Hazard identification and consumer safety characterization for trans-1-chloro-3,3,3-trifluoropropene (trans-1233zd)

Trans-1233zd was developed as a refrigerant and propellant in consumer products; its toxicity has been studied extensively. The scope of this assessment is to apply the confirmed NOAEC to conduct Benchmark Dose Modeling (BMD) and determine the Point of Departure (POD). In a previously published 13-week inhalation study, a NOAEC was identified at 4000 ppm. Due to uncertainty concerning the cardiac lesion, an external pathology peer review of heart tissues was undertaken using published best practices and consistent nomenclature and diagnostic criteria. The cardiac lesion observed at 4000 ppm was considered to be spontaneous based on lesion location and microscopic features. BMD was applied to derive the BMDL₀₅ and BMDL₁₀; the more conservative BMDL₀₅ was used as the POD for risk assessment to calculate the Reference Exposure Levels (RELs). The 2-Box Air Dispersion Model was used to calculate the exposure to consumer products. Both the acute and chronic exposure concentrations calculated were compared to the acute and chronic RELs. The acute and chronic exposure to trans-1233zd in the assessed consumer products are below the RELs and deemed safe for their intended uses.