Provenance

Reference data from EU CLP Annex VI and published regulations — verify against your supplier's SDS before use.

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Substance profile

Antimony Trioxide

Antimony Trioxide is colorless, cubic form (valentinite); colorless (senarmontite) and is odorless.

CAS 1309-64-4 O3Sb2 291.52 g/mol Warning

01 · Identification

What Antimony Trioxide is

Antimony Trioxide is colorless, cubic form (valentinite); colorless (senarmontite) and is odorless. Its molecular formula is O3Sb2 and its molecular weight is 291.52 g/mol. It boils at 1425 °C, melts at 655 °C, is slightly soluble in water.

Under the GHS it carries the signal word Warning. It is classed as carcinogens.

02 · Identifiers

Antimony Trioxide identifiers and molecular data

Antimony Trioxide CAS number and EC number

CAS number1309-64-4
EC number215-175-0
Index number (CLP Annex VI)051-005-00-X

Antimony Trioxide molecular formula and molecular weight

Molecular formulaO3Sb2
Molecular weight291.52 g/mol
Chemical class Carcinogens

03 · GHS classification

Antimony Trioxide hazard classification

Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.

Antimony Trioxide pictograms and signal word

Signal wordWarning

Antimony Trioxide hazard class and category

GHS hazard classes Antimony Trioxide falls into
Hazard class Category From code Pictogram
Carcinogenicity GHS chapter 3.6 Category 2 H351 GHS08

Antimony Trioxide hazard statements (H-codes)

Hazard statements assigned to Antimony Trioxide
CodeHazard statement
H351 Suspected of causing cancer <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>.

This page lists only the codes assigned to Antimony Trioxide. The full reference lives on the hazard statements hub, the precautionary statements hub and the GHS pictograms hub.

Safety Data Sheet

Getting an SDS for Antimony Trioxide

A Safety Data Sheet is written for a product, not for a substance: the supplier of the grade you actually buy issues it, so two suppliers of Antimony Trioxide issue two different sheets. That is why there is no single authoritative SDS for a substance to download — what there is, is the job of collecting the sheets for the products you hold and keeping them current as suppliers revise them.

04 · Precautionary statements

Antimony Trioxide precautionary statements

CLP Annex VI assigns 4 precautionary statements to Antimony Trioxide. They are grouped the way a label groups them: what to do before handling, what to do when something has already happened, how to store it and how to dispose of it.

Response

What to do once exposure, spillage or fire has already happened.

Reading the notation. is a blank the supplier fills in — not a truncated sentence.· [square brackets] mark a part printed only when it applies.

05 · Names in the regulation

Antimony Trioxide name in 23 EU languages

CLP Annex VI Part 3 is published in every language edition of the regulation, and the identification column is written out in each of them. Nothing below is translated by us: each line is the name as that edition prints it. Under Art. 18(2) the substance name from Annex VI is a lawful product identifier, so this is the wording to put on a label going to that market — and where the cell lists several designations, any one of them qualifies.

Language Name in CLP Annex VI Part 3
Bulgarian български антимонов триоксид
Spanish español Trióxido de antimonio
Czech čeština oxid antimonitý
Danish dansk antimontrioxid
German Deutsch Diantimontrioxid Antimontrioxid
Estonian eesti antimontrioksiid
Greek ελληνικά τριοξείδιο του αντιμονίου
English English antimony trioxide
French français trioxyde d'antimoine
Croatian hrvatski antimonov trioksid
Italian italiano triossido di diantimonio
Latvian latviešu antimona trioksīds
Lithuanian lietuvių stibio trioksidas
Hungarian magyar antimon-trioxid
Maltese Malti triossidu tal-antimonju
Dutch Nederlands diantimoontrioxide
Polish polski tlenek antymonu(III) tritlenek antymonutlenek antymonawy
Portuguese português trióxido de antimónio
Romanian română trioxid de antimoniu
Slovak slovenčina oxid antimonitý
Slovenian slovenščina antimonov trioksid
Finnish suomi antimonitrioksidi
Swedish svenska antimontrioxid

All 23 language editions of Annex VI carry this entry. Irish is the twenty-fourth official EU language and has no line here for a different reason: no consolidated CLP text has ever been published in Irish, so there is no Irish edition of Annex VI to quote a name from. Source: consolidated CLP, CELEX 02008R1272, language editions. © European Union, https://eur-lex.europa.eu — only the electronic Official Journal of the European Union is authentic.

06 · Label elements

Antimony Trioxide GHS label elements

Everything CLP Annex VI fixes for Antimony Trioxide, laid out the way it appears on a label. The greyed lines are the parts only the supplier can fill in.

GHS08 Health hazard pictogram

Warning

Antimony Trioxide

  • Suspected of causing cancer <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>.
  • Obtain special instructions before use.
  • Wear protective gloves/protective clothing/eye protection/face protection/hearing protection/
  • IF exposed or concerned:
  • Get medical advice/attention.

Supplier name, address and telephone number· Product identifier·Nominal quantity

Need this as an actual label? Open Antimony Trioxide in the GHS label constructor →

07 · Health hazards

Antimony Trioxide health hazards and exposure limits

Antimony Trioxide carcinogenicity classification

Under the conditions of these 2-year inhalation studies, there was some evidence of carcinogenic activity (see a summary of the Peer Review Panel comments and the public discussion on this Technical Report in Appendix L) of antimony trioxide in male Wistar Han rats based on increased combined incidences of alveolar/bronchiolar adenoma or carcinoma in the lung and on increased incidences of benign pheochromocytoma of the adrenal medulla. There was some evidence of carcinogenic activity of antimony trioxide in female Wistar Han rats based on increased incidences of alveolar/bronchiolar adenoma in the lung and on increased combined incidences of benign or malignant pheochromocytoma of the adrenal medulla. The combined occurrence of cystic keratinizing epithelioma and squamous cell carcinoma in the lung may have been related to exposure. There was clear evidence of carcinogenic activity of antimony trioxide in male B6C3F1/N mice based on increased incidences of alveolar/bronchiolar carcinoma of the lung. Increases in the incidences of fibrous histiocytoma in the skin, as well as the combined incidences of fibrous histiocytoma or fibrosarcoma in the skin of male mice were also considered to be related to exposure. There was clear evidence of carcinogenic activity in female B6C3F1/N mice based on increases in the incidences of alveolar/bronchiolar adenoma and alveolar/bronchiolar carcinoma of the lung and on increased incidences of malignant lymphoma. The occurrence of squamous cell carcinoma of the skin may have been related to exposure.

Source: US National Toxicology Program · TR-590: Toxicology and Carcinogenesis Studies of Antimony Trioxide (CASRN 1309-64-4) in Wistar Han Rats and B6C3F Mice (Inhalation Studies) (2017 )

Evaluation: There is inadequate evidence for the carcinogenicity of antimony trioxide in humans. There is sufficient evidence for the carcinogenicity of antimony trioxide in experimental animals. Overall evaluations: Antimony trioxide is probably carcinogenic to humans (Group 2B).

Source: Hazardous Substances Data Bank (HSDB)

An IARC group and a CLP classification answer different questions. IARC judges whether the evidence for cancer in humans is strong enough; CLP Annex VI is the legally binding EU classification. A substance can carry one and not the other.

Antimony Trioxide occupational exposure limits

US occupational exposure limits reported for Antimony Trioxide. PEL is enforceable (OSHA), REL is a recommendation (NIOSH), IDLH is the concentration at which escape becomes impossible without injury.
Limit Value Source
PEL 0.5 [mg/m3], as Sb Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
IDLH 50.0 [mg/m3], as Sb Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
IDLH 50 mg/cu m, as Sb /Antimony/ Hazardous Substances Data Bank (HSDB)

These are United States values. The European Union sets its own indicative and binding limits, and the figure that applies at a given workplace is the one in the local regulation — not the one shown here.

08 · Physical and chemical properties

Antimony Trioxide properties

Every value is shown with the conditions it was measured under and the source it came from. Where sources disagree, all values are listed rather than one being picked — the difference is usually a different form of the substance, not an error.

Antimony Trioxide boiling point

Property Value Conditions Source
Boiling point 1425 °C (2597 °F) HSDB
1425 °C (2597 °F) at 760 mmHg DOE PAC
1550 °C (2822 °F) sublimes, at 760 mmHg CAMEO

Antimony Trioxide melting point

Property Value Conditions Source
Melting point 655 °C (1211 °F) HSDB
656 °C (1212.8 °F) ICSC

Antimony Trioxide density

Property Value Conditions Source
Density 5.67 g/cm³ valentinite HSDB
5.9 g/cm³ at 24 °C ICSC
5.2 g/cm³ at 25 °C CAMEO

Antimony Trioxide solubility

Property Value Conditions Source
Solubility Slightly soluble in water HSDB
Very slightly soluble in water HSDB
Soluble in KOH HSDB

Antimony Trioxide vapor pressure

Property Value Conditions Source
Vapor pressure 1 mmHg at 574 °C HSDB
1 mmHg at 573.89 °C CAMEO
0.9751 mmHg at 574 °C ICSC

Antimony Trioxide flash point

Property Value Conditions Source
Flash point Not Applicable. Not flammable. (USCG, 1999) CAMEO

Antimony Trioxide lower explosive limit (LEL)

Property Value Conditions Source
Lower explosive limit (LEL) Not Applicable. Not flammable. (USCG, 1999) CAMEO

Antimony Trioxide upper explosive limit (UEL)

Property Value Conditions Source
Upper explosive limit (UEL) Not Applicable. Not flammable. (USCG, 1999) CAMEO

Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.

09 · Fire and explosion

Antimony Trioxide fire and explosion behaviour

These are descriptions rather than measured values, so they are kept out of the table above and quoted here with the source that reported them.

Antimony Trioxide fire potential

When powdered antimony trioxide is heated in air, it ignites and burns.

Source: Hazardous Substances Data Bank (HSDB)

10 · Handling and storage

Antimony Trioxide storage and handling

Antimony Trioxide safe storage

Separated from food and feedstuffs.

Source: ILO-WHO International Chemical Safety Cards (ICSCs)

Antimony Trioxide storage conditions

Safe Storage: Separated from food and feedstuffs.

Source: Hazardous Substances Data Bank (HSDB)

Antimony Trioxide incompatible materials

Incompatible with chlorinated rubber and heat of 216 °C and with BrF3.

Source: Hazardous Substances Data Bank (HSDB)

Antimony Trioxide reactivity

ANTIMONY TRIOXIDE ignites and burns when heated in powdered form in air [Mellor 9:425 1946-47]. Reacts violently with bromine trifluoride [Mellor Vol. 9 425.1939].

Source: CAMEO Chemicals

Planning storage for a mix of chemicals? Check Antimony Trioxide in the storage compatibility matrix →

11 · Questions

Antimony Trioxide — frequently asked questions

What is the CAS number of Antimony Trioxide?

The CAS number of Antimony Trioxide is 1309-64-4. Its EC number is 215-175-0.

What is the chemical formula of Antimony Trioxide?

The molecular formula of Antimony Trioxide is O3Sb2 and its molecular weight is 291.52 g/mol.

What does a Antimony Trioxide label have to show?

Under CLP Annex VI the label for Antimony Trioxide carries the pictogram Health hazard and the signal word is Warning.

Is Antimony Trioxide flammable?

CLP Annex VI assigns Antimony Trioxide no flammability hazard class. That is not a statement that it cannot burn: the harmonised list only records the hazards that were assessed for it. The flash point reported for it is Not Applicable. Not flammable. (USCG, 1999) (CAMEO).

Is Antimony Trioxide a carcinogen?

CLP Annex VI assigns Antimony Trioxide H351 — suspected of causing cancer. That is category 2: the evidence points that way but is not conclusive.

What is the exposure limit for Antimony Trioxide?

The US occupational exposure limit reported for Antimony Trioxide is 0.5 [mg/m3], as Sb (Haz-Map, Information on Hazardous Chemicals and Occupational Diseases). Limits differ by country: the EU sets its own indicative and binding values, and the figure that applies at a given workplace is the one in the local regulation.

What is the boiling point of Antimony Trioxide?

The boiling point reported for Antimony Trioxide is 1425 °C (2597 °F) (HSDB).

What is the melting point of Antimony Trioxide?

The melting point reported for Antimony Trioxide is 655 °C (1211 °F) (HSDB).

How should Antimony Trioxide be stored?

Safe Storage: Separated from food and feedstuffs. (Hazardous Substances Data Bank (HSDB))

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