-Argyria using unknown silver compound & concentrations as prescription nasal spray over 40 years ago as a child.
• Worth more than its weight in silver for burns - Mass. firm taps growing market for dressings infused with the metal, Ross Kerber, The Boston Globe, 2005-05-10
• Man's skin turns dark blue 2:09 His name is Paul Karason, and he's blue. It's not makeup or paint. KFSN's Gene Haagenson reports. www.cnn.com December 19, 2007