o-cresol

95-48-7

phenol * 2 - 20 %

Disinfectant; food antioxidant, perfume manufacturing; dye
manufacturing; plastics and resins manufacturing.

Clear to yellow solid. 
Liquid in warm temperature. 
Will sink
and dissolve at moderate rate.

Phenolic, tarry odour. 
Recognition odour in air: 0.26 ppm;
lower odour threshold; 0.016 ppm; upper odour threshold: 4.1
ppm; medium taste threshold: 0.001 ppm (Sax 1986).

Odor threshold: detection: 1.4 mg/l
Taste threshold conc.: 0.003 mg/l (Verschueren 1983)

108.15

2-Cresol has a low volatility from water, having a calculated
Henry's Law constant of 1.6x10-6 atm-m3/mol (Leuenberger et al 
1985).

The value for Koc measured on Brookstone clay loam soil (pH
5.7) is 22 and that predicted from the water solubility.

Koc's for phenols predicted from water solubilities are only
good for soils with organic carbon contents greater than
approx. 0.5 %. 
Adsorptivities are greater than predicted for
soils with low organic carbon content because interactions such
as H-bonding are dominant (Boyd 1982) (Southworth & Keller 
1986).


On five fine-textured B horizon clay soils (pH 4.5 - 7.8) the
distribution between soil and water ranged from 2.8 to 500. 
For
these subsurface soils the levels of free iron oxide and pH the
key factors in determining adsorption capacity.

(Artiola-Fortuny & Fuller 1982).

Flammability: moderate. 
Combustion with moderate heating.

Toxic combustion products hazardous.

Explosiveness: Stable. 
Vapors form explosive mixtures with air.

Photooxidation half-life in air:
16hr - 1.6hr, based upon measured rate data for the vapor phase
reaction with hydroxyl radicals in air (Howard 1991).

In the atmosphere during the daytime 2-cresol reacts pricipally
with photochemically-generated hydroxyl radicals primarily by
ring addition but also by H abstraction with a resulting
half-life of 9.6 hr. 
However in the nighttime especially in
moderately polluted atmospheres where concentrations of O3 and
NO2 are high, reaction with NO3 radicals is a major sink for
2-cresol (half-life 2 min) with the formation of nitrocresols.

Under photochemical smog conditions half-lives have been
measured to be 1-5 hr with nitrocresol formation (Howard 1989).

Photo-oxidation: an aqueous solution of cresol (n.s.i.) is
destroyed by photooxidation using visible light as a direct
energy source and methyleneblue as a dye-sensitizer (Sargent & 
Sanks 1974).

Photooxidation half-life in water:
145d - 2.75d, scientific judgement based upon reported reaction
rate constants for OH and RO2 with the phenol class (Howard 
1991).

The photolysis half-life of 4-cresol in pure water by sunlight
is 35 days and it will presumable be similar for the 2-cresol.

Since absorptivity increases with pH from pH 5.1 to 8.9, so may
the photolysis rate (Smith et al. 1978).

Aerobic half-life:
7d - 1d, scientific judgement based upon unacclimated aerobic 
screening test data (Howard 1991).

Anaerobic half-life:
28d - 4d, scientific judgement based upon unacclimated aqueous 
aerobic biodegradation half-life (Howard 1991).

Decomposition period by a soil microflora: 1 day 
(Verschueren 1983).

Confirmed to biodegradable (Anon. 1987).

Degradation of o-cresol:
*-------------------------------------------------------------*
ENVIRONMENT    INIT.CONC   REDOX-     TEMP   DEGRADATION    REF
                  mg/l     COND.       °C        %/day
*-------------------------------------------------------------*
water              20      aerobic     25       99/7         a
sludge         appr. 50    anaerobic   25        0/56        b
sludge         appr. 50    anaerobic   35        0/56        b
soil suspension    10      aerobic     25      100/1         c
*-------------------------------------------------------------*
a) Bunch & Chamber 1967          c) Alexander & Lustigman 1966
b) Horowitz et al. 1982          (Anon 1987b).

Biodegrades at moderate rate but can after aesthetics at very
low concentration levels (Sax 1986).

Inhibition of nitrification in activated sludgeat 11-16 mg/l
(75 % reduction) ( n.s.i.) 
(Verschuren 1983).

Inhibition of degradation of glucose by Pseudomonas fluorescens
at 50 mg/l. 
Inhibition of degradation of glucose by E. coli at
600 mg/l (Bringmann & Kuhn 1960).

Decomposition period by a soil microflora: 1 day (Verschuren
1983).

2-Cresol biodegradas rabidly in screening studies using soil,
sewage, avtivated sludge or municipal wastewater inocula.
acclimation is frequently not necessary. 
It is completely
degraded in river water in 2 and 7 days at 20 °C and 4 °C,
respectively (Howard 1989).

No mineralization was observed when 2-cresol was incubated with
two digester sludge samples for 8 weeks under anaerobic
conditions, nor was there any mineralization in 29 weeks when
it was incubated with anaerobic freshwater sediment (Horowitz 
et al. 1982).

Potential for accumulation positive. 
Chronic toxicant
properties via all routes suggest accumulative effects (Sax
1986).

Using the log octanol/water partition coefficient of 1.95, a
bioconcentration factor of 18 is estimated. 
Therefore 2-cresol
would not be expected to biocontrate significantly in fish
(Lyman et al. 1982).

Jaundice, dermatitis (Sax 1986).

Direct contact: Dangerous to skin and eyes (Sax 1986).

General sensation: Corrosive to body tissues; toxic by
inhalation, skin absorption, ingestion. 
May cause skin
eruptions. 
Absorption may lead to liver and kidney damage
(Sax 1986).

Acute hazard level: 8 g can be fatal to a man. 
Toxic via all
routes. 
Extremely corrosive irritant and allergen. 
Emits highly
toxic vapors when heated to decomposition. 
Chronic hazard
level: Dermatitis and/or liver and kidney damage (Sax 1986).

Skin and eye irritation data:
skn, rbt, 524 mg, 24 hr, severe;
eye, rbt, 105 mg, severe (Sax 1986).

LC50, 40 mg/l, 48hr, Mexican axolotl (3-4 w after hatching).

LC50, 38 mg/l, 48hr, claved toad (3-4 w after hatching)
(Slooff & Baerselmann 1980).

LD0, 60 mg/l, E. coli (Verschueren 1983)

Toxicity threshold (cell multiplication inhibition test):
Pseudomonas putida: 33 mg/l
(Bringmann & Kühn 1980a)

940 ppm inhibited 50 % sewage organisms subject to chlorination
and subsequently lower taste thresholds (Sax 1986).

6 - 40 mg/l, inhibitory, Scenedesmus;
5 - 10 mg/l, inhibitory, Macrocystis pyrifera;
55 mg/l, 1 hr, killed, sunfish;
60 mg/l, killed, minnow;
70 mg/l, 3 hr, killed, roach;
110 mg/l, 5 hr, killed, roach;
10 mg/l, 1 hr, lethal, perch 
(Sax 1986).

Toxicity threshold (cell multiplication inhibition test):
Microcystis aeruginosa        6.8 mg/l  Bringmann & Kühn 1976
Scenedesmus quadricauda        11 mg/l  Bringmann & Kühn 1980a
Entosiphon sulcatum            17 mg/l  Bringmann & Kühn 1980a
Uronema parduczi Chatton-Lwoff 31 mg/l  Bringmann & Kühn 1980b

LC50, 48hr, 165 mg/l, Tubificidae
LC50, 48hr, 34 mg/l, Chironomus gr. thummi
LC50, 48hr, 135 mg/l, Erpobdella octoculata
LC50, 48hr, 160 mg/l, Lymnaea stagnalis
LC50, 48hr, 24 mg/l, Dugesia cf. lugubris
LC50, 48hr, 75 mg/l, Hydra oligactis
LC50, 48hr, 80 mg/l, Corixa punctata
LC50, 48hr, 46 mg/l, Ischura elegans
LC50, 48hr, 10 mg/l, Nemoura cinerea
LC50, 48hr, 50 mg/l, Cloeon dipterum
(Slooff 1983)

Air pollution: high
(Sax 1986).

Manifacturing source: coal tar refing; petroleum refing;
organic chemical mfg.; wood processing.

Natural sources (water and air): coal, petroleum, constituent
in wood, constituent in natural runoff.

Man caused sources (water and air): automobile exhaust, roadway
runoff, runoff from asphalt, general use of plastics, petroleum
distillates, fuels, perfumes, oils lubricants, metal cleaning
and scouring compounds, laboratory chemical, constituent of
domestic sewage (EPA 1975).