Organic UV filter chemicals (UVFCs) are the active ingredients in most sun protection products which serve the purpose of absorbing harmful UV-A and UV-B rays. Hundreds of tons of these chemicals are produced annually and introduced into the environment through direct contact with water or through indirect contact via wastewater effluent. They can be absorbed through skin upon topical application, and some organic UVFCs act as endocrine disruptors. It is known that some organic UVFCs break down upon exposure to sunlight due to their photolytic properties. In most cases, the potential cytotoxicities of the photoproducts are unknown. In this work, photolysis products of octyl dimethyl para-aminobenzoic acid (OD-PABA) generated under simulated sunlight are isolated, identified, and assessed for cytotoxicity through the aid of a neutral red assay to determine cell viability using human mesenchymal stromal cells (hMSCs), a physiologically relevant cell line because of its prevalence within various tissues and organs. OD-PABA itself was also assessed for cytotoxicity to distinguish whether toxicity changes after photodegradation. It was found that OD-PABA demonstrated cytotoxic effects at a concentration of 1 mM. Whole OD-PABA photolysate displayed significantly higher levels of cytotoxicity compared to that exhibited by the parent compound at the same equivalent concentration, with an EC50 value of 0.71 (+/- 0.02) mM. Ongoing research is focused on the isolation and assessment of individual photoproducts for cytotoxic effects. In addition, sub-cytotoxic concentrations of OD-PABA and its photoproducts will be investigated to determine their potential to cause genetic mutations, which could explain the association between OD-PABA and endocrine disruption.