Great question, @jamesc! The GOE carries the world's highest quality colloidal silver. The nanoparticles are only 10 nm; numerous studies have concluded this is the optimal size for getting into tissues, doing its business, and being flushed from the system. Nanoparticles > 35 nm can potentially collect in tissues, particularly under the skin.

Poor quality silver products (that is, those with nanoparticles > 35 nm, and silver salts and silver proteins erroneously marketed as colloidal silver) have the potential to turn a person blue in a condition called argyria. Silver particles collect under the skin and react with sunlight in the same chemical process that develops an x-ray. There are no other side effects to argyria, save an unsightly and irreversible change in skin color. Again, the nanoparticles in GOE colloidal silver are only 10 nm, thus there is no potential for developing argyria, because the tiny nanoparticles pass harmelessly through the body after working their antibacterial and antiviral powers.

Studies are confirming the efficacy of 10 nm, 100 ppm colloidal silver against a range of diseases. Studies that show potential accumulation of silver in tissues are looking at larger particle size at extremely high concentrations (such as giving 300 mg of 18+ nm nanoparticles to rats.) This study concludes that even at those enormous doses, there is a mere possibility of liver damage: https://toxnet.nlm.nih.gov/cgi-bin/sis/search/a?dbs+hsdb:@term+@DOCNO+7715)

Plus, as @quinneaker points out, nascent iodine has the incredible property of detoxing heavy metals. Even if you did take enormous quantities of silver by drinking bottles and bottles and bottles of poor quality solutions at a time, nascent iodine can push it all through your system without build up or side effects.