Phosphoric Acid

Phosphoric Acid Chemical formula

💊 Chemical information

Acide phosphorique; Acido Fosfórico; Acidum phosphoricum; Concentrated Phosphoric Acid; E338; Fosfato ru _ gštis; Fosfórico, ácido; Fosforihappo; Fosforsyra; Foszforsav; Kwas fosforowy; Kyselina fosforečná; Orthophosphoric Acid; Phosph. Acid; Phosphorsäure.
Chemical formula: H3PO4 = 98.00.
CAS — 7664-38-2.


Eur. includes various concentrations. Also in USNF.

Ph. Eur. 6.2 (Phosphoric Acid, Concentrated; Phosphoric Acid BP 2008). It contains 84 to 90% w/w of H 3 PO 4 . A clear, colourless, corrosive, syrupy liquid. When stored at a low temperature it may solidify, forming a mass of colourless crystals which do not melt until the temperature reaches 28°. Miscible with water and with alcohol. Store in glass containers.

Ph. Eur. 6.2 (Phosphoric Acid, Dilute). It contains 9.5 to 10.5% w/w H 3 PO 4 and is prepared by mixing phosphoric acid 115 g with water 885 g.

USNF 26 (Phosphoric Acid). It contains 85 to 88% w/w of H 3 PO 4 . A colourless, odourless liquid of syrupy consistency. Miscible with water and with alcohol. Store in airtight containers.

USNF 26 (Diluted Phosphoric Acid). It contains 9.5 to 10.5% w/v H 3 PO 4 and may be prepared by mixing phosphoric acid 69 mL with purified water to 1000 mL. A clear, colourless, odourless liquid. Store in airtight containers.

💊 Adverse Effects and Treatment

As for Hydrochloric Acid.

Toxicity from mixing cleaning agents.

For reference to the adverse effects of mixing phosphoric acid-based and hypochlorite-based cleaning agents see Sodium Hypochlorite.

💊 Uses and Administration

Phosphoric acid has industrial uses. Dilute phosphoric acid has been used well diluted in preparations intended for the management of nausea and vomiting; it has also been included in preparations for vaginal infections. Phosphoric acid is used in dentistry to etch tooth enamel.


Phosphoric acid has been used in homoeopathic medicines under the following names: Acidum phosphoricum; Phosphoricum acidum; Ac. phos.

💊 Preparations

USP 31: Sodium Fluoride and Phosphoric Acid Gel.

Proprietary Preparations

Fr.: Phosoforme†. Multi-ingredient: Arg.: Plus & White†; Austral.: Emetrol†; Braz.: Paratonico; Chile: Homeofortin III†; Fr.: Actiphos†; Biotone†; Ionyl; Marinol; Phosphoneuros; Gr.: Enter-Out; Kathargon; Mineralin; Phospho-Laxat; Phosphoclean; Trifalac; Israel: Peptical; S.Afr.: Emetrol; Emex; Spain: Oximen; Thai.: Quinradon-N; USA: Emetrol; Formula EM; Nausetrol.
Published May 08, 2019.