The USA's Toxins in Packaging Clearinghouse (TPCH) has released a report with recommendations for testing glass containers for compliance with state toxics in packaging laws. "Sample preparation methods must be sufficiently aggressive to liberate lead from glass in order to properly measure true metals concentration in glass for compliance with state laws," said Ron Ohta, a senior scientist with the California Dept Toxic Substances Control (DTSC). TPCH sent glass samples containing known concentrations of lead to 9 commercial laboratories in the USA and one laboratory in Europe for testing. The results indicated that US Environmental Protection Agency SW-846 Method 3052, "Microwave Assisted Acid Digestion of Siliceous and Organically Based Matrices" and comparable sample preparation methods using hydrofluoric acid (HF) for silica-based materials like glass were effective in determining total lead content. Methods using HF without the application of an external heat source such as microwave, oven bomb or hot plate, did not perform as well. TPCH and its member states also promote the use of XRF spectroscopy for screening glass matrix samples for compliance with state toxics in packaging laws in the recent guidance in conjunction with the research report. XRF spectroscopy offers an alternative to EPA Method 3052 and the use of HF and provides for non-destructive analysis of metals in glass matrices. Recent XRF screening of glass bottles by TPCH indicated that some wine bottles may exceed allowable levels of lead in packaging. State toxics in packaging laws prohibit the sale and distribution of packaging with greater than a total of 100ppm for four metals: lead; cadmium; mercury; and hexavalent chromium - combined. Some green wine bottles originating in South America and Europe were found by TPCH to exceed the 100ppm regulatory limit. "Importers and distributors of wine should be monitoring bottles for compliance with state toxic in packaging laws" comments TPCH Chair, David Westcott of the Connecticut Department of Energy and Environmental Protection. "Companies should ask their suppliers to provide a certificate of compliance for bottles, or have bottles tested in the USA for compliance with state laws. A small investment in testing will be less costly than removing wine bottles from retail shelves and the resultant damage to their brand." www.toxicsinpackaging.org/docs/press-release-glass-matrix-test.pdf
