General Description
Colorless solid with a tar like odor. Sinks and mixes slowly with water.
Reactivity Profile
P-CRESOL(106-44-5) is sensitive to heat. P-CRESOL(106-44-5) is also sensitive to light. This chemical is incompatible with strong oxidizers and strong alkalis. P-CRESOL(106-44-5) will attack some forms of plastics, coatings and rubber.
Air & Water Reactions
Insoluble in water.
Hazard
Questionable carcinogen.
Health Hazard
INHALATION: Irritation of nose or throat. EYES: Intense irritation and pain, swelling of conjunctiva and corneal damage may occur. SKIN: Intense burning, loss of feeling, white discoloration and softening. Gangrene may occur. INGESTION: Burning sensation in mouth and esophagus. Vomiting may result. Absorption by all routes may cause muscular weakness, gastroenteric disturbance, severe depression and collapse. Effects are primarily on central nervous system, edema of lungs, injury of spleen and pancreas may occur.
Potential Exposure
Cresol is used as a disinfectant and fumigant; as an ore flotation agent, and as an intermediate in the manufacture of chemicals, dyes, plastics, and antioxidants. A mixture of isomers is generally used; the concentrations of the components are determined by the source of the cresol.
First aid
If this chemical gets into the eyes, remove any contact lenses at once and irrigate immediately for at least 15 minutes, occasionally lifting upper and lower lids. Seek medical attention immediately. If this chemical contacts the skin, remove contaminated clothing and wash immediately with soap and water. Seek medical attention immediately. If this chemical has been inhaled, remove from exposure, begin rescue breathing (using universal precautions, including resuscitation mask) if breathing has stopped and CPR if heart action has stopped. Transfer promptly to a medical facility. When this chemical has been swallowed, get medical attention. Give large quantities of water and induce vomiting. Do not make an unconscious person vomit. Medical observation is recommended for 24 to 48 hours after breathing overexposure, as pulmonary edema Cresols 931 may be delayed. As first aid for pulmonary edema, a doctor or authorized paramedic may consider administering a drug or other inhalation therapy
Shipping
UN2076 Cresols, liquid, Hazard class: 6.1; Labels: 6.1-Poisonous materials, 8-Corrosive material. UN3455 Cresols, solid, Hazard class: 6.1; Labels: 6.1- Poisonous materials, 8-Corrosive material.
Incompatibilities
Vapors may form explosive mixture with air. Incompatible with strong acids; oxidizers, alkalies, aliphatic amines; amides, chlorosulfonic acid; oleum. Decomposes on heating, producing strong acids and bases, causing fire and explosion hazard. Liquid attacks some plastics and rubber. Attacks many metals.
Waste Disposal
Wastewaters may be subjected to biological treatment. Concentrations may be further reduced by ozone treatment. High concentration wastes may be destroyed in special waste incinerators.
Physical properties
Colorless to pink crystals with a phenolic odor. Odor threshold concentration in water is 55 ppb
(Buttery et al., 1988). An experimentally determined odor threshold concentration of 1 ppbv was
reported by Leonardos et al. (1969) which exceeds the odor threshold concentration of 0.054 ppbv
reported by Nagata and Takeuchi (1990).
Occurrence
Has been found in a score of essential oils including ylang ylang and oil of jasmine (Gildemeister & Hoffman, 1966).
Definition
ChEBI: A cresol that consists of toluene substituted by a hydroxy group at position 4. It is a metabolite of aromatic amino acid metabolism produced by intestinal microflora in humans and animals.
Preparation
It can be prepared by fractional distillation of coal tar where it occurs together with the ortho- and para- isomers.
Production Methods
The cresols (cresylic acids) are methyl phenols and generally
appear as a mixture of isomers. p-Cresol is a 4-methyl
derivative of phenol and is prepared from m-toluic acid
or obtained from coal tar or petroleum. Crude
cresol is obtained by distilling “gray phenic acid” at a
temperature of ～180–201°C. p-Cresol may be separated
from the crude or purified mixture by repeated fractional
distillation in vacuo. It can also be prepared synthetically by
diazotization of the specific toluene or by fusion of the
corresponding toluenesulfonic acid with sodium hydroxide.
Aroma threshold values
Detection: 55 to 100 ppb.
Flammability and Explosibility
Notclassified
Carcinogenicity
o-Cresol has been induced a few
papillomas but no carcinomas in tumor studies.
Source
As 3+4-methylphenol, detected in distilled water-soluble fractions of 87 octane gasoline
(6.03 mg/L), 94 octane gasoline (0.60 mg/L), Gasohol (1.76 mg/L), No. 2 fuel oil (1.84 mg/L), jet
fuel A (0.43 mg/L), diesel fuel (1.318 mg/L), and military jet fuel JP-4 (0.92 mg/L) (Potter, 1996).
A high-temperature coal tar contained 4-methylphenol at an average concentration of 0.27 wt %
(McNeil, 1983).
Occurs naturally in brown juniper, Spanish cedar, peppermint (2 to 20 ppb), tarragon, asparagus
shoots, ylang-ylang, jasmine, tea leaves, coffee beans, Japanese privet, white mulberries,
raspberries, vanilla, blueberries, sour cherries, anise, and tamarind (Duke, 1992).
A liquid swine manure sample collected from a waste storage basin contained 4-methylphenol
at a concentration of 4.9 mg/L (Zahn et al., 1997).
Environmental Fate
Biological. Protocatechuic acid (3,4-dihydroxybenzoic acid) is the central metabolite in the
bacterial degradation of 4-methylphenol. Intermediate by-products include 4-hydroxybenzyl
alcohol, 4-hydroxybenzaldehyde, and 4-hydroxybenzoic acid. In addition, 4-methylphenol may
undergo hydroxylation to form 4-methylcatechol (Chapman, 1972). Chloroperoxidase, a fungal
enzyme isolated from Caldariomyces fumago, reacted with 4-methylphenol forming 4-methyl-2-
chlorophenol (Wannstedt et al., 1990). Under methanogenic conditions, inocula from a municipal sewage treatment plant digester degraded 4-methylphenol to phenol prior to being mineralized to
carbon dioxide and methane (Young and Rivera, 1985).
Photolytic. Photooxidation products reported include 2,2′-dihydroxy-4,4′-dimethylbiphenyl, 2-
hydroxy-3,4′-dimethylbiphenyl ether, and 4-methylcatechol (Smith et al., 1978). Anticipated
products from the reaction of 4-methylphenol with ozone or OH radicals in the atmosphere are
hydroxynitrotoluene and ring cleavage compounds (Cupitt, 1980). Absorbs UV light at a
maximum wavelength of 278 nm (Dohnal and Fenclová, 1995).
Chemical/Physical. Kanno et al. (1982) studied the aqueous reaction of 4-methylphenol and
other substituted aromatic hydrocarbons (toluidine, 1-naphthylamine, phenol, 2- and 3-
methylphenol, pyrocatechol, resorcinol, hydroquinone, and 1-naphthol) with hypochlorous acid in
the presence of ammonium ion. They reported that the aromatic ring was not chlorinated as
expected but was cleaved by chloramine forming cyanogen chloride. The amount of cyanogen
chloride formed was increased as the pH was lowered (Kanno et al., 1982).
Metabolism
p-Cresol is oxidized at the methyl group in both dogs and rabbits to yield ρ-hydroxybenzoic acid. In the rabbit up to 10% of oral doses of 0.25-0.5 g is excreted as free and conjugated p-hydroxybenzoic acid (Williams, 1959).
Purification Methods
It can be separated from m-cresol by fractional crystalisation of its melt. Purify it by distillation, by precipitation from *benzene solution with pet ether, and via its benzoate, as for phenol. Dry it under vacuum over P2O5. It has also been crystallised from pet ether (b 40-60o) and by conversion to sodium p-cresoxyacetate which, after crystallisation from water is decomposed by heating with HCl in an autoclave [Savard Ann Chim (Paris) 11 287 1929]. The 3,5-dinitrobenzoate (prepared with 3,5-dinitrobenzoyl chloride in dry pyridine, and recrystallised from EtOH or aqueous Me2CO) has m 189o. [Beilstein 6 II 2093.]
