Comparação do teor de cloro ativo em diferentes marcas de água sanitária comercializadas em Goiânia e região

Abstract

Household bleach (“água sanitária”) is a widely used disinfectant whose effectiveness depends on maintaining an active chlorine content between 2.0% and 2.5% (w/w), as required by Brazilian legislation. This study aimed to determine and compare the active chlorine content and pH of five commercial brands sold in Goiânia and surrounding areas (Ypê, Qboa, Ki Joia, Zupp, and Geo), evaluating their compliance and stability over four months of storage (April to July 2026). Active chlorine was determined by the iodometric method (ABNT NBR 9425:2005) and pH by potentiometry. Initial contents ranged from 2.14% to 2.26%, with a progressive reduction of 3.20% to 7.96% by the end of the period, with no sample falling below the minimum regulatory limit. ANOVA indicated a difference between manufacturing-year groups (2025 and 2026) close to the significance threshold (F = 3.84; p = 0.066), suggesting an influence of manufacturing time on stability. pH ranged from 11.90 to 12.31, with a slight and similar decrease across all brands. It is concluded that the products met the minimum quality requirements, reinforcing the importance of controlling storage and distribution conditions