Antimony trioxide is an inorganic compound with the formula Sb2O3. It appears white in color and it is an odourless white crystalline powder, sparingly soluble in water. It is the most important compound prepared from antimony. It is found in nature and extracted from the minerals valentinite and senarmontite. Antimony trioxide dissolves in aqueous solutions only with hydrolysis. Antimony trioxide is an amphoteric oxide and it exhibits redox nature, it can be readily oxidized to antimony pentoxide and related antimony (V) compounds, but it is also easily reduced to antimony, sometimes with production of stibine.

Typical applications for antimony trioxide includes flame retardant synergist for use in plastics, rubber, paints, paper, textiles, and electronics; polyethylene terephthalate polymerization catalyst this PET bottles are used as best containers for beverages, a clarifying agent for glass, an opacifier for porcelain and enamel and a white pigment for paint. When used as flame retardant, antimony trioxide is often used in combination with halogenated compounds. It is also used in vulcanization of rubber. Antimony Trioxide can be used as an additive in glass and ceramic products; it is also used as flocculent in Titanium Dioxide production.

Antimony Trioxide is mainly produced by the process called smelting of stibnite ore, which is oxidized to crude Sb2O3 using furnaces operating at approximately 850° C to 1,000° C. Crude Sb2O3 is purified by sublimation, which allows it to be separated from the more volatile arsenic trioxide.


There is wide spectrum of flame retardants, among this Antimony trioxide is the most excellent compound. It’s increased Fire Safety Ensures high levels of fire safety and it also immensely increases flame retardant effectiveness. Actually this compound does not react as flame-retardants directly instead is used as synergists to enhance the activity.

There are several classes of flame retardants, among this Antimony trioxide is the best compound. Antimony Trioxide (ATO) provides unique properties not easily obtained through other products when applied in a variety of industrial processes. Increasing Fire Safety Ensuring high levels of fire safety. ATO greatly increases flame retardant effectiveness. Flame Retardant are substances that can be chemically inserted into the polymer molecule or be phisically blended in polymers after polymerization to suppress, reduce, delay or modify the propagation of a flame through a plastic materials. Antimony trioxide does not react as flame-retardants directly. Antimony Trioxide are used as synergists to enhance the activity of halogenated flame-retardants by stepwise releasing the halogenated radicals to retard gas phase chain reaction of flame spread. Many industries use antimony as a flame retardant synergist including but not limited to the plastics, textiles, rubber, paper, and paint industries. Antimony Trioxide can be used as an appropriate synergist for flame retarding polyvinyl chloride (PVC), polypropylene (PP), high impact polystyrene (HIPS), polyethylene (PE), ethylene propylene diene rubber (EPDM), acrylonitrile butadiene styrene (ABS), epoxies, phenolic, polyurethanes, and many others. Apart from this antimony trioxide and other antimony compounds also used as flame retardant.

The Leading Catalyst for Manufacture of polyethylene terephthalate (PET Plastics) ATO is the major catalyst for the production of PET plastic used in the packaging of mineral water and soft drinks. PET is one of the best materials for plastic bottles, with a history of safe use by millions of consumers every day. ATO’s safe use in the production of PET bottles has been confirmed by the World Health Organisation (2003) and the European Food Safety Authority (2004). The use of ATO as a catalyst in PET bottles does NOT impact the safety of the beverages.

Antimony trioxide can also be used as a fining agent or as degasser in the manufacturing of glass.It is added to the glass melt to remove bubbles from the solution. Many specialty glass companies use antimony trioxide for this purpose.

Antimony trioxide is used as an opacifier for porcelain and enamel and a white pigment for paint. Antimony oxide is a white crystalline powder so as a result it can be used as a white pigment for paint; it is sometimes used with other materials to form yellow pigments. It is also used in vulcanization of rubber. Antimony Trioxide can be used as an additive in glass and ceramic products and as a catalyst in the chemical industry. It is also used as flocculent in Titanium Dioxide production  and ingredient in ZnO varistors


Antimony trioxide has suspected carcinogenic potential for humans. Occupational exposure may occur during mining, processing and smelting of antimony ores, in glass and ceramics production, and during the manufacture and use of products containing antimony trioxide.


    Spcification Typical
Antimony Oxide Minimum 99.5% 99.5%
Antimony (Sb) Minimum 83.3% 83.3%
Arsenic (As) Maximum 0.2% 0.075%
Lead (Pb) Maximum 0.1% 0.050%
Iron (Fe) Maximum 0.002% < 0.0004%
Selenium Maximum 50 ppm < 50ppm
Specific Gravity Maximum 5.2-5.6 5.2-5.6
Average Particle Size FSSS(microns)   1.1-1.8 1.2-1.6
Color   Excellent White  
Residue on 325 mesh (% max/min)   0.5% < 0.1%
Weight per cubic ft. (approx)   44 to 55 lbs  
Antimony Oxide Safety Data Sheet
Product Identification
CAS No. 1309-64-4
EINECS 2151750
Synonims antimony trioxide, antimony(III) oxide
DENSITY 5.2.-5.7 g/cm3
VAPOR PRESSURE 0.406 mmHg at 550°C
VAPOR DENSITY (Air = 1) Not available.
SOLUBILITY IN H2O .001g/100ml @25°C
APPEARANCE AND ODOR White, crystalline powder; odorless.
Thermal Decomposition: None expected.
Conditions Contributing To Instability: None expected
Incompatibility: Avoid contact with acids, bases, reducing agents; toxic products of reaction may be generated.
Hazardous Decomposition Products: None expected.None expected.