LINEAR ALKYLBENZENE SULFONATE (LAS) - UNEP Chemicals

OECD SIDS LINEAR ALKYLBENZENE SULFONATE (LAS)
Teratogenicity:
There were no indications of teratogenic or embryotoxic effects at any level
in either group tested.
Method: LAS was applied to depilated areas on the chests and backs of female rats 12-
18 weeks of age. Five to six hours prior to treatment an exposure site
(roughly 24 cm 2 ) in the dorsothoracic region of each animal from group II
through IX was clipped to a length of 1 mm. The animals were reclipped
every 48 hr throughout the study. Group I animals were unclipped, group II
animals were clipped but not treated and group III animals were clipped and
treated with tap water. The mated female rats were treated daily from day 0
through day 20 of gestation. A 0.5-ml sample of the appropriate
concentration of LAS and/or tap water was applied once daily to the clipped
area and spread with a gloved finger over as much of the exposure site as
possible. Each application was carried out slowly over a 3-min period. In
the 1, 5 and 20% LAS groups (groups VII, VIII and IX, respectively
corresponding to 20, 100 and 400 mg/kg/day) the test material was allowed
to remain on the backs of the animals for 30 min. after which it was removed
with warm tap water. The test material was not removed from the backs of
the animals in the 0.05, 0.1 and 0.5% LAS groups (groups IV, V and VI
corresponding to 1, 2 and 10 mg/kg/day). Animal body weight and food
consumption were determined during the treatment period. Daily
observations were also made for toxicological effects.
GLP: Yes [ ] No [X] ? [ ]
Test substance: LAS; mean chain length: 11.7; mean molecular weight: 344, activity:
20.5%
Reference: Daly, I.W., Schroeder, R.E. and Killeen, J.C. 1980. A teratology study of
topically applied linear alkylbenzene sulphonate in rats. Fd. Cosmet.
Toxicol. 18:55-58.
Reliability: 2 Valid with restrictions
(n)
Species/strain: Mouse/CD-1
Sex: Female [X]; Male [ ]; Male/Female [ ]; No data [ ]
Administration: Dermal
Exposure period: days 2 through 13 of gestation
Frequency of treatment:daily
Doses: 0.03, 0.3, or 3% LAS in aqueous solution onto the shaved skin (5, 50 and 500
mg/kg bw d)
Control group: Yes [X]; No [ ]; No data [ ];
Concurrent no treatment [X]; Concurrent vehicle [ ]; Historical [ ]
NOAEL Maternal: 0.03% (5 mg/kg bw d)
NOAEL teratogenicity: 0.3% (50 mg/kg bw d)
Results: Maternal toxicity:
At the high dose, severe local irritation was observed resulting in body
weight loss and hypersensitivity (i.e., animals were increasingly irritable),
which was also observed at the medium dose. The conclusion of the authors
was that LAS caused marked toxicity at the high dose and moderate or mild
toxicity at the medium dose.
Teratogenicity:
At the lowest dose, the dose with no maternal toxicity, no differences were
observed among the LAS group and the control group with respect to number
of litters, viable young, litter weight, foetal weight, embryonic deaths,
implantations, corpora lutea, pre- and post implantation embryonic loss. The
incidences of major malformations, minor visceral or skeletal anomalies, and
skeletal variants were not different between controls and the LAS group.
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