Phosphorous acid [H3PO3] — Ingredient sheet

Phosphorous acid [H3PO3]

Inorganic phosphorus acid that forms phosphite (phosphonate) ions in water.

Characteristics

• Partially oxidized form of phosphorus, unlike fully oxidized phosphoric acid (H3PO4).
• Diprotic acid: only two of its three hydrogens are acidic.
• Plants absorb phosphite but do not convert it into phosphate.
• Trials indicate phosphite does not replace phosphate as a phosphorus nutrient.

Role in the preparation: In a solution it acts as an acidifying agent and a source of phosphite ions; it does not replace phosphate as a nutrient phosphorus supply.

Caution: Corrosive acid: wear gloves and goggles, store dry and closed, and check your country's specific regulations before any use, as its status differs from that of fertilisers.

Sources: University of Florida IFAS Extension – HS254: Phosphorous acid and its derivatives

Documentary information: this is neither a recommendation for use nor a plant-protection or veterinary claim. Check your country's regulations before any use.