Two samples of lead crystal ware were found to release lead in substantial concentrations into vinegar stored in the containers. Although both cruets would technically meet FDA safety guidelines, the fact that such vessels are frequently used for long term storage would still result in their posing a potential health hazard. The phenomenon of acid hardening of the glass was observed, and markedly lowered the rate of lead release. Such acid hardening is recommended as a means of reducing hazard due to the leaching of lead. The two vessels were quite dissimilar in their susceptibilities to attack by acid. One vessel was found to be less resistant to acid attack in its deeper layers, while an opposite trend was evidenced for the other. The heretofore unknown phenomenon of “half-concentration” was discovered. Computer analysis of the data generated reliable mathematical models for the lead release process.
