Substance profile
Cobalt(II) oxide
Cobalt(II) oxide is powder or cubic or hexagonal crystals.
01 · Identification
What Cobalt(II) oxide is
Cobalt(II) oxide is powder or cubic or hexagonal crystals. Its molecular formula is CoO and its molecular weight is 74.933 g/mol. It melts at 1935 °C.
Under the GHS it carries the signal word Warning.
02 · Identifiers
Cobalt(II) oxide identifiers and molecular data
Cobalt(II) oxide CAS number and EC number
Cobalt(II) oxide molecular formula and molecular weight
Other names for Cobalt(II) oxide
- cobalt oxide
03 · GHS classification
Cobalt(II) oxide hazard classification
Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.
Cobalt(II) oxide pictograms and signal word
Cobalt(II) oxide hazard class and category
| Hazard class | Category | From code | Pictogram |
|---|---|---|---|
| Acute toxicity - oral GHS chapter 3.1 | Category 4 | H302 | GHS07 |
| Skin sensitisation GHS chapter 3.4 | Category 1 or 1A or 1B | H317 | GHS07 |
| Hazardous to the aquatic environment - acute GHS chapter 4.1 | Category 1 | H400 | GHS09 |
| Hazardous to the aquatic environment - chronic GHS chapter 4.1 | Category 1 | H410 | GHS09 |
Where two values are shown with “or”, the hazard statement is shared by more than one category or by more than one class, and the code alone does not say which. H272, for example, belongs to oxidising liquids and to oxidising solids — the physical state decides. The binding answer for a specific entry is in the CLP Annex VI table itself.
Cobalt(II) oxide hazard statements (H-codes)
| Code | Hazard statement |
|---|---|
| H302 | Harmful if swallowed. |
| H317 | May cause an allergic skin reaction. |
| H400 | Very toxic to aquatic life. |
| H410 | Very toxic to aquatic life with long lasting effects. |
This page lists only the codes assigned to Cobalt(II) oxide. 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 Cobalt(II) oxide
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 Cobalt(II) oxide 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
Cobalt(II) oxide precautionary statements
CLP Annex VI assigns 12 precautionary statements to Cobalt(II) oxide. 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.
Prevention
What to do before and during handling so the hazard never happens.
Response
What to do once exposure, spillage or fire has already happened.
Disposal
What has to happen to the contents and the empty container.
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
Cobalt(II) oxide 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 | кобалтов оксид |
| Spanish español | Óxido de cobalto |
| Czech čeština | oxid kobaltnatý |
| Danish dansk | cobaltoxid |
| German Deutsch | Cobaltoxid |
| Estonian eesti | koobaltoksiid |
| Greek ελληνικά | οξείδιο του κοβαλτίου |
| English English | cobalt oxide |
| French français | oxyde de cobalt |
| Croatian hrvatski | kobaltov oksid |
| Italian italiano | ossido di cobalto |
| Latvian latviešu | kobalta oksīds |
| Lithuanian lietuvių | kobalto oksidas |
| Hungarian magyar | kobalt-oxid |
| Maltese Malti | ossidu tal-kobalt |
| Dutch Nederlands | kobaltoxide |
| Polish polski | tlenek kobaltu(II) |
| Portuguese português | óxido de cobalto |
| Romanian română | oxid de cobalt |
| Slovak slovenčina | oxid kobaltnatý |
| Slovenian slovenščina | kobaltov oksid |
| Finnish suomi | kobolttioksidi |
| Swedish svenska | koboltoxid |
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
Cobalt(II) oxide GHS label elements
Everything CLP Annex VI fixes for Cobalt(II) oxide, laid out the way it appears on a label. The greyed lines are the parts only the supplier can fill in.
Warning
Cobalt(II) oxide
- Harmful if swallowed.
- May cause an allergic skin reaction.
- Very toxic to aquatic life.
- Very toxic to aquatic life with long lasting effects.
- Avoid breathing dust/fume/gas/mist/vapours/spray.
- Do not eat, drink or smoke when using this product.
- Contaminated work clothing should not be allowed out of the workplace.
- Avoid release to the environment.
- Wear protective gloves/protective clothing/eye protection/face protection/hearing protection/…
- IF SWALLOWED:
- Call a POISON CENTER/doctor/… if you feel unwell.
- Get medical advice/attention.
- Rinse mouth.
- If skin irritation or rash occurs:
- Collect spillage.
- Dispose of contents/container to …
Supplier name, address and telephone number· Product identifier·Nominal quantity
Need this as an actual label? Open Cobalt(II) oxide in the GHS label constructor →
07 · Health hazards
Cobalt(II) oxide health hazards and exposure limits
Cobalt(II) oxide hazard summary
May cause skin sensitization and asthma after prolonged contact; [ICSC] A skin and eye irritant; [MSDSonline] See Cobalt.
Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
Cobalt(II) oxide carcinogenicity classification
... There is sufficient evidence for the carcinogenicity of cobalt(II) oxide in experimental animals. ... Overall Evaluation: Cobalt and cobalt compounds are possibly carcinogenic to humans (Group 2B). /Cobalt and cobalt compounds/
Source: Hazardous Substances Data Bank (HSDB)
There is inadequate evidence for the carcinogenicity of cobalt and cobalt compounds in humans. There is sufficient evidence for the carcinogenicity of cobalt metal powder in experimental animals. There is limited evidence for the carcinogenicity of metal alloys containing cobalt, chromium and molybdenum in experimental animals. ... Overall Evaluation: Cobalt and cobalt compounds are possibly carcinogenic to humans (Group 2B). /Cobalt and cobalt compounds/
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.
08 · Physical and chemical properties
Cobalt(II) oxide 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.
Cobalt(II) oxide melting point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Melting point | 1935 °C (3515 °F) | ICSC | |
| 1830 °C (3326 °F) | DOE PAC | ||
| 1935 °C (3515 °F) | approximate | HSDB |
Cobalt(II) oxide density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Density | 6.66 g/cm³ | at 21.3 °C, Density of Liquids and Solids | HSDB |
| 6.45 g/cm³ | at 25 °C | DOE PAC | |
| 6.2 g/cm³ | range, midpoint shown | HSDB |
Cobalt(II) oxide solubility
| Property | Value | Conditions | Source |
|---|---|---|---|
| Solubility | Practically insoluble in water | HSDB | |
| Insoluble in water | HSDB | ||
| In water, 4.88 mg/L at 20 °C, 3.27 mg/L at 37 °C (column elution method) | at 20 °C | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
09 · Handling and storage
Cobalt(II) oxide storage and handling
Cobalt(II) oxide safe storage
Separated from hydrogen peroxide.
Source: ILO-WHO International Chemical Safety Cards (ICSCs)
Cobalt(II) oxide storage conditions
Keep container tightly closed in a dry and well-ventilated place. Keep in a dry place. Storage class (TRGS 510): Non-combustible, acute toxic Cat. 1 and 2 / very toxic hazardous materials.
Source: Hazardous Substances Data Bank (HSDB)
Cobalt(II) oxide incompatible materials
Incompatible materials: Strong oxidizing agents.
Source: Hazardous Substances Data Bank (HSDB)
Planning storage for a mix of chemicals? Check Cobalt(II) oxide in the storage compatibility matrix →
10 · Questions
Cobalt(II) oxide — frequently asked questions
What is the CAS number of Cobalt(II) oxide?
The CAS number of Cobalt(II) oxide is 1307-96-6. Its EC number is 215-154-6.
What is the chemical formula of Cobalt(II) oxide?
The molecular formula of Cobalt(II) oxide is CoO and its molecular weight is 74.933 g/mol.
What does a Cobalt(II) oxide label have to show?
Under CLP Annex VI the label for Cobalt(II) oxide carries the pictograms Exclamation mark and Environment and the signal word is Warning.
Is Cobalt(II) oxide flammable?
CLP Annex VI assigns Cobalt(II) oxide 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.
Is Cobalt(II) oxide a carcinogen?
CLP Annex VI records no harmonised carcinogenicity classification for Cobalt(II) oxide. Annex VI is a list of agreed classifications, not a list of substances found safe, so this is an absence of a classification rather than a clean bill of health. IARC places it in Group 2B: possibly carcinogenic to humans.
What is the melting point of Cobalt(II) oxide?
The melting point reported for Cobalt(II) oxide is 1935 °C (3515 °F) (ICSC).
How should Cobalt(II) oxide be stored?
Keep container tightly closed in a dry and well-ventilated place. Keep in a dry place. Storage class (TRGS 510): Non-combustible, acute toxic Cat. 1 and 2 / very toxic hazardous materials. (Hazardous Substances Data Bank (HSDB))
Nearby
Substances next to Cobalt(II) oxide
Keep going: substances starting with C, or search the whole database by name, CAS number, pictogram or signal word.