HomeProducts

Hypophosphorous acid

CAS Number
6303-21-5
EC Number
228-601-5
Chemical Formula
H3O2P
Molecular Weight
65.996 g/mol

Description

Hypophosphorous acid (CAS 6303-21-5 ), also known as phosphinic acid and commonly abbreviated as HPA, is a reducing acid used across chemical manufacturing, surface treatment, and stabilization processes. It functions primarily as a strong reducing agent and antioxidant, preventing oxidative degradation in sensitive formulations and enabling metal deposition in industrial finishing applications. In electroless nickel plating, HPA serves as the reducing agent that drives metal deposition onto non-conductive substrates, making it a process-critical input for electronics and precision component manufacturing. Pharmaceutical manufacturers use it to prevent discoloration and oxidative breakdown in active ingredient formulations during production and storage. It ensures the stability of sensitive chemical compounds. In textile and leather processing, it controls unwanted oxidation during dyeing and finishing operations, improving color consistency and product shelf life for high-quality consumer goods. Water treatment applications rely on HPA for pH regulation and as a reducing agent to manage dissolved oxygen and metal ion activity in complex industrial process water systems. Hypophosphorous acid is supplied as an aqueous solution, with 50% concentration being the most commercially standard grade. Technical and industrial grades are the primary market offerings for most users. Pharmaceutical-grade material is available to meet stricter purity requirements for drug manufacturing applications. Bulk liquid supply in IBC containers and drums is the typical packaging format for buyers. Contact us for supply of Hypophosphorous acid Request Quote

Other Names (Synonyms)

phosphinic acid | Acid, Phosphinic | RefChem:929168 | 8B1RL9B4ZJ | Hydroxyphosphine oxide | Phosphine oxide, hydroxy- | Phosphonous acid | HPA

Key Technical Features

  • High Purity Grade standard
  • Consistent Batch Quality
  • Full Regulatory & REACH Support
  • Global Logistics Network enabled

Physical Properties

Melting Point26.5 °C
Boiling Point108 °C (759.8513 mmHg)
Density1.479 g/cm³ @ Temp: 20 °C
Appearancecolourless liquid
ColorColorless
Formhygroscopic crystals or colorless oily liquid
Water SolubilitySOLUBLE
Vapor Pressure<17 mmHg ( 20 °C)
pHpKa1= 1.00(25℃)

Safety & Handling

Danger
GHS05· Corrosive

Hazard Statements

H290May be corrosive to metals
H314Causes severe skin burns and eye damage
H318Causes serious eye damage

Precautionary Statements

P234Keep only in original packaging.
P260Do not breathe dust/fume/gas/mist/vapours/spray.
P264Wash … thoroughly after handling.
P280Wear protective gloves/protective clothing/eye protection/face protection.
P316Get emergency medical help immediately.
P317Get emergency medical help.
P321Specific treatment (see … on this label).
P363Wash contaminated clothing before reuse.
P390Absorb spillage to prevent material damage.
P405Store locked up.
P406Store in a corrosion-resistant/… container with a resistant inner liner.
P501Dispose of contents/container in accordance with local regulations.
P265Wash … thoroughly after handling.
P340IF INHALED: Remove person to fresh air and keep comfortable for breathing.
P331Rinse mouth. Do NOT induce vomiting.
P354IF ON SKIN: Take off immediately all contaminated clothing. Rinse skin with water/shower.
P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.

Trade & Regulatory

HS Code28111990
UN Number3264
ADR Class8
Packing GroupIII
Storage Class8B - Non-combustible corrosive hazardous materials
WGK (Germany)1