What is Antimony?

Antimony is a chemical element with the symbol Sb and atomic number 51. It is a semimetallic element that exists in two forms: a metallic form, which is bright, silvery, hard, and brittle, and a non-metallic form, which is a grey powder. Antimony is a poor conductor of heat and electricity and is stable in dry air, showing resistance to dilute acids and alkalis. Some alloys of antimony expand upon cooling.

What is Antimony used for?

Alloys and Batteries: Antimony is used in lead storage batteries, solder, sheet and pipe metal, motor bearings, and castings.
Semiconductors: It is used in semiconductors and as an alloy in certain electronics.
Flame Retardants: Antimony oxide is added to textiles, plastics, rubber, adhesives, pigments, and paper to prevent combustion.
Other Uses: It is also used in ceramics, paints, ammunition, fireworks, and enamels for plastics, metal, and glass.
Medical Uses: Some antimony compounds have medical applications.

Sources of Emission and Routes of Exposure

Sources of Emission

• Industry: Antimony oxides can be released as a by-product of smelting lead and other metals (emissions to air, land, or water), as well as from coal-fired power plants.
• Diffuse Sources: Emissions can come from refuse incinerators, small industrial facilities, and the burning of fossil fuels.
• Natural Sources: Antimony occurs naturally in the earth's crust, and volcanoes can release antimony oxides. It is also common in coal and petroleum.
• Transport Sources: Vehicle exhaust contributes to emissions of antimony.
• Consumer Products: Antimony is found in various consumer products like plastics, textiles, rubber, adhesives, pigments, and paper, as well as in alloys used in solder, sheet, and pipe metal.

Routes of Exposure

• Air, Water, and Food: General exposure occurs through food, drinking water, and air containing low levels of antimony.
• Occupational Exposure: Higher levels of exposure can occur for workers in industries that process or use antimony ore.
• Polluted Areas: Areas with high levels of antimony may lead to exposure through air, water, and soil.

Health Effects

Acute Effects

Inhalation: Skin and eye effects, such as "antimony spots" (rash around sweat glands) and ocular conjunctivitis, have been reported.

Oral Exposure: Can result in gastrointestinal effects.

Animal Studies: High exposure levels have shown effects on the lungs, cardiovascular system, and liver.

Chronic Effect

Respiratory Effects: Chronic exposure can cause antimony pneumoconiosis, chronic bronchitis, and pleural adhesions.

Cardiovascular Effects: Includes increased blood pressure and heart muscle damage.

Gastrointestinal Disorders: Long-term exposure can lead to gastrointestinal issues.

Animal Studies: Effects on the respiratory, cardiovascular, and kidney systems. Oral exposure in animals has shown blood, liver, CNS, and gastrointestinal effects.

EPA Reference Concentration (RfC): For antimony trioxide, it is 0.0002 mg/m³ based on respiratory effects in rats.

Reference Dose (RfD): 0.0004 mg/kg/day for antimony based on longevity, blood glucose, and cholesterol levels in rats.

Reproductive/Developmental Effects

• Spontaneous Abortions: Increased incidence of spontaneous abortions in women working in antimony plants.
• Menstrual Disturbances: Reported in women exposed to antimony compounds.
• Animal Studies: Decreased offspring in rats exposed to antimony before conception and during gestation.

Cancer Risk

• Human Studies: Inhalation exposure did not affect cancer incidence in workers.
• Animal Studies: Lung tumors were observed in rats exposed to antimony trioxide.
• EPA Classification: Antimony is not classified for carcinogenicity.

Antimony Safety

First Aid Measures

• Eye Contact: Immediately flush eyes with water for 15 minutes and seek medical attention.
• Skin Contact: Wash skin with water, remove contaminated clothing, and seek medical attention.
• Inhalation: Move to fresh air, provide artificial respiration or oxygen if necessary, and seek medical help.
• Ingestion: Do not induce vomiting unless directed by medical personnel. Seek medical attention immediately.

Exposure Controls & Personal Protection

Engineering Controls

Use process enclosures or local exhaust ventilation to maintain airborne levels below recommended exposure limits.

Use ventilation to control dust, fume, or mist exposure.

Personal Protective Equipment (PPE)

• Routine PPE: Splash goggles, lab coat, dust respirator, gloves.
• Large Spill PPE: Full suit, dust respirator, boots, gloves, self-contained breathing apparatus. Consult a specialist before handling this product.

Regulation

United States

Australia

Safe Work Australia has set an eight-hour time weighted average (TWA) exposure limit for antimony of 0.5 mg/m3 

Australian Drinking Water Guidelines (NHMRC and ARMCANZ, 1996):

Maximum of 0.003 mg/L (i.e. 0.000003 g/L)