MANEEWATTANAPINYO et. al. 2011
“Oral administration of AgNPs at a limited dose of 5,000 mg/kg produced neither mortality nor acute toxic signs.
The results indicated that the LD50 of colloidal AgNPs is greater than 5,000 mg/kg body weight.”
This safe concentration is yet about 100 times higher than SilverLife 3 PPM silver solution.