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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:
not specified
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: GLP status not known, near guideline study, published in peer reviewed literature, no restrictions, fully adequate for assessment.
Justification for type of information:
N/A

Data source

Reference
Reference Type:
publication
Title:
Unnamed
Year:
1983

Materials and methods

Test guideline
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
yes
Remarks:
TA102 not used
Principles of method if other than guideline:
Liquid preincubation protocol using Salmonella strains TA98, TA100, TA1535 and TA1537 in the absence or presence of liver S9 from male Sprague-Dawley rats and Syrian hamsters induced with Aroclor 1254.
GLP compliance:
not specified
Type of assay:
bacterial reverse mutation assay

Test material

Constituent 1
Chemical structure
Reference substance name:
o-xylene
EC Number:
202-422-2
EC Name:
o-xylene
Cas Number:
95-47-6
Molecular formula:
C8H10
IUPAC Name:
o-xylene
Details on test material:
supplied by Aldrich, Lot number HD061297
Specific details on test material used for the study:
not specified

Method

Target gene:
not specified
Species / strain
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Cytokinesis block (if used):
N/A
Metabolic activation:
with and without
Metabolic activation system:
rat liver S-9, Aroclor 1254 induced; hamster liver S-9, Aroclor 1254 induced
Test concentrations with justification for top dose:
0, 1.0, 3.3, 10.0, 33.0, 100.0, 333.0 µg/plate
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: DMSO
Controls
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: 2-Aminoanthracene, 4-Nitro-o-phenylenediamine, sodium azide, 9-aminoacridine
Remarks:
Positive and true negative controls tested as coded samples
Details on test system and experimental conditions:
METHOD OF APPLICATION: liquid preincubation

DURATION
- Preincubation period: 20 mins
- Exposure duration: 48 hours

NUMBER OF REPLICATIONS: Three plates were used and the experiment was repeated at least 1 week after completion of the initial test.

DETERMINATION OF CYTOTOXICITY
- Method: relative total growth
Rationale for test conditions:
not specified
Evaluation criteria:
Initially data were evaluated in an ad hoc manner. A positive response was indicated by a reproducible, dose-related increase, whether or not it was twofold over background.
Statistics:
The data were evaluated using an analysis based on models presented by Margolin et al, 1981 (methods not described).

Results and discussion

Test resultsopen allclose all
Key result
Species / strain:
S. typhimurium TA 1535
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
not examined
True negative controls validity:
not examined
Positive controls validity:
valid
Key result
Species / strain:
S. typhimurium TA 1537
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
not examined
True negative controls validity:
not examined
Positive controls validity:
valid
Key result
Species / strain:
S. typhimurium TA 98
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
not examined
True negative controls validity:
not examined
Positive controls validity:
valid
Key result
Species / strain:
S. typhimurium TA 100
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
>100 µg/plate without activation and >333 µg/plate with activation
Vehicle controls validity:
valid
Untreated negative controls validity:
not examined
True negative controls validity:
not examined
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 102
Remarks:
strain not tested
Metabolic activation:
not applicable
Genotoxicity:
not determined
Cytotoxicity / choice of top concentrations:
not determined
Vehicle controls validity:
not examined
Untreated negative controls validity:
not examined
True negative controls validity:
not examined
Positive controls validity:
not examined
Additional information on results:
N/A
Remarks on result:
other: all strains/cell types tested

Any other information on results incl. tables

N/A

Applicant's summary and conclusion

Conclusions:
Interpretation of results:
negative

negative with and without metabolic activation
Executive summary:

o-xylene was not genotoxic when tested with and without metabolic activation in Salmonella typhimurium strains TA98, TA100, TA1535 and TA1537 at concentrations up to 100 µg/plate (limit of cytotoxicity) using a liquid preincubation procedure and with metabolic activation at a concentration of 333 µg/plate.