Cadmium-containing quantum dot nanoparticles (QDs) are integrated into electronic displays because of their ability to efficiently convert colors. There are conflicting accounts as to whether these particles present a hazard to the environment, as they have been studied either as (1) embedded QDs in display screen films or (2) as model QDs with small, hydrophilic ligands. We synthesized QDs featuring the core-shell structure and the thick polymer coating present in commercial devices, to probe their fate under low pH conditions. The role of dioxygen was also explored in this context. We also used liver cells to compare the toxicity of pristine QDs to those subjected to acid dissolution.