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Toxicological information

Genetic toxicity: in vitro

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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
Study period:
no data
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Acceptable, well-documented study report which meets basic scientific principles.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1989
Report Date:
1989

Materials and methods

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

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): 2,3,6-Trimethylphenol
- Analytical purity: 99.4%
- Impurities (identity and concentrations): no data
- Storage condition of test material: room temperature
No further data.

Method

Target gene:
For Salmonella typhimurium strains, the amino acid histidine locus is the target gene.
Species / strain
Species / strain:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Metabolic activation:
with and without
Metabolic activation system:
rat liver S-9, induced with Aroclor 1254
Test concentrations with justification for top dose:
20 - 5000 µg/plate; see below
Vehicle:
- Vehicle(s)/solvent(s) used: DMSO
- Justification for choice of solvent/vehicle: no data
Controls
Negative controls:
yes
Solvent controls:
yes
Positive controls:
yes
Positive control substance:
other: 2-aminoanthracene, N-methyl-N'-nitro-N-nitroso-guanidine, 4-nitro-o-phenylendiamine, 9-aminoacridine; depending on strain and activation condition
Details on test system and conditions:
METHOD OF APPLICATION: in agar (plate incorporation) and preincubation;
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
Statistics:
no data

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:
yes
Remarks:
>= 2500 µg/plate (SPT); >= 1500 µg/plate (PIT)
Vehicle controls valid:
yes
Negative controls valid:
yes
Positive controls valid:
yes
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Any other information on results incl. tables

No increase in the number of revertants was observed with any tester strain under any test condition.

Bacteriotoxicity (indicated by reduced bacterial growth) was observed in the SPT at doses >= 2500 µg/plate and in the PIT at 1500 µg/plate.

The test substance was completely soluble in the vehicle chosen; no precipitation was noted at any concentration tested.

Applicant's summary and conclusion

Executive summary:

REPORT SUMMARY

The substance 2,3,6-Trimethylphenol was tested for mutagenicity in the Ames test.

Strains: TA 1535, TA 100, TA 1537, TA 98

Dose range: 20 µg - 5000 µg/plate (SPT; TA 100, TA 98)

4 µg - 2500 µg/plate (SPT; TA 1535, TA 1537)

4 µg - 1500 µg/plate (PIT; all tester strains )

Test conditions: Standard plate test ( SPT) and preincubation test ( PIT) both with and without metabolic activation (rat liver S-9 mix) .

Solubility: Complete solubility of the test substance in DMSO.

Toxicity: A bacteriotoxic effect was observed in the standard plate test at doses => 2500 µg/plate and in the preincubation test at 1500 µg/plate.

Mutagenicity: 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.

Assessment:

According to the results of the present study, the test substance 2,3,6-Trimethylphenol is not mutagenic in the Ames test under the experimental conditions chosen here.