Aluminium hydroxide, Al(OH)3, is found in nature as the mineral gibbsite (also known as hydrargillite) and its three much rarer polymorphs: bayerite, doyleite, and nordstrandite.

The waste solid, bauxite tailings, is removed and aluminium hydroxide is precipitated from the remaining solution of sodium aluminate.

While the mud was considered non-toxic due to low levels of heavy metals, the associated slurry had a pH of 13.

[13][14][15][16][17] These mixtures start to decompose at temperatures around 180 °C (356 °F) to 220 °C (428 °F) (depending on the type of aluminium hydroxide used), absorbing a considerable amount of heat in the process and giving off water vapour.

[18] In addition to behaving as a fire retardant, it is very effective as a smoke suppressant in a wide range of polymers, most especially in polyesters, acrylics, ethylene vinyl acetate, epoxies, polyvinyl chloride (PVC) and rubber.

[12] Under the generic name "algeldrate", aluminium hydroxide is used as an antacid in humans and animals (mainly cats and dogs).

Such products can cause constipation, because the aluminium ions inhibit the contractions of smooth muscle cells in the gastrointestinal tract, slowing peristalsis and lengthening the time needed for stool to pass through the colon.

[23] This compound is also used to control hyperphosphatemia (elevated phosphate, or phosphorus, levels in the blood) in people and animals suffering from kidney failure.

The aluminium salt, when ingested, binds to phosphate in the intestines and reduce the amount of phosphorus that can be absorbed.

[citation needed] Vaccine formulations containing aluminium hydroxide stimulate the immune system by inducing the release of uric acid, an immunological danger signal.

However, it has little capacity to stimulate cellular (Th1) immune responses, important for protection against many pathogens,[28] nor is it useful when the antigen is peptide-based.