Parabens are used as preservatives in sanitizers and cosmetic products causing environmental concern, because presented potential as endocrine disrupters. Among these compounds, the most used are methylparaben and propylparaben. Thus, a study was proposed to evaluate the interaction between different concentrations (mmol L-1) of the variables methylparaben [MP] and propylparaben [PP], against the acute toxicity of the microcrustacean Artemia salina (A. salina) and Allium cepa (A. cepa) applying the 22 factorial design with an added center point. Responses were used: percent A. salina mortality (% mortality), A. cepa root growth inhibition (% root inhibition) and mitotic index (%MI). For A. salina, after 72 hours of exposure with the combina...