Sodium Hypophosphite Monohydrate NaH₂PO₂

Sodium hypophosphite monohydrate (NaH₂PO₂·H₂O) is an odorless white crystalline solid, readily soluble in water and deliquescent, supplied lab grade. It is a strong reducing agent toward metal ions and is stable under normal conditions, though reactive with strong oxidizers.

Its principal industrial role is as the reducing agent in electroless nickel-phosphorus plating, depositing uniform, corrosion and wear resistant coatings on metals, plastics and ceramics, including complex shapes that electroplating cannot reach evenly. It is also used in organic synthesis, in polymer stabilization and as a phosphorus source in specialty chemical work.