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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:
1992
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Published study but containing sufficient details to be able to judge it reliable for hazard assessment. Part of a programme of work by the NTP. Data tables available for results. TA102 not included. Full documentation in NTP studies available.

Data source

Reference
Reference Type:
publication
Title:
Unnamed
Year:
1992

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
no
GLP compliance:
not specified
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): Ethyl Acetate
- Analytical purity: >99%

Method

Species / strainopen allclose all
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Details on mammalian cell type (if applicable):
- Type and identity of media:
- Culture prepared at 37C overnight with shaking in Oxoid #2 broth or in defined minimal medium supplemented with biotin and histidine. Phenotype analysed at time of use.
Species / strain / cell type:
S. typhimurium TA 97
Details on mammalian cell type (if applicable):
- Type and identity of media:
- Culture prepared at 37C overnight with shaking in Oxoid #2 broth or in defined minimal medium supplemented with biotin and histidine. Phenotype analysed at time of use.
Metabolic activation:
with and without
Metabolic activation system:
Aroclor 1254 induced male SD rat and male Syrian hamster liver S9 fraction, each used at two concentrations (10% and 30%)
Test concentrations with justification for top dose:
0 ; 100 ; 333 ; 1000 ; 3333 ; 10000 µg/plate. Doses were prepared using dimethyl sulphoxide as the solvent; a maximum of 0.5 ml solvent was added to each plate. Each dose was tested in triplicate without activation, and with 10% rat and hamster liver S-9.
Controlsopen allclose all
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
sodium azide
Remarks:
Migrated to IUCLID6: used for TA1535 and TA100 without metabolic activation
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
9-aminoacridine
Remarks:
Migrated to IUCLID6: used for TA97 without metabolic activation
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: 4-nitro-o-phenylenediamine used for TA98 without metabolic activation
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: 2-aminoanthracene for all strains with metabolic activation
Details on test system and experimental conditions:
METHOD OF APPLICATION: preincubation

DURATION
- Preincubation period: 20 mins at 37C
- Expression time (cells in growth medium): 2 days at 37C

NUMBER OF REPLICATIONS: 5 concentrations in triplicate without metabolic activation, and with 10% and 30% liver S-9 from rat and hamster. Replicate tests were performed after the initial trial to confirm these results.
Evaluation criteria:
A material was considered mutagenic if it produced a reproducible, dose-related increase in revertants over the solvent control, under a single metabolic activation condition, in replicate trials. A material was considered questionable if the positive response was elicited at only one concentration, or if the response could not be reproduced. A chemical was designated as non-mutagenic only after it was tested without metabolic activation, and with 10% and 30% rat and hamster S-9.

Results and discussion

Test resultsopen allclose all
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
Remarks:
up to maximum dose tested (10000ug/ml)
Vehicle controls validity:
valid
Untreated negative controls validity:
not examined
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 97
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Remarks:
up to maximum dose tested (10000ug/ml)
Vehicle controls validity:
valid
Untreated negative controls validity:
not examined
Positive controls validity:
valid
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Any other information on results incl. tables

After a negative result was obtained, the substance was retested without metabolic activation and with 30% S-9. Repeat experiments were performed at least one week following the initial trial.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative
Executive summary:

Zeiger et al (1992) reported that ethyl acetate was negative in a Salmonella gene mutation assay (Ames Tester Strains TA97, TA98, TA100, TA1535, and TA1537), with and without exogenous metabolic activation.