Environmental scientists urge caution, viewing sucralose as a highly persistent pollutant. Because of its chlorinated structure—eerily similar to persistent 'forever chemicals'—the molecule resists standard wastewater treatment. It flows virtually unchanged into rivers and oceans. Once in the aquatic food chain, it causes behavioral and metabolic changes in marine life, suggesting that our collective desire for zero-calorie sweetness is quietly rewriting the chemistry of our wild waters.