Antimony Trioxide Profile

INDUSTRIAL CHEMICALS  POSSIBLE CARCINOGEN (IARC 2B)

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
ALARA 
0.5
AB Sb2O3, production
Sb & its compounds
 
0.5
BC, MB, ON, NB, NL, PEI, NS Sb2O3, production
Sb & its compounds
ALARA 
0.5
SK, NT, NU Sb2O3
Sb & its compounds
 
0.5; 1.5 [stel]
QC Sb2O3
Sb & its compounds
Sb2O3 production (as SB)
0.5 
0.5 
ALARA
YT Sb2O3 production (as SB) 0.5 
0.5; 0.75 [stel]
Other Jurisdictions Substance OEL (mg/m3)
ACGIH 2018 TLV Sb2O3, production
Sb & its compounds
ALARA 
0.5
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

Jurisdiction Limit Year
Canadian and Ontario Drinking Water Guidelines
(Antimony)
0.006 mg/L 2017[23]
2016[24]
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: 5 μg/L

2017[25]
Ontario Ambient Air Quality Criteria Annual: 0.12 µg/m3
24-hour: 0.6 µg/m3
2016[26]

Antimony trioxide was not included in other Canadian government environmental guidelines reviewed.[27,28,29,30]

Canadian Agencies/Organizations

Agency Designation/Position Year
Health Canada DSL – high priority substance
(greatest potential for exposure)
2006[31]
Challenge to Industry Batch 9 2010[32]
National Classification System for Contaminated Sites Rank = “High hazard”, potential human carcinogen (antimony) 2008[33]
Agreement Respecting the Great Lakes Basin Ecosystem Listed as a “Hazardous Polluting Substance 1987[34]
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[35]
DSL = domestic substance list

Antimony trioxide was not included in other Canadian government chemical listings reviewed.[36]

 

Main Uses

Antimony trioxide is mainly used as a chemical synergist in chlorinated and brominated flame-retardants, increasing the retardants’ effectiveness.[37] 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.[37] It is also used as a pigment and/or clarifying agent in certain glasses and ceramics.[38] As of 1995, antimony trioxide gained popularity as an additive in optical glass, replacing arsenious oxide.[39]

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

Canadian market demands for antimony trioxide are met through imports.[39] Most of the market for antimony trioxide is in flame retardants for use in vinyl fabrics, wire & cable, and other plastics and rubber.[39]

Approximately 125,000 tonnes of antimony metal are mined globally on an annual basis.[40] China is the dominant producer, taking on approximately 85% of production. South Africa, Russia and Bolivia produce lesser amounts.[40] Canada produces a very small fraction (0.1%) of global antimony metal.[41] The two primary lead smelters in Canada, located in Trail, BC and Bathurst, NB recover antimony metal as by-product from the ores. They also recycle antimonial-lead from lead-acid batteries.[41]

Four secondary lead smelters located in Quebec, Ontario, and BC use recycled batteries and isolate antimony metal from lead alloys during the process.[41] The Beaverbrook antimony mine in Newfoundland was closed in 1998 and reopened in 2008 when market conditions were more favourable. Its operations were again suspended in 2013 due to high operating costs.[40]

Production and Trade

Activity Quantity Year
Canadian Production 234 t of ‘antimony’ 2001[42]
Domestic Consumption 517 t of ‘antimony’ 2000[42]
Export: 2 t of ‘antimony oxides’ 2015[43]
Import: 1,548 t of ‘antimony oxides’ 2015[43]
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.[44] However, Environment Canada reports that exposures from this pathway are low.[44]

Other sources of environmental exposure include food, drinking water, and air.[3,44] Overall, levels of antimony trioxide in water are low due to its poor solubility in water.[44] 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.[45]

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

NPRI and US Household Products Database

NPRI 2015[46]
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 Household Products 2016[47]
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 9,700 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) and welders. Other occupations that may be significantly exposed to antimony trioxide are textile processing and glass forming workers.

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.[38]

Workers in facilities that recycle lead-acid batteries may also be exposed to antimony.[48] Firefighters and other emergency workers may be exposed when materials containing antimony trioxide as a fire retardant combust.[38] 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.

Sources

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. Hazardous Substances Data Bank (HSDB) (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. Government of Newfoundland and Labrador. Regulation 5,12 Occupational Health and Safety Regulations (2012)
12. Government of the Northwest Territories. Occupational Health and Safety Regulations, R-039-2015 (2016) (PDF)
14. The Canadian Legal Information Institute (CanLII). Government of Nunavut’s Occupational Health and Safety Regulations, Nu Reg 003-2016 (2010)
16. Government of Prince Edward Island. Occupational Health and Safety Act Regulations Chapter 0-1 (2013) (PDF)
18. Government of Saskatchewan. The Occupational Health and Safety Regulations, 1996 (2016) (PDF)
19. The Canadian Legal Information Institute (CanLII). Yukon’s Occupational Health Regulations, O.I.C. 1986/164 (2012) (PDF)
20. Occupational Safety and Health Administration (OSHA). Annotated PELs (2018)
24. The Canadian Legal Information Institute (CanLII). Ontario Drinking Water Quality Standards, O Reg 169/03 (2017)
25. Government of British Columbia. Contaminated Sites Regulation B.C. Reg. 375/96 (2017)
26. Ontario Ministry of the Environment and Climate Change. Ontario’s Ambient Air Quality Criteria (2016)
27. Health Canada. Cosmetic Ingredients Hotlist (2014)
28. Government of Canada. List of Permitted Food Additives (2017)
30. Alberta Environment and Parks. Ambient Air Quality Objectives (2017)
31. Health Canada. Prioritization of the DSL (2006)
32. Government of Canada. List of all Challenge Substances (2010)
33. Canadian Council of Ministers of the Environment (CCME). National Classification System for Contaminated Sites (2008) (PDF)
34. International Joint Commission. Revised Great Lakes Water Quality Agreement of 1978 (1978) (PDF)
36. Environment and Climate Change Canada. CEPA List of Toxic Substances (2016)
37. International Antimony Association (i2a). Antimony Trioxide(ATO) (2014) (PDF)
38. National Toxicology Program (NTP). Brief Review of Toxicology Literature; Antimony Trioxide (2005) (PDF)
39. Camford Information Services Inc. CPI Product Profiles: Antimony Trioxide (1995)
40. Newfoundland Labrador Department of Natural Resources. Value of Mineral Shipments (2015)
41. Natural Resources Canada. Canadian Minerals Yearbook: Lead (2009) (PDF)
43. International Trade Centre. TradeMap (Free subscription required)
46. Environment and Climate Change Canada. National Pollutant Release Inventory (NPRI) Facility Search (Substance name: ‘Antimony and its compounds’)
47. US Household Products Database. Household Products (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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