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Toxicological information

Genetic toxicity: in vivo

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Administrative data

Endpoint:
in vivo mammalian germ cell study: cytogenicity / chromosome aberration
Remarks:
Type of genotoxicity: chromosome aberration
Type of information:
other: published data
Adequacy of study:
supporting study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
study well documented, meets generally accepted scientific principles, acceptable for assessment
Justification for type of information:
Linear Alkylbenzene Sulfonate (LAS)) is a very close analogue of Calcium dodecylbenzenesulfonate (CAS No 26264-06-2, EC Number; 247-557-8) ) and read-across is valid.

Data source

Reference
Reference Type:
publication
Title:
Absence of chromosome damage in the bone marrow of rats fed detergent actives for 90 days
Author:
Hope J
Year:
1977
Bibliographic source:
Mutation Research, 56, 47-50

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
Method: Four detergent actives, sodium lauryl sulphate(sodium dodecyl sulphate), DOBS 055, Dobanol 25 sulphate LCU and Dobanol 25 sulphate HCB, were fed to rats in the diet for 90 days at the maximum tolerated dose, 1.13 percent active ingredient in each case. Sodium lauryl sulphate and DOBS 055 were also fed at half this concentration. Chromosome preparations were made from the bone marrow and scored for the presence of rearrangements, chromatid gaps and breaks and isochromatid gaps and breaks.
GLP compliance:
not specified
Type of assay:
chromosome aberration assay

Test material

Constituent 1
Reference substance name:
dodecylbenzene sulphonate, sodium salt
IUPAC Name:
dodecylbenzene sulphonate, sodium salt
Details on test material:
DOBS 055 (DOBS055=product name) (LAS (C10-C15)) (impurities = tetralins, tetralin sulphonates, sodium sulphate and sodium hydroxide)-Manufactured by Lever Bros. Ltd. from Shell alkylate was obtained as a paste of 44% active ingredient in water.-Nominally dodecylbenzene sulphonate, sodium salt, this material has a chain length of 10 to 15 carbon atoms, the sulphonate group is in the para position, and the benzene ring may be attached randomly along the aliphatic chain.

Test animals

Species:
rat
Strain:
other: Colworth/wistar rat
Sex:
male/female
Details on test animals or test system and environmental conditions:
Weight: weanlings of about 60 g Test substance was fed to six male and female weanling rats in each dose group

Administration / exposure

Route of administration:
other: Oral (diet)
Duration of treatment / exposure:
90 days
Doses / concentrations
Remarks:
Doses / Concentrations:
1.13%, 0.56%
Basis:
nominal in diet
No. of animals per sex per dose:
six male and female
Control animals:
yes
Positive control(s):
Negative control group of six males and females received the same diet without detergent active and positive control group fed the control diet for 90 days and then given 25 mg/kg by intra-peritoneal injection of cyclophosphamide 20 or 24 h.

Examinations

Details of tissue and slide preparation:
Two hours before sacrifice the animals were injected intra-peritoneally with 4 mg/kg colchicine, and were killed in a CO2 lethal chamber; one femur was removed and the bone marrow flushed out with 0.9% saline. The bone marrow cells were spun down and resuspended in hypotonic (0.56%) KCl solution at 40 deg C for 20 min. The swollen cells were spun down, resuspended in small amount of 0.56% KCl, and fixative (methanol; glacial acetic acid, 3:1) was added gently to avoid clumping of the cells. The cells were again spun down, resuspended in fresh fixative and fixed for 1 h. After fixation the cells were spun down, resuspended in a small amount of fresh fixative, dropped on to clean microscopic slides and the slides dried in a current of warm air. Slides were stained for 12 min in Giemsa (1:9 in pH 6.8 buffer) and mounted with coverslips.Chromosome preparations were made from eight animals per day over several days; animals from each dose group were distributed evenly over each of the days. This ensured that any variations in the quality of the preparations was spread evenly among the various groups.
Evaluation criteria:
Slide were scanned at X100 to select divisions. Divisions were scored at X 1000 for re-arrangements, chromatid gaps and breaks and isochromatid gaps and breaks. Ten divisions were scored from each slide, and six slides from each animal. There was thus a maximum of 360 divisions scored for each test group. All slides were coded and scored blind.

Results and discussion

Test results
Sex:
male/female
Genotoxicity:
negative
Additional information on results:
After LAS (C10-C15) were fed to groups of six male and six female Colworth/Wistar rats in the diet at concentrations of 0.56 or 1.13% (equivalent to 280 or 565 mg/kg bw/day) for 90 days, No alteratuons were seen in chromosomes in bone marrow. (Table)

Applicant's summary and conclusion

Conclusions:
Interpretation of results : negative
LAS was not exhibit a clastogenic effect under the test condition.

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