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

Azobenzene

Azobenzene is a chemical substance with the molecular formula C12H10N2.

CAS 103-33-3 C12H10N2 182.22 g/mol Danger

01 · Identification

What Azobenzene is

Azobenzene is a chemical substance with the molecular formula C12H10N2. Its molecular formula is C12H10N2 and its molecular weight is 182.22 g/mol.

Under the GHS it carries the signal word Danger.

02 · Identifiers

Azobenzene identifiers and molecular data

Azobenzene CAS number and EC number

CAS number103-33-3
EC number203-102-5
Index number (CLP Annex VI)611-001-00-6

Azobenzene molecular formula and molecular weight

Molecular formulaC12H10N2
Molecular weight182.22 g/mol

03 · GHS classification

Azobenzene hazard classification

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

Azobenzene pictograms and signal word

Signal wordDanger

Azobenzene hazard class and category

GHS hazard classes Azobenzene falls into
Hazard class Category From code Pictogram
Acute toxicity - oral GHS chapter 3.1 Category 4 H302 GHS07
Acute toxicity - inhalation GHS chapter 3.1 Category 4 H332 GHS07
Germ cell mutagenicity GHS chapter 3.5 Category 2 H341 GHS08
Carcinogenicity GHS chapter 3.6 Category 1A or 1B H350 GHS08
Specific target organ toxicity - repeated exposure GHS chapter 3.9 Category 2 H373 GHS08
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.

Azobenzene hazard statements (H-codes)

Hazard statements assigned to Azobenzene
CodeHazard statement
H350 May cause cancer <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>.
H341 Suspected of causing genetic defects <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>.
H332 Harmful if inhaled.
H302 Harmful if swallowed.
H373 May cause damage to organs <or state all organs affected, if known> through prolonged or repeated exposure <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>.
H400 Very toxic to aquatic life.
H410 Very toxic to aquatic life with long lasting effects.

This page lists only the codes assigned to Azobenzene. 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 Azobenzene

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 Azobenzene 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

Azobenzene precautionary statements

CLP Annex VI assigns 15 precautionary statements to Azobenzene. 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.

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

Azobenzene 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 азобензен
Spanish español Azobenceno
Czech čeština azobenzen
Danish dansk azobenzen
German Deutsch Azobenzol
Estonian eesti asobenseen
Greek ελληνικά αζωβενζόλιο
English English azobenzene
French français azobenzène
Croatian hrvatski azobenzen
Italian italiano azobenzene
Latvian latviešu azobenzols
Lithuanian lietuvių azobenzenas
Hungarian magyar azobenzol
Maltese Malti ażobenżen
Dutch Nederlands azobenzeen
Polish polski azobenzen difenylodiazen
Portuguese português azobenzeno
Romanian română azobenzen
Slovak slovenčina difenyldiazén
Slovenian slovenščina azobenzen
Finnish suomi atsobentseeni
Swedish svenska azobensen

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

Azobenzene GHS label elements

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

GHS08 Health hazard pictogramGHS07 Exclamation mark pictogramGHS09 Environment pictogram

Danger

Azobenzene

  • May cause cancer <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>.
  • Suspected of causing genetic defects <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>.
  • Harmful if inhaled.
  • Harmful if swallowed.
  • May cause damage to organs <or state all organs affected, if known> through prolonged or repeated exposure <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>.
  • Very toxic to aquatic life.
  • Very toxic to aquatic life with long lasting effects.
  • Obtain special instructions before use.
  • Do not breathe dust/fume/gas/mist/vapours/spray.
  • Do not eat, drink or smoke when using this product.
  • Use only outdoors or in a well-ventilated area.
  • Avoid release to the environment.
  • Wear protective gloves/protective clothing/eye protection/face protection/hearing protection/
  • IF SWALLOWED:
  • IF INHALED:
  • IF exposed or concerned:
  • Call a POISON CENTER/doctor/ if you feel unwell.
  • Get medical advice/attention.
  • Get medical advice/attention if you feel unwell.
  • Rinse mouth.
  • Collect spillage.
  • Dispose of contents/container to

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

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

07 · Questions

Azobenzene — frequently asked questions

What is the CAS number of Azobenzene?

The CAS number of Azobenzene is 103-33-3. Its EC number is 203-102-5.

What is the chemical formula of Azobenzene?

The molecular formula of Azobenzene is C12H10N2 and its molecular weight is 182.22 g/mol.

What does a Azobenzene label have to show?

Under CLP Annex VI the label for Azobenzene carries the pictograms Health hazard, Exclamation mark and Environment and the signal word is Danger.

Is Azobenzene flammable?

CLP Annex VI assigns Azobenzene 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 Azobenzene a carcinogen?

Yes. CLP Annex VI classifies Azobenzene as a category 1A or 1B carcinogen and assigns it H350: may cause cancer.

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