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Evaluation of a four-zone exposure model for predicting TCPP concentrations in a low-energy test house



Dustin Poppendieck, Mengyan Gong, Stephen Zimmerman, Lisa Ng


Numerous chemicals exist indoors. Due to limited resources, it's infeasible to assess indoor exposure of each chemical for all indoor conditions through measurements alone. Hence, indoor exposure models have been developed because of their ability to predict time-varied exposure for a wide range of chemicals under different conditions. The Indoor Environmental Concentrations in Buildings with Conditioned and Unconditioned Zones (IECCU) model was developed by the United States Environmental Protection Agency. This study evaluates the IECCU by comparing airborne tris(1-chloro-2-propyl) phosphate (TCPP) concentrations measured from 2013 to 2018 in a test house to model predictions. Inputs to IECCU included building and environment (i.e., air zones, interzonal airflow rates, temperature in each zone), parameters for both source (spray polyurethane foam (SPF)) and sinks (gypsum and wallboard), and simulation conditions. Simulations were conducted using three sets of inputs. Simulation 1 and 2 differed in using quantified versus design inputs for temperatures and airflow rates. Simulation 1 and 3 differed in the configured air zones in the IECCU model
Building and Environment


Poppendieck, D. , Gong, M. , Zimmerman, S. and Ng, L. (2021), Evaluation of a four-zone exposure model for predicting TCPP concentrations in a low-energy test house, Building and Environment, [online], (Accessed April 17, 2024)
Created May 3, 2021, Updated March 8, 2024