Sodium hypophosphite

Sodium hypophosphite (NaPO₂H₂) is the sodium salt of hypophosphorous acid. It is a solid at room temperature, appearing as odorless white crystals. It is soluble in water, and easily absorbs moisture from the air.

Sodium hypophosphite should be kept in a cool, dry place, isolated from oxidizing materials. It decomposes when heated and produces toxic phosphine gas, causing irritation to the respiratory tract.

Uses

Sodium hypophosphite is mainly used for electroless nickel-plating. With this method, a durable nickel-phosphorus film can coat objects with irregular surfaces, and can widely be used ionics, aviation and the petroleum field.

It also can be used as a food additive.

DEA List I status

The United States Drug Enforcement Administration designated sodium hypophosphite as a List I chemical under 21 CFR 1310.02 effective November 17, 2001, specifically mentioning the compound together with several other salts of hypophosphorous acid.