Amber glass is used worldwide for the production of containers for beverages and pharmaceutical prdoucts prone to degration from UV light. Several previously published works have definitively established the chemical structure of the amber chromophore group and several interesting papers were devoted to practical amber colour management. However, this type of reduced glass sometimes shows instability and/or inhomogeneity in colour as well as quality, particularly from gaseous inclusions of various dimensions. Unstable amber glass is commonly believed to be extremely reduced whilst too oxidized amber glass is too pale to satisfy the UV protection requirements. An investigation made on commercial containers of soda-lime-silica glasses have demonstrated different practical ratios of sulphide content and colour.
