A hydrogel having a floatability where from 40% to 90% of a solution and/or suspension to be thickened are thickened starting from the surface of the liquid and the rest of the solution and/or suspension to be thickened is thickened starting from the bottom of the container, a process for preparing the hydrogel and also its use for absorbing blood and/or body fluids, especially in hygiene articles, or for thickening aqueous solutions and/or suspensions, especially for thickening medical wastes.
