Comparative study of the structure and durability of commercial silicate glasses for food consumption and cosmetic packaging

Four commercial glass compositions were investigated to understand their mechanisms of alteration in light of current and future regulations on food contact materials. Lead crystal (fine glassware), soda-lime (food and cosmetic containers), borosilicate (cookware) and barium glass (tableware) powders and slabs were altered for 3 years in 4% (v/v) acetic acid at pH 2.4 and 70 °C. The leaching solution was analyzed by ICP-AES while glass slabs were investigated by ToF-SIMS and Spectroscopic Ellipsometry. In acidic medium, the polymerization of the silicate network and glass composition impacted alteration rates and depleted depths of alkalis and alkaline-earth elements. Yet the rate of hydrolysis measured from Si release remained similar under identical conditions, regardless of glass structure and composition. For lead crystal glass, repolymerization of the silicate network was observed during alteration.

Léa Brunswic, Frédéric Angeli, Thibault Charpentier, Stéphane Gin, Pierre Asplanato, Huseyin Kaya, Seong H. Kim