Phosphorous acid (H3PO3) CAS:13598-36-2 is an inorganic compound that, although less common than phosphoric acid (H3PO4), has many important uses in industry, agriculture and chemistry. The following are its main applications:

1. Agriculture

-Fertilizer additives and fungicides

Phosphorous acid and its salts (such as potassium phosphite, sodium phosphite) are widely used as fungicides to control crop diseases (such as late blight, downy mildew). It works by activating the plant's natural defense mechanism (inducing disease resistance) and providing phosphorus to promote plant growth.

-Efficient phosphorus source

Phosphite can be gradually converted into phosphate through oxidation and absorbed by plants, especially as a supplement to slow-release phosphate fertilizer in phosphorus-deficient soils.

2. Chemical industry

-Reductant

Phosphorous acid has strong reducing properties and is used in chemical synthesis to reduce metal ions (such as reducing gold and silver ions to elements) or remove oxides.

-Organic synthesis intermediates

Used to produce phosphites (such as triethyl phosphite), which are further synthesized into pesticides, flame retardants, plastic additives, etc. For example, phosphite derivatives may be involved in the synthesis of glyphosate (herbicide).

3. Water treatment

-Corrosion inhibitors and scale inhibitors

Phosphite can inhibit the corrosion of metal pipes and equipment, prevent the deposition of calcium, magnesium and other scale layer, often used in cooling water system and boiler water treatment.

4. Other uses

-Flame retardant materials

Phosphite derivatives can be added to plastics and rubber as flame retardants, which can slow down combustion by promoting the formation of carbonized layer.

-Electroplating and surface treatment

Used for metal surface treatment, enhance the adhesion and corrosion resistance of the coating.

-Laboratory reagents

As a component of an analytical reagent or buffer solution.

Attention

-Stability: Phosphorous acid is easily decomposed under heating or alkaline conditions to produce phosphoric acid and highly toxic phosphine (PH3), which should be stored and used with caution.

-Toxicity: It is irritating to skin and mucous membranes. Protective equipment should be worn during operation.

The versatility of phosphorous acid CAS:13598-36-2 makes it indispensable in a number of industries, especially in agriculture and fine chemicals.