Implications of Printing Ink Composition for Ambient Air Pollutants

Emissions from volatile chemical products (VCPs) have become increasingly important to anthropogenic organic carbon emissions, and consequently to anthropogenic ozone and secondary organic aerosol (SOA), as emission control strategies have reduced contributions from combustion sources. Industrial and consumer printing inks contribute considerably to VCP emissions, yet emission speciation profiles for printing inks are outdated and ignore the increasing market share of water-based inks. This study develops organic compound emissions profiles for one organic solvent-based industrial ink and two water-based consumer inks using microchamber emissions tests. The composition of the solvent-based ink differed from the declared composition. Emissions profiles were applied to estimates of SOA and O₃ formation potential and inhalation risk. The chemical species that drive the estimated O₃ formation potential correspond closely to species that drive total emissions mass. However, this study shows species responsible for SOA and chronic inhalation risk are present in low quantities in inks and those endpoints may be under-emphasized in mass-weight emission profiles. The SOA and O₃ formation from printing inks is estimated to have decreased about 42% since 2001, principally due to decreasing total ink usage but aided by increased use of water-based inks, which have low potential to form SOA and O₃.