In response to SGCDpro's concern that there are no standard test procedures to determine the heavy-metal content of glass bottles, the TPCH contracted 4 private laboratories & an enamel manufacturer suggested by SGCDpro. The TPCH had been asked to specify an appropriate standard test procedure to give decorators confidence that certifications of colours used in decorating glass packaging would not cause enforcement actions. Based on a reversal of a long-standing TPCH interpretation, from Sept/09, glass bottles and the enamels used to decorate them are considered to be separate packaging components. As a result, the bottle & each colour must be certified not to exceed 100ppm of the incidental presence of a total of heavy metals. No heavy metals may be intentionally introduced into any of the decoration materials. The TPCH concluded that "Laboratories currently have the capabilities to analyse enamels for the restricted metals. TPCH does not believe it is appropriate to suggest any one method as "the" standard tests method for which to test enamels. Rather, TPCH continues to recommend performance objectives for testing, and to suggest that rigorous QA/QC practices be used to support claims of compliance. The performance objective is to determine the accurate total concentration of metal present to evaluate compliance with state statutes. In the absence of the exemption for vitrified labels to pass the TCLP or CA WET, the enamel components are ideally tested prior to application to the glass container. As with any packaging component subject to state requirements, packaging certifications can be based on testing by or QA/QC documentation of the supplier/s of the packaging components."
