Antimony Trioxide Profile


CAS No. 1309-64-4
IARC Monograph Vol. 47, 1989 (Group 2B)

Antimony Trioxide Profile

General Information

Antimony trioxide (Sb2O3) is a slightly soluble, white crystalline powder.[1] It is produced by smelting antimony-containing ores[1] or reacting antimony trichloride with water.[2] Antimony is not abundant in the earth’s crust.[3] Antimony trioxide may also be referred to as diantimony trioxide (DAT), antimony oxide, or in manufacturing as antimony white.[4] There are numerous other synonyms and product names; see the Hazardous Substances Data Bank (HSDB) for more information.[4]

Antimony trioxide was last classified by the International Agency for Research on Cancer (IARC) in 1989 as Group 2B, possibly carcinogenic to humans, based on inadequate evidence in humans and sufficient evidence in animals.[1] Antimony trioxide is a respiratory carcinogen in female rats.[1]

The epidemiological literature on exposure to antimony trioxide is not extensive and is limited by difficulty in controlling for confounding variables. Recent reviews of studies report excesses of lung cancer in antimony exposed smelter workers, but factors such as smoking, exposures to PAHs and other metals (e.g. arsenic), were not appropriately controlled.[2,5]

Antimony trioxide has also been linked to pneumoconiosis, bronchitis, and airway inflammation.[3] Digestive and neurologic symptoms have been reported from high levels of exposure, but causal relationships have not been established.[3] An early study reported that exposure is associated with an increase in spontaneous abortions, premature birth, and slow growth rates in offspring.[6] The study’s control of confounding variables and exposure assessment techniques, however, were unclear.[7]

Regulations and Guidelines

Occupational exposure limits (OEL)[8,9,10,11,12,13,14,15,16,17,18,19,20,21,22]

Canadian Jurisdictions Substance OEL (mg/m3)
Canada Labour Code Sb2O3, production
Sb & its compounds
AB Sb2O3, production
Sb & its compounds
BC, MB, ON, NB, NL, PEI, NS Sb2O3, production
Sb & its compounds
SK, NT, NU Sb2O3
Sb & its compounds
0.5; 1.5 [stel]
QC Sb2O3
Sb & its compounds
Sb2O3 production (as SB)
YT Sb2O3 production (as SB) 0.5 
0.5; 0.75 [stel]
Other Jurisdictions Substance OEL (mg/m3)
ACGIH 2020 TLV Sb2O3, production
Sb & its compounds
mg/m3 = milligrams per cubic meter
ALARA = as low as reasonably achievable
stel = short term exposure limit (15 min. maximum)
ACGIH = American Conference of Governmental Industrial Hygienists
TLV = threshold limit value

Canadian environmental guidelines and standards*

Jurisdiction Limit Year
Canadian and Ontario Drinking Water Guidelines
0.006 mg/L 2017[23]
BC’s Contaminated Sites Regulation, BC Reg 375/96 Sets soil standards for the protection of human health for antimony:
Agricultural and low density residential sites: 250 μg/g
Urban park and high density residential sites: 500 μg/g
Commercial sites: 1,500 μg/g
Industrial sites: 40,000 μg/g


Drinking water: 6 μg/L

Ontario Ambient Air Quality Criteria Annual: 0.12 µg/m3
24-hour: 0.6 µg/m3
Ontario’s Air Pollution – Local Air Quality Regulation Standards 24-hour standard: 25 µg/m3; Prohibited discharge into the air if the concentration of antimony trioxide exceeds the standard 2020[27]
Quebec’s Clean Air Regulation 1 year limit: 0.17 µg/m3 (antimony, metal and compounds); Prohibited discharge into the air if the concentration of antimony trioxide exceeds the standard 2011[28]
*Standards are legislated and legally enforceable, while guidelines (including Ontario ambient air quality criteria) describe concentrations of contaminants in the environment (e.g. air, water) that are protective against adverse health, environmental, or aesthetic (e.g. odour) effects

Canadian agencies/organizations

Agency Designation/Position Year
Health Canada DSL – high priority substance
(greatest potential for exposure)
Challenge to Industry Batch 9 2010[30]
National Classification System for Contaminated Sites Rank = “High hazard”, potential human carcinogen (antimony) 2008[31]
Cosmetic Ingredient Hotlist Not permitted 2004[32]
PMRA List of formulants List 4B: List 4B contains formulants, some of which may be toxic, for which there are sufficient data to reasonably conclude that the specific use pattern of the pest control product will not adversely affect public health and the environment 2018[33]
Environment Canada’s National Pollutant Release Inventory NPRI Part (Threshold Category): 1A, Reportable to NPRI if manufactured, processed, or otherwise used at quantities greater than: 10 tonnes (for antimony and its compounds) 2016[34]
DSL = domestic substance list

Antimony trioxide was not included in other Canadian government guidelines, standards, or chemical listings reviewed.


Main Uses

Antimony trioxide is mainly used as a chemical synergist in chlorinated and brominated flame-retardants, increasing the retardants’ effectiveness.[35] Flame retardants containing antimony trioxide are used widely in producing textiles, plastics, rubber, and paints.[1]

Antimony trioxide is the main catalyst used to produce polyethylene terephthalate (PET) and polyester fibers. PET is commonly used in plastic packaging for water and soft drinks.[35] It is also used as a pigment and/or clarifying agent in certain glasses and ceramics.[36] As of 1995, antimony trioxide gained popularity as an additive in optical glass, replacing arsenious oxide.[37]

Antimony metal increases hardness and strength in lead alloys and is used in lead storage batteries, solder, sheet and pipe metal, bearings, castings, and pewter.[3] Antimony trioxide is produced when elemental antimony is heated and/or oxidized.[3]

Canadian Production and Trade

Antimony trioxide is primarily used to create household flame retardants and plastic (polyethylene terephthalate).[38]

Antimony is naturally occurring in the Cordilleran (west coast) and Appalachian (east coast) regions of Canada.[39] Approximately 401 tonnes of antimony is mined in Canada annually, and it is considered a “critical mineral for the economic success of Canada”.[39,40] China, Belgium and France are the highest exporters globally, each exporting over 10,000 tonnes annually.[41]

At full capacity, Beaver Brook Antimony Mine Inc. in Newfoundland will mine approximately 160,000 tones of antimony per year.[42,43] Operations were temporarily suspended in November 2020 due to the COVID-19 pandemic however mining resumed at the end of September 2021.[42]

Production and trade

Activity Quantity Year
Canadian Production 76 t 2013[44]
Export: 109 t (of ‘antimony oxides’) 2021[45]
Import: 2,395 t (of ‘antimony oxides’) 2021[45]
t = tonne

Environmental Exposures Overview

The main source of exposure to antimony trioxide for the general population is through dermal contact with household items that contain flame retardants, such as paint, mattress covers and furniture upholstery.[46] However, Environment Canada reports that exposures from this pathway are low.[46]

Other sources of environmental exposure include food, drinking water, and air.[3,46] Overall, levels of antimony trioxide in water are low due to its poor solubility in water.[46] Higher levels of exposure may occur around smelters, incinerators, and near combustion of petroleum and coal products.[3] Higher levels of exposure to antimony trioxide have also been associated with smokers and those exposed to secondhand smoke.[47]

Searches of Environment Canada’s National Pollutant Release Inventory (NPRI) and the US Consumer Product Information Database yielded the following results on current potential for exposure to antimony trioxide in Canada:

NPRI and US Consumer Product Information Database

NPRI 2015[48]
Substance name: ‘Antimony and its compounds’
Category Quantity Industry
Released into Environment 2.9 t Non-ferrous metal (except aluminum)
production and smelting,
petroleum and coal product manufacturing,
Metal ore mining,
Other electrical equipment manufacturing,
oil and gas extraction (46 facilities)
Disposed of 508 t
Sent to off-site recycling 184 t
t = tonne
US Consumer Products 2016[49]
Search Term # Products Product Type
‘Antimony oxide’ 26 Insulation (solid or fibre form)

Occupational Exposures Overview

Inhalation is the most important route of occupational exposure, however oral and dermal contact are also a concern.[3]

CAREX Canada estimates that approximately 8,700 Canadians are exposed to antimony trioxide in the workplace. The primary industrial groups exposed are public administration, followed by glass and glass product manufacturing. In terms of occupations, the largest exposed groups are police officers (exposed in firing ranges), welders and related machine operators, artisans and craftspersons, and glass forming and finishing machine operators and glass cutters.

Other workers likely to be exposed include those involved in: antimony trioxide production; antimony processing, smelting, and packaging of antimony compounds; production of ceramics and alloys that contain Sb2O3; and manufacture and application of flame retardants.[36]

Workers in facilities that recycle lead-acid batteries may also be exposed to antimony.[50] Firefighters and other emergency workers may be exposed when materials containing antimony trioxide as a fire retardant combust.[36] Exposures may also occur for workers involved producing PET bottles, where antimony trioxide is used as the main catalyst.

For more information, see the occupational exposure estimate for antimony trioxide.


Photo: Wikimedia Commons, Rob Lavinsky

1. International Agency for Research on Cancer (IARC). Monograph summary, Volume 47 (1989) (PDF)
3. Agency for Toxic Substances and Disease Registry (ATSDR). Toxicological Profile for antimony and its compounds (1992) (PDF)
4. US National Library of Medicine. PubChem (Search term: ‘Antimony trioxide’)
5. De Boeck M, Kirsch-Volders M, Lison D. “Cobalt and antimony: Genotoxicity and carcinogenicity” Mutat Res 2003;533:135-152.
6. Belyaeva, A.P. “The effect of antimony on reproduction.” Gig. Truda. Prof. Zabol. 1976;11(1):32-37.
7. US Environmental Protection Agency (EPA). Provisional Peer Reviewed Toxicity Values for Antimony Trioxide (2008)  (PDF)
11. The Canadian Legal Information Institute (CanLII) Manitoba Regulation 217/2006 Workplace Safety and Health Regulation (2022)
13. Government of Newfoundland and Labrador. Regulation 5,12 Occupational Health and Safety Regulations (2018)
14. Government of the Northwest Territories. Occupational Health and Safety Regulations, R-039-2015 (2020) (PDF)
16. The Canadian Legal Information Institute (CanLII). Government of Nunavut’s Occupational Health and Safety Regulations, Nu Reg 003-2016 (2010)
18. Government of Prince Edward Island. Occupational Health and Safety Act Regulations Chapter 0-1 (2013) (PDF)
20. The Canadian Legal Information Institute (CanLII) The Occupational Health and Safety Regulations, 1996 (2022)
21. The Canadian Legal Information Institute (CanLII). Yukon’s Occupational Health Regulations, O.I.C. 1986/164 (2020) (PDF)
22. Occupational Safety and Health Administration (OSHA). Annotated PELs (2020)
24. The Canadian Legal Information Institute (CanLII). Ontario Drinking Water Quality Standards, O Reg 169/03 (2020)
25. Government of British Columbia. Contaminated Sites Regulation B.C. Reg. 375/96 (2021)
26. Ontario Ministry of the Environment and Climate Change. Ontario’s Ambient Air Quality Criteria (2019)
27. Health Canada. Cosmetic Ingredients Hotlist (2019)
28. Government of Canada. List of Permitted Food Additives (2017)
29. Health Canada. Prioritization of the DSL (2006)
30. Government of Canada. List of all Challenge Substances (2010)
31. Canadian Council of Ministers of the Environment (CCME). National Classification System for Contaminated Sites (2008) (PDF)
32. Health Canada. Cosmetic Ingredient Hotlist (2019)
34. Environment and Climate Change Canada. National Pollutant Release Inventory (NPRI) Facility Search (2022)
35. International Antimony Association (i2a). Antimony Trioxide (ATO) (2014)
36. National Toxicology Program (NTP). Brief Review of Toxicology Literature; Antimony Trioxide (2005) (PDF)
37. Camford Information Services Inc. CPI Product Profiles: Antimony Trioxide (1995)
39. The Canadian Encyclopedia. Antimony (2016)
40. Natural Resources Canada. Critical minerals (2021)
41. World Integrated Trade Solution. Antimony oxides exports by country in 2019 (2019)
42. Government of Newfoundland and Labrador. Mining in Newfoundland and Labrador (2021) (PDF)
45. International Trade Centre. TradeMap (Free subscription required)
48. Environment and Climate Change Canada. National Pollutant Release Inventory (NPRI) Facility Search (Substance name: (NA – 01) Antimony (and its compounds))
49. Consumer Product Information Database (CPID).What’s in it? (2022) (Search term: ‘Antimony trioxide’)


Other Resources

  1. Agency for Toxic Substances and Disease Registry (ATSDR). ToxFAQs Sheet: Antimony (1995)
  2. Shotyk W, Krachler M, Chen B. “Contamination of Canadian and European bottled waters with antimony from PET containers.” J Environ Monit 2006;8:288-292.
  3. Krachler M, Zheng J, Koerner R, Zdanowicz C, Fisher D, Shotyk W. “Increasing atmospheric antimony contamination in the northern hemisphere: snow and ice evidence from Devon Island, Arctic Canada.” J Environ Monit 2005;7:1169 – 1176.

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