Substance profile
Diazomethane
Diazomethane is a yellow gas with a musty odor.
01 · Identification
What Diazomethane is
Diazomethane is a yellow gas with a musty odor. It boils at -23 °C, melts at -145 °C.
Under the GHS it carries the signal word Danger. It is classed as hazardous Air Pollutants (HAPs).
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 |
|---|---|
| H350 | May cause cancer <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>. |
03 · Physical and chemical properties
Diazomethane 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 |
|---|---|---|---|
| Boiling point | -23 °C (-9.4 °F) | HSDB | |
| -22.78 °C (-9 °F) | NIOSH | ||
| -22.78 °C (-9 °F) | at 760 mmHg | CAMEO | |
| Melting point | -145 °C (-229 °F) | HSDB | |
| Density | 1.45 g/cm³ | HSDB | |
| 1.45 g/cm³ | at 25 °C | DOE PAC | |
| Solubility | Soluble in ... benzene, alcohol | HSDB | |
| Very soluble in ether and dioxane | HSDB | ||
| Decomposes in water | decomposes | HSDB | |
| Vapor pressure | 3900 mmHg | at 25 °C | ICSC |
| 760 mmHg | above this value | NIOSH | |
| Flash point | NA (Gas) | NIOSH | |
| Flammable gas | ICSC | ||
| Autoignition temperature | 100 °C (212 °F) | HSDB | |
| 100 °C (212 °F) | explosion | ICSC | |
| Vapor density | 1.45 (air = 1) | HSDB | |
| 1.4 (air = 1) | ICSC |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
04 · Fire and explosion
Fire and explosion behaviour of Diazomethane
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
... MAY EXPLODE VIOLENTLY ON HEATING OR IN CONTACT WITH ROUGH SURFACES. IN ETHER OR BENZENE, IN WHICH DIAZOMETHANE IS SOL, THE DANGER OF EXPLOSION IS MUCH DECREASED.
Source: HSDB
CALCIUM SULFATE IS UNSUITABLE DESICCANT FOR DRYING-TUBES IN DIAZOMETHANE SYSTEMS. CONTACT OF DIAZOMETHANE VAPOR & SULFATE CAUSES EXOTHERM WHICH MAY LEAD TO DETONATION.
Source: HSDB
DIAZOMETHANE WILL UNDERGO VIOLENT THERMAL DECOMP. ABOVE 200 °C, VAPOR MAY EXPLODE VIOLENTLY. EXPLOSIONS AT LOW TEMPERATURES CAN OCCUR IF TRACES OF ORGANIC MATTER ARE PRESENT.
Source: HSDB
05 · Handling and storage
Storing and handling Diazomethane
Storage conditions
Diazomethane should be stored in a cool, dry, well-ventilated area in tightly sealed containers that are labeled in accordance with OSHA's Hazard Communication Standard. Containers of diazomethane should be protected from shock, heat, sparks, open flames and physical damage and should be stored separately from alkali metals, calcium sulfate, calcium chloride, boiling stones, or copper powder. Outside or detached storage is preferred. Empty containers of diazomethane should be handled appropriately.
Source: Hazardous Substances Data Bank (HSDB)
Incompatible materials
Contact between diazomethane and alkali metals, calcium sulfate, calcium chloride, boiling stones, or copper powder will cause explosions.
Source: Hazardous Substances Data Bank (HSDB)
Reactivity
DIAZOMETHANE undergoes violent thermal decomposition. Above 200 °C. the vapors may explode violently if rough glass surfaces are present. Explosions at low temperatures can occur if traces of organic matter are present. [J. Phys. Chem. 35:1403(1931)]. Produces explosions with alkali metals. Reacts with copper powder and to some extent all solid surfaces to produce nitrogen and solid white polymethylene. Reacts with dimethylaminodimethylarsine and trimethyltin in ether with vigorous foaming.
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check Diazomethane in the storage compatibility matrix →