Abstract: The present invention relates to a boron-containing aqueous solution comprising at least one amino compound and/or one organic polyhydroxylated compound, characterized in that: it comprises a theoretical amount of B2O3 of between 25 and 55% by weight, at least one solubilized complex between at least one boron-containing product and the amino compound and/or one organic polyhydroxylated compound, and optionally at least one biocide and/or one antifoam and/or one anionic or non-ionic surfactant, it is obtained from at least one initial boron-containing solute consisting of a mixture of at least one borate, boric acid and/or B2O3 and optionally at least one strong base, and its pH is between 6 and 9. Application: Addition to starch paste, brightening products or biocides and for the decontamination of radioactive materials, inter alia.