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Sodium tetraborate

CAS Number
1330-43-4
EC Number
215-540-4
Chemical Formula
B4Na2O7
Molecular Weight
201.2 g/mol

Description

Sodium tetraborate ( CAS 1330-43-4 ), also known by its E-number E285 , is the anhydrous form of borax — a mineral salt used across industrial and food-contact applications as a preservative and buffering agent. It also functions as a flame retardant and cleaning booster. Its anhydrous form offers a higher boron content and lower moisture contribution compared to hydrated grades, which matters for formulators managing water activity. In building and construction, it is applied to wood treatments and insulation materials to provide flame retardancy and resistance to fungal degradation. Textile and leather processors use it in bath formulations to control pH. This chemical helps improve the uptake of dyes and finishing agents. Water treatment operations rely on it as a buffering compound to stabilize pH in industrial process water, ensuring consistent chemical reactions. At permitted levels under the E285 designation, it functions as a preservative in certain food contact and packaging applications in regulated markets. Sodium tetraborate anhydrous is supplied as a white powder. It is also available as fine granules. Standard commercial grades include technical and food-grade specifications, with purity typically at 99% or higher. Packaging ranges from 25 kg bags to bulk quantities. Contact us for supply of Sodium tetraborate Request Quote

Other Names (Synonyms)

sodium borate anhydrous | disodium tetraborate, anhydrous | anhydrous borax | Boron sodium oxide (B4Na2O7) | Borax glass | Sodium Tetraborate, Anhydrous | Sodium biborate | Borax Anhydrous | E285

Key Technical Features

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

Physical Properties

Melting Point741 °C
Boiling Point1571 °C
Density2.367 g/cm³
Flash Point1575°C
AppearanceBorax is a noncombustible (an inherent fire retardant), bluish-gray or green, odorless crystalline powder or granules.
ColorWhite
FormSolid
Water Solubility26 g/L (20 ºC)
Vapor Pressure7.3 hPa (1200 °C)
Refractive Index1.501
pH9.0-10.5 (25℃, 0.1M in H2O)

Safety & Handling

Danger
GHS08· Health HazardGHS07· Irritant

Hazard Statements

H302Harmful if swallowed
H315Causes skin irritation
H319Causes serious eye irritation
H320Causes eye irritation
H335May cause respiratory irritation
H360May damage fertility or the unborn child
H370Causes damage to organs
H372Causes damage to organs through prolonged or repeated exposure
H373May causes damage to organs through prolonged or repeated exposure
H402Harmful to aquatic life
H412Harmful to aquatic life with long lasting effects

Precautionary Statements

P203Obtain, consult and follow expert instructions for use.
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.
P273Avoid release to the environment.
P280Wear protective gloves/protective clothing/eye protection/face protection.
P318IF exposed or concerned, get medical advice.
P319Get medical advice/attention if you feel unwell.
P321Specific treatment (see … on this label).
P330Rinse mouth.
P405Store locked up.
P501Dispose of contents/container in accordance with local regulations.
P265Wash … thoroughly after handling.
P317Get emergency medical help.
P352IF ON SKIN: Wash with plenty of water.
P340IF INHALED: Remove person to fresh air and keep comfortable for breathing.
P316Get emergency medical help immediately.
P317Get emergency medical help.
P317If eye irritation persists: Get medical advice/attention. Get emergency medical help.
P364Take off contaminated clothing and wash it before reuse.
P233Store in a well-ventilated place. Keep container tightly closed.
P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.

Trade & Regulatory

HS Code28401100
UN Number1760
ADR Class8
Packing GroupII
Storage Class6.1D - Non-combustible acute toxic Cat.3 toxic hazardous materials or hazardous materials causing chronic effects
WGK (Germany)1