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

Abstract

Four commercial glass compositions were investigated to understand their mechanisms of alteration in light of the 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 acetic acid (4% vol) 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. As a result, in acidic medium, the polymerization of the silicate network as well as the glass composition impacted the alteration rates and depleted depths of alkalis and earth-alkalis elements. Yet the rate of hydrolysis measured from the release of Si, remained similar under identical alteration conditions, whatever the glass structure and composition. For lead crystal glass, repolymerization of the silicate network was observed in the course of alteration.