Propylene Glycol

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  • Identifiers

    CAS number
    57-55-6

    Molecular formula
    C3H8O2

    SMILES
    CC(CO)O

    Safety labels

    Irritant
    Irritant

    Health Hazard
    Health

  • Odor profile

    Sweet 53.35%
    Alcoholic 43.94%
    Odorless 43.17%
    Ethereal 34.61%
    Caramellic 33.38%
    Buttery 32.37%
    Solvent 26.85%
    Oily 25.98%
    Creamy 22.25%
    Fishy 21.74%

    Scent© AI

  • Properties

    XLogP3-AA
    -0.9

    Molecular weight
    76.09 g/mol

    Vapor pressure est.

    • hPa @ 20°C
    • hPa @ 25°C

    Evaporation rate
    Moderate

    Melting point expt.

    • -76 °F (NTP, 1992)
    • -60 °C
    • -59 °C
    • -76 °F

    Boiling point

    • 370.8 °F at 760 mmHg (NTP, 1992)
    • 187.6 °C
    • 188.2 °C
    • 370.8 °F

    Flash point est.
    89.69 ˚C

    Flash point expt.

    • 210 °F (NTP, 1992)
    • 99 °C
    • 104 °C Pensky-Martens closed cup
    • 210 °F (99 °C) (Closed cup)
    • 225 °F (Open cup)
    • 101 °C c.c.
    • 210 °F

    Solubility expt.

    • greater than or equal to 100 mg/mL at 70 °F (NTP, 1992)
    • 1000000 mg/L (at 20 °C)
    • Soluble in water, ethanol and acetone
    • Soluble in benzene
    • Miscible with acetone and chloroform; soluble in ether. Will dissolve many essential oils, but is immiscible with fixed oils.
    • In water, 1X10+6 mg/L at 20 °C /miscible/
    • Solubility in water: miscible

  • Synonyms

    • propylene glycol
    • 1,2-propanediol
    • 57-55-6
    • propane-1,2-diol
    • 1,2-Propylene glycol
    • 1,2-dihydroxypropane
    • 2-Hydroxypropanol
    • Isopropylene glycol
    • Methylethyl glycol
    • Methylethylene glycol
    • Monopropylene glycol
    • Dowfrost
    • Sirlene
    • Trimethyl glycol
    • 2,3-Propanediol
    • Propylene Glycol USP
    • Solargard P
    • alpha-Propyleneglycol
    • Solar Winter BAN
    • dl-Propylene glycol
    • DL-1,2-Propanediol
    • Ucar 35
    • 1,2-Propylenglykol
    • (RS)-1,2-Propanediol
    • Sentry Propylene Glycol
    • PG 12
    • FEMA No. 2940
    • (+-)-1,2-Propanediol
    • Kilfrost ABC-S
    • (+-)-Propylene glycol
    • Caswell No. 713
    • General lube
    • Kollisolv pg
    • CCRIS 5929
    • HSDB 174
    • 1,2 Propanediol
    • All purpose lubricant
    • AI3-01898
    • alpha-Propylene glycol
    • 1,2-Propylenglykol [German]
    • NSC 69860
    • HOCH2CH(OH)Me
    • MeCH(OH)CH2OH
    • EPA Pesticide Chemical Code 068603
    • CHEBI:16997
    • Propyleneglycolum
    • .alpha.-Propylene glycol
    • CH3CH(OH)CH2OH
    • HOCH2CH(OH)CH3
    • 1,2-(RS)-Propanediol
    • propylene glycerol
    • Propylene glycol (solvent)
    • 1,2-propandiol
    • EINECS 200-338-0
    • (+/-)-1,2-propanediol
    • 1000PG
    • MFCD00064272
    • NSC-69860
    • SDM No. 27
    • 1,2-propane-diol
    • Ins-1520
    • UNII-6DC9Q167V3
    • BRN 1340498
    • DTXSID0021206
    • PROPANEDIOL-
    • 6DC9Q167V3
    • Propylene glycol dl-form
    • S-(+)-Propylene glycol
    • Ins no.1520
    • 123120-98-9
    • propylenglycol
    • Propylene glycol [USP:JAN]
    • DTXCID901206
    • 1,2-Propanediol (8CI,9CI)
    • ( inverted exclamation markA)-1,2-Propanediol
    • 1,2-PDO
    • E-1520
    • EC 200-338-0
    • (2RS)-PROPANE-1,2-DIOL
    • NSC69860
    • L-1,2-propanediol
    • Poly(propylene glycol) average Mn 400
    • NCGC00090739-02
    • Poly(propylene glycol) average Mn 2000
    • Poly(propylene glycol) average Mn 4000
    • Prolugen
    • Propylene glycol (USP:JAN)
    • PROPYLENE GLYCOL (II)
    • PROPYLENE GLYCOL [II]
    • propylene-glycol
    • C3H8O2
    • Propan-1,2-Diol
    • Ilexan P
    • PROPYLENE GLYCOL (MART.)
    • PROPYLENE GLYCOL [MART.]
    • PROPYLENE GLYCOL (USP-RS)
    • PROPYLENE GLYCOL [USP-RS]
    • 1,2-(RS)-Propanediol; 1,2-Dihydroxypropane; 1,2-Propylene glycol
    • PROPYLENE GLYCOL (EP MONOGRAPH)
    • PROPYLENE GLYCOL [EP MONOGRAPH]
    • Glycol, Propylene
    • CAS-57-55-6
    • PROPYLENE GLYCOL (USP MONOGRAPH)
    • PROPYLENE GLYCOL [USP MONOGRAPH]
    • 63625-56-9
    • GLYCEROL IMPURITY C (EP IMPURITY)
    • GLYCEROL IMPURITY C [EP IMPURITY]
    • 1,2-propane diol
    • ()-1,2-propanediol
    • (S)-(+)-Propylene glycerol
    • Propilenoglicol
    • Propylenglykol
    • Propylenglycolum
    • Systane Balance
    • Metiletilenglicol
    • Propyleeniglykoli
    • Vet Lube
    • Glicol propilenico
    • Glikol propylenowy
    • 1-2-propanediol
    • 1.2-propanediol
    • OB Lube
    • 2-Dihydroxypropanol
    • Propylene glycol; (RS)-propane-1,2-diol; Glycerol Imp. C (EP); GR 43314X; Glycerol Impurity C
    • Systane COMPLETE
    • 1,2 -propanediol
    • Lubiseptol Lubricant
    • 1,2-Hydroxypropane

  • Applications

    Propylene glycol (PG, Propane-1,2-diol, CAS 57-55-6) is a clear, odorless, hygroscopic liquid completely miscible with water and widely used as a solvent and humectant in cosmetics and personal-care products, a pharmaceutical excipient for injectables, syrups and ointments, food additive E1520 that preserves moisture, flavor and texture, a major component of e-cigarette liquids, an antifreeze and heat-transfer fluid in HVAC systems, an aircraft de-icing agent, a carrier for flavors and fragrances, a solvent in printing inks, paints, plastics, detergents and lubricants, as well as in textile, leather and unsaturated polyester resin production; thanks to its low toxicity, biodegradability and FDA “generally recognized as safe” status, PG has become a versatile material that enhances stability, safety and performance across a broad spectrum of consumer and industrial products.

  • Solubility @25˚C

    Solvent Solubility (g/L)
    ethanol 204.04
    methanol 481.44
    isopropanol 85.44
    water 2461.08
    ethyl acetate 13.68
    n-propanol 128.48
    acetone 31.87
    n-butanol 95.98
    acetonitrile 31.92
    DMF 233.87
    toluene 1.43
    isobutanol 68.15
    1,4-dioxane 38.15
    methyl acetate 19.45
    THF 52.22
    2-butanone 19.52
    n-pentanol 36.57
    sec-butanol 69.58
    n-hexane 1.86
    ethylene glycol 546.38
    NMP 164.3
    cyclohexane 2.93
    DMSO 193.43
    n-butyl acetate 9.62
    n-octanol 14.95
    chloroform 10.17
    n-propyl acetate 9.42
    acetic acid 587.54
    dichloromethane 9.56
    cyclohexanone 32.01
    propylene glycol 372.71
    isopropyl acetate 7.93
    DMAc 131.99
    2-ethoxyethanol 126.83
    isopentanol 51.36
    n-heptane 3.15
    ethyl formate 41.26
    1,2-dichloroethane 6.16
    n-hexanol 34.64
    2-methoxyethanol 343.87
    isobutyl acetate 5.24
    tetrachloromethane 7.06
    n-pentyl acetate 8.41
    transcutol 126.73
    n-heptanol 22.4
    ethylbenzene 1.18
    MIBK 8.96
    2-propoxyethanol 90.78
    tert-butanol 75.47
    MTBE 11.69
    2-butoxyethanol 68.08
    propionic acid 186.17
    o-xylene 2.49
    formic acid 1278.82
    diethyl ether 9.74
    m-xylene 1.95
    p-xylene 1.87
    chlorobenzene 2.59
    dimethyl carbonate 11.81
    n-octane 1.08
    formamide 692.68
    cyclopentanone 49.99
    2-pentanone 15.32
    anisole 5.44
    cyclopentyl methyl ether 19.18
    gamma-butyrolactone 70.5
    1-methoxy-2-propanol 146.06
    pyridine 16.14
    3-pentanone 10.22
    furfural 83.95
    n-dodecane 0.75
    diethylene glycol 185.1
    diisopropyl ether 3.19
    tert-amyl alcohol 62.35
    acetylacetone 17.11
    n-hexadecane 0.73
    acetophenone 8.24
    methyl propionate 17.71
    isopentyl acetate 7.88
    trichloroethylene 12.13
    n-nonanol 12.47
    cyclohexanol 51.39
    benzyl alcohol 17.3
    2-ethylhexanol 16.08
    isooctanol 15.96
    dipropyl ether 9.24
    1,2-dichlorobenzene 2.93
    ethyl lactate 22.84
    propylene carbonate 32.81
    n-methylformamide 241.93
    2-pentanol 35.6
    n-pentane 2.5
    1-propoxy-2-propanol 55.37
    1-methoxy-2-propyl acetate 14.23
    2-(2-methoxypropoxy) propanol 39.15
    mesitylene 1.81
    ε-caprolactone 36.75
    p-cymene 2.5
    epichlorohydrin 33.07
    1,1,1-trichloroethane 4.59
    2-aminoethanol 549.5
    morpholine-4-carbaldehyde 143.35
    sulfolane 98.11
    2,2,4-trimethylpentane 1.67
    2-methyltetrahydrofuran 31.77
    n-hexyl acetate 10.46
    isooctane 0.96
    2-(2-butoxyethoxy)ethanol 63.26
    sec-butyl acetate 5.1
    tert-butyl acetate 8.83
    decalin 1.13
    glycerin 622.22
    diglyme 83.72
    acrylic acid 226.82
    isopropyl myristate 3.86
    n-butyric acid 138.69
    acetyl acetate 10.83
    di(2-ethylhexyl) phthalate 8.73
    ethyl propionate 7.88
    nitromethane 205.55
    1,2-diethoxyethane 11.82
    benzonitrile 8.38
    trioctyl phosphate 7.22
    1-bromopropane 3.33
    gamma-valerolactone 90.98
    n-decanol 8.71
    triethyl phosphate 7.8
    4-methyl-2-pentanol 15.89
    propionitrile 19.92
    vinylene carbonate 30.27
    1,1,2-trichlorotrifluoroethane 131.58
    DMS 7.2
    cumene 1.61
    2-octanol 10.18
    2-hexanone 8.59
    octyl acetate 6.72
    limonene 4.3
    1,2-dimethoxyethane 59.45
    ethyl orthosilicate 8.01
    tributyl phosphate 7.11
    diacetone alcohol 38.11
    N,N-dimethylaniline 6.42
    acrylonitrile 32.81
    aniline 14.32
    1,3-propanediol 451.48
    bromobenzene 1.36
    dibromomethane 5.79
    1,1,2,2-tetrachloroethane 11.28
    2-methyl-cyclohexyl acetate 8.7
    tetrabutyl urea 10.86
    diisobutyl methanol 7.8
    2-phenylethanol 13.14
    styrene 1.39
    dioctyl adipate 8.37
    dimethyl sulfate 24.46
    ethyl butyrate 9.8
    methyl lactate 53.69
    butyl lactate 21.04
    diethyl carbonate 6.3
    propanediol butyl ether 75.82
    triethyl orthoformate 9.52
    p-tert-butyltoluene 2.59
    methyl 4-tert-butylbenzoate 16.16
    morpholine 79.86
    tert-butylamine 30.88
    n-dodecanol 6.42
    dimethoxymethane 41.59
    ethylene carbonate 23.56
    cyrene 48.13
    2-ethoxyethyl acetate 11.83
    2-ethylhexyl acetate 5.85
    1,2,4-trichlorobenzene 3.91
    4-methylpyridine 11.15
    dibutyl ether 5.17
    2,6-dimethyl-4-heptanol 7.8
    DEF 42.33
    dimethyl isosorbide 41.15
    tetrachloroethylene 15.66
    eugenol 25.88
    triacetin 14.73
    span 80 44.65
    1,4-butanediol 165.94
    1,1-dichloroethane 4.14
    2-methyl-1-pentanol 27.07
    methyl formate 115.23
    2-methyl-1-butanol 60.45
    n-decane 1.15
    butyronitrile 20.03
    3,7-dimethyl-1-octanol 10.8
    1-chlorooctane 2.48
    1-chlorotetradecane 1.22
    n-nonane 1.13
    undecane 0.88
    tert-butylcyclohexane 1.14
    cyclooctane 1.3
    cyclopentanol 81.97
    tetrahydropyran 21.85
    tert-amyl methyl ether 11.29
    2,5,8-trioxanonane 63.62
    1-hexene 3.27
    2-isopropoxyethanol 55.43
    2,2,2-trifluoroethanol 311.11
    methyl butyrate 15.0

    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