A laboratory analysis of eighteen commercial bottled water brands in Ecuador found that 55.6 percent exhibited discrepancies between their declared fluoride content and laboratory-measured levels. The investigation also determined that half of the evaluated brands had pH values at or below 5.5, a critical threshold associated with enamel demineralization. Across the tested products, physicochemical parameters differed significantly.
The research was conducted by investigators across multiple academic institutions in Ecuador, including Universidad UTE, Universidad Católica de Santiago de Guayaquil, and Universidad de las Fuerzas Armadas. Given that bottled water is widely consumed and regional evidence remained limited, the team sought to evaluate whether differing water sources and manufacturing processes alter the physicochemical properties of commercially distributed waters, assessing fluoride concentrations, pH, electrical conductivity, and label concordance.
In their methodology, the authors sampled eighteen commercial bottled water brands available in Ecuador. Laboratory tests measured fluoride concentration in milligrams per liter, pH levels, and electrical conductivity expressed in microsiemens per centimeter. To identify statistically significant differences among brands and examine associations among the measured physicochemical variables, the researchers applied one-way analysis of variance and Spearman rank correlation with a significance threshold established at alpha equal to 0.05.
The laboratory measurements confirmed discrepancies between declared and observed fluoride levels in ten of the eighteen commercial brands. Only two brands had fluoride concentrations within the 0.7 to 1.5 milligrams per liter range recommended by international health organizations for caries prevention: Omizu Sparkling, which measured 0.85 ± 0.07 milligrams per liter, and Aki, which reached 1.45 ± 0.04 milligrams per liter. The researchers observed that Aki approached the maximum safety limit, whereas Omizu Sparkling displayed the highest labeling discrepancy at 325 percent.
Statistical evaluations showed that physicochemical parameters differed significantly across commercial brands with a significance value of p less than 0.01. Fifty percent of the evaluated waters demonstrated pH levels at or below 5.5, indicating potentially erosive properties. Furthermore, the analysis established a statistically significant positive correlation between electrical conductivity and measured fluoride concentrations, yielding a Spearman correlation coefficient of r equal to 0.592 with p less than 0.001.
The authors concluded that commercially available bottled waters in Ecuador predominantly exhibit sub-optimal fluoride levels alongside potentially erosive pH values. In light of the substantial proportion of brands showing inaccurate labeling, the findings emphasize the necessity of stricter regulatory enforcement for commercial label declarations, as well as heightened clinical awareness among dental professionals regarding the physicochemical characteristics of bottled water.
Subject of Research: Physicochemical properties and labeling concordance of commercial bottled waters in Ecuador
Article Title: Fluoride label concordance, pH, and electrical conductivity of commercial bottled waters in Ecuador
Article References: Armas Vega, A., Zambrano Bonilla, M. C., Armas-Vega, F., Chamba Macas, M. F., Urbano Salazar, E., & Carpio-Salvatierra, B. (2026). Fluoride label concordance, pH, and electrical conductivity of commercial bottled waters in Ecuador. Frontiers in Oral Health, 7, Article 2018749. https://doi.org/10.3389/froh.2026.2018749
Image Credits: AI Generated
DOI: 10.3389/froh.2026.2018749
Keywords: bottled water, fluoride concentration, water quality, pH levels, electrical conductivity, labeling concordance, dental health, Ecuador, Fluoride, label, concordance, electrical
