Antimony Trioxide
Full Profile
General Information
Antimony trioxide (Sb2O3) is a slightly soluble, white crystalline powder.[2] Antimony trioxide is produced from the smelting of antimony-containing ores[2] or by reacting antimony trichloride with water.[3] Antimony is not abundant in the earth's crust.[4] Antimony trioxide may also be referred to as diantimony trioxide (DAT), antimony oxide or in manufacturing as antimony white.[5] There are numerous other synonyms and product names; see HSDB for more information.[5]
Antimony trioxide was last classified by IARC in 1989 as Group 2B, possibly carcinogenic to humans, based on inadequate evidence in humans and sufficient evidence in animals.[2] Antimony trioxide is a respiratory carcinogen in female rats.[2]
The epidemiological literature 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 for.[3,6]
Antimony trioxide has also been linked to pneumoconiosis, bronchitis, and airway inflammation.[4] Digestive and neurologic symptoms have been reported from high levels of exposure, but causal relationships have not been established.[4] An early study reported an increase in spontaneous abortions, premature birth, and slow growth rates in offspring.[7] The study's control of confounding variables and exposure assessment techniques, however, were unclear.[8]
Antimony trioxide has been ranked by CAREX Canada as a Group A (immediate high priority) for occupational settings and as a Group B (possible high priority) for environmental settings. Prioritization was based on the carcinogenicity and other toxic properties of the substance, the prevalence of exposure in Canada, and the feasibility of assessing exposure.
Regulations and Guidelines
Occupational Exposure Limits (OEL)
| Canadian Jurisdictions | Substance | OEL (mg/m3) |
|---|---|---|
| Canada Labour Code | Sb2O3 Sb & its compounds |
ALARA 0.5 |
| AB, SK, ON, QC, YT, NT, NU | Sb2O3 Sb & its compounds |
- 0.5 |
| BC, MB, NB, NL, PEI, NS | Sb2O3 Sb & its compounds |
ALARA 0.5 |
| Other Jurisdictions | Substance | OEL (mg/m3) |
| ACGIH 2011 TLV | Sb2O3 Sb & its compounds |
ALARA 0.5 |
Canadian Environmental Guidelines
| Jurisdiction | Limit | Year |
|---|---|---|
| Canadian Drinking Water Guidelines | 0.006 mg/L | 2010[9] |
Antimony trioxide was not included in other Canadian government environmental guidelines reviewed.[12-13]
Canadian Agencies/Organizations
| Agency | Designation/Position | Year |
|---|---|---|
| Health Canada | DSL – high priority substance (greatest potential for exposure) |
2006[13] |
| Challenge to Industry | Batch 9 | 2010[15] |
Antimony trioxide was not included in other Canadian government chemical listings reviewed.[14]
Main Uses
Antimony trioxide is mainly used as a chemical synergist in chlorinated and brominated flame-retardants, increasing the retardants' effectiveness.[16] Flame retardants containing antimony trioxide are used widely in the production of textiles, plastics, rubber, and paints.[2]
Antimony trioxide is the main catalyst in the production of polyethylene terephthalate (PET) and polyester fibers. PET is commonly used in the plastic packaging of water and soft drinks.[16] It is also used as a pigment and/or clarifying agent in certain glasses and ceramics.[17] As of 1995, antimony trioxide was gaining popularity as an additive in optical glass, replacing arsenious oxide.[18]
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.[4] Antimony trioxide is produced when elemental antimony is heated and/or oxidized.[4]
Canadian Production and Trade
Canadian market demands for antimony trioxide are met through imports.[18] Most of the market for antimony trioxide is in flame retardants for use in vinyl fabrics, wire & cable, and other plastics and rubber.[18]
Approximately 125,000 metric tonnes of antimony metal are mined globally on an annual basis.[19] China is the dominant producer, with approximately 85% of production. South Africa, Russia and Bolivia produce lesser amounts.[19] Canada produces a very small fraction (0.1%) of global antimony metal.[20] 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.[20]
Two secondary lead smelters use recycled batteries and isolate antimony metal from lead alloys during the process.[20] The Beaverbrook antimony mine in Newfoundland was operational in 1997/98; it is now being maintained until market conditions are favourable.[19] An antimony mine in New Brunswick was active in 1996 but, as of 2003, had not resumed production.[20]
Production and Trade
| Activity | Quantity | Year |
|---|---|---|
| Canadian Production | 234 t of 'antimony' | 2001[21] |
| Domestic Consumption | 517 t of 'antimony' | 2000[21] |
| Export: Mainly to US | 41 t of 'antimony oxides' | 2007[22] |
| Import: Mainly from China, Mexico | 1,600 t of 'antimony oxides' | 2007[22] |
Occupational Exposures
Inhalation is the most important route of occupational exposure, but potential also exists for dermal and ingestion exposure (in order of importance).[4] The main occupations exposed include workers involved in antimony trioxide production, antimony processing, smelting, and packaging of antimony compounds, production of ceramics, glasses and alloys that contain Sb2O3, and manufacture and application of flame retardants.[17]
Workers in lead-acid battery recycling facilities may also be exposed to antimony.[23] Combustion of materials containing antimony trioxide as a fire retardant may result in exposures to fire fighters and other emergency workers.[17] Exposures may also occur for workers involved in the production of PET bottles, where antimony trioxide is used as the main catalyst.
Environmental Exposures
Sources of environmental exposure include food, drinking water and air.[4] Higher levels of exposure may occur around smelters, incinerators, and near combustion of petroleum & coal products.[4] Antimony trioxide is also a contaminant found in paints, plastics, surface coatings, textiles, curtains, and insulation where it is included as a flame retardant.[17]
Searches of environmental and consumer product databases yielded the following results on current potential for exposure to antimony trioxide in Canada:
NPRI and US Household Products Database
| NPRI 2009[26] | ||
|---|---|---|
| Search term: 'antimony trioxide' | ||
| Category | Quantity | Industry |
| Released into Environment | 9.5 t | Mining, processing & smelting industries, and and gas & ceramics industries (56 companies) |
| Disposed of | 707 t | |
| Sent to off-site recycling | 144 t | |
| US Household Products 2010[25] | ||
|---|---|---|
| Search Term | # Products | Product Type |
| 'antimony oxide' | 26 | Insulation (solid or fibre form) |
Sources
- Wikimedia Commons Photo
- IARC monograph summary, Volume 47 (1989) (PDF)
- NRC (National Research Council). 2000. Toxicological Risks of Selected Flame-Retardant Chemicals. National Academy Press, Washington, DC.
- ATSDR Toxicological Profile for antimony and its compounds (1992) (PDF)
- Hazardous Substances Database entry for antimony trioxide (Search term: 'antimony trioxide')
- M. De Boeck et al, (2003) 'Cobalt and antimony: Genotoxicity and carcinogenicity' Mutation Research. Vol. 533, pp. 135-152
- Belyaeva, A.P. 1967. The effect of antimony on reproduction. Gig. Truda. Prof. Zabol. 11(1): 32-37. (Russian)
- EPA: Integrated Risk Information System Antimony Trioxide
- Guidelines for Canadian Drinking Water Quality (2010)
- Heath Canada (2010) Cosmetic Ingredients Hotlist
- Health Canada (2006) Food Additives Permitted for Use in Canada
- Exposure Guidelines for Residential Indoor Air Quality (1987) (PDF)
- Health Canada's Prioritization of the DSL
- CEPA List of Toxic Substances
- List of all Challenge Substances, Government of Canada Chemicals Management Plan
- International Antimony Oxide Industry Association
- NTP: Brief Review of Toxicology Literature; Antimony Trioxide (2005)
- CPI Product Profiles, Camford Information Services Inc: Antimony Trioxide (1995)
- VVC Exploration (mining company with 10% stake in the Beaverbrook Mine)
- Natural Resources Canada; Minerals and Metals Sector: Antimony Trioxide (2002)
- MBendi: Information on Canada Mining – Antimony Trioxide
- TradeMap (free subscription required)
- Harper, M. et al. (2006) 'A comparison of portable XRF and ICP-OES analysis for lead on filters from a lead ore concentrator mill and a lead-acid battery recycler.' J. Environ. Monit. 8(3):384-392
- The National Pollutant Release Inventory
- Household Products Database (US)
Other Resources
- ATSDR ToxFAQs Sheet: Antimony (1995)
- Bromine Science and Environmental Forum
- Shotyk, W., et al (2006). 'Contamination of Canadian and European bottled waters with antimony from PET containers.' Journal of Environmental Monitoring. Vol. 8, pp. 288-292
- Krachler, M, et al. Increasing atmospheric antimony contamination in the northern hemisphere: snow and ice evidence from Devon Island, Arctic Canada. J. Environ. Monit., 2005, 7, 1169 - 1176