LINEAR ALKYLBENZENE SULFONATE (LAS) - UNEP Chemicals

OECD SIDS LINEAR ALKYLBENZENE SULFONATE (LAS)
(f)
Type: Toxicokinetics
Method: Studies were conducted with isolated human skin preparations as well as in
vivo investigations of percutaneous administration of LAS to rats. Two C12
LAS solutions were tested: a 3 mM solution in 25% v/v polyethylene glycol
400 in water, and a 3 mM suspension in water prepared by homogenizing and
equilibration in an all-glass homogenizer.
Results: No radioactivity was detected in urine or faeces.
Test substance: LAS (CAS #25155-30-0); activity: >99%
Remarks: These studies demonstrated that penetration through skin and subsequent
systemic absorption of this surfactant does not occur to any significant extent
at 24 to 48 hrs.
Reference: Howes, D. 1975. The percutaneous absorption of some anionic surfactants.
J. Soc. Cosmet. Chem. 26:47-63.
Reliability: 2 Valid with restrictions
(g)
Type: in vitro studies with fertilised eggs
Method: Eggs from B6 x C3F1 female mice, which were fertilised in vitro with sperm
from C3 x 101F1 male mice, were treated with LAS for 1 hour at the
pronucleus stage and then cultivated for 5 days.
Results: Eggs treated with LAS at concentrations of less than 0.025% developed to
the blastocyst stage as well as the untreated ones. At higher concentrations
no egg developed beyond the 1-cell stage. The group that was treated with
natural soap had no effect up to a concentration of 0.05%.
Test substance: Commercial LAS detergent (Japan)
Remarks: The authors suggest that LAS interrupts mouse pregnancy by killing
fertilized eggs, however, the relevance of the results obtained in this assay for
the in vivo situation has not been proven.
Reference: Ishii, Y., Samejima, Y., Saji, F. and Nomura, T. 1990. Effect of alcohol
sulfate, linear alkylbenzene sulfonate, and natural soap on the development of
fertilized eggs of the mouse in vitro. Mutat. Res. 242:151-155.
Reliability: 2 Valid with restrictions
5.11 EXPERIENCE WITH HUMAN EXPOSURE
(a)
Type: Human Repeat Insult Patch Test
Number of Subjects: 95 (at completion)
Methods: LAS was applied at 0.10% (w/v) on the upper arms of volunteers, under
occlusive patch conditions. Test material was applied for 24 hours, 3 times a
week, for 3 weeks during the induction period. After a 14-17-day rest, a 24hour
challenge patch was applied on the original and alternate arm sites.
Results: There was no evidence of skin sensitization on the 95 subjects who
completed the test.
Test Material: LAS; activity: 30.0%
Reference: The Procter & Gamble Company, unpublished data, Report No. ISC-124-
0470.
Reliability: 4 Not assignable
(b)
Type: Human Repeat Insult Patch Tests.
Number of subjects: 2,294 (exposed to LAS as a raw material)
17,887 (exposed to LAS in formulations)
Results: No evidence of skin sensitization.
UNEP PUBLICATIONS 306