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DESIGNATIONS
CAS No.: 1319-77-3
Registry names: Cresols
Chemical names: o-Cresol, m-cresol, p-cresol
Synonyms, Trade names: ortho-Cresol, meta-cresol, para-cresol, 1,2-cresol, 1,3-cresol, 1,4-cresol, hydroxytoluene, methylphenol, methylhydroxybenzene, tricresol
Chemical name (German): o-Cresol, m-Cresol, p-Cresol (also Kresol)
Chemical name (French): o-Crésol, m-crésol, p-crésol
Appearance: colourless or brownish liquid/crystals; similar smell to Lysol disinfectant
BASIC CHEMICAL AND PHYSICAL DATA
Empirical formula: |
C7H8O |
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Rel. molecular mass: |
108.14 g |
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Density: |
1.03 g/cm3 |
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Relative gas density: |
3.74 |
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meta |
ortho | para | |
Boiling point: |
203°C |
191°C | 202°C |
Melting point: |
11°C |
31°C | 35°C |
Vapour pressure: |
0.065 hPa |
0.35 hPa | 0.06 hPa |
Flash point: |
86°C |
81°C | 86°C |
Ignition temperature: |
560°C |
555°C | 555°C |
Solvolysis/solubility: |
2% |
2% | 2% (in water) |
Conversion factors: |
1 ppm = 4.49 mg/m3 1 mg/m3 = 0.22 ppm |
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ORIGIN AND USE
Usage:
Cresols are used as disinfectants, perfumes, preserving agents or herbicides (98% DNOC,
UCPA). They are also used in the textile industry as cleaning agents.
Origin/derivation:
Cresols are derived from coal or petroleum and can be found in wood and other biogenic
materials. They are thus released into the environment by combustion processes in motor
vehicles and domestic heating systems (asphalt abrasion, vaporisation of plastics,
perfumes, metal degreasing etc.). The so called "crude cresol" which is obtained
from the heavy oil of coal tar contains considerable amounts of m- and p-cresol.
Toxicity
Mammals: |
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Rat: |
LD50 1.35 g/kg, oral (o-cresol) |
acc. VERSCHUEREN. 1983 |
LD50 2.02 g/kg, oral (m-cresol) |
acc. VERSCHUEREN. 1983 |
|
LD50 1.8 g/kg, oral (p-cresol) |
acc. VERSCHUEREN. 1983 |
|
Rabbit: |
LD50 0.8 g/kg, oral (o-cresol) |
acc. VERSCHUEREN. 1983 |
LD50 1.1 g/kg, oral (m-cresol) |
acc. VERSCHUEREN. 1983 |
|
LD50 1.1 g/kg, oral (p-cresol) |
acc. VERSCHUEREN. 1983 |
|
Aquatic organisms: |
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Green algae: |
LD0 40 mg/l |
acc. VERSCHUEREN. 1983 |
Blue algae: |
LD0 6.8 mg/l |
acc. VERSCHUEREN. 1983 |
Water flea: |
LD0 16 mg/l (o-cresol) |
acc. VERSCHUEREN. 1983 |
LD0 28 mg/l (m-cresol) |
acc. VERSCHUEREN. 1983 |
|
LD0 12 mg/l (p-cresol) |
acc. VERSCHUEREN. 1983 |
|
Goldfish: |
TLm 49.1-19 mg/l (24-96h) (o-cresol) |
acc. VERSCHUEREN. 1983 |
Carp: |
TLm 30 mg/l (24h) (o-cresol) |
acc. VERSCHUEREN. 1983 |
TLm 25 mg/l (24h) (m-cresol) |
acc. VERSCHUEREN. 1983 |
|
TLm 21 mg/l (24h) (p-cresol) |
acc. VERSCHUEREN, 1983 |
|
Characteristic effects:
Humans/mammals: Cresols have a disinfectant and corrosive effect due to the degradation of proteins. They ingress into the organism via the skin and mucous membranes and cause skin diseases. Resorptive paralysis of the central nervous system ultimately leads to liver and kidney disease. The intake of small quantities can result in dizziness or loss of consciousness, poisoning, delirium and the secretion of copius amounts of saliva and sweat. The symptoms of cresol poisoning are similar to those of phenol, producing white and subsequently brownish-black scabs on the skin.
Plants: Cresols inhibit the degradation of glucose.
ENVIRONMENTAL BEHAVIOUR
Water:
Cresols sink in water and dissolve very slowly. Even if considerably diluted, they still
form poisonous, corrosive mixtures which have a toxic effect on aquatic organisms. If
cresols ingress into the groundwater the water will no longer be suitable for drinking.
There may be accumulation in sediment due to the adsorption of cresols on clay minerals.
Air:
Strong heat will form explosive mixtures which are denser than air and creep along the
ground. Cresols are therefore not transported into the atmosphere and are usually washed
out again by precipitation. This effect can cause pollution of groundwater in the vicinity
of large-scale emission sources. The majority of cresols are subject to photochemical
degradation.
Soil:
Cresols are absorbed by plants and broken down by them. The accumulation of cresols in
soil depends on the type of soil involved (adsorption on clay minerals).
Degradation, decomposition products:
Cresols are subject to photochemical degradation.
Food chain:
(refer to information sheets "phenols" and "chlorophenols")
ENVIRONMENTAL STANDARDS
| Medium/ acceptor | Sector | Country/ organ. | Status | Value | Cat. | Remarks | Source |
Air: |
D | L |
0.2 mg/m3 | MIK | Long-time value | acc. BAUM, 1988 | |
| D | L |
0.6 mg/m3 | MIK | Short-time value | acc. BAUM, 1988 | ||
| DDR | (L) |
0.03 mg/m3 | Short-time value | acc. HORN, 1989 | |||
| DDR | (L) |
0.01 mg/m3 | Long-time value | acc. HORN, 1989 | |||
| Workp | D | L |
22 mg/m3 | MAK | DFG, 1989 | ||
| Workp | DDR | (L) |
40 mg/m3 | Short-time value | acc. HORN, 1989 | ||
| Workp | DDR | (L) |
20 mg/m3 | Long-time value | acc. HORN, 1989 | ||
| Workp | SU | (L) |
0.5 mg/m3 | PDK | acc. SORBE, 1989 | ||
| Workp | USA | (L) |
22 mg/m3 | TWA | ACGIH, 1986 |
Notes:
In accordance with the TA-Luft, cresols are assigned to class 1 where the concentration
may not exceed 20 mg/m3 with a mass flow of 0.1 kg/h or more in the Federal
Republic of Germany.
For further standards refer to "phenols ".
Assessment/comments
When handling cresols the skin should be protected and the substance is to be kept away from naked flames. Protective clothing and good ventilation have to be provided. Usage should be reduced as far as possible because of its considerable toxicity.