LINEAR ALKYLBENZENE SULFONATE (LAS) - UNEP Chemicals

OECD SIDS LINEAR ALKYLBENZENE SULFONATE (LAS)
Reference: Mackay, D., Di Guardo, A., Paterson, S., Kicsi, G., Cowan, C. and Kane, D.
1996. Assessment of chemical fate in the environment using evaluative,
regional and local scale models: Illustrative application to chlorobenzene and
linear alkylbenzene sulfonates. Environ. Toxicol. Chem. 15:1638-1648.
Reliability: 2 Valid with restrictions
(b)
Media: Air-biota [ ]; Air-biota-sediment-soil-water [X]; Soil-biota [ ];
Water-air [ ]; Water-biota [ ]; Water-soil [ ]
Method: Fugacity level I [ ]; Fugacity level II [ ]; Fugacity level III [X]; Fugacity
level IV [ ]; Other (calculation) [ ]; Other (measurement)[ ] Multi-media
model HAZCHEM derived from MacKay type level III model, including a
water purification module (comparable to SIMPLETREAT model used by
the Netherlands Authorities). Regional model for Europe. Includes
probabilistic evaluation of natural variability and inaccuracy in determination
of input parameters using Monte Carlo simulation. Input parameters held
constant in the simulations for the LAS used in the model were based on the
best available data at the time of modeling and are:
Molecular weight 347
Melting point (°C) 10
Vapor pressure (Pa) 1 x 10 -10
Solubility (mg/L) 350
Log Kow 2.5
Half-life life in air (h) 8
Half-life in water (h) 35
Half-life in soil (h) 339
Half-life in sediment (h) 17
Soil-water partitition coefficient (L/kg) 1000
Sediment-water partitition coefficient (L/kg) 1000
Suspended solids-water partitition coefficient (L/kg) 1000
Parameters that were varied using lognormal distributions for the Monte
Carlo simulations included water surface and arable land fractions, depths of
various compartments, fraction organic carbon in various compartments,
advective residence times, temperature, and others.
Results: Predicted concentrations in the various compartments as defined by the model
as shown in the table below. Degradation in the soil was not taken into
account and the model was not calibrated. Measured concentrations in arable
soil were generally below 1 ppm. Results are the 5 th and 95 th percentile values
from the Monte Carlo analysis and the normal average.
Average 5 percentile 95 percentile
air (ug/m 3 ) 3.23 E-12 -- --
biota (ppm) 5.99 E-2 7.11 E-3 1.95 E-1
sediment (ppm) 4.90 E-3 3.23 E-3 1.38 E-2
arable soil (ppm) 44.2 7.02 1.11 E+2
suspended. matter (ppm) 3.79 0.449 12.3
dissolved in water (mg/L) 3.79 E-3 4.49 E-4 1.23 E-2
suspended in water (mg/L) 7.81 E-5 1.54 E-5 2.16 E-4
Remarks: Input data were the best estimates from ECETOC Task Force members,
including detergent industries. Note the predicted average value for arable
soil was reported in ECETOC 1993 as 4.42E-4, which is not possible given
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