Substance profile
Ammonium dichromate
Ammonium dichromate is bright orange-red monoclinic prisms and is odorless.
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 · GHS classification
Hazards and label elements
Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.
| Code | Hazard 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. |
Precautionary statements: P201, P260, P261, P270, P271, P272, P273, P280, P301, P302, P304, P308, P310, P312, P313, P314, P330, P331, P333, P352, P391, P501
03 · 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.
| Property | Value | Conditions | Source |
|---|---|---|---|
| Melting point | 170 °C (338 °F) | DOE PAC | |
| 180 °C (356 °F) | decomposes | HSDB | |
| Density | 2.15 g/cm³ | ICSC | |
| 2.155 g/cm³ | at 25 °C | HSDB | |
| 2.15 g/cm³ | at 25 °C | CAMEO | |
| 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 | |
| Autoignition temperature | 225 °C (437 °F) | HSDB | |
| 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.
04 · Fire and explosion
Fire and explosion behaviour of Ammonium dichromate
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.
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
05 · Handling and storage
Storing and handling Ammonium dichromate
Storage conditions
Keep container tightly closed in a dry and well-ventilated place.
Source: Hazardous Substances Data Bank (HSDB)
Incompatible materials
Incompatible materials: Strong reducing agents, alcohols, strong acids. Do not store near acids.
Source: Hazardous Substances Data Bank (HSDB)
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 →