Fluoride concentration in table salts sold in the city of Bogotá, Colombia

Objectives: the aim of this study was to determine the fluoride concentration in table salts sold in Bogotá, Colombia, as well as to verify whether the values were consistent with the information provided by the manufacturer and with the standards of the national program of domestic salt fluoridation.
Methods: Twenty one different samples of table salt were purchased in the main supermarkets of Bogotá, comprising coarse, refined and seasoned salts. Samples were analyzed by the direct method (n=15) or by hexamethyldisiloxane-facilitated diffusion (n=6), using an specific ion electrode (9409 BN-Orion, USA), coupled to an ion analyzer (Orion 720 A, Orion, USA). Electrodes were calibrated with standards containing 0.5 to 20 µg F for direct method and 0,13 to 17,07 µg F for hexamethyldisiloxane-facilitated diffusion method. Analyses were performed in triplicate and data were submitted to descriptive statistical analysis.
Results: Mean (SD) fluoride concentration for all samples was 135.9 (43.8) ppm F, ranging from 4.1 to 209.8 ppm F. The majority of samples (95%) had values below those recommended for fluoridated salt program in Colombia (180-220 ppm F). Mean (SD) fluoride concentration in seasoning-containing samples was 101.5 (50.6), ranging from 4.1 to 163.5ppm F, despite this information was not reported on the labels. Fluoride concentrations for the 2 brands of low-sodium salts were 88.2 and 94 ppm F.
Conclusions: Most of the salts analyzed did not comply with the fluoride concentration norm for salt consumption in Colombia. Therefore, monitoring of the fluoride concentrations in salts for human consumption should be performed on a regular basis, so that fluoride levels are kept at safe and effective levels for caries control.