Sorry for the late reply, but I am not getting all my alerts.
That is why we only recommend colloidal silver from two companies, Utopia Silver and Mesosilver. Their product is comparable and that is the best silver you will find on the market. With high quality colloidal silver, there is absolutely no danger of argyria. Argyria becomes a problem when other ingredients, such as salt and animal proteins are included. Another cause of argyria is poorly made colloidal silver using tap water.