Benzene

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  • Identifiers

    CAS number
    71-43-2

    Molecular formula
    C6H6

    SMILES
    C1=CC=CC=C1

    Safety labels

    Flammable
    Flammable

    Irritant
    Irritant

    Health Hazard
    Health

    Retention indicies (RI)

    • DB5: 660.0
    • Carbowax: 934.5

  • Odor profile

    Sweet 56.84%
    Pungent 51.33%
    Metallic 42.16%
    Green 37.56%
    Rose 35.14%
    Geranium 31.36%
    Camphoreous 30.77%
    Earthy 24.19%
    Gassy 22.94%
    Dry 22.6%

    Scent© AI

    Odor threshold

    • Odor Threshold Low: 34.0 [mmHg]. Odor Threshold High: 119.0 [mmHg]. Detection odor thresholds from AIHA
    • 4.68 PPM
    • In air: 4.9 mg/cu m (characteristic odor), in water: 2.0 mg/l.
    • distinct odor: 310 mg/cu m= 90 ppm
    • human odor perception: 3.0 mg/cu m=1 ppm

  • Properties

    XLogP3-AA
    2.1

    pKa est.
    7.63 (neutral)

    Molecular weight
    78.11 g/mol

    Vapor pressure est.

    • hPa @ 20°C
    • hPa @ 25°C

    Evaporation rate
    Ultra fast

    Melting point expt.

    • 41.9 °F (NTP, 1992)
    • 5.558 °C
    • 5.5 °C
    • 6 °C
    • 41.9 °F
    • 42 °F

    Boiling point

    • 176.2 °F at 760 mmHg (NTP, 1992)
    • 80.08 °C
    • 80.00 to 81.00 °C. @ 760.00 mm Hg
    • 80 °C
    • 176.2 °F
    • 176 °F

    Flash point est.
    -6.97 ˚C

    Flash point expt.

    • 12 °F (NTP, 1992)
    • 12 °F
    • 12 °F (-11 °C) Closed Cup
    • -11.0 °C (12.2 °F) (Closed cup)
    • -11 °C c.c.

    Solubility expt.

    • 1 to 5 mg/mL at 64 °F (NTP, 1992)
    • In water, 1.79X10+3 mg/L at 25 °C
    • Miscible with alcohol, chloroform, ether, carbon disulfide, acetone, oils, carbon tetrachloride, and glacial acetic acid
    • Miscible with ethanol, ethyl ether, acetone, chloroform; coluble in carbon tetrachloride
    • 1.79 mg/mL
    • Solubility in water, g/100ml at 25 °C: 0.18
    • 0.07%

  • Synonyms

    • benzene
    • benzol
    • 71-43-2
    • Cyclohexatriene
    • benzole
    • Pyrobenzole
    • Benzine
    • Benzen
    • Coal naphtha
    • Pyrobenzol
    • Mineral naphtha
    • Phene
    • Phenyl hydride
    • Benzolene
    • Bicarburet of hydrogen
    • Motor benzol
    • Benzeen
    • Benzin
    • Benzolo
    • Fenzen
    • [6]Annulene
    • Nitration benzene
    • (6)Annulene
    • Benzol 90
    • NCI-C55276
    • Benzine (Obs.)
    • Rcra waste number U019
    • Benzin (Obs.)
    • Benzinum
    • Caswell No. 077
    • Benzene, pure
    • 1,3,5-cyclohexatriene
    • CCRIS 70
    • HSDB 35
    • NSC 67315
    • UN 1114
    • CHEBI:16716
    • EINECS 200-753-7
    • EPA Pesticide Chemical Code 008801
    • DTXSID3039242
    • AI3-00808
    • UNII-J64922108F
    • BENZENE (BENZOL)
    • NSC-67315
    • UN1114
    • DTXCID20135
    • CHEMBL277500
    • J64922108F
    • EC 200-753-7
    • NSC67315
    • MFCD00003009
    • 54682-86-9
    • BENZENE (IARC)
    • BENZENE [IARC]
    • BENZENE (MART.)
    • BENZENE [MART.]
    • BENZENE (USP-RS)
    • BENZENE [USP-RS]
    • phenylmanganese iodide
    • Benzeen [Dutch]
    • Benzen [Polish]
    • Fenzen [Czech]
    • Benzolo [Italian]
    • BNZ
    • Benzene 100 microg/mL in Methanol
    • Benzene, ACS reagent, >=99.0%
    • BENZENE (1,3,5-D3)
    • 62485-97-6
    • benzene,iodomanganese(1+)
    • Benzolum
    • Benzene (including benzene from gasoline)
    • p-benzene
    • benzene-
    • C6H6
    • 26181-88-4
    • 1hyz
    • 1swi
    • benzin /obsolete/
    • 1,4-phenylene
    • benzine /obsolete/
    • [6]-annulene
    • Benzene ACS Grade
    • Benzene HPLC grade
    • Benzene, for HPLC
    • Caswell no 077
    • {[6]Annulene}
    • MINERAL NAPHTA
    • Ph-H
    • Phenyl; Phenyl Radical
    • 2z9g
    • 4i7j
    • HEADACHE INSOMNIA
    • BENZENE [VANDF]
    • BENZINUM [HPUS]
    • Benzene + aniline combo
    • BENZENE [HSDB]
    • BENZENE [MI]
    • Benzene, labeled with carbon-14 and tritium
    • WLN: RH
    • BENZENE [WHO-DD]
    • 22 - BTEX in Soil
    • Epitope ID:116867
    • Benzene, purification grade
    • Benzene, analytical standard
    • 5 - VOCs
    • Benzene, LR, >=99%
    • ghl.PD_Mitscher_leg0.503
    • Benzene, anhydrous, 99.8%
    • Benzene, AR, >=99.5%
    • 34J - WFD J
    • 3,4-DNH
    • 1l83
    • 220l
    • 223l
    • 7 - VOCs (Perkin Elmer tubes)
    • Benzene 10 microg/mL in Methanol
    • DTXSID101337601
    • DTXSID301037374
    • trans-N-Methylphenylcyclopropylamine
    • BCP26158
    • Benzene 20 microg/mL in Triacetin
    • Benzene, for HPLC, >=99.8%
    • Benzene, for HPLC, >=99.9%
    • Tox21_202487
    • BDBM50167939
    • BM 613
    • MSK001098
    • STL264205

  • Applications

    Benzene (CAS 71-43-2) is a cornerstone petrochemical feedstock: alkylated to ethylbenzene for styrene and SBR/ABS rubbers; converted via the cumene process to phenol and acetone; hydrogenated to cyclohexane for adipic acid and caprolactam in nylon; linearly alkylated to produce LAB for detergent surfactants; nitrated then reduced to aniline for dyes, polyurethanes (MDI/TDI) and pharmaceuticals; chlorinated/derivatized for agrochemicals, additives and engineering resins; additionally used under strict control as a solvent, analytical standard and as deuterated benzene (C6D6) for NMR, and historically as a gasoline octane improver now largely restricted due to toxicity; as a Group 1 carcinogen, its use requires closed systems, vapor recovery, strict exposure limits and substitution with safer solvents whenever feasible.

  • Solubility @25˚C

    Solvent Solubility (g/L)
    ethanol 41.6
    methanol 34.35
    isopropanol 31.93
    water 0.14
    ethyl acetate 232.28
    n-propanol 44.66
    acetone 121.29
    n-butanol 40.83
    acetonitrile 150.42
    DMF 129.05
    toluene 108.55
    isobutanol 29.19
    1,4-dioxane 224.25
    methyl acetate 183.81
    THF 279.11
    2-butanone 148.6
    n-pentanol 32.8
    sec-butanol 39.31
    n-hexane 35.1
    ethylene glycol 10.8
    NMP 159.27
    cyclohexane 37.17
    DMSO 139.18
    n-butyl acetate 164.48
    n-octanol 26.56
    chloroform 554.79
    n-propyl acetate 123.3
    acetic acid 80.34
    dichloromethane 543.7
    cyclohexanone 153.51
    propylene glycol 18.13
    isopropyl acetate 116.2
    DMAc 145.66
    2-ethoxyethanol 56.84
    isopentanol 35.23
    n-heptane 49.74
    ethyl formate 83.84
    1,2-dichloroethane 282.21
    n-hexanol 46.24
    2-methoxyethanol 78.57
    isobutyl acetate 70.62
    tetrachloromethane 94.59
    n-pentyl acetate 73.51
    transcutol 265.2
    n-heptanol 26.19
    ethylbenzene 71.54
    MIBK 65.95
    2-propoxyethanol 75.33
    tert-butanol 42.06
    MTBE 78.1
    2-butoxyethanol 51.4
    propionic acid 87.23
    o-xylene 67.35
    formic acid 14.58
    diethyl ether 139.06
    m-xylene 61.47
    p-xylene 78.1
    chlorobenzene 142.79
    dimethyl carbonate 75.08
    n-octane 15.74
    formamide 34.77
    cyclopentanone 226.38
    2-pentanone 120.51
    anisole 145.37
    cyclopentyl methyl ether 130.92
    gamma-butyrolactone 280.04
    1-methoxy-2-propanol 73.3
    pyridine 269.11
    3-pentanone 125.97
    furfural 243.21
    n-dodecane 9.08
    diethylene glycol 41.11
    diisopropyl ether 49.54
    tert-amyl alcohol 47.59
    acetylacetone 166.74
    n-hexadecane 10.29
    acetophenone 124.46
    methyl propionate 148.55
    isopentyl acetate 111.85
    trichloroethylene 592.63
    n-nonanol 27.13
    cyclohexanol 39.05
    benzyl alcohol 52.49
    2-ethylhexanol 47.21
    isooctanol 23.61
    dipropyl ether 172.15
    1,2-dichlorobenzene 148.49
    ethyl lactate 46.39
    propylene carbonate 181.32
    n-methylformamide 66.86
    2-pentanol 34.1
    n-pentane 22.33
    1-propoxy-2-propanol 83.42
    1-methoxy-2-propyl acetate 135.67
    2-(2-methoxypropoxy) propanol 72.4
    mesitylene 40.33
    ε-caprolactone 160.5
    p-cymene 55.66
    epichlorohydrin 297.64
    1,1,1-trichloroethane 330.85
    2-aminoethanol 23.6
    morpholine-4-carbaldehyde 186.47
    sulfolane 256.87
    2,2,4-trimethylpentane 12.59
    2-methyltetrahydrofuran 195.58
    n-hexyl acetate 77.62
    isooctane 9.65
    2-(2-butoxyethoxy)ethanol 83.52
    sec-butyl acetate 89.5
    tert-butyl acetate 109.36
    decalin 27.19
    glycerin 25.11
    diglyme 210.1
    acrylic acid 83.23
    isopropyl myristate 51.62
    n-butyric acid 115.01
    acetyl acetate 185.99
    di(2-ethylhexyl) phthalate 36.03
    ethyl propionate 141.98
    nitromethane 192.46
    1,2-diethoxyethane 180.96
    benzonitrile 102.07
    trioctyl phosphate 22.97
    1-bromopropane 177.75
    gamma-valerolactone 217.36
    n-decanol 20.93
    triethyl phosphate 71.39
    4-methyl-2-pentanol 22.62
    propionitrile 121.26
    vinylene carbonate 158.98
    1,1,2-trichlorotrifluoroethane 198.69
    DMS 106.97
    cumene 46.25
    2-octanol 18.95
    2-hexanone 102.41
    octyl acetate 53.88
    limonene 79.23
    1,2-dimethoxyethane 156.54
    ethyl orthosilicate 66.92
    tributyl phosphate 33.91
    diacetone alcohol 85.04
    N,N-dimethylaniline 93.62
    acrylonitrile 160.35
    aniline 76.96
    1,3-propanediol 30.2
    bromobenzene 189.19
    dibromomethane 350.86
    1,1,2,2-tetrachloroethane 415.96
    2-methyl-cyclohexyl acetate 98.49
    tetrabutyl urea 44.93
    diisobutyl methanol 41.35
    2-phenylethanol 58.76
    styrene 99.35
    dioctyl adipate 82.58
    dimethyl sulfate 115.69
    ethyl butyrate 190.83
    methyl lactate 55.34
    butyl lactate 45.25
    diethyl carbonate 128.83
    propanediol butyl ether 33.89
    triethyl orthoformate 123.12
    p-tert-butyltoluene 51.36
    methyl 4-tert-butylbenzoate 89.22
    morpholine 191.72
    tert-butylamine 34.89
    n-dodecanol 18.17
    dimethoxymethane 106.36
    ethylene carbonate 123.97
    cyrene 68.83
    2-ethoxyethyl acetate 105.62
    2-ethylhexyl acetate 107.88
    1,2,4-trichlorobenzene 170.61
    4-methylpyridine 173.3
    dibutyl ether 96.12
    2,6-dimethyl-4-heptanol 41.35
    DEF 150.13
    dimethyl isosorbide 165.85
    tetrachloroethylene 236.95
    eugenol 69.22
    triacetin 112.29
    span 80 64.7
    1,4-butanediol 12.42
    1,1-dichloroethane 234.99
    2-methyl-1-pentanol 34.74
    methyl formate 56.49
    2-methyl-1-butanol 35.9
    n-decane 15.11
    butyronitrile 102.11
    3,7-dimethyl-1-octanol 34.62
    1-chlorooctane 43.02
    1-chlorotetradecane 20.4
    n-nonane 16.23
    undecane 11.16
    tert-butylcyclohexane 23.14
    cyclooctane 20.52
    cyclopentanol 48.9
    tetrahydropyran 165.97
    tert-amyl methyl ether 74.99
    2,5,8-trioxanonane 154.53
    1-hexene 79.08
    2-isopropoxyethanol 45.26
    2,2,2-trifluoroethanol 35.89
    methyl butyrate 146.63

    Scent© AI

1 4

IFRA standard 51

Recommendation
Prohibition / Specification
Maximum acceptable concentrations in the finished product (%)
Category 1
Products applied to the lips
 See notebox Category 7A
Rinse-off products applied to the hair with some hand contact
 See notebox
Category 2
Products applied to the axillae
 See notebox Category 7B
Leave-on products applied to the hair with some hand contact
 See notebox
Category 3
Products applied to the face/body using fingertips
 See notebox Category 8
Products with significant anogenital exposure
 See notebox
Category 4
Products related to fine fragrance
 See notebox Category 9
Products with body and hand exposure, primarily rinse off
 See notebox
Category 5A
Body lotion products applied to the body using the hands (palms), primarily leave on
 See notebox Category 10A
Household care products with mostly hand contact
 See notebox
Category 5B
Face moisturizer products applied to the face using the hands (palms), primarily leave on
 See notebox Category 10B
Household care products with mostly hand contact, including aerosol/spray products (with potential leave-on skin contact)
 See notebox
Category 5C
Hand cream products applied to the hands using the hands (palms), primarily leave on
 See notebox Category 11A
Products with intended skin contact but minimal transfer of fragrance to skin from inert substrate without UV exposure
 See notebox
Category 5D
Baby Creams, baby Oils and baby talc
 See notebox Category 11B
Products with intended skin contact but minimal transfer of fragrance to skin from inert substrate with potential UV exposure
 See notebox
Category 6
Products with oral and lip exposure
 See notebox Category 12
Products not intended for direct skin contact, minimal or insignificant transfer to skin
 See notebox

Prohibition
Benzene should not be used as a fragrance ingredient.

Specification
The level of Benzene has to be kept as low as practicable and should never exceed 1 ppm in the fragrance compound/mixture or fragrance oil.
Since the introduction of the original Restriction on the use of Benzene by IFRA in 1988, there have been significant changes in manufacturing practices that permit the reduction of the maximum permitted level of this substance. These include use of technological improvements allowing replacement of this solvent for the extraction of fragrance materials and in eliminating its presence as an impurity in alternative extraction solvents.

Botanical

Name CAS Botanical Proportion
Carrot seed (France) 1 8015-88-1 Daucus carota L., fam. Apiaceae (Umbelliferae) 0.01%
Ginger (Australia) 1 8007-08-7 Zingiber officinale Roscoe, fam. Zingiberaceae 0.05%
Ginger (India) 3 8007-08-7 Zingiber officinale Roscoe, fam. Zingiberaceae 0.03%
Styrax (China) 8024-01-9 Liquidamber formosana Hance, fam. Hamamelidaceae 0.16%
Curcuma aromatica (India) 1 petiole Curcuma aromatica Salisb., fam. Zingiberaceae 0.2%
Sage, dalmatian (Serbia-Montenegro) 1a leaf Salvia officinalis L., fam. Lamiaceae (Labiatae) 0.01%
Patchouli (China) 3a root 8014-09-3 Pogostemon cablin Benth., fam. Lamiaceae (Labiatae) 0.03%
Patchouli (China) 3b rhizome 8014-09-3 Pogostemon cablin Benth., fam. Lamiaceae (Labiatae) 0.12%
Ageratum conyzoides (Nigeria) 85480-32-6 Ageratum conyzoides L., fam. Asteraceae (Compositae) 0.01%