Registration Dossier

Toxicological information

Genetic toxicity: in vitro

Currently viewing:

Administrative data

Endpoint:
in vitro gene mutation study in bacteria
Remarks:
Type of genotoxicity: gene mutation
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: GLP guideline study with acceptable restrictions. Although 5 strains were tested no strain for detection of cross-linking or oxidising mutagens was included.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1990
Report Date:
1990

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
yes
Remarks:
Strain for detection of oxidising or cross-linking mutagens is missing, but in accordance with guideline at the time of testing.
GLP compliance:
yes
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Test material form:
solid: pellets
Details on test material:
- Name of test material (as cited in study report): stearyl erucamide
- Physical state: solid, off-white beads
- Analytical purity: 95%
- Lot/batch No.: B.4946
- Expiration date of the lot/batch: 6 months (reveived 24 Apr 1990)
- Stability under test conditions: not determined in this study
- Storage condition of test material: 4 °C in the dark

Method

Target gene:
His-operon
Species / strain
Species / strain / cell type:
S. typhimurium, other: TA 1535, TA 1537, TA 1538, TA 98, TA 100
Metabolic activation:
with and without
Metabolic activation system:
Aroclor 1254-induced rat liver S-9
Test concentrations with justification for top dose:
50, 150, 500, 1500, 5000 µg/plate
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: hexane
- Justification for choice of solvent/vehicle: solubility of test compound in vehicle
Controlsopen allclose all
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
Remarks:
hexane
True negative controls:
no
Positive controls:
yes
Positive control substance:
9-aminoacridine
Remarks:
TA 1537 without S-9

Migrated to IUCLID6: 80 µg/plate
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
Remarks:
hexane
True negative controls:
no
Positive controls:
yes
Positive control substance:
N-ethyl-N-nitro-N-nitrosoguanidine
Remarks:
TA 100 and TA 1535 without S-9

Migrated to IUCLID6: 3 µg/plate (TA 100), 5 µg/plate (TA 1535)
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
Remarks:
hexane
True negative controls:
no
Positive controls:
yes
Positive control substance:
2-nitrofluorene
Remarks:
TA 98 and TA 1538 without S-9

Migrated to IUCLID6: 1 µg/plate (TA 98) and 2 µg/plate (TA 1538)
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
Remarks:
hexane
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: 2-aminoanthracene: 0.5 µg/plate with TA 1538 and TA 98, 1 µg/plate with TA 100, and 2 µg/plate with TA 1535 and TA 1537.
Remarks:
all strains with S-9
Details on test system and experimental conditions:
METHOD OF APPLICATION: in agar (plate incorporation)

DURATION
- Exposure duration: 3 days

NUMBER OF REPLICATIONS: triplicates; independent repetition of complete test

DETERMINATION OF CYTOTOXICITY
- Method: relative total growth; other: reduction of background growth
Evaluation criteria:
Positive: increase in revertant colony numbers of at least twice of those of the concurrent solvent controls, with some evidence of a positive dose-relationship, in two separate experiments, with any bacterial strain either in presence or absence of S9-mix. No statistical analysis is performed.
Negative: no reproducible increases in revertant colony numbers of at least 1.5 times of those of the concurrent solvent controls, at any dose level with any bacterial strain. No statistical analysis is performed.
Ambiguous: If the results fail to satisfy the criteria for a clear positive or negative response as described the following approach is taken: 1) Repeat tests with modified experimental method may be performed. These modifications include (but are not restricted to) the use of a narrower dose range than that already tested; the use of different levels of liver homogenate S-9 fraction in the S-9 mix. Should an increase in revertant colony numbers be observed which satisfies the 'positive' criteria the material is considered to be mutagenic. No statistical analysis is performed. 2) If no clear 'positive' response can be obtained the test data may be subjected to analysis to determine the statistical significance of any observed increases in revertant colony numbers. The statistical procedure used is normally analysis of variance followed by Student's t-test.
Statistics:
In case of ambiguous results analysis of variance followed by Student's t-test is performed. In case of unequivocally positive or negative results according to the described criteria, no statistical analysis is performed.

Results and discussion

Test results
Species / strain:
S. typhimurium, other: TA 1535, TA 1537, TA100, TA98, TA 1538
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity, but tested up to precipitating concentrations
Remarks:
Precipitation starting at 1500 µg/plate in test 1 and at 5000 µg/plate in test 2.
Vehicle controls validity:
valid
Untreated negative controls validity:
not examined
Positive controls validity:
valid
Additional information on results:
TEST-SPECIFIC CONFOUNDING FACTORS
- Precipitation: Starting at 1500 µg/plate with and without metabolic activation in all strains in test 1 and at 5000 µg/plate with and without activation in all strains in test 2.

RANGE-FINDING/SCREENING STUDIES:
Dose range finding tests were performed with 5, 50, 500 and 5000 µg/plate. No cytotoxicity was observed, therefore 5000 µg/plate was chosen as maximum concentration for main test.

ADDITIONAL INFORMATION ON CYTOTOXICITY: No cytotoxicity was observed.
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Any other information on results incl. tables

Maximum mean number of revertants (Test with highest revertant numbers chosen):

 

Mean revertant numbers ±SD

 

without S-9

with S-9

Strain

Solvent control

Test substance (µg/plate)

Solvent control

Test substance (µg/plate)

TA 1535

10±2.6

11±3.1 (150)

13±1.5

13±3.0 (50)

TA 1537

12±2.5

11±2.6 (150)

9±1.4

11±2.0 (50)

TA 1538

11±1.5

11±1.5 (500)

10±1.7

15±1.5 (500)

TA 98

23±1.2

25±2.0 (500)

23±3.6

24±0.6 (500)

TA 100

75±5.1

87±6.1 (150)

93±5.5

90±9.1 (5000)

 

The concurrent positive controls demonstrated the validity of the test system.

No substantial increases in revertant colony numbers of any of the tester strains were observed following treatment with the test substance at any dose level, neither in the presence nor absence of metabolic activation.

Conclusion:

Under the conditions chosen the test substance was not mutagenic in bacteria.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative