Benzo[a]pyrene

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  • Identifiers

    CAS number
    50-32-8

    Molecular formula
    C20H12

    SMILES
    C1=CC=C2C3=C4C(=CC2=C1)C=CC5=C4C(=CC=C5)C=C3

    Safety labels

    Irritant
    Irritant

    Health Hazard
    Health

    Environmental Hazard
    Environmental

  • Odor profile

    Fragrance
    Floral 70.3%
    Animal 36.31%
    Rose 33.67%
    Geranium 33.53%
    Fruity 32.61%
    Pungent 32.61%
    Orange 27.27%
    Metallic 27.16%
    Neroli 22.19%
    Grape 21.43%

     

    Flavor
    Bitter 68.48%
    Animal 24.29%
    Very strong 19.04%
    Indole 18.4%
    Moth ball 17.96%
    Tar 17.9%
    Naphthelene 17.56%
    Tarry 17.31%
    Fecal 16.93%
    Nitrile 16.48%

     

    Odor impact est.
    Low

  • Properties

    XLogP3-AA
    6.0

    pKa est.
    7.21 (neutral)

    Molecular weight
    252.3 g/mol

    Vapor pressure est.

    • hPa @ 20°C
    • hPa @ 25°C

    Evaporation rate
    Ultra slow

    Melting point expt.

    • 349.7 to 351.5 °F (NTP, 1992)
    • 179 °C
    • 178.1 °C
    • 3497-3515 °F

    Boiling point

    • 887 °F at 760 mmHg (NTP, 1992)
    • BP: 310-312 °C at 10 mm Hg
    • Boiling point: > 360 °C at 760 mm Hg
    • 496 °C
    • 5612 °F

    Flash point

    • 238.71 ˚C est.

    Solubility expt.

    • less than 1 mg/mL at 63 °F (NTP, 1992)
    • In water, 1.62X10-3 mg/L at 25 °C
    • Soluble in benzene, toluene, xylene, and ether; slightly soluble in alcohol
    • Very soluble in chloroform
    • Solubility in aqueous caffeine is higher than in water; also, native DNA has a solubilizing effect
    • Solubility in water, g/100ml at 20 °C:

  • Synonyms

    • benzo[a]pyrene
    • 50-32-8
    • 3,4-Benzopyrene
    • BENZO(A)PYRENE
    • benzo[pqr]tetraphene
    • 3,4-Benzpyrene
    • benzo[def]chrysene
    • Benzpyrene
    • 6,7-Benzopyrene
    • 3,4-BP
    • Benz[a]pyrene
    • 3,4-Benz[a]pyrene
    • 3,4-Benzopirene
    • 3,4-Benzpyren
    • B(a)P
    • Benz(a)pyrene
    • Benzo(d,e,f)chrysene
    • 3,4-Benz(a)pyrene
    • 3,4 Benzpyrene
    • (B(a)P)
    • RCRA waste number U022
    • Benzo[d,e,f]chrysene
    • 3,4-Benzo(a)pyrene
    • B[a]p
    • NSC 21914
    • 3,4 Benzopyrene
    • Benzo(def)chrysene
    • 3,4-benzylpyrene
    • BP
    • CCRIS 76
    • CHEBI:29865
    • HSDB 2554
    • Benzo[A]-Pyrene
    • 3,4-Benzypyrene
    • EINECS 200-028-5
    • UNII-3417WMA06D
    • DTXSID2020139
    • AI3-50461
    • 3417WMA06D
    • MFCD00003602
    • NSC-21914
    • CHEMBL31184
    • DTXCID40139
    • NSC21914
    • benzo(pqr)tetraphene
    • BENZO(A)PYRENE-7 8-D2 98
    • 3,4-Benzopyrene (purified by sublimation)
    • BENZO(A)PYRENE (IARC)
    • BENZO(A)PYRENE [IARC]
    • 3,4-Benzpyren [German]
    • 3,4-Benzopirene [Italian]
    • Benzo[a]pyrene (BaP)
    • RCRA waste no. U022
    • Benzopireno
    • Benzo(a)pyrene radical cation
    • Benzo(a)pyrene, radical ion(1+)
    • Benzo(a)pyrene, radical ion(1-)
    • Benzo (a) pyrene
    • Benzo[d,f]chrysene
    • W62
    • 6,7-Benzpyren
    • Benzo(a)pyrene, labeled with tritium
    • Benzo(3,4)pyrene, radical ion(1+)
    • 42299-33-2
    • 6699-27-0
    • Spectrum_001871
    • Coal tar pitch volatiles: benzo(a)pyrene
    • SpecPlus_000953
    • Benzo[a]pyrene 1000 microg/mL in Acetone
    • Spectrum2_001081
    • Spectrum3_001695
    • Spectrum4_000609
    • Spectrum5_001824
    • 3 pound not4-Benzopyrene
    • Benzo[a]pyrene 10 microg/mL in Acetonitrile
    • Benzo[a]pyrene 100 microg/mL in Acetonitrile
    • Benzo[a]pyrene 100 microg/mL in Cyclohexane
    • Benzo[a]pyrene (Standard)
    • Epitope ID:117721
    • BENZO(A)PYRENE [MI]
    • BSPBio_003250
    • KBioGR_001138
    • KBioSS_002390
    • MLS002695983
    • BIDD:ER0497
    • DivK1c_007049
    • SPBio_001122
    • 3,4-Benzopyrene (carcinogen)
    • BENZO(A)PYRENE [HSDB]
    • KBio1_001993
    • KBio2_002385
    • KBio2_004953
    • KBio2_007521
    • KBio3_002470
    • MSK4305
    • HMS3089C04
    • HMS3746C17
    • 52 - Low Level CIP2 contaminants
    • Benzo[a]pyrene, >=96% (HPLC)
    • Tox21_200710
    • 3,4-BENZPYRENE (CARCINOGEN)
    • BDBM50137506
    • CCG-39759
    • AKOS015907666
    • CS-7789
    • FB18224
    • HY-107377R
    • CAS-50-32-8
    • WLN: L D6 B6666 2AB TJ
    • NCGC00178185-01
    • NCGC00178185-02
    • NCGC00258264-01
    • 34505-58-3
    • NCI60_001824
    • SMR000393676
    • SY048151
    • DB-071166
    • HY-107377
    • B0085
    • NS00006321
    • C07535
    • A828067
    • Benzo[a]pyrene, vial of 1 g, analytical standard
    • Q306051
    • Benzo[a]pyrene;3,4-Benz[a]pyrene;3,4-Benzopyrene
    • BRD-K09668667-001-02-0
    • Benzo[a]pyrene, certified reference material, TraceCERT(R)
    • Benzo[a]pyrene, analytical standard, for environmental analysis

  • Applications

    Benzo[a]pyrene, CAS number: 50-32-8, is primarily treated as an analytical reference standard and a model compound for studying PAHs, not a commercial additive. Real-world applications focus on analytical and environmental contexts: providing calibration standards for PAH analysis (GC/LC-MS) in environmental monitoring of air, water, and soil; serving as a model carcinogen in toxicology and mechanistic studies of metabolic activation and DNA adduct formation; used in environmental remediation research as a target contaminant in soil, sediment, and ash treatment assessments; informing material safety and regulatory discussions for PAH-containing products such as coal tar-derived materials and bitumen by indicating contamination levels; and supporting risk assessment frameworks and regulatory compliance through exposure and limit-setting studies. Because BaP occurs in mixtures and as a contaminant rather than a formulated additive, its use is subject to local regulations and formulation limits.

    gpt-5-nano

  • Solubility @25˚C

    Solvent Solubility (g/L)
    ethanol 0.11
    methanol 0.09
    isopropanol 0.07
    water 0.0
    ethyl acetate 1.45
    n-propanol 0.15
    acetone 0.72
    n-butanol 0.15
    acetonitrile 0.12
    DMF 4.63
    toluene 4.43
    isobutanol 0.12
    1,4-dioxane 7.55
    methyl acetate 1.19
    THF 17.36
    2-butanone 1.55
    n-pentanol 0.23
    sec-butanol 0.13
    n-hexane 0.08
    ethylene glycol 0.05
    NMP 12.15
    cyclohexane 0.15
    DMSO 1.75
    n-butyl acetate 4.51
    n-octanol 0.68
    chloroform 1.73
    n-propyl acetate 2.76
    acetic acid 0.38
    dichloromethane 3.9
    cyclohexanone 5.12
    propylene glycol 0.06
    isopropyl acetate 2.31
    DMAc 7.74
    2-ethoxyethanol 0.91
    isopentanol 0.24
    n-heptane 0.31
    ethyl formate 0.63
    1,2-dichloroethane 4.48
    n-hexanol 0.62
    2-methoxyethanol 0.87
    isobutyl acetate 4.22
    tetrachloromethane 0.34
    n-pentyl acetate 5.09
    transcutol 12.81
    n-heptanol 0.76
    ethylbenzene 5.85
    MIBK 2.3
    2-propoxyethanol 2.28
    tert-butanol 0.19
    MTBE 0.94
    2-butoxyethanol 2.34
    propionic acid 0.39
    o-xylene 4.3
    formic acid 0.09
    diethyl ether 0.95
    m-xylene 3.83
    p-xylene 4.79
    chlorobenzene 1.51
    dimethyl carbonate 3.3
    n-octane 0.33
    formamide 0.27
    cyclopentanone 9.71
    2-pentanone 1.46
    anisole 11.01
    cyclopentyl methyl ether 4.82
    gamma-butyrolactone 9.26
    1-methoxy-2-propanol 0.81
    pyridine 8.62
    3-pentanone 2.06
    furfural 9.84
    n-dodecane 0.27
    diethylene glycol 1.2
    diisopropyl ether 1.0
    tert-amyl alcohol 0.32
    acetylacetone 5.5
    n-hexadecane 0.36
    acetophenone 10.64
    methyl propionate 1.8
    isopentyl acetate 7.33
    trichloroethylene 10.2
    n-nonanol 0.96
    cyclohexanol 0.32
    benzyl alcohol 2.18
    2-ethylhexanol 1.29
    isooctanol 0.97
    dipropyl ether 3.82
    1,2-dichlorobenzene 3.78
    ethyl lactate 1.59
    propylene carbonate 4.86
    n-methylformamide 0.55
    2-pentanol 0.15
    n-pentane 0.04
    1-propoxy-2-propanol 2.25
    1-methoxy-2-propyl acetate 10.6
    2-(2-methoxypropoxy) propanol 6.56
    mesitylene 3.54
    ε-caprolactone 6.26
    p-cymene 5.43
    epichlorohydrin 12.06
    1,1,1-trichloroethane 2.04
    2-aminoethanol 0.12
    morpholine-4-carbaldehyde 14.28
    sulfolane 13.59
    2,2,4-trimethylpentane 0.16
    2-methyltetrahydrofuran 5.24
    n-hexyl acetate 5.7
    isooctane 0.16
    2-(2-butoxyethoxy)ethanol 6.13
    sec-butyl acetate 3.75
    tert-butyl acetate 6.32
    decalin 0.79
    glycerin 0.24
    diglyme 21.17
    acrylic acid 0.57
    isopropyl myristate 5.04
    n-butyric acid 0.57
    acetyl acetate 2.9
    di(2-ethylhexyl) phthalate 5.43
    ethyl propionate 3.57
    nitromethane 1.14
    1,2-diethoxyethane 9.78
    benzonitrile 2.22
    trioctyl phosphate 2.52
    1-bromopropane 1.18
    gamma-valerolactone 14.35
    n-decanol 0.79
    triethyl phosphate 7.07
    4-methyl-2-pentanol 0.29
    propionitrile 0.28
    vinylene carbonate 4.83
    1,1,2-trichlorotrifluoroethane 5.46
    DMS 12.05
    cumene 5.25
    2-octanol 0.62
    2-hexanone 2.92
    octyl acetate 4.07
    limonene 4.37
    1,2-dimethoxyethane 6.95
    ethyl orthosilicate 6.93
    tributyl phosphate 3.39
    diacetone alcohol 3.14
    N,N-dimethylaniline 12.15
    acrylonitrile 0.59
    aniline 1.58
    1,3-propanediol 0.19
    bromobenzene 2.73
    dibromomethane 1.83
    1,1,2,2-tetrachloroethane 5.8
    2-methyl-cyclohexyl acetate 10.9
    tetrabutyl urea 6.53
    diisobutyl methanol 1.52
    2-phenylethanol 3.9
    styrene 4.41
    dioctyl adipate 9.63
    dimethyl sulfate 7.08
    ethyl butyrate 6.3
    methyl lactate 1.16
    butyl lactate 3.0
    diethyl carbonate 5.47
    propanediol butyl ether 1.48
    triethyl orthoformate 7.53
    p-tert-butyltoluene 5.47
    methyl 4-tert-butylbenzoate 14.02
    morpholine 4.61
    tert-butylamine 0.15
    n-dodecanol 0.71
    dimethoxymethane 4.22
    ethylene carbonate 2.89
    cyrene 7.39
    2-ethoxyethyl acetate 9.87
    2-ethylhexyl acetate 8.26
    1,2,4-trichlorobenzene 6.71
    4-methylpyridine 4.52
    dibutyl ether 3.92
    2,6-dimethyl-4-heptanol 1.52
    DEF 3.84
    dimethyl isosorbide 25.3
    tetrachloroethylene 4.3
    eugenol 9.83
    triacetin 10.34
    span 80 4.63
    1,4-butanediol 0.09
    1,1-dichloroethane 0.78
    2-methyl-1-pentanol 0.54
    methyl formate 0.73
    2-methyl-1-butanol 0.24
    n-decane 0.44
    butyronitrile 0.28
    3,7-dimethyl-1-octanol 1.24
    1-chlorooctane 1.65
    1-chlorotetradecane 1.04
    n-nonane 0.34
    undecane 0.34
    tert-butylcyclohexane 0.85
    cyclooctane 0.2
    cyclopentanol 0.42
    tetrahydropyran 3.14
    tert-amyl methyl ether 1.54
    2,5,8-trioxanonane 17.4
    1-hexene 0.42
    2-isopropoxyethanol 1.15
    2,2,2-trifluoroethanol 0.24
    methyl butyrate 3.6

    Scent© AI

1 4

IFRA standard 51

Recommendation
No restriction
Maximum acceptable concentrations in the finished product (%)
Category 1
Products applied to the lips
 No restriction Category 7A
Rinse-off products applied to the hair with some hand contact
 No restriction
Category 2
Products applied to the axillae
 No restriction Category 7B
Leave-on products applied to the hair with some hand contact
 No restriction
Category 3
Products applied to the face/body using fingertips
 No restriction Category 8
Products with significant anogenital exposure
 No restriction
Category 4
Products related to fine fragrance
 No restriction Category 9
Products with body and hand exposure, primarily rinse off
 No restriction
Category 5A
Body lotion products applied to the body using the hands (palms), primarily leave on
 No restriction Category 10A
Household care products with mostly hand contact
 No restriction
Category 5B
Face moisturizer products applied to the face using the hands (palms), primarily leave on
 No restriction Category 10B
Household care products with mostly hand contact, including aerosol/spray products (with potential leave-on skin contact)
 No restriction
Category 5C
Hand cream products applied to the hands using the hands (palms), primarily leave on
 No restriction Category 11A
Products with intended skin contact but minimal transfer of fragrance to skin from inert substrate without UV exposure
 No restriction
Category 5D
Baby Creams, baby Oils and baby talc
 No restriction Category 11B
Products with intended skin contact but minimal transfer of fragrance to skin from inert substrate with potential UV exposure
 No restriction
Category 6
Products with oral and lip exposure
 No restriction Category 12
Products not intended for direct skin contact, minimal or insignificant transfer to skin
 No restriction