|Infobox on Cresol|
|Example of Cresol|
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Description / Application
Cresols are organic compounds which are methylphenols. They are a widely occurring natural and manufactured group of aromatic organic compounds which are categorized as phenols (sometimes called phenolics). Depending on the temperature, cresols can be solid or liquid because they have melting points not far from room temperature. Like other types of phenols, they are slowly oxidized by long exposure to air and the impurities often give cresols a yellowish to brownish red tint. Cresols have an odour characteristic to that of other simple phenols, reminiscent to some of a "Coal Tar" smell. The name creosol reflects their structure, being phenols, and their traditional source, creosote. The word tricresol can be used as a synonym for cresol where it means a mixture of o-, m- and p-cresols.
In its chemical structure, a molecule of cresol has a methyl group substituted onto the ring of phenol. There are three forms (isomers) of cresol: ortho-cresol (o-cresol), meta-cresol (m-cresol), and para-cresol (p-cresol). These forms occur separately or as a mixture. About half of the world's supply of cresols are extracted from coal tar. The rest is produced synthetically, by methylation of phenol or hydrolysis of chlorotoluenes.
Cresols are used to dissolve other chemicals, as disinfectants and deodorizers, and to make specific chemicals that kill insect pests.
Cresol solutions are used as household cleaners and disinfectants, perhaps most famously under the trade name Lysol. In the past, cresol solutions have been used as antiseptics in surgery, but they have been largely displaced in this role by less toxic compounds.
Cresols are found in many foods and in wood and tobacco smoke, Crude Oil, Coal Tar, and in brown mixtures such as creosote, cresolene and cresylic acids, which are wood preservatives. Small organisms in soil and water produce cresols when they break down materials in the environment.
Shipment / Storage
Cresol is a mixture of isomers obtained from coal tar or petroleum. It is a colourless, yellowish or pinkish liquid with a phenolic odour. The product is soluble in alcohol, glycol, dilute alkalies and water.
- Boiling point: 191°C
- Melting point: 31°C
- Flash point: 81°C
- Auto-ignition temperature: 555°C
For overseas carriage aspects of Chemicals, the readers are recommended to acquire or have access to a good chemical dictionary, and a copy of the International Maritime Dangerous Goods (IMDG) Code, issued by the International Maritime Organisation. Also consult the applicable MSDS sheet.
Most exposures to cresols are at very low levels that are not harmful. When cresols are breathed, ingested, or applied to the skin at very high levels, they can be very harmful. Effects observed in people include irritation and burning of skin, eyes, mouth, and throat; abdominal pain and vomiting; heart damage; anemia; liver and kidney damage; facial paralysis; coma; and death.
Breathing high levels of cresols for a short time results in irritation of the nose and throat. Aside from these effects, very little is known about the effects of breathing cresols, for example, at lower levels over longer times.
Ingesting high levels results in kidney problems, mouth and throat burns, abdominal pain, vomiting, and effects on the blood and nervous system.
Skin contact with high levels of cresols can burn the skin and damage the kidneys, liver, blood, brain, and lungs.
Short-term and long-term studies with animals have shown similar effects from exposure to cresols. No human or animal studies have shown harmful effects from cresols on reproduction.
It is not known what the effects are from long-term ingestion or skin contact with low levels of cresols.
See also: http://www.chemicalland21.com/industrialchem/organic/ortho-CRESOL.htm