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

Ammonium dichromate

Ammonium dichromate is bright orange-red monoclinic prisms and is odorless.

CAS 7789-09-5 Cr2H8N2O7 252.07 g/mol Danger

01 · Identification

What Ammonium dichromate is

Ammonium dichromate is bright orange-red monoclinic prisms and is odorless. Its molecular formula is Cr2H8N2O7 and its molecular weight is 252.07 g/mol. It melts at 170 °C.

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

02 · Identifiers

Ammonium dichromate identifiers and molecular data

Ammonium dichromate CAS number and EC number

CAS number7789-09-5
EC number232-143-1
Index number (CLP Annex VI)024-003-00-1

Ammonium dichromate molecular formula and molecular weight

Molecular formulaCr2H8N2O7
Molecular weight252.07 g/mol
Chemical class Carcinogens

03 · GHS classification

Ammonium dichromate hazard classification

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

Ammonium dichromate pictograms and signal word

Signal wordDanger

Ammonium dichromate hazard class and category

GHS hazard classes Ammonium dichromate falls into
Hazard class Category From code Pictogram
Oxidising liquids or Oxidising solids Category 2 or 3 H272 GHS03
Acute toxicity - oral GHS chapter 3.1 Category 3 H301 GHS06
Acute toxicity - dermal GHS chapter 3.1 Category 4 H312 GHS07
Acute toxicity - inhalation GHS chapter 3.1 Category 1 or 2 H330 GHS06
Skin corrosion/irritation GHS chapter 3.2 Category 1A or 1B or 1C H314 GHS05
Respiratory sensitisation GHS chapter 3.4 Category 1 or 1A or 1B H334 GHS08
Skin sensitisation GHS chapter 3.4 Category 1 or 1A or 1B H317 GHS07
Germ cell mutagenicity GHS chapter 3.5 Category 1A or 1B H340 GHS08
Carcinogenicity GHS chapter 3.6 Category 1A or 1B H350 GHS08
Specific target organ toxicity - repeated exposure GHS chapter 3.9 Category 1 H372 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.

Ammonium dichromate hazard statements (H-codes)

Hazard statements assigned to Ammonium dichromate
CodeHazard statement
H272 May intensify fire; oxidiser.
H350 May cause cancer <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>.
H340 May cause genetic defects <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>.
H360FD May damage fertility. May damage the unborn child.
H330 Fatal if inhaled.
H301 Toxic if swallowed.
H312 Harmful in contact with skin.
H372 Causes 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>.
H314 Causes severe skin burns and eye damage.
H334 May cause allergy or asthma symptoms or breathing difficulties if inhaled.
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 Ammonium dichromate. 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 Ammonium dichromate

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 Ammonium dichromate 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

Ammonium dichromate precautionary statements

CLP Annex VI assigns 22 precautionary statements to Ammonium dichromate. 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

Ammonium dichromate 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 амониев дихромат
Spanish español Dicromato de amonio
Czech čeština dichroman amonný
Danish dansk ammoniumdichromat
German Deutsch Ammoniumdichromat
Estonian eesti ammooniumdikromaat
Greek ελληνικά διχρωμικό αμμώνιο
English English ammonium dichromate
French français dichromate d'ammonium
Croatian hrvatski amonijev dikromat
Italian italiano dicromato di ammonio
Latvian latviešu amonija dihromāts
Lithuanian lietuvių amonio dichromatas
Hungarian magyar ammónium-dikromát
Maltese Malti dikromat tal-ammonju
Dutch Nederlands ammoniumdichromaat
Polish polski dichromian(VI) amonu
Portuguese português dicromato de amónio
Romanian română dicromat de amoniu
Slovak slovenčina dichróman amónny
Slovenian slovenščina amonijev dikromat
Finnish suomi ammoniumdikromaatti
Swedish svenska ammoniumdikromat

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

Ammonium dichromate GHS label elements

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

GHS03 Flame over circle pictogramGHS06 Skull and crossbones pictogramGHS08 Health hazard pictogramGHS05 Corrosion pictogramGHS09 Environment pictogram

Danger

Ammonium dichromate

  • May intensify fire; oxidiser.
  • May cause cancer <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>.
  • May cause genetic defects <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>.
  • May damage fertility. May damage the unborn child.
  • Fatal if inhaled.
  • Toxic if swallowed.
  • Harmful in contact with skin.
  • Causes 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>.
  • Causes severe skin burns and eye damage.
  • May cause allergy or asthma symptoms or breathing difficulties if inhaled.
  • May cause an allergic skin reaction.
  • 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.
  • Avoid breathing 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.
  • 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:
  • IF ON SKIN:
  • IF INHALED:
  • IF exposed or concerned:
  • Immediately call a POISON CENTER/doctor/
  • Call a POISON CENTER/doctor/ if you feel unwell.
  • Get medical advice/attention.
  • Get medical advice/attention if you feel unwell.
  • Rinse mouth.
  • Do NOT induce vomiting.
  • If skin irritation or rash occurs:
  • Wash with plenty of water/
  • Collect spillage.
  • Dispose of contents/container to

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

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

07 · Health hazards

Ammonium dichromate health hazards and exposure limits

Ammonium dichromate hazard summary

A strong oxidizing agent that is a skin and eye irritant, a dangerous fire risk, and potentially explosive if in contact with organic substances; [Hawley] A skin, eye, nose, and throat irritant; [HSDB] May cause asthma, perforation of the nasal septum, and skin ulcers; [CAMEO] Explosion hazard; An irritant; May cause serious eye injury; May cause skin and respiratory sensitization after prolonged contact; [MSDSonline] See Chromium and linked occupational diseases.

Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases

Ammonium dichromate carcinogenicity classification

Evaluation: There is sufficient evidence in humans for the carcinogenicity of chromium(VI) compounds. Chromium(VI) compounds cause cancer of the lung. Also positive associations have been observed between exposure to Chromium(IV) compounds and cancer of the nose and nasal sinuses. There is sufficient evidence in experimental animals for the carcinogenicity of chromium(VI) compounds. Chromium(VI) compounds are carcinogenic to humans (Group 1). /Chromium(VI) compounds/

Source: Hazardous Substances Data Bank (HSDB)

Chromium Hexavalent Compounds: known to be human carcinogens. /Chromium hexavalent compound/

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.

Ammonium dichromate occupational exposure limits

US occupational exposure limits reported for Ammonium dichromate. PEL is enforceable (OSHA), REL is a recommendation (NIOSH), IDLH is the concentration at which escape becomes impossible without injury.
Limit Value Source
PEL 0.005 [mg/m3], as Cr(VI) Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
IDLH 15 mg Cr(VI)/m3 ; A potential occupational carcinogen. (NIOSH, 2024) CAMEO Chemicals
IDLH 250 mg/cu m (as Cr(II)). /Chromium(II) compounds (as Cr)/ Hazardous Substances Data Bank (HSDB)
IDLH 25 mg/cu m (as Cr(III)). /Chromium(III) compounds (as Cr)/ 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

Ammonium dichromate 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.

Ammonium dichromate melting point

Property Value Conditions Source
Melting point 170 °C (338 °F) DOE PAC
180 °C (356 °F) decomposes HSDB

Ammonium dichromate density

Property Value Conditions Source
Density 2.15 g/cm³ ICSC
2.155 g/cm³ at 25 °C HSDB
2.15 g/cm³ at 25 °C CAMEO

Ammonium dichromate solubility

Property Value Conditions Source
Solubility 35.6 g/100 g water at 20 °C at 20 °C HSDB
Solubility in water, g/100ml at 20 °C: 36 (good) at 20 °C ICSC
In water: 30.8 g/100 mL at 15 °C; 89 g/100 mL at 30 °C at 15 °C HSDB

Ammonium dichromate autoignition temperature

Property Value Conditions Source
Autoignition temperature 225 °C (437 °F) HSDB

Ammonium dichromate lower explosive limit (LEL)

Property Value Conditions Source
Lower explosive limit (LEL) Combustible solid HSDB
Confined ammonium dichromate undergoing thermal decomposition, will explode. decomposes HSDB

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

09 · Fire and explosion

Ammonium dichromate 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.

Ammonium dichromate fire potential

Moderately flammable.

Source: Hazardous Substances Data Bank (HSDB)

Fire and explosion

Explosiveness: Under ordinary conditions, not dangerously reactive, but can react explosively with certain organic substances when brought into intimate contact with them. Reactive only under extreme conditions.

Source: HSDB

10 · Handling and storage

Ammonium dichromate storage and handling

Ammonium dichromate safe storage

Fireproof. Provision to contain effluent from fire extinguishing. Separated from organic solvents, combustible substances and reducing agents. Well closed. Store in an area without drain or sewer access.

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

Ammonium dichromate storage conditions

Keep container tightly closed in a dry and well-ventilated place.

Source: Hazardous Substances Data Bank (HSDB)

Ammonium dichromate incompatible materials

Incompatible materials: Strong reducing agents, alcohols, strong acids. Do not store near acids.

Source: Hazardous Substances Data Bank (HSDB)

Ammonium dichromate reactivity

It is an oxidizing reagent, it readily reacts with reducing materials, in large quantity it may produce a violent reaction. Direct exposure to heat or shock will explode it. When heated to decomposition it emits toxic fumes of ammonia and nitrogen oxides [Sax, 9th ed., 1996, p. 205].

Source: CAMEO Chemicals

Planning storage for a mix of chemicals? Check Ammonium dichromate in the storage compatibility matrix →

11 · Transport

Ammonium dichromate UN number and transport classification

Transport classification is a separate system from the GHS classification above. It decides how a package is marked and how a load may be carried; it does not follow from the workplace label, and the workplace label does not follow from it. The entries below are linked by CAS number, never by name.

Ammonium dichromate under UN 1439 — shipping name, class and packing group

Europe · ADR 2025, Table A

Proper shipping name (3.1.2) Class Classification code PG Labels (column 5)
AMMONIUM DICHROMATE 5.1 O2 II
  • ADR label model 5.1 — Oxidizing substance
5.1

Source: ADR 2025, Table A of Chapter 3.2 · ECE/TRANS/352 Vol. I (UNECE). Class 5.1 is “Oxidizing substances” (ADR 2.1.1.1).

Proper shipping name (column 2) Class or division PG Labels (column 6)
Ammonium dichromate 5.1 II
  • US DOT OXIDIZER label (§172.426)
5.1

Source: 49 CFR 172.101 Hazardous Materials Table · eCFR, revision 2026-08-03. Class 5.1 is “Oxidizer” (49 CFR 173.2).

Full UN 1439 entry — special provisions, packing instructions, quantity limits and the orange plate →

12 · Questions

Ammonium dichromate — frequently asked questions

What is the CAS number of Ammonium dichromate?

The CAS number of Ammonium dichromate is 7789-09-5. Its EC number is 232-143-1.

What is the chemical formula of Ammonium dichromate?

The molecular formula of Ammonium dichromate is Cr2H8N2O7 and its molecular weight is 252.07 g/mol.

What does a Ammonium dichromate label have to show?

Under CLP Annex VI the label for Ammonium dichromate carries the pictograms Flame over circle, Skull and crossbones, Health hazard, Corrosion and Environment and the signal word is Danger.

Is Ammonium dichromate flammable?

CLP Annex VI assigns Ammonium dichromate 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 Ammonium dichromate a carcinogen?

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

What is the exposure limit for Ammonium dichromate?

The US occupational exposure limit reported for Ammonium dichromate is 0.005 [mg/m3], as Cr(VI) (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 melting point of Ammonium dichromate?

The melting point reported for Ammonium dichromate is 170 °C (338 °F) (DOE PAC).

How should Ammonium dichromate be stored?

Keep container tightly closed in a dry and well-ventilated place. (Hazardous Substances Data Bank (HSDB))

Nearby

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