Substance profile
p-benzoquinone
p-benzoquinone is yellow monoclinic prisms from water or petroleum ether with a penetrating odor resembling that of chlorine.
01 · Identification
What p-benzoquinone is
p-benzoquinone is yellow monoclinic prisms from water or petroleum ether with a penetrating odor resembling that of chlorine. Its molecular formula is C6H4O2 and its molecular weight is 108.09 g/mol. It boils at 180 °C, melts at 116 °C.
Under the GHS it carries the signal word Danger. It is classed as hazardous Air Pollutants (HAPs).
Other names for p-benzoquinone
- quinone
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 |
|---|---|
| H331 | Toxic if inhaled. |
| H301 | Toxic if swallowed. |
| H335 | May cause respiratory irritation. |
| H315 | Causes skin irritation. |
| H319 | Causes serious eye irritation. |
| H400 | Very toxic to aquatic life. |
Precautionary statements: P260, P264, P270, P271, P273, P280, P301, P302, P304, P305, P310, P313, P330, P332, P337, P338, P352, P391, P501
03 · Physical and chemical properties
p-benzoquinone 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 | 180 °C (356 °F) | approximate | ICSC |
| Sublimes | sublimes | NIOSH | |
| SUBLIMES (NTP, 1992) | sublimes | CAMEO | |
| Melting point | 115.7 °C (240.3 °F) | HSDB | |
| 115.56 °C (240 °F) | NIOSH | ||
| 115.72 °C (240.3 °F) | CAMEO | ||
| Density | 1.32 g/cm³ | NIOSH | |
| 1.318 g/cm³ | at 20 °C | HSDB | |
| Solubility | SOL IN ALKALIES, HOT PETROLEUM ETHER | HSDB | |
| > 10% in ether | HSDB | ||
| > 10% in ethanol | HSDB | ||
| Vapor pressure | 0.1 mmHg | at 25 °C | HSDB |
| Flash point | 292.78 °C (559 °F) | CAMEO | |
| 65.56 °C (150 °F) | range, midpoint shown | HSDB | |
| Autoignition temperature | 560 °C (1040 °F) | HSDB | |
| Lower explosive limit (LEL) | Combustible Solid | NIOSH | |
| Vapor density | 3.7 (air = 1) | HSDB | |
| Odor threshold | 0.4000 mg/cu m (low); 0.4000 mg/cu m (high); 2.00 mg/cu m (irritating concentration) | HSDB | |
| Odor Threshold Low: 0.1 [ppm] | Haz-Map | ||
| Odor Threshold High: 0.15 [ppm] | Haz-Map |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
04 · Fire and explosion
Fire and explosion behaviour of p-benzoquinone
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
Drums containing moist quinone self heated, generating smoke and internal pressure. ... The moist material showed an exotherm at 40-50 °C and decomposed at 60-70 °C, ... owing to pressure impurities. Drums exposed to direct sunlight soon attain a surface temperature of 50-60 °C.
Source: HSDB
05 · Handling and storage
Storing and handling p-benzoquinone
Incompatible materials
Contact with strong oxidizers may cause fires & explosions.
Source: Hazardous Substances Data Bank (HSDB)
Reactivity
BENZOQUINONE acts as an oxidizing agent (NTP, 1992).
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check p-benzoquinone in the storage compatibility matrix →