Naphthalene

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  • Identifiers

    CAS number
    91-20-3

    Molecular formula
    C10H8

    SMILES
    C1=CC=C2C=CC=CC2=C1

    Safety labels

    Irritant
    Irritant

    Health Hazard
    Health

    Environmental Hazard
    Environmental

    Retention indicies (RI)

    • DB5: 1180.2
    • Carbowax: 1740.14

  • Odor profile

    Pungent 62.43%
    Metallic 51.05%
    Geranium 49.99%
    Rose 46.72%
    Green 45.59%
    Camphoreous 45.43%
    Sweet 37.91%
    Earthy 32.42%
    Medicinal 30.47%
    Dry 29.91%

    Scent© AI

    Odor threshold>

    • Odor Threshold Low: 0.0095 [mmHg]. Odor Threshold High: 0.64 [mmHg]. Detection odor threshold from AIHA (mean = 0.038 ppm)
    • Odor detection in water 6.80 ppm (purity not specified)
    • At least as low as 0.3 ppm.
    • Odor threshold (water) 0.021 mg/L (w/v); odor threshold (air) 0.084 ppm (v/v)

  • Properties

    XLogP3-AA
    3.3

    Molecular weight
    128.17 g/mol

    Vapor pressure est.

    • hPa @ 20°C
    • hPa @ 25°C

    Evaporation rate
    Moderately fast

    Melting point expt.

    • 176.4 °F (NTP, 1992)
    • 80.2 °C
    • Sublimes appreciably at temperatures above melting point; volatile with steam
    • 80.3 °C
    • 80 °C
    • 176 °F

    Boiling point

    • 424 °F at 760 mmHg (NTP, 1992)
    • 217.9 deg C
    • 217.00 to 219.00 °C. @ 760.00 mm Hg
    • 218 °C
    • 424 °F

    Flash point est.
    87.82 ˚C

    Flash point expt.

    • 190 °F (NTP, 1992)
    • 174 °F (NFPA, 2010)
    • 174 °F; 79 °C (Closed cup)
    • 80 °C c.c.
    • 174 °F

    Solubility expt.

    • less than 1 mg/mL at 72 °F (NTP, 1992)
    • In water, 31 mg/L at 25 °C
    • 1 g/13 mL ethanol or methanol; 1 g/3.5 mL benzene or toluene; 1 g/8 mL olive oil or tupentine; 1 g/2 mL chloroform or carbon tetrachloride; 1 g/1.2 mL carbon disulfide. Very soluble in ether, hydronaphthalenes, and in fixed and volatile oils.
    • 0.031 mg/mL at 25 °C
    • Solubility in water at 20 °C: very poor
    • 0.003%

  • Synonyms

    • naphthalene
    • 91-20-3
    • Naphthalin
    • Albocarbon
    • Tar camphor
    • White tar
    • Naphthene
    • Naphthaline
    • Camphor tar
    • Moth balls
    • Moth flakes
    • naphtalene
    • Dezodorator
    • Naftalen
    • Mighty 150
    • Naphthalinum
    • RCRA waste number U165
    • Mighty RD1
    • naftaleno
    • naftalina
    • naphtaline
    • naphthalen
    • napthalene
    • Naphtalinum
    • Mothballs
    • Caswell No. 587
    • NCI-C52904
    • Naphthalene, pure
    • NSC 37565
    • CCRIS 1838
    • HSDB 184
    • Naphtalene [ISO:French]
    • EINECS 202-049-5
    • NSC-37565
    • EPA Pesticide Chemical Code 055801
    • UNII-2166IN72UN
    • DTXSID8020913
    • CHEBI:16482
    • AI3-00278
    • 2166IN72UN
    • MFCD00001742
    • Naphthalene-1,2,3,4-13C4
    • UN1334
    • CHEMBL16293
    • DTXCID00913
    • EC 202-049-5
    • NSC37565
    • Naphthalene, 99%
    • NCGC00090793-02
    • 287399-39-7
    • Naphtalene (ISO:French)
    • NAPHTHALENE (IARC)
    • NAPHTHALENE [IARC]
    • NAPHTHALENE (MART.)
    • NAPHTHALENE [MART.]
    • Naftalen [Polish]
    • NAPHTHALENE (USP-RS)
    • NAPHTHALENE [USP-RS]
    • Naphthalene, analytical standard
    • Naphthalene [BSI:ISO]
    • C10H8
    • CAS-91-20-3
    • Naphthalene, molten
    • Naphthalene (molten)
    • UN2304
    • RCRA waste no. U165
    • NAPHTHALENE (1,2,3,4,5,6,7,8-D8)
    • Naphthalene, crude or refined
    • 2-naphthalen
    • 1-Naphthalene
    • 2-Naphthalene
    • Naphthalene, 98%
    • 1,4-naphthalenediyl
    • NAPHTHALENE [MI]
    • NAPHTHALENE [ISO]
    • NAPHTHALENE [HSDB]
    • NAPHTHALENE, REFINED
    • NAPHTHALINUM [HPUS]
    • NAPHTHALENE [WHO-DD]
    • MLS001055498
    • WLN: L66J
    • BIDD:ER0665
    • DTXSID201315549
    • HMS3039N15
    • Tox21_111023
    • Tox21_202004
    • Tox21_300008
    • BDBM50159249
    • Naphthalene, for synthesis, 98.5%
    • STL282720
    • AKOS000119977
    • USEPA/OPP Pesticide Code 055801
    • FN10260
    • Naphthalene 100 microg/mL in Methanol
    • UN 1334
    • UN 2304
    • Naphthalene 10 microg/mL in Cyclohexane
    • NCGC00090793-01
    • NCGC00090793-03
    • NCGC00090793-04
    • NCGC00090793-05
    • NCGC00254058-01
    • NCGC00259553-01
    • BS-22320
    • Naphthalene 10 microg/mL in Acetonitrile
    • SMR000677944
    • Naphthalene 100 microg/mL in Acetonitrile
    • Naphthalene, SAJ first grade, >=98.0%
    • DB-361346
    • N0004
    • N0885
    • NS00008377
    • EN300-21626
    • C00829
    • D97670
    • SBI-0654024.0001
    • Naphthalene, suitable for scintillation, >=99%
    • L001166
    • Naphthalene, molten [UN2304] [Flammable solid]
    • Q179724
    • SR-01000854997
    • Melting point standard 79-81C, analytical standard
    • SR-01000854997-2
    • F0001-2217
    • Naphthalene, certified reference material, TraceCERT(R)
    • Z104506008
    • Naphthalene, crude or refined [UN1334] [Flammable solid]
    • Naphthalene, United States Pharmacopeia (USP) Reference Standard

  • Applications

    Naphthalene (CAS 91-20-3) is a key bicyclic aromatic hydrocarbon used mainly as a chemical intermediate: air oxidation to phthalic anhydride for alkyd/polyester resins and plasticizers; conversion to 1- and 2-naphthol, naphthylamines, and naphthoquinones for azo/disperse dyes, optical brighteners, and pharmaceutical/agrochemical intermediates (e.g., 1‑naphthol–derived carbaryl), and to 2,6‑naphthalenedicarboxylic acid for poly(ethylene naphthalate); sulfonation to naphthalene sulfonates and formaldehyde condensates employed as dispersants and high-range water reducers in concrete, as well as in gypsum, ceramics, coatings, pigments, and pesticide formulations; historically as a moth repellent (now restricted); additionally in melting-point/thermal calibration, phase‑change thermal storage, rubber auxiliaries, and PAH research, with stringent safety, health, and environmental controls due to its volatility, flammability, and toxicity.

  • Solubility @25˚C

    Solvent Solubility (g/L)
    ethanol 71.12
    methanol 50.88
    isopropanol 57.96
    water 0.18
    ethyl acetate 511.41
    n-propanol 75.65
    acetone 588.43
    n-butanol 80.12
    acetonitrile 278.21
    DMF 743.02
    toluene 441.14
    isobutanol 59.81
    1,4-dioxane 1369.32
    methyl acetate 484.24
    THF 1137.52
    2-butanone 480.82
    n-pentanol 84.77
    sec-butanol 65.54
    n-hexane 165.39
    ethylene glycol 13.3
    NMP 916.61
    cyclohexane 174.76
    DMSO 535.12
    n-butyl acetate 734.48
    n-octanol 107.87
    chloroform 919.02
    n-propyl acetate 569.0
    acetic acid 108.23
    dichloromethane 1257.72
    cyclohexanone 928.62
    propylene glycol 15.7
    isopropyl acetate 394.07
    DMAc 484.79
    2-ethoxyethanol 143.15
    isopentanol 84.03
    n-heptane 131.72
    ethyl formate 287.62
    1,2-dichloroethane 1062.1
    n-hexanol 132.17
    2-methoxyethanol 165.1
    isobutyl acetate 440.81
    tetrachloromethane 249.95
    n-pentyl acetate 338.39
    transcutol 619.23
    n-heptanol 86.43
    ethylbenzene 389.28
    MIBK 326.5
    2-propoxyethanol 227.69
    tert-butanol 88.82
    MTBE 236.96
    2-butoxyethanol 150.41
    propionic acid 128.31
    o-xylene 275.56
    formic acid 17.28
    diethyl ether 418.45
    m-xylene 290.68
    p-xylene 418.91
    chlorobenzene 499.55
    dimethyl carbonate 307.42
    n-octane 73.91
    formamide 61.38
    cyclopentanone 1167.86
    2-pentanone 444.89
    anisole 639.13
    cyclopentyl methyl ether 677.79
    gamma-butyrolactone 1131.87
    1-methoxy-2-propanol 142.7
    pyridine 837.63
    3-pentanone 459.58
    furfural 777.57
    n-dodecane 50.43
    diethylene glycol 98.28
    diisopropyl ether 213.32
    tert-amyl alcohol 87.91
    acetylacetone 694.45
    n-hexadecane 60.01
    acetophenone 503.14
    methyl propionate 418.78
    isopentyl acetate 535.9
    trichloroethylene 1443.44
    n-nonanol 108.92
    cyclohexanol 134.24
    benzyl alcohol 168.49
    2-ethylhexanol 157.53
    isooctanol 84.96
    dipropyl ether 529.45
    1,2-dichlorobenzene 487.37
    ethyl lactate 127.53
    propylene carbonate 680.64
    n-methylformamide 210.32
    2-pentanol 76.71
    n-pentane 65.92
    1-propoxy-2-propanol 206.15
    1-methoxy-2-propyl acetate 460.92
    2-(2-methoxypropoxy) propanol 181.52
    mesitylene 221.74
    ε-caprolactone 799.97
    p-cymene 195.47
    epichlorohydrin 1264.35
    1,1,1-trichloroethane 869.91
    2-aminoethanol 26.34
    morpholine-4-carbaldehyde 956.07
    sulfolane 1246.25
    2,2,4-trimethylpentane 41.21
    2-methyltetrahydrofuran 799.04
    n-hexyl acetate 415.98
    isooctane 43.08
    2-(2-butoxyethoxy)ethanol 230.0
    sec-butyl acetate 414.43
    tert-butyl acetate 448.78
    decalin 153.35
    glycerin 28.11
    diglyme 673.11
    acrylic acid 112.97
    isopropyl myristate 232.68
    n-butyric acid 207.59
    acetyl acetate 455.61
    di(2-ethylhexyl) phthalate 111.02
    ethyl propionate 526.46
    nitromethane 454.79
    1,2-diethoxyethane 706.98
    benzonitrile 347.17
    trioctyl phosphate 100.7
    1-bromopropane 513.95
    gamma-valerolactone 1142.46
    n-decanol 89.24
    triethyl phosphate 239.91
    4-methyl-2-pentanol 65.75
    propionitrile 246.12
    vinylene carbonate 600.27
    1,1,2-trichlorotrifluoroethane 334.13
    DMS 537.87
    cumene 244.2
    2-octanol 82.86
    2-hexanone 521.14
    octyl acetate 236.2
    limonene 269.46
    1,2-dimethoxyethane 757.6
    ethyl orthosilicate 218.72
    tributyl phosphate 142.11
    diacetone alcohol 244.88
    N,N-dimethylaniline 409.67
    acrylonitrile 320.04
    aniline 226.32
    1,3-propanediol 55.47
    bromobenzene 682.84
    dibromomethane 812.16
    1,1,2,2-tetrachloroethane 976.8
    2-methyl-cyclohexyl acetate 397.28
    tetrabutyl urea 215.13
    diisobutyl methanol 131.61
    2-phenylethanol 209.35
    styrene 459.63
    dioctyl adipate 274.63
    dimethyl sulfate 456.39
    ethyl butyrate 639.75
    methyl lactate 113.7
    butyl lactate 140.82
    diethyl carbonate 406.0
    propanediol butyl ether 87.55
    triethyl orthoformate 360.48
    p-tert-butyltoluene 182.67
    methyl 4-tert-butylbenzoate 287.12
    morpholine 764.41
    tert-butylamine 73.84
    n-dodecanol 78.82
    dimethoxymethane 551.2
    ethylene carbonate 563.73
    cyrene 205.5
    2-ethoxyethyl acetate 432.63
    2-ethylhexyl acetate 531.27
    1,2,4-trichlorobenzene 508.9
    4-methylpyridine 722.77
    dibutyl ether 439.03
    2,6-dimethyl-4-heptanol 131.61
    DEF 595.89
    dimethyl isosorbide 603.21
    tetrachloroethylene 731.0
    eugenol 220.12
    triacetin 357.4
    span 80 151.75
    1,4-butanediol 29.24
    1,1-dichloroethane 649.44
    2-methyl-1-pentanol 86.03
    methyl formate 237.95
    2-methyl-1-butanol 77.99
    n-decane 81.07
    butyronitrile 244.73
    3,7-dimethyl-1-octanol 124.3
    1-chlorooctane 219.0
    1-chlorotetradecane 106.88
    n-nonane 84.78
    undecane 61.97
    tert-butylcyclohexane 132.35
    cyclooctane 106.36
    cyclopentanol 166.84
    tetrahydropyran 803.58
    tert-amyl methyl ether 225.63
    2,5,8-trioxanonane 424.38
    1-hexene 315.9
    2-isopropoxyethanol 137.68
    2,2,2-trifluoroethanol 62.4
    methyl butyrate 640.1

    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

Botanical

Name CAS Botanical Proportion
Blackcurrant bud, absolute 68606-81-5 Ribes nigrum L., fam. Grossulariaceae 0.25%
Cassie absolute (blossom) 8023-82-3 Acacia farnesiana (L.) Willd., fam. Mimosaceae (Leguminosae) 1.26%
Coleonema pulchellum Coleonema pulchellum Williams (C. pulchrum Hook.), fam. Rutaceae 0.02%
Mentha spicata (Greece) Chemotype I Mentha spicata L. (Chemotype I), fam. Lamiaceae (Labiatae) 0.01%
Rue (Malaysia) 1 8014-29-7 Ruta graveolens L., fam. Rutaceae 0.05%
Saffron 1 8022-19-3 Crocus sativus L., fam. Iridaceae 0.1%
Melittis melissophyllum Melittis melissophylum L., ssp. albida Guss, fam. Lamiaceae (Labiatae) 0.08%
Narcissus poeticus absolute 8023-75-4 Narcissus poeticus L., fam. Amaryllidaceae 0.1%
Tagetes 2 8016-84-0 Tagetes minuta L. (Marigold), fam. Asteraceae (Compositae) 0.05%
Pistacia lentiscus fruit 90082-83-0 Pistacia lentiscus L., fam. Anacardiaceae 0.01%
Rue (Egypt) 8014-29-7 Ruta graveolens L., fam. Rutaceae 0.09%
Salvia triloba 2 (Greece) Salvia triloba L. (S. fruticosa Mill.), fam. Lamiaceae (Labiatae) 0.1%
Wartara (India) 1 pericarp Zanthoxylum armatum DC. (Z. alatum Roxb.), fam. Rutaceae 0.21%
Rhus coriaria Rhus coriaria L., fam. Anarcadiaceae 1.0%
Artemisia atrovirens (China) Artemisia atrovirens Hand.-Mazz., fam. Asteraceae (Compositae) 1.52%
Genet headspace 2 8023-80-1 Spartium junceum L., fam. Leguminosae (Papilionaceae) 0.01%
Plumeria rubra flower headspace (China) Plumeria rubra L. cultivar Acutifolia, fam. Apocynaceae 2.3%
Juniperus rigida (Japan) 2 Juniperus rigida Mig., fam. Cupressaceae 0.05%
Juniperus rigida (China) Juniperus rigida Mig., fam. Cupressaceae 0.05%
Juniperus rigida (Korea) Juniperus rigida Mig., fam. Cupressaceae 0.2%
Nicotiana forgetiana flower Nicotiana forgetiana Hort. ex Hensley (subgenus Petunioides), Solanaceae 0.71%
Pistacia vera fruit hull (Turkey) Pistacia vera L., fam. Anacardiaceae 0.11%
Origanum micranthum (Turkey) Origanum micranthum Vogel, fam. Lamiaceae (Labiatae) 0.03%
Teucrium heterophyllum (Madeira) Teucrium heterophyllum L'Her. (T. canariensis), fam. Lamiaceae (Labiatae) 0.95%
Lavandula pinnata Lavandula pinnata L. fil va. pinnata, fam Lamiaceae (Labiatae) 0.4%
Indian curry leaf tree (leaf) Murraya koenigii Spreng., fam. Rutaceae 0.4%
Celery seed (China) 3a 8015-90-5 Apium graveolens L., fam. Apiaceae (Umbelliferae) 0.79%
Celery seed (China) 3b 8015-90-5 Apium graveolens L., fam. Apiaceae (Umbelliferae) 0.33%
Pelargonium reniforme Pelargonium reniforme Curt., fam. Geraniaceae 0.1%
Psidium cattleianum fruit (R‚union Island) Psidium cattleianum Sabine, fam. Myrtaceae 0.1%
Juniper leaf (Sweden) 8012-91-7 Juniperus communis L., fam. Cupressaceae 0.05%
Hyptis crenata (Brazil) Hyptis crenata Pohl ex Benth, fam. Lamiaceae (Labiatae) 0.02%
Kohlrabi, green (seed) Brassica oleraceae var. gongylodes, fam. Brassicaceae (Cruciferae) 0.4%
Nepeta betonicifolia (Turkey) Nepeta betonicifolia C.A. Meyer, fam. Lamiaceae (Labiatae) 0.2%
Calamus (India) 3 root 8015-79-0 Acorus calamus L., fam. Araceae 0.52%
Carapa guianensis Carapa guianensis Aubl., fam. Meliaceae 0.2%
Decalepis hamiltonii root (India) Decalepis hamiltonii (Wight & Arn), fam. Asclepiadaceae 0.08%
Leea guineensis (Cameroon) 1a wood Leea guineensis G. Don, fam. Leeaceae 4.8%
Tordylium apulum fruit (Turkey) Tordylium apulum L., fam. Apiaceae (Umbelliferae) 3.9%
Tordylium pustulosum fruit (Turkey) Tordylium pustulosum Boiss., fam. Apiaceae (Umbelliferae) 1.5%
Argyranthemum adauctum ssp. erythrocarpon Argyranthemum adauctum ssp. erythrocarpon Humphries, fam. Asteraceae 0.01%
Hypericum perfoliatum (Greece) Hypericum perfoliatum L., fam. Guttiferae (Hyperiaceae) 0.02%
Oregano, greek (Greece) 2 84012-24-8 Origanum vulgare L. ssp. hirtum (Link) Ietsw., fam. Lamiaceae (Labiatae) 0.2%