Silver Properties: Physical, chemical, and biological  
Compiled by Walter Sorochan

Posted 2010; updated May 25,2019.This information has not been approved by FDA:  Read  Disclaimer

Silver was the main germ killer before penicillin and other antibiotics were discovered. Since the end of the second war, silver as as germ fighter has been replaced by other germocides. However, silver as a bacteria and virus killer is better than today's germicides and antibiotics in that nanotech colloidal silver in concentrations less than 20 ppm instantly kills bacteria, viruses and fungi; not allowing these to mutate. Colloidal silver is safe to use as it is excreted from the body in several days and is not stored.

The information below is a direct quote from the authors Wadhera Akhil MD and Max Fung MD..   The authors elaborate on the properties of various silver products, primarily silver salts, before the year 2005.    Their comments do NOT take into account the newer generation of silver products, like silver sol, which have entirely different pharmacological properties and affects on the human body as  contrasted to silver salt and  silver protein products! Readers should be aware that silver sol was created with advanced technology after the authors wrote this report. This report is significant in that it provides relevant information that may clarify silver information while on the other hand, add confusion to and contradict previous information about absorption and elimination of silver from the body.

The excerpt below is from authors Wadhera and Fung: Wadhera
"Silver is the forty-seventh element of the periodic table and has an atomic weight of 107.87. The term silver originates from the Anglo-Saxon word siolfur. (The symbol Ag comes from the Latin word for silver, argentum). Pure silver is a brilliant white metal with a melting point of 961.78° C and a boiling point of 2162° C. It is a little harder than gold and is very ductile and malleable. Pure silver has the highest electrical and thermal conductivity of all metals and possesses the lowest contact resistance. Silver is stable in normal air and water but tarnishes when exposed to ozone, hydrogen sulphide, or air that contains sulphur. Silver occurs in ores including argentite, lead, lead-zinc, copper, and gold [4]. It is a soft metal that is used medically in surgical instruments, dental prostheses, and in alloys.

Inorganic silver compounds are germicidal and hence have been used extensively in the field of medicine. These compounds denature proteins by binding to the reactive groups of proteins resulting in their precipitation. They inactivate enzymes by reacting with the sulfhydryl groups to form hemisilver sulfides. They also react with the amino-, carboxyl-, phosphate-, and imidazole-groups and diminish the activities of lactate dehydrogenase and glutathione peroxidase [5].

Silver absorption, transportation, deposition and excretion: A major portion of ingested silver is absorbed in the small intestine [1]. On the basis of animal and human experiments it is considered that up to 10 percent of ingested silver salt is initially absorbed. This percentage may be much higher if the mucous membranes of the oral cavity are disrupted. Some soluble silver salts corrode the gastrointestinal mucosa and increase the amount of silver absorbed.

Most of the absorbed silver is transported through blood as a soluble colloid with plasma protein. The plasma protein that is most commonly bound with silver is albumin, forming silver albuminate. The blood level of silver in argyremic patients is reported to vary from nondetectable to 0.005 mg Ag/l [6]. However, Blumberg and Carey report a single patient whose spectrographic analysis of blood reveals blood silver levels of 0.5 mg/l, approximately 1 week after discontinuing the use of silver nitrate capsules [7].

Some of the silver in plasma is carried as a salt and may be deposited in various tissues after being reduced to its metallic form. The highest concentrations of silver are found in the skin, liver, spleen, and adrenals. Although originally believed to not penetrate the blood-brain barrier, it has been shown now that parenterally administered silver salts can accumulate in neurons and glial cells of the brain and spinal cord. The amount of silver deposited in the various tissues is directly proportional to the blood supply of the respective organ.

Animal studies demonstrate that most of the absorbed silver is eliminated through the gastrointestinal system. Even subcutaneously administered silver is excreted in the stool. Renal excretion of silver also occurs and has been shown for one patient to occur up to 3 months after administration of silver [7].

Toxicology of silver: Adverse health effects of silver depend on the dose and form of exposure, the duration of exposure, the route of exposure (i.e., ingestion, inhalation, or skin contact), and also on the exposed individual's characteristics (age, sex, nutritional status, and state of health). The general population is exposed to silver mostly through very low levels of silver present in food and drinking water and sometimes in the air. The silver in these sources is a result of the naturally occurring silver in water and soil. Naturally occurring silver can contribute to up to 1 × 10-6 mg silver/m3 of air, 0.2-2.0 parts of silver per billion parts of water (ppb) in lakes and river waters and 0.2-0.3 parts of silver per million parts of soil (ppm). Although the Environmental Protection Agency (EPA) recommends that the silver level in drinking water not exceed 50 ppb, drinking water supplies in the United States have been found to contain silver levels up to 80 ppb [8]. Studies conducted by Hamilton in 1972 found the daily oral intake of silver from a typical diet to be 27-88 µg per day [9].

Th EPA publishes an oral reference dose (RfD) that is based on the assumption that thresholds exist for certain toxic effects such as cellular necrosis. This dose is expressed in units of micrograms per kg per day and is an estimate of the maximum amount of daily silver exposure to the human population that is not associated with any appreciable deleterious effects over a lifetime. Current RfD for oral silver exposure is 5 micrograms per kg per day. When consumed in relatively smaller quantities, no pathologic changes or inflammatory reactions other than argyria have been shown to result from silver deposition [6]. However, if silver is administered in high doses, whether orally or intravenously, there is ample evidence of adverse effects including death. On the basis of animal experiments, many authors in the late nineteenth century determined that intravenous administration of inorganic silver has the most significant impact on the central nervous system (manifested as weakness and rigidity of the legs, loss of voluntary movements) and on the cardiac conduction system (abnormal conduction) [1].

Consumption of large doses of colloidal silver can result in coma, pleural edema, and hemolysis. Colloidal silver is also toxic to the bone marrow and may be associated with agranulocytosis. The toxic effects of inorganic silver ingested orally in large doses are very similar to any corrosive solution. Such ingestion can result in burning of the throat and epigastrium, leading to abdominal pain, vomiting, and diarrhea. The patient often suffers convulsions and goes into shock. The single lethal dose of silver nitrate has been estimated to be 10 gm. Silver salts are more toxic than silver proteins or colloidal silver." Source:  Akhil Wadhera MD and Max Fung MD, "Systemic argyria associated with ingestion of colloidal silver," Dermatology Online Journal, 11 (1): 12; 2005. [ Authors from Department of Dermatology, University of California Davis.]   Superb report on Argyria
Furst and Schlauder studied the carcinogenic potential of silver and gold; they concluded that finely divided silver powder injected intramuscularly did not induce any form of cancer [10]."

Author References [ from authors ]

1. Hill WR, Pillsbury DM. Argyria, The Pharmacology of Silver. 1st edn. The Williams and Wilkins Co. 1939.

2. Kaye ET. Topical antibacterial agents. Infect Dis Clin North Am. 2000 Jun;14(2):321-39. Review. PubMed

3. Farmer ER, Hood AF. Pathology of the Skin. 2nd edn. Appleton & Lange. 2000;507-508.

4. Chemistry: webElements Periodic Table: Professional Edition: Silve:key information. Last accessed 02/01/05.

5. Fung MC, Bowen DL. Silver products for medical indications: risk-benefit assessment. J Toxicol Clin Toxicol. 1996;34(1):119-26. Review. PubMed

6. U.S. Environmental Protection Agency, Integrated Risk Information System.Silver (CASRN 7440-22-4). Last accessed 2/01/05.

7. Blumberg H, Carey TN. Argyremia: Detection of unsuspected and obscure argyria by the spectrographic demonstration of high blood silver. JAMA. 1934;103(20):1521-1524.

8. Agency for Toxic Substances and Disease Registry, Public Health Statement for Silver, December 1990. Last accessed 02/01/05.

9. Abundance of the chemical elements in man's diet and possible relations with environmental factors. Hamilton, E.I. and M.J. Minski. 1972/1973. Sci. Total Environ. 1: 375-394.

10. Furst A, Schlauder MC. Inactivity of two noble metals as carcinogens. J Environ Pathol Toxicol. 1978 Sep-Oct;1(1):51-7. PubMed

11. Gaul LE, Staud AH. Clinical spectroscopy. Seventy cases of generalized argyrosis following organic and colloidal silver medication. JAMA. 1935;104:1387-1390.

12. Ohbo Y, Fukuzako H, Takeuchi K, Takigawa M. Argyria and convulsive seizures caused by ingestion of silver in a patient with schizophrenia. Psychiatry Clin Neurosci. 1996 Apr;50(2):89-90. PubMed

13. Moss AP, Sugar A, Hargett NA, Atkin A, Wolkstein M, Rosenman KD. The ocular manifestations and functional effects of occupational argyrosis. Arch Ophthalmol. 1979 May;97(5):906-8. PubMed

14. Schlotzer-Schrehardt U, Holbach LM, Hofmann-Rummelt C, Naumann GO. Multifocal corneal argyrosis after an explosion injury. Cornea. 2001 Jul;20(5):553-7. PubMed

15. Pariser RJ. Generalized argyria. Clinicopathologic features and histochemical studies. Arch Dermatol. 1978 Mar;114(3):373-7. PubMed

16. Over-the-counter drug products containing colloidal silver ingredients or silver salts. Department of Health and Human Services (HHS), Public Health Service (PHS), Food and Drug Administration (FDA). Final rule. Fed Regist. 1999 Aug 17;64(158):44653-8. PubMed

17.Wadhera Akhil MD and Max Fung MD, "Systemic argyria associated with ingestion of colloidal silver," Dermatology Online Journal 11 (1): 12 Department of Dermatology, University of California Davis. Wadhera "

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