TDCPP (Fyrol FR 2) is classified under the chlorinated trialkyl organophosphate flame retardant (OPFR) group of compounds primarily utilized as additives in commercial products.

A dose-dependent decrease of cell viability after TDCPP exposure with LC50 at 202 μg/mL. A concentration-dependent apoptotic sign was observed in HCECs after exposing to ≥2 μg/mL TDCPP. Endoplasmic reticulum stress induction was evidenced by up-regulation of its biomarker genes (ATF-4, CHOP, BiP, and XBP1). Furthermore, alternation of Bcl-2/Bax expression, mitochondrial membrane potential loss, cellular ATP content decrease, and caspase-3 and -9 activity increase were observed after exposing to 2 or 20 μg/mL TDCPP. Implicated the involvement of endoplasmic reticulum stress in TDCPP-induced HCEC apoptosis, probably mediated by mitochondrial apoptotic pathway. TDCPP exposure induced toxicity to human cornea.

Human corneal epithelial cells (HCECs) were cultured in DMEM supplemented with 10% FBS, 10 ng/mL EGF, and 1% penicillin-streptomycin solution in an incubator with 5% CO2 at 37℃.?After reaching confluence, HCECs were replanted into 6/24/ 96-well plates or petri dishes with different initial densities and cultured for 24 h to reach ~70% confluence.?Then, TDCPP dissolved in n-hexane was solvent-exchanged to DMSO and serially diluted by DMEM to achieve concentrations from 0.034 to 340 μg/mL.?For cell exposure, the culture medium was aspirated and treated with TDCPP solutions (DMSO <0.1%) for 24 h with 0.1% DMSO solution as vehicle control[1].