Silver

Guidelines

Unit of measurement

μg/l

World Health Organisation Standards (1993)

No guideline

Standards for private water supplies in England (2016)

Not mentioned

Standards for private water supplies in Scotland (2006)

10

Standards for private water supplies in Wales (2017)

Not mentioned

European Union Drinking Water Directive (1998)

Not mentioned

Silver

Very large doses of silver can cause an unsightly condition known as argyria which causes the sufferer's skin to turn a purple or purple-grey colour. In smaller doses, it is not thought to be a particularly toxic element. It is used widely in domestic water filters to prevent bacterial growth. It is, therefore, a good idea to reject the first draw of water from these units when a new cartridge is fitted in case any loosely bound silver is liberated and enters into the drinking water.