Phosphorous Acid

Airedale Chemical Phosphorous Acid is the compound described by the formula H3PO3. This acid is diprotic in that it readily ionizes two protons not triprotic.

Airedale Chemical Phosphorous Acid is an intermediate in the preparation of other Phosphorus compounds. In solid form Airedale Chemical Phosphorous Acid is a white crystal with a distinctive odour. In solution form Airedale Chemical Phosphorous Acid is a clear to colourless liquid with a distinctive odour.

Phosphorus based flame retardants are easy to process halogen free compounds which offer excellent fire safety performance. They are widely used in plastics, polyurethane foams, coatings, and textiles. Phosphate esters are found in PVC, polycarbonate/ acrylonitrile butadiene styrene (PC/ABS) blends and polycarbonate, and act as good plasticizers e.g. tricresyl phosphate, triphenyl phosphate and dimethylpropane phosphonate. Phosphonates and phosphinates are used in flexible polyurethane foams for automotive and building applications.

Airedale Chemical supply phosphorous acid in 25kg bags for solids and the liquid solutions in 25L, 200L and 1000L IBC’s. For information on how Airedale can become your phosphorus acid supplier get in touch with an expert member of our team today.

Other Names: Dihydroxyphosphine oxide, Dihydroxy(oxo)-λ5-phosphane, Dihydroxy-λ5-phosphanone, Orthophosphorous acid, Oxo-λ5-phosphanediol, Oxo-λ5-phosphonous acid



Grade: TECH

This product is available in the following sizes

  • 25L Drum
  • 200L Drum
  • 1000L Container
  • Bulk Transfer
  • 25kg Bag Solid/Powder only chemicals



Phosphorous acid is used to prepare phosphite salts, such as potassium phosphite, which serve as excellent agricultural fungicides. These salts, in addition to aqueous solutions of pure phosphorous acid, are very effective in controlling a variety of microbial plant diseases. An important and nutritious element in all living species, phosphorous compounds are also applied extensively as fertilizer e.g. phosphites, phosphonates or phosphates

Life Science

Used in chemical reactions as a reducing agent that is somewhat less vigorous than the related Hypophosphorous Acid

Water Treatment

One of the most important use of phosphorous acid is the production of phosphonates for industrial water treatment. Phosphonates are employed as chemical additives to function in a wide range of antiscalants and corrosion inhibitors, because they have high stability in the presence of oxidizing agents e.g. 2-phosphonobutane-1,2,4-tricarboxylic acid.

Oil & Gas

Phosphorus based compounds are used extensively in the oil industry as additives. These chemicals have properties which aid lubrication, oxidation and inflammability. They also have good thermal and cold resistance attributes. e.g. tributyl phosphate, tris(2-ethylhexyl) phosphate

Plastics & Polymers

Phosphorus compounds are used as PVC stabilsers to prevent decomposition and impart enhanced resistance to daylight, weathering and heat ageing. As lead based stablisers are being phased out within Europe, materials such as calcium phosphite are now widely used.

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