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

Benzo[a]pyrene

Benzo[a]pyrene is pale yellow monoclinic needles from benzene and methanol with a faint aromatic odor.

CAS 50-32-8 C20H12 252.3 g/mol Danger

01 · Identification

What Benzo[a]pyrene is

Benzo[a]pyrene is pale yellow monoclinic needles from benzene and methanol with a faint aromatic odor. Its molecular formula is C20H12 and its molecular weight is 252.3 g/mol. It boils at 475 °C, melts at 179 °C.

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

CAS number50-32-8
EC number200-028-5
Index number601-032-00-3
Molecular formulaC20H12
Molecular weight252.3 g/mol
Chemical class Carcinogens

Other names for Benzo[a]pyrene

  • benzo[def]chrysene

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.

Signal wordDanger
Hazard statements assigned to Benzo[a]pyrene
CodeHazard statement
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.
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, P261, P272, P273, P280, P308, P313, P333, P391, P501

03 · Physical and chemical properties

Benzo[a]pyrene 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 475 °C (887 °F) at 760 mmHg CAMEO
496 °C (924.8 °F) ICSC
3100 °C (5612 °F) OSHA
Melting point 179 °C (354.2 °F) HSDB
178.1 °C (352.6 °F) ICSC
181.1 °C (358 °F) DOE PAC
Density 1.351 g/cm³ HSDB
1 g/cm³ CAMEO
1.4 g/cm³ at 20 °C ICSC
Solubility Soluble in benzene, toluene, xylene, and ether; slightly soluble in alcohol HSDB
Very soluble in chloroform HSDB
In water, 1.62X10-3 mg/L at 25 °C at 25 °C HSDB
Vapor pressure 5.49e-9 mmHg at 25 °C HSDB
1e-8 mmHg Haz-Map
Upper explosive limit (UEL) 2719 °F OSHA
Vapor density 8.7 (air = 1) HSDB

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

04 · Handling and storage

Storing and handling Benzo[a]pyrene

Storage conditions

Keep container tightly closed in a dry and well-ventilated place.[Sigma-Aldrich; Safety Data Sheet for Benzo

Source: Hazardous Substances Data Bank (HSDB)

Incompatible materials

Incompatible materials: Strong oxidizing agents.[Sigma-Aldrich; Safety Data Sheet for Benzo

Source: Hazardous Substances Data Bank (HSDB)

Reactivity

BENZO[A]PYRENE undergoes photo-oxidation after irradiation in indoor sunlight or by fluorescent light in organic solvents. Incompatible with strong oxidizing agents including various electrophiles, peroxides, nitrogen oxides and sulfur oxides. Oxidized by ozone, chromic acid and chlorinating agents. Readily undergoes nitration and halogenation. Hydrogenation occurs with platinum oxide (NTP, 1992).

Source: CAMEO Chemicals

Planning storage for a mix of chemicals? Check Benzo[a]pyrene in the storage compatibility matrix →

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