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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:
1995-09-22 to 1995-10-17
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: This study is classified as reliable without restriction because it was conducted in accordance with OECD 471 guideline for reversion assays and was GLP compliant.
Justification for type of information:
A discussion and report on the read across strategy is given as an attachment in Section 13.
Cross-reference
Reason / purpose:
read-across: supporting information

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1995
Report Date:
1995

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
GLP compliance:
yes
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): SHOP Internal Olefins C6-8
- Substance type: Alkenes, C6-8
- Physical state: Clear colourless liquid

Method

Target gene:
Not specified
Species / strain
Species / strain:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Metabolic activation:
with and without
Test concentrations with justification for top dose:
50, 158, 500, 1580, and 5000 ug/plate
Vehicle:
- Vehicle(s)/solvent(s) used: DMSO
- Justification for choice of solvent/vehicle: Not provided
Controls
Negative controls:
yes
Solvent controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: Benzo(a)pyrene and 2-nitrofluorene
Details on test system and conditions:
METHOD OF APPLICATION: in agar (plate incorporation)

DURATION
- Preincubation period: 10 hours
- Exposure duration: 2 days

NUMBER OF REPLICATIONS: 3


Evaluation criteria:
The Salmonella strains are checked by testing for growth inhibition in spot tests by using 1) Crystal violet inhibition zone at greater than 14 mm in diameter when 10 µl of a 1 mg/mL crystal violet solution was spotted onto plate centre indicated a possession of deep-rough (rfa) character, or when 2) Mitomycin C solution was spotted onto plate centre indicated a defective DNA repair system (uvrB).
Statistics:
Statistical methods, if employed, are not reported in the study.

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:
no
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

The preliminary toxicity test did not cause any visible thinning of the background lawn of non-revertant cells as a result of exposure to Shop IO C6-8. Positive controls indicated that the test system was working appropriately. In the main mutagenicity test, no increase in revertant colony numbers over control were obtained with any of the four tester strains exposed to Shop IO C6-8 at concentrations ranging from 50 to 5000 µg/plate. Based on these results, SHOP Internal Olefins C6-8 was not mutagenic in the presence or absence of S9. 

Applicant's summary and conclusion

Conclusions:

negative

SHOP Internal Olefins C6-8 is not mutagenic in the presence or absence of S9.
Executive summary:

In a bacterial reverse mutation assay, Shop IO C6-8 was initially tested to determine its potential to cause cytotoxicity. Based on the outcome of this experiment, the main mutagenicity study was conducted on Salmonella typhimurium strains, TA1537, TA1535, TA100 and TA98 using 50, 158, 500, 1580, or 5000 µg/plate both in the presence and absence of S9. This test was conducted in triplicate. After a 2 day incubation period, number of revertant colonies was counted, either manually or with an automated colony counter. Growth of the background lawn of non-revertant cells on minimal plates was also verified. Results obtained with all strains were confirmed in a second, independent experiment.

The preliminary toxicity test did not cause any visible thinning of the background lawn of non-revertant cells as a result of exposure to Shop IO C6-8. Positive controls indicated that the test system was working appropriately. In the main mutagenicity test, no increase in revertant colony numbers over control were obtained with any of the four tester strains exposed to Shop IO C6-8 at concentrations ranging from 50 to 5000 µg/plate. Based on these results, SHOP Internal Olefins C6-8 was not mutagenic in the presence or absence of S9. 

 

This study received a Klimisch score of 1 and is classified as “reliable without restrictions” because it was conducted in accordance with OECD 471 guideline for reversion assays and was GLP compliant.