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Diss Factsheets

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: restrictions: non-GLP study, E. coli not tested

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1991
Report date:
1991

Materials and methods

Test guideline
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
no
GLP compliance:
no
Type of assay:
bacterial reverse mutation assay

Test material

Constituent 1
Chemical structure
Reference substance name:
2,5-dimethylhexane-2,5-diol
EC Number:
203-731-5
EC Name:
2,5-dimethylhexane-2,5-diol
Cas Number:
110-03-2
Molecular formula:
C8H18O2
IUPAC Name:
2,5-dimethylhexane-2,5-diol
Details on test material:
Name of the test substance used in the study report: 2,5-Dimethylhexandiol-2,5-diol
Physical state: solid (waxy), white
Analytical purity: 99.5%
Lot/batch No.: 21922-108
Stability under test conditions: yes

Method

Species / strain
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Metabolic activation:
with and without
Metabolic activation system:
Aroclor induced rat liver S-9 mix
Test concentrations with justification for top dose:
20, 100, 500, 2500, 5000 ug/plate
Vehicle / solvent:
water
Controls
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
Positive controls:
yes
Positive control substance:
other: with metabolic activation: 2-aminoanthracene; without metabolic activation: N-methyl-N'-nitro-N-nitrosoguanidine, 4-nitro-o-phenylendiamine and 9-aminoacridine chioride monohydrate
Details on test system and experimental conditions:
Experiment 1: Standard plate test
Test tubes containing 2 ml soft agar kept in a water bath at 45°C, and remaining components added in the following order:
0.1 ml test solution or solvent
0.1 ml bacterial suspension
0.5 ml S9 mix (in tests with metabolic activation) or 0.5 ml phosphate buffer (in tests without metabolic activation).
After mixing, the samples are poured onto Vogel-Bonner agar plates.

Experiment 2: Preincubation test
0.1 ml test solution or solvent, 0.1 ml bacterial suspension and 0.5 ml S9 mix are incubated at 37°C for the duration of 20 minutes. Subsequently, 2 ml of soft agar is added and, after mixing, the samples are poured onto the Vogel-Bonner agar plates.

Experiment1&2
In each experiment 3 test plates per dose or per control used; after incubation at 37°C for 48 hours in the dark, the bacterial colonies ( his+ revertants) are counted.
Evaluation criteria:
In general, a substance to be characterized as positive in the Ames test has to fulfill the following requirements:
- doubling of the spontaneous mutation rate (control)
- dose-response relationship
- reproducibility of the results

Results and discussion

Test results
Species / strain:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Additional information on results:
An increase in the number of his+ revertants was not observed both in the standard plate test and in the preincubation test either without S-9 mix or after the addition of a metabolizing system.
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Applicant's summary and conclusion

Conclusions:
According to the results of the present study, the test substance 2,5-dimethylhexane-2,5-diol is not mutagenic in the Salmonella typhimurium reverse mutation assay under the experimental conditions chosen.
Executive summary:

The substance 2,5-Dimethylhexandiol-2,5 was tested for mutagenicity in the Ames test (standard plate test and preincubation test) both in the presence and in the absence of a metabolizing system obtained from rat liver (S-9 mix) using the strains TA 1535, TA 100, TA 1537 and TA 98. An increase in the number of revertants was not observed in both tests either without S-9 mix or after the addition of a metabolizing system.