LINEAR ALKYLBENZENE SULFONATE (LAS) - UNEP Chemicals

OECD SIDS LINEAR ALKYLBENZENE SULFONATE (LAS)
Concentration: 2.7 and 4.1 µM
BCF: Values of Steady-State Bioconcentration Factor (BCFss) and Average Length
of Alkyl Chain (nC,Av) are shown in the following table.
expt comp*
BCFss
L/kg
nC,Av
C10-2 1.7
A
C11-2
C12-2
5.8
47.6
10.8
C13-2 353.8
C11-5 6.1
B
C12-2
C12-5
99.1
10.0
11.7
C13-5 34.0
C11-5 9.8
C
C12-2
C12-3
168.4
42.1
11.4
C12-6 31.9
C10-2 6.0
C11-2 31.9
C12-2 211.5
D
C13-2
C10-in
987.2
3.0
10.6
C11-in 9.1
C12-in 29.9
C13-in 112.4
*In the format Cn-m, n and m are the length of the alkyl chain and the position at
which the sulfophenyl moiety is substituted to the alkyl chain, respectively.
Elimination: Yes [X] No [ ] ? [ ]
Method: OECD 305 E. The exposure phase in Experiment A was 48-hours. The
exposure phase in Experiments B-D ranged from 168 to 192 hours. Due to
the rapid equilibrium demonstrated in these studies, a longer exposure period
was not needed. Fish were then transferred to untreated water for the
depuration phase (duration not stated).
Type of test: calculated [ ]; measured [X]
static [ ]; semi-static [ ]; flow-through [X]
GLP: Yes [ ] No [ ] ? [X]
Test substance: LAS (C10-13), tested individually and as mixtures, activity: >97.4%
Remarks: As shown in the table, BCF values ranged between 2-1000 L/kg.
Experiments A, B and D showed that BCFs increase with increasing alkyl
chain length for a given isomer. In addition, the results of Experiments B and
C demonstrate that the closer the p-sulfophenyl moiety is positioned to the
terminal carbon of the alkyl chain, the higher the BCF. However, alkyl chain
length has a much bigger effect than does the phenyl position. To address
differences in composition of mixtures, bioconcentration potential was
calculated for a mixture typical of LAS in European detergent formulations
(C10 12%, C11 29%, C12 34%, C13 24%; average alkyl chain length = C11.6)
and a mixture typical of LAS in filtered Mississippi river water (C10 45%, C11
23%, C12 23%, C13 2%; average chain length = C10.8), using BCF values for
the individual components. This calculation of BCF for the typical mixtures
was done using the following equation developed in the above testing:
(ΣCf,i/ΣCw,i)rel = Σ(øi,w · BCFi,rel)
UNEP PUBLICATIONS 170