Biodissolution and cellular response to MoO3 nanoribbons and a new framework for early hazard screening for 2D materials. Two-dimensional materials are a class of ultra-thin but highly functional materials that promise improvements in semiconductor electronics, energy capture and storage, or catalysis, as compared to traditional materials. The fiber- or plate-like shape and nanosize thickness of these materials raises questions regarding their fate, toxicity and risk throughout production and use. Here we present a framework to evaluate the potential hazard of 2D materials, considering both biopersistence and cytotoxicity. The aim of this approach is to rapidly identify and prioritize materials with the highest potential risk for more detailed study. A novel 2D material, MoO3 was evaluated using the framework, and determined to be of low priority for further evaluation due to its rapid degradation into low-hazard dissolution products. Evan Gray Author Browning, Cynthia Author Wang, Mengjing Author Gion, Kyle Author Chao, Eric Author Koski, Kristie Author Kane, Agnes Author Hurt, Robert Author 2018-11-07 2D nanomaterials biopersistence cytotoxicity nanotoxicity text peer-reviewed journal article This research was supported by the National Institute of Environmental Health Sciences (NIEHS) Superfund Research Program of the National Institutes of Health under award number P42ES013660.