Normalizing the environmental impacts to percent removal of methylene blue revealed different trends compared to the mass-normalized results (Figure ). MPCP had the lowest environmental impacts across all the categories, indicating that its higher removal efficiency compensates for the impacts associated with its production. TPCP had the highest impacts for all categories except human toxicity: carcinogenic, suggesting that its lower removal efficiency exacerbates the environmental burdens when considering its functional performance. The divergence in trends between the mass-normalized and percent removal-normalized results highlights the importance of considering the intended application and functionality of the chitosan particles when assessing their environmental sustainability. While the mass-normalized results provide insights into the inherent environmental impacts of the production process, the percent removal-normalized results offer a more comprehensive understanding of the particles' environmental performance in the context of their pollutant removal capabilities.