m-Cresol - ipcs inchem

OECD SIDS
m- / p-CRESOL
m-cresol and p-cresol the main target compartment was estimated to be water (96.3 %) (Calculated
distribution between environmental compartments: m-cresol resp. p-cresol: air: 2.33 / 2.46 %,
water: 96.32 / 96.26 %, soil: 0.69 / 0.66 %, bottom sediment: 0.65 / 0.62 %, suspended sediment:
0.001 / 0.001 %, biota: 0.0004 / 0.0004 %). The distribution of cresols between aqueous solution
and air is described by the Henry’s law constant. Experimentally determined values of 0.09 Pa
m 3 /mol for m-cresol (Altschuh et al. 1999) and 0.10 Pa m 3 /mol for p-cresol (Gaffney et al. 1987)
are available. Both values indicate a low volatility from aqueous solution according to the criteria of
Thomas (1990).
The distribution between the organic phase of soil solids and water was determined in batch
equilibrium experiments similar to the OECD Guideline 106. For a clay loam soil Boyd (1982)
determined Koc values of 34.58 for m-cresol and 48.66 for p-cresol indicating a low sorption
potential for the cresol isomers according to the criteria of Blume and Ahlsdorf (1993).
2.1.2 Abiotic Degradation
With regard to its chemical structure m-cresols and p-cresols are not expected to hydrolyse under
environmental conditions.
Several investigations are available about the indirect photolysis by OH-radicals in the atmosphere.
In his critical review Atkinson (1994) recommended values for the reaction constant kOH at room
temperature of 6.4 x 10-11 cm3 molecule-1 s-1 for m-cresol and 4.7 x 10-11 cm3 molecule-1 s-1
for p-cresol. Based on a tropospheric OH radical concentration of 5 x 105 molecules cm-3
corresponding half-lives of 6.0 h for m-cresol and 8.2 h for p-cresol can be calculated. Semadeni et
al. (1995) determined the temperature dependency of the reaction constants in a smog chamber
experiment: the calculated half-life is 3.8 h both for m-cresol (299 K) and p-cresol (301 K).
Because of the presence of a chromophore cresols are expected to undergo photolytical degradation
in the hydrosphere. Scully and Hoigne (1987) determined the rate constants for the reaction of p-
cresol with singlet oxygen in a laboratory experiment. Solutions of p-cresol (