Once the packaging enters the waste stream, however, these metals can infiltrate landfill leachate, incinerator ash and stack emissions.
Packaging constitutes one-third of the municipal solid waste stream.
Pennsylvania facilities disposed of roughly 15 million tons of municipal solid waste in 1996. In such volumes and concentrations, toxic metals in packaging can present environmental and health risks when they are not properly managed. Pennsylvania's Act 112 of 1994, the Safe Packaging Act, regulates the concentration of these metals in all packaging offered for sale or used for promotional purposes in the state. This includes all packaging components, coatings, inks and labels. The law addresses both the intentional introduction and incidental presence of the four metals.