The TPCH screened 125 single-use bags for the presence of lead, cadmium, mercury and hexavalent chromium in the inks used to print or color the bags.
The report, XRF Screening of Packaging Components: Inks & Colorants, found only three bags, two yellow and one red, failed the screening test for lead (see graphic) . However, each of the failed samples contained about 1 percent lead by weight of the bag, far beyond what state laws allow.
“This means that for every 100 pounds of these shopping bags, we’re introducing about 1 pound of lead into commerce,” said Alex Stone with the State of Washington’s Department of Ecology, which performed the screening with TPCH.
The TPCH learned from previous screenings that compliance could be problematic with yellow plastic shopping bags. The results of the latest screening confirm retailers should proceed with caution when specifying or buying yellow plastic shopping bags, TPCH said.
Despite the findings, states and TPCH were pleased by the results, which may indicate manufacturers and distributors of plastic shopping and mailing bags are paying more attention to sourcing and testing for compliance with toxics in packaging laws, according to the report.
A screening conducted by the TPCH in 2007 showed almost 17 percent non-compliance for plastic shopping bags.
This latest screening included some retail brand shopping bags that failed the 2007 test. The results this time indicated the new bags were in compliance.
The TPCH routinely screens packaging for presence of regulated metals using X-ray fluorescence, or XRF, analysis. Samples failing the XRF screening with >100 parts per million of a regulated metal were sent to a laboratory to confirm the results.
A study released last year by the TPCH found widespread inaccuracies in testing for lead and cadmium in packaging samples. The TPCH sent packaging samples to six private analytical laboratories and the California Department of Toxic Substances Control Environmental Chemistry Laboratory.
Four out of the seven reported unacceptable results, while one laboratory with offices nationwide reported inaccurate results for five out of the eight samples they tested. Only one packaging sample out of the 42 analyzed resulted in a false negative, which incorrectly indicated that the sample was in compliance with state laws.