LINEAR ALKYLBENZENE SULFONATE (LAS) - UNEP Chemicals

OECD SIDS LINEAR ALKYLBENZENE SULFONATE (LAS)
serum protein and degeneration of the renal tubes. The 0.2% group showed
increased weight of the cecum and slight degeneration of the renal tubes, the
0.07% group showed no adverse effects related to the administration of LAS.
The intake of LAS in the 0.07% group was about 40 mg/kg bw d.
GLP: Yes [ ] No [X] ? [ ]
Test substance: C10-14 LAS, sodium salt (CAS #69669-44-9). C10 10.6%, C11 34.1%, C12
27.7%, C13 19.0%, C14 8.7%; average alkyl chain length = C11.8; mean
molecular weight: 345.8.
Remarks: Information as cited in IPCS document. This is a key study for repeated dose
toxicity because it represents the lowest LOAEL (see SIAR Table 6).
Reference: 1) European Commission. 2000a. Benzenesulfonic acid, C10-13-alkyl derivs.,
sodium salts. Year 2000 CD-ROM edition.
2) Yoneyama, M. Fujii, T., Ikawa, M., Shiba, H., Sakamoto, Y., Yano, N.,
Kobayashi, H., Ichikawa, H. and Hiraga, K. 1972. Studies on the toxicity of
synthetic detergents. (II) Subacute toxicity of linear and branched alkyl
benzene sulfonates in rats. Ann. Rep. Tokyo Metrap. Res. Lab. Public
Health. 24:409-440. (In Japanese). cited in IPCS (1996); Environmental
Health Criteria 169: Linear Alkylbenzene Sulfonates (LAS) and Related
Compounds. WHO, Geneva, Switzerland.
Reliability: 4 This study is assigned a reliability score of 4 because the original report
was not available for review. However, the study was evaluated by IPCS
prior to inclusion in their criteria document.
(g)
Species/strain: Rat
Sex: Female [ ]; Male [ ]; Male/Female [X]; No data [ ]
Administration: gavage
Exposure period: 10 weeks
Doses: 50, 100 or 250 mg/kg bw d
Control: Yes [X]; No [ ]; No data [ ];Concurrent no treatment [X];
Concurrent vehicle [ ]; Historical [ ]
LOEL: 50 mg/kg bw d
Results: Histopathology was evaluated in the females only. At the highest dose level,
the kidneys showed mild degeneration and desquamation of the tubular
epithelium and there was a moderate degree of fatty change in the liver as
well as proteinaceous degeneration. Sections of the intestine did not exhibit
any significant histologic variation. Adenosine triphosphatase activity was
inhibited with increasing dose in both sexes while alkaline phosphatase and
acid phosphatase activities were increased with increasing dose. The activity
of lactate dehydrogenase was significantly inhibited at all dose levels in
females but was not measured in males. SGOT and SGPT were significantly
decreased in females at 100 and 250 mg/kg/day and SGPT was inhibited in
males at 250 mg/kg/day.
Method: Twenty four male (50+/-5g) and 36 female (40+/-5g) rats were given daily
oral (cannula) doses of LAS detergent solution (0, 50, 100 and 250 mg/kg)
by gavage for 10 weeks. Animals were maintained on standard pellet diets
and drinking water ad libitum. After 10 weeks, animals were fasted for 24
hours and sacrificed. Liver, kidney, heart, and intestine were removed
immediately, weighed, and parts sectioned for histological examinational.
The remaining parts of the liver and kidney homogenized in ice cold 0.25 M
sucrose solution using Potter-Elvehjem type homogenizer and 10% w/v
homogenates were prepared for histopathology and enzyme analysis. The
activities of adenosine triphoshatase (ATPase), acid phosphatase (ACP),
alkaline phosphatase (ALP), glutamic oxaloacetic transaminase (GOT), and
glutamic pyruvic transaminase (GPT) were determined in the homogenates.
GLP: Yes [ ] No [X] ? [ ]
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