Concentrations of colloidal silver at 5 parts per million or higher have been found to kill numerous infectious
bacteria[1] in a controversial study from BYU
[2]. Prior to
1938, colloidal silver was widely used by physicians as a mainstream
antibiotic.
[3] It was produced by pharmaceutical companies under various names, including Protargol and Argyrol. But the material was costly and the
pharmaceutical industry developed fast-acting, less-expensive sulfa drugs and penicillin. Colloidal silver has been approved by the EPA as a disinfectant for hospitals and medical centers.