Oxidation of commercial antioxidants is driving increasing atmospheric abundance of organophosphate esters: Implication for global regulation

Summary

Organophosphate esters (OPEs) are chemicals of global concern due to their adverse effects on humans and the environment. Environmental OPEs are thought to originate via direct emissions; therefore, existing OPE regulations focus on limiting the use of certain OPEs in commercial products. Here, we present experimental and field evidence that OPEs can also be formed from reactions between atmospheric ozone and organophosphite antioxidants (OPAs; a group of mass-produced chemicals), representing an important indirect source of environmental OPEs. We demonstrate that tris(2,4-di-tert-butylphenyl) phosphate (TDtBPP), a novel OPE formed from OPA chemical transformation, is globally distributed from megacities to the Antarctic and Arctic, with concentrations in Arctic air significantly increasing since 1994. Furthermore, TDtBPP is substantially more persistent in the environment and may pose a higher risk relative to the traditional OPEs. These results highlight the importance to consider chemical transformations of contaminants in developing environmental regulations to protect environmental health.