Description
Professions that involve dealing with the combustion of
coal or wood may be exposed to higher levels of cresols than
the general population. Environmental tobacco smoke is also
a source of cresol exposure. Average cresol concentration may
vary between the brand and type of cigarette in a 45-cubic
meter chamber after six cigarettes had been smoked (ranged
from 0.17 to 3.9 mg m3), although low levels of cresol can be
detected in certain foods and tap water, and these do not
constitute major sources of exposure for most population.
Detectable levels of cresols have been reported in several consumer products including tealeaves, tomatoes, and ketchup
as well as butter, oil, and various cheeses. Exposure to children
occurs by the same routes that affect adults. Children are likely
to be exposed to cresols through inhalation of contaminated air
from automobile exhaust, waste incineration, and secondhand
smoke.
Chemical Properties
Cresol is a mixture of the three isomeric cresols, o-, m-, and p-cresol. Cresols are slightly soluble in water. m-Isomer: Colorless or yellow liquid with characteristic odor.
Chemical Properties
Cresol,a clear amber to red liquid, also known as cresylic acid, methylphenol, and tricresol,is a mixture of three isomers of cresol derived from coaltar and is used in making plastics, ore flotation, refining petroleum, and as a strong antiseptic. Orthocresol is a color less solid with a melting point of 30 °C(86 OF) that is soluble in alcohol,but only slightly soluble in water. It is used in making disinfectants and as a plasticizer. Metacresol is a colorless liquid used in the manufacture of photographic developers,printing inks, and paint removers.It is also used as a leather preservative.The least soluble isomer, paracresol, is a colorless solid and is used in the production of dyes and pharmaceuticals.
Chemical Properties
Cresol consists of a mixture of cresol isomers, predominantly mcresol,and other phenols obtained from coaltar or petroleum.It is a colorless,yellowish to pale brownish-yellow,or pink-colored liquid, with a characteristic odor similar to phenol but more tarlike. An aqueous solution has a pungent taste.
Uses
Cresol is used in disinfectants and fumigants,in the manufacture of synthetic resins, inphotographic developers and explosives.
Uses
Disinfectant, phenolic resins, tricresyl phosphate, ore flotation, textile scouring agent, organic
intermediate, manufacture of salicylaldehyde,
coumarin, and herbicides, surfactant, synthetic food
flavors (para isomer only).
Uses
Cresols (mixtures of the ortho-, meta-, and para-isomers) are
synthesized by sulfonation or oxidation of toluene compounds
or can be derived from coal tar and petroleum. Commercial
grade crude cresol is generally a mixture of 20% o-cresol, 40%
m-cresol, and 30% p-cresol. Phenol and xylenols are often
found as minor contaminants. Manufacture of synthetic resins,
tricresyl phosphate, salicylaldehyde, coumarin, and herbicides
employ cresols. Degreasing compounds in textile scouring,
paintbrush cleaners as well as fumigants in photographic
developers, and explosives contains cresols. Cresols are also
often used as antiseptics, disinfectants, and antiparasitic agents
in veterinary medicine. Estimated breakdown of cresol and
cresylic acid use is 20% phenolic resins, 20% wire enamel
solvents, 10% agricultural chemicals, 5% phosphate esters, 5%
disinfectants and cleaning compounds, 5% ore flotation, and
25% miscellaneous purposes. Overall, use of cresols as antimicrobial
outweighs any other property.
Production Methods
Cresol may be obtained from coal tar or prepared synthetically by either sulfonation or oxidation of toluene.
Definition
A mixture of isomers obtained from coal tar or
petroleum.
General Description
Colorless to yellow liquids with a tarry odor. Flash point 178°F. Insoluble in water. Density 8.7 lb / gal. Poisonous by ingestion and skin absorption and corrosive to skin.
Air & Water Reactions
Insoluble in water.
Reactivity Profile
Mixing CRESOL in equal molar portions with any of the following substances in a closed container caused the temperature and pressure to increase: chlorosulfonic acid, nitric acid, oleum, [NFPA 1991].
Hazard
Irritant, corrosive to skin and mucous membranes, absorbed via skin. Questionable carcinogen.
Health Hazard
The toxic actions of cresol are similar tothose of phenol. The para-isomer is somewhat more toxic than the other two isomers.The toxic symptoms are weakness, confu-sion, depression of the central nervous system, dyspnea, and respiratory failure. It isan irritant to the eyes and skin. Skin con-tact can cause burn and dermatitis. Chroniceffects are gastrointestinal disorders, nervousdisorders, tremor, confusion, skin eruptions,oliguria, jaundice, and liver damage. SkinLD50 values in rats for o-, m-, and p-phenolsare 620, 1100, and 750 mg/kg, respectively.
Dietz and Mulligan (1988a,b) have investigated the subchronic toxicity of meta- andpara-cresols in Sprague-Dawley rats after13 weeks of oral gavage. There was noadverse effects from a dose of 50 mg/kg/day.High dose levels of 150 mg/kg/day producedcentral nervous system depression and reduction of body weight gain. p-Cresol was foundto be hepatotoxic and nephrotoxic, inducinga mild anemic effect. The acute toxicity ofmethyl phenols did not show any relationshipto the number or position of methyl groupson the phenol nucleus. In an acute toxicitystudy on Daphnia magna, Devillers (1988)found cresols to be more toxic than phenol,xylenols, and trimethylphenols.
Health Hazard
LIQUID: Will burn skin and eyes. Harmful if swallowed.
Fire Hazard
Combustible. POISONOUS GASES MAY BE PRODUCED IN FIRE. Flammable toxic vapors given off in a fire. Sealed closed containers can build up pressure if exposed to heat.
Chemical Reactivity
Reactivity with Water No reaction; Reactivity with Common Materials: No reaction; Stability During Transport: Stable; Neutralizing Agents for Acids and Caustics: Not pertinent; Polymerization: Not pertinent; Inhibitor of Polymerization: Not pertinent.
Pharmaceutical Applications
Cresol is used at 0.15-0.3% concentration as an antimicrobial preservative in intramuscular, intradermal, and subcutaneous injectable pharmaceutical formulations. It is also used as a preservative in some topical formulations and as a disinfectant. Cresol is not suitable as a preservative for preparations that are to be freeze-dried.
Safety
Reports of adverse reactions to cresol are generally associated with the use of either the bulk material or cresol-based disinfectants, which may contain up to 50% cresol, rather than for its use as a preservative. However, a recent case of cutaneous hypersensitivity reaction to the m-cresol component of an insulin formulation detected via intradermal and patch testing has been reported.
Cresol is similar to phenol although it is less caustic and toxic. However, cresol is sufficiently caustic to be unsuitable for skin and wound disinfection. In studies in rabbits, cresol was found to be metabolized and excreted primarily as the glucuronide.
A patient has survived ingestion of 12g of cresol though with severe adverse effects.
LD50 (mouse, oral): 0.76g/kg
LD50 (rabbit, skin): 2g/kg
LD50 (rat, oral): 1.45g/kg
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 anycontact lenses at once and irrigate immediately for at least15 min, occasionally lifting upper and lower lids. Seek medical attention immediately. If this chemical contacts theskin, remove contaminated clothing and wash immediatelywith soap and water. Seek medical attention immediately. Ifthis chemical has been inhaled, remove from exposure,begin rescue breathing (using universal precautions, including resuscitation mask) if breathing has stopped and CPR ifheart action has stopped. Transfer promptly to a medicalfacility. When this chemical has been swallowed, get medical attention. Give large quantities of water and inducevomiting. Do not make an unconscious person vomit.Medical observation is recommended for 24-48 h afterbreathing overexposure, as pulmonary edema may bedelayed. As first aid for pulmonary edema, a doctor orauthorized paramedic may consider administering a corticosteroid spray.
Environmental Fate
It acts by disruption of the cell membrane by denaturation of
proteins and enzymes of the cell.
storage
Cresol and aqueous cresol solutions darken in color with age and on exposure to air and light. Cresol should be stored in a well-closed container, protected from light, in a cool, dry place.
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.
Toxicity evaluation
Cresol’s production and use as a solvent, disinfectant, and
chemical intermediate in the production of synthetic resins
may result in its release to the environment through various
waste streams. Cresols are also released to the environment
through automobile exhaust and tobacco smoke. Cresols are
a group of widely distributed natural compounds formed as
metabolites of microbial activity and excreted in the urine of
mammals. Cresols occur in various plant lipid and oil
constituents. If released to air, an extrapolated vapor pressure
range of 0.11–0.299 mm Hg at 25°C for the various isomers
indicates cresols will exist solely as a vapor in the ambient
atmosphere. Vapor-phase cresols will be degraded in the
atmosphere by photochemical reaction and produce hydroxyl
radicals. The half-life for this reaction in air is estimated to be
6–9 h. If released to soil, cresols are expected to have high
mobility based upon Koc values of 22–49 measured in soil.
Volatilization from moist soil surfaces is expected to occur
slowly based upon Henry’s Law constants. Cresols are not expected
to volatilize from dry soil surfaces based upon the
extrapolated vapor pressure range. Cresols biodegrade quickly
in soils with half-lives of few days. If released into water, cresols
do not adsorb to suspended solids and sediment in the water.
Cresols biodegrade quickly in water with half-lives of severaldays to few weeks. Volatilization from water surfaces is expected
to occur slowly based upon the range of Henry’s Law
constants for the various isomers. Estimated volatilization halflives
for a model river and model lake range from 21 to 29 and
235–327 days, respectively. Cresols are not expected to
undergo hydrolysis since they lack functional groups that
hydrolyze under environmental conditions. Direct photolysis
in sunlit surface occurs and products occur at a much slower
rate than biodegradation. Log bioconcentration factor values of
1.3 and 1.03 measured in ide and zebrafish respectively
suggests that the potential for bioconcentration in aquatic
organisms is low.
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.
Incompatibilities
Cresol has been reported to be incompatible with chlorpromazine. Antimicrobial activity is reduced in the presence of nonionic surfactants.
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.
Regulatory Status
Included in the FDA Inactive Ingredients Database (IM, IV, intradermal, and SC injections). Included in parenteral medicines licensed in the UK. Included in the Canadian List of Acceptable Non-medicinal Ingredients.
