Chemicals of Emerging Concern Emitted from Water-Based Paints: Experiments and Modeling

Water-based paints, despite being marketed as environmentally friendly, emit various chemicals of emerging concern (CECs) that may pose health risks indoors. This study characterizes CEC emissions from water-based paints through systematic experiments and modeling. Four CECs, covering a broad range of volatility, were tested experimentally. Results showed distinct emission patterns for chemicals with varying volatility: high-volatility CECs, like diethylene glycol butyl ether, exhibited rapid peak-and-decay emissions, while low-volatility triethylene glycol bis(2-ethylhexanoate) showed persistent emissions over 100 days. A dynamic mass transfer model was developed and validated against experimental data. The partition coefficient between polymer particles and air (Kpa) and the diffusion coefficient within the polymer (Dp) were identified as the key parameters governing emissions. The model classified emissions of 20 common CECs into short (<10 days), medium (10-100 days), and long-term (>1000 days) profiles, highlighting prolonged exposure risks for low-volatility compounds. Substrate effects showed that permeable substrates reduced initial emissions of volatile CECs but had minimal impact on long-term release. The model was applied to a residential indoor scenario, demonstrating its utility for exposure assessment. These findings improve the understanding of CEC emissions from water-based paints and provide valuable insights for more accurate risk assessments and safer product design.