Water Quality Branch
environmental protection department
Ministry of Environment, Lands and Parks
Ambient Water Quality Criteria for
Silver
Prepared pursuant to Section 2(e) of the
Environment Management Act, 1981
Approved: ______________ _____________________________
Date Executive Director
Environmental Protection Department
Canadian Cataloguing in Publication Data
Warrington, P. D. (Patrick Douglas), 1942-
Ambient water quality criteria for silver
[Vol. 2] constitutes technical appendix.
Includes bibliographic references.
ISBN 0-7726-1786-4
1. Water quality - Standards - British Columbia.
2. Silver - Environmental aspects - British Columbia. I. BC Environment. Environmental Protection Department. II. Title.
TD227.B7W374 1993 363.73'946'09711 C93-092175-5
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. There is no evidence that silver is naturally transformed to a hazardous biologically-available form (such as mercury into methyl mercury). 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.