Everything in life and in nature has the potential for good and ill. 
Colloidal Silver is no exception

According to the EPA potentially problematic conditions associated with silver ingestion
include:
Argyria (a gray or bluish gray skin discoloration caused by an accumulation of silver in the dermal layer)
"The critical effect in humans ingesting silver is argyria, a medically benign
but permanent bluish-gray discoloration of the skin. Argyria results from the
deposition of silver in the dermis and also from silver-induced production of
melanin. Although silver has been shown to be uniformly deposited in exposed and unexposed areas, the increased pigmentation becomes more pronounced in areas exposed to sunlight due to photoactivated reduction of the metal.
Although the deposition of silver is permanent, it is not associated with any adverse health effects. No pathologic changes or inflammatory reactions have been shown to result from silver deposition."

The EPA has no record on file of any person having contracted argyria through the use of  liquid colloidal silver.  A 2002 interview with Stan Jones ( a gentleman who ingested roughly 8oz of concentrated large particle colloidal silver daily for a period of nearly three years), the only documented victim of argyria due to liquid colloidal silver ingestion of whom we are aware, is available to interested parties.  For a free copy: Send a SASE to: Silver Bullet  Enterprises, 3620 W. 10^th St., #180, Greeley, CO 80634.  Specify that you want a free copy of the interview with Stan Jones.
The records of argyria on file at the EPA date to the 1930's and earlier.

"Gaul and Staud (1935) reported 70 cases of generalized argyria following
organic and colloidal silver medication, including 13 cases of generalized "..argyria following intravenous silver arsphenamine injection therapy Argyria developed after a total dose of 4,7 or 8 g in some patients, while in others, argyria did not develop until after a total dose of 10, 15 or 20g."

"The authors concluded that argyria may become clinically apparent after a total accumulated i.v. (intra- veinous) Dose of approximately 8 g of silver arsphenamine. The book entitled "Argyria. The Pharmacology  of  Silver" reached the same conclusion."

All these cases appear to have been caused by the ingestion of silver compounds or silver powder. None were caused by the usage of liquid colloidal silver. Furthermore, the most common cause
appears to be related to treatments involving injection of  silver compounds.
As an additional consideration, the EPA reports that 90 to 99% of ingested silver is excreted through the gastro-intestinal tract within two (2) days.                                                                                                   

"Furchner et al. (1968) studied the absorption and retention of ingested silver (as silver nitrate, amount not specified) in mice, rats, monkeys and dogs. In all four species, very little silver was absorbed from the GI tract. Cumulative
excretion ranged from 90 to 99% on the second day after ingestion, with <1% of  the dose being retained in <1 week in monkeys, rats and mice. Dogs had a slightly greater retention."

This does not mean that the potential for argyria can be ignored. It just indicates that one should be prudent in his/her consumption of any form of silver.

The EPA rates the risk of argyria from Silver usage as low.  (A reputed cure(?) for Argyria)

Vitamin E and Selenium deficiency (pre-cursors to glutathione production)
This is important due to the symptoms which MAY (or may not) OCCUR in conjunction with this condition.

These adverse symptoms are most likely to appear in conjunction with long-term supplementation.

• Liver Damage (hepatic necrosis)

"Hepatic necrosis and ultrastructural changes of the liver have been induced by
silver administration to vitamin E and/or selenium deficient rats (Wagner et al., 1975; Diplock et al., 1967; Bunyan et al., 1968). Investigators have hypothesized that this toxicity is related to a silver-induced selenium  deficiency that inhibits the synthesis of the
seleno-enzyme glutathione peroxidase. In animals supplemented with selenium and/or
vitamin E, exposures of silver as high as 140 mg/kg/day (100 mg Ag/L drinking water) were well-tolerated (Bunyan et al., 1968). "

Cataract Formation (although the EPA does not address this particular phenomenon, it is a well documented consequence of selenium/vitamin E/glutathione deficiency see" Archives of Opthomology [2000; 118:1556-1563&# 93;")
If glutathione are abnormal, they can affect the health of the eye in a major way (Bunin et al. 1992). maintain the water balance in the lens. It also is synthesized within the lens and is made of three amino acids: glycine, cysteine, and glutamic acid. '

Selenium and Vitamin E

Selenium and vitamin E may work synergistically in protecting against cataracts and these two nutrients have been shown to reduce the risk of cancer and cardiovascular disease. Therefore, 400 to 800 IU a day of vitamin E and 200 to 600 mcg a day of selenium would appear to be prudent methods of protecting against cataract formation and maintaining good overall health. A low plasma vitamin E level was shown to increase the risk of lens opacities (Rouhiainen 1996). Selenium works with alpha-lipoic acid to increase cellular concentrations of glutathione. As previously discussed, glutathione is a critical antioxidant in  protecting against free radicals in the eye lens."

Roger Altman Eng. Sc. D. , in his book "Colloidal Silver: Where does it go when you drink it? How long does it stay there?" , copyright 1999, states :

"Conclusions:
Ingestion of properly prepared CS does not result in silver accumulating in the body. There is no evidence that silver deposits significantly in hair or fingernails and, in fact, the data support the conclusion that after taking more than 2 mg of CS per day for several months, silver seems to be purged from the body (mostly through urine) at about the same rate at which it is consumed. Furthermore, upon terminating CS intake, it appears that as much as half the silver residing in body tissue will be purged (through urine and feces, but more and more through feces as time goes on) In less than a month. Even this relatively short residence time could be reduced substantially if several liters of water were consumed daily."

Mr. Altman's work utilized a single subject, (himself) and therefore is statistically and technically of little value. However, his tests and other methodology appear both  pragmatic and sound, providing the reader some valid direction in seeking the truth of the matter. Mr. Altman's e-mail address is: rogaltman@aol.com
Diarrhea - We understand that the initial ingestion of Colloidal Silver may cause a "die off" of bacteria in the gastro-intestinal tract. This results in an almost immediate, but short-lived case of diarrhea. This appears to be the body's way of eliminating dead pathogens. The easiest method of preventing this phenomenon appears to be "start with a small dose and increase incrementally until the desired dosage is reached." This particular bit of information has been relayed to us by word of mouth, and should be considered anecdotal.

Conflicts with prescription medications -We have not read of any specific    contra-indications or interactions with prescription medications. However, new medicines are being introduced almost daily, and anything is possible. As an example, grapefruit causes problems with some medications. Consult your Medical Professional prior to starting or changing any course of treatment.

Silver allergies - We find no record of this occurrence.  That doesn't mean that it cannot     occur, just that we have not found a record of such an occurrence.

Silver Toxicity - the known symptoms are shown on the following page. Utilizing the maxim "If the results you are getting are not what you desire, DO SOMETHING DIFFERENT ", the author recommends vigilant observation of one&# 39;s own  symptoms.

Based on the studies referenced above, the following dietary changes:

• the addition of selenium, & vitamin e,


• adding copious amounts of purified water


• reducing the known amounts of silver intake (ingested or otherwise)

The following set of symptoms relating to severe silver toxicity  does not appear to have sufficient credibility to require any form of mention by the US EPA, or the US FDA. 

The silver administered in homeopathic care includes various silver powders and silver compounds, as opposed to liquid colloidal silver.

However, the following  information does come from the "LECTURES ON HOMEOPATHIC MATERIA  MEDICA", by JAMES TYLER KENT, A.M., M.D. Late Professor of Materia Medica in Hering College, Chicago.

As such, it MAY OR MAY NOT BE ACCURATE.
These symptoms have been included as guidelines. It is always better to be aware of all      possibilities than to get an unpleasant surprise. As we mentioned above, the FDA & EPA appear to give no credence to this information.

• Silver Metal Poisoning Toxicity Symptomology
Anti Psoric and possibly anti-sycotic

• Direct effect on cartilage
• Direct effect on nerves and nerve sheaths
• Effects the brain/nervous system over time
• gradually softens tissues
• targets "intellectual" sections of the brain
• Slight changes to voluntary systems ( undefined )
• May affect reasoning abilities
• Physical symptoms of neck and back pain, and tearing pain throughout body
• Mental fatigue and restlessness with vertigo


• Symptoms masked by coffee/caffeine intake


• Symptoms temporarily relieved by exercise


• Cold weather increases pain from Rheumatism


• Increased joint pain


• knotting of cartilage


• Effects left testes and right ovaries ( hardening )


• Mental and emotional excitement to the point of rage


• Experience of shock sensations in the limbs upon going to sleep


• Skin irritation, itching sensation that cannot be relieved


• Painful tension in the throat


• Gray mucus from throat and sinuses


• Heart Palpitations while lying on the back

Quotes referring to the EPA come directly from The EPA report " Silver; CASRN 7440-22-4"
Which is publicly available on the web.
Information attributed to the "Life Extension Foundation " is available on their  website, and similar information is available elsewhere, with comparable conclusions.