- Product Name:
- 2-Isopropyl-5-methylphenol (thymol)
- Product Categories:
- Monocyclic Monoterpenes
- Mol File:
Thymol Chemical Properties
- Melting point:
- 48-51 °C(lit.)
- Boiling point:
- 232 °C(lit.)
- 0.965 g/mL at 25 °C(lit.)
- vapor pressure
- 1 mm Hg ( 64 °C)
- 3066 | THYMOL
- refractive index
- nD20 1.5227; nD25 1.5204
- Flash point:
- 216 °F
- storage temp.
- Store at RT.
- ethanol: soluble50mg/mL
- Crystals or Crystalline Powder
- Thyme-like odor
- PH Range
- Water Solubility
- 0.1 g/100 mL (20 ºC)
- JECFA Number
- Stable. Incompatible with strong oxidizing agents, organic materials, strong bases.
- CAS DataBase Reference
- 89-83-8(CAS DataBase Reference)
- NIST Chemistry Reference
- Phenol, 5-methyl-2-(1-methylethyl)-(89-83-8)
- EPA Substance Registry System
- Thymol (89-83-8)
- Hazard Codes
- Risk Statements
- Safety Statements
- UN 3261 8/PG 3
- WGK Germany
- HS Code
- Hazardous Substances Data
- 89-83-8(Hazardous Substances Data)
- LD50 orally in rats: 980 mg/kg (Jenner)
Thymol Usage And Synthesis
white crystals or powder with a pungent odour
Thymol occurs as colorless or often large translucent crystals, or as a white crystalline powder with a herbal odor (aromatic and thymelike) and a pungent caustic taste.
Thymol is the main constituent
of thyme and some origanum oils; it also occurs in many other essential
oils. It forms colorless crystals (mp 51.5°C) with a spicy, herbal, slightly medicinal
odor reminiscent of thyme. Thymol is prepared on a technical scale in a continuous
high-temperature, high-pressure, liquid-phase, ortho-alkylation process,
fromm-cresol and propylene, in the presence of activated aluminumoxide hydrate.
The crude thymol mixture, consisting of approximately 60% thymol, unreacted m-cresol (about 25%), and other (iso)propyl-substituted products, is separated by fractional distillation. Most of the by-products are recycled.
Thymol is used as a dry top note in lavender compositions, in men’s fragrances, and as a disinfectant in oral care products. It is also important as a startingmaterial for the production of racemic menthol.
Anethole is used in large quantities in the alcoholic beverage industry and in oral hygiene products. Some crude anethole is converted into anisaldehyde.
Thymol has a characteristic herbaceous, warm and aromatic odor with a sweet, medicinal, spicy flavor
Reported in the essential oils of Monarda punctata, Satureia thymera, Origanum floribundum, Ocimum viride, Ocimum gratissimum and particularly in thyme (Thymus vulgaris L., T. capitatus, T. serpillum L.), where it is contained up to 50%. Also reported found in citrus peel oils, orange and tangerine juice, bilberry, cranberry, blueberry, papaya, blackberry, celery seed, chive, clove bud, cumin seed, ginger, peppermint oil, corn mint oil, Scotch spearmint oil, nutmeg, parsley, thyme, Gruyere cheese, parmesan cheese, romano cheese, white wine, black tea, plum, sweet and wild marjoram, fenugreek, mango, cardamom, dill herb and seed, licorice, lovage leaf, buckwheat, sweet corn, elder flower, cherimoya, rosemary, lemon balm, Spanish sage, anise hyssop, sweet grass oil, eucalyptus oil and mastic gum oil.
Thymol is an antimicrobial compound which can increase the efficacy of antibiotics involving drug resistant bacteria. It inhibits growth and lactate production as well as reduces cellular glucose upta ke within the bacteria.
Thymol is obtained from the volatile oil of thyme (Thymus vulgaris Linne′ (Fam. Labiatae)) by fractional distillation followed by extraction and recrystallization. Thyme oil yields about 20–30% thymol. Thymol may also be produced synthetically from pcymene, menthone, or piperitone, or by the interaction of m-cresol with isopropyl chloride.
thymol: A pungent-smelling colourless crystalline compound, C10H14O;m.p. 51°C. It occurs in various essentialoils, particularly oil of thyme,and can be made by using iron(III)chloride to oxidize piperitone (itselfextracted from eucalyptus oil). Itsantiseptic properties are exploited ingargles and mouthwashes.
Aroma threshold values
Detection: 86 to 790 ppb
Taste threshold values
Phenolic, medicinal, woody and spicy
Thymol is a phenolic antiseptic, which has antibacterial and
antifungal activity. However, it is not suitable for use as a
preservative in pharmaceutical formulations because of its low
aqueous solubility. The antimicrobial activity of thymol against
eight oral bacteria has been studied in vitro. Inhibitory activity was
noted against almost all organisms, and a synergistic effect was
observed for combinations of thymol and eugenol, and of thymol
and carvacrol. The activity of thymol against bacteria commonly
involved in upper respiratory tract infections has also been
Thymol is a more powerful disinfectant than phenol, but its low water solubility, its irritancy to tissues, and its inactivation by organic material, such as proteins, limit its use as a disinfectant. Thymol is chiefly used as a deodorant in antiseptic mouthwashes, gargles, and toothpastes, such as in Compound Thymol Glycerin BP, in which it has no antiseptic action.
Thymol is also a true antioxidant and has been used at concentrations of 0.01% as an antioxidant for halothane, trichloroethylene, and tetrachloroethylene. The antioxidant activity of thymol and thymol analogues has been described. More recently, thymol has been shown to enhance the in vitro percutaneous absorption of a number of drugs, including 5- fluorouracil, piroxicam, propranolol, naproxen, and tamoxifen. Studies have also demonstrated that the melting point of lidocaine is significantly lowered when it is mixed with thymol.
The inhalation of thymol, in combination with other volatile substances, is used to alleviate the symptoms of colds, coughs, and associated respiratory disorders. Externally, thymol has been used in dusting powders for the treatment of fungal skin infections; thymol has been shown to have synergistic antifungal effects when combined with ketoconazole. Thymol was formerly used in the treatment of hookworm infections but has now been superseded by less toxic substances.
In dentistry, thymol has been mixed with phenol and camphor to prepare cavities before filling, and mixed with zinc oxide to form a protective cap for dentine.
Thymol has been included in food, perfume, and cosmetic products, and has also been used as a pesticide and fungicide.
Isopropyl m-cresol is extracted from oil of Thymus vulgaris(thyme, of the mint family) by partitioning into alkalineaqueous medium followed by acidification. The crystals obtainedfrom the mother liquor are large and colorless, with athymelike odor. Thymol is only slightly soluble in water,but it is extremely soluble in alcohols and other organic solvents.Thymol has mild fungicidal properties and is used inalcohol solutions and in dusting powders for the treatmentof tinea (ringworm) infections.
Poison by ingestion and intravenous routes. Moderately toxic by subcutaneous route. Experimental reproductive effects. Mutation data reported. An allergen. Incompatible with acetanilide. When heated to decomposition it emits acrid smoke and irritating fumes. An FDA over-the-counter drug used as an antibacterial and antifungal agent.
Thymol is used in cosmetics, foods, and pharmaceutical applications
as an excipient. However, thymol may be irritating when
inhaled or following contact with the skin or eyes. It may also cause
abdominal pain and vomiting, and sometimes stimulation followed
by depression of the central nervous system following oral
consumption; fats and alcohol increase absorption and aggravate
Respiratory arrest, attributed to acute nasal congestion and edema, has been reported in a 3-week-old patient due to the erroneous intranasal application of Karvol, a combination product that includes thymol. The patient recovered, but it was recommended that inhalation decongestants should not be used in children under the age of 5 years.
LD50 (guinea pig, oral): 0.88 g/kg
LD50 (mouse, IP): 0.11 g/kg
LD50 (mouse, IV): 0.1 g/kg
LD50 (mouse, oral): 0.64 g/kg
LD50 (mouse, SC): 0.243 g/kg
LD50 (rat, oral): 0.98 g/kg
Thymol should be stored in well-closed, light-resistant containers, in a cool, dry, place. Thymol is affected by light.
Thymol is incompatible with iodine, alkalis, and oxidizing agents. It liquefies, or forms soft masses, on trituration with acetanilide, antipyrine, camphor, monobromated camphor, chloral hydrate, menthol, phenol, or quinine sulfate. The antimicrobial activity of thymol is reduced in the presence of proteins.
GRAS listed. Included in the FDA Inactive Ingredients Database (inhalation, liquid; oral, powder for solution). Included in nonparenteral medicines (topical creams and ointments) licensed in the UK. Included in the Canadian List of Acceptable Nonmedicinal Ingredients.
- 010-82848833- ;010-82848833-
- Origanum oil
- Paraquat dichloride
- Thymolphthalein Complexone
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- Basic Violet 1
- Chloromethyl isopropyl carbonate
- Phenol Red
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- Methyl acrylate