1981 Original signed by Don Fast Executive Director Environmental Protection Department February 19, 1996. This document is one in a series that establishes ambient water quality criteria for British Columbia. It includes an overview which is followed by the main body of the report. This document sets criteria for silver to protect freshwater and marine aquatic life. Criteria were not set for human, livestock or wildlife drinking water, recreational waters, irrigation water or industrial water uses, since, either suitable data documenting the effects of silver for these uses were lacking, or the criteria would have been about 1000 times higher than the aquatic life criteria and therefore redundant.
Silver is most toxic to microscopic organisms or larval forms of aquatic animals.
Ionic silver is more toxic to aquatic organisms than silver compounds. Thiosulphate-complexed silver breaks down to silver sulphide which is less toxic than the silver ion. Silver criteria are summarized in the chapter on Recommended Criteria. A more detailed discussion of the criteria is presented in the main body of the report. A natural or man-made chemical present in the environment does not always lead to human or animal exposure.