Potassium bromate (KBrO₃) is a strong oxidizing agent historically used as a flour improver due to its ability to strengthen the gluten network by oxidizing thiol groups (-SH) to disulfide bonds (-SS-), increasing bread volume and crumb structure. This review integrates the physicochemical, toxicological, and regulatory evidence on its use in food. From a chemical standpoint, bromate is thermodynamically unstable at baking temperatures and is reduced to potassium bromide (KBr), which is considered harmless; however, the conversion is incomplete, dependent on process variables (dose, time, temperature, humidity, and pH), and leaves detectable residues in the final product. In vivo experimental evidence demonstrates systemic carcinogenicity in animal models, with the induction of renal adenocarcinomas, peritoneal mesotheliomas, and thyroid tumors; the molecular mechanism involves the generation of reactive oxygen species (ROS), oxidative DNA damage (8-OHdG), and proximal renal tubule necrosis. The International Agency for Research on Cancer (IARC) classifies potassium bromate in Group 2B (possibly a human carcinogen), and the Joint FAO/WHO Expert Committee on Food Additives (JECFA) withdrew its endorsement for use in baking in 1992. Consequently, its use is prohibited in the European Union, the United Kingdom, Canada, Brazil, Argentina, China, India, Nigeria, Sri Lanka, Peru, and Colombia. The United States maintains a divergent position: the FDA retains bromate under the GRAS category according to 21 CFR 172.730, with a limit of 75 ppm in flour, without having revised its status since the 1970s. This persistent US regulation, coupled with documented use in more than two hundred commercial products, constitutes an avoidable risk of chronic dietary exposure, which this review examines in detail. Keywords: Potassium bromate; KBrO₃; carcinogenesis; baking; flour improver; IARC Group 2B; JECFA GRAS; food toxicology; public health; regulation of food additives.