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Inorganic Acids REACH

Phosphonic acid

CAS Number
13598-36-2
EC Number
237-066-7
Chemical Formula
H3O3P
Molecular Weight
81.996 g/mol
Industries:Water TreatmentTextile, Leather & PaperPharmaceuticals & HealthcareAgriculture & Feed

Description

Phosphonic acid (CAS 13598-36-2 ) is an inorganic phosphorus-based acid used industrially as a pH regulator, reducing agent, and stabilizer across water treatment, agriculture, and specialty chemical manufacturing. Its reducing character makes it effective in processes requiring controlled acidic conditions without introducing strong oxidizing byproducts. In water treatment, it functions as a pH adjustment agent and scale-inhibition precursor. It supports corrosion control programs in industrial cooling and boiler systems. Textile and paper processors use it to manage bath acidity during dyeing and bleaching operations, where consistent pH control directly affects product quality. In agriculture, it serves as a building block or acidulant in formulating phosphonate-based fungicides and fertilizer adjuvants. Pharmaceutical manufacturers use it as a reagent and intermediate in synthesizing active pharmaceutical ingredients. These applications require controlled reducing conditions. Phosphonic acid is supplied as an aqueous solution, with concentration typically ranging around 50% by weight for industrial use. Technical grade is the standard commercial offering, though higher-purity specifications are available to meet pharmaceutical intermediate requirements. Packaging options typically include drums and intermediate bulk containers. Contact us for supply of Phosphonic acid Request Quote

Other Names (Synonyms)

RefChem:6132 | Phosphorus trihydroxide | Dihydroxyphosphine oxide | Phosphorous acid

Key Technical Features

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

Physical Properties

Melting Point~73 °C (approx)
Boiling Point200 °C
Density1.651 g/mL at 25 °C(lit.)
Flash Point200°C
Appearancewhite crystalline solid
ColorWhite
FormCrystals
Water SolubilitySOLUBLE
Vapor Pressure0.001Pa at 20℃
pHpKa1= 1.10, pKa2 = 6.33(25℃)

Safety & Handling

Danger
GHS05· CorrosiveGHS07· Irritant

Hazard Statements

H290May be corrosive to metals
H302Harmful if swallowed
H314Causes severe skin burns and eye damage
H318Causes serious eye damage
H335May cause respiratory irritation

Precautionary Statements

P234Keep only in original packaging.
P260Do not breathe dust/fume/gas/mist/vapours/spray.
P261Avoid breathing dust/fume/gas/mist/vapours/spray.
P264Wash … thoroughly after handling.
P270Do not eat, drink or smoke when using this product.
P271Use only outdoors or in a well-ventilated area.
P280Wear protective gloves/protective clothing/eye protection/face protection.
P316Get emergency medical help immediately.
P317Get emergency medical help.
P319Get medical advice/attention if you feel unwell.
P321Specific treatment (see … on this label).
P330Rinse mouth.
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.
P317Get emergency medical help.
P340IF INHALED: Remove person to fresh air and keep comfortable for breathing.
P233Store in a well-ventilated place. Keep container tightly closed.
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 Code28092019
UN Number2834
ADR Class8
Packing GroupIII
Storage Class8A - Combustible corrosive hazardous materials
WGK (Germany)1