Registration Dossier

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:
20 October 2015 - 14 January 2016
Reliability:
1 (reliable without restriction)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2016
Report Date:
2016

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
GLP compliance:
yes (incl. certificate)
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
other: white solid
Details on test material:
Roche number : RO5463921-000
Batch : FIS201405080058
Molecular mass : 310,3 g/mol
Purity : 101,2 % (m/m)
Expiry date : 11 June 2016
Storage conditions : at room temperature, light protected

Method

Target gene:
- S. typhimurium: Histidine gene
- E. coli: Tryptophan gene
Species / strainopen allclose all
Species / strain:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Details on mammalian cell lines (if applicable):
Properly maintained: yes
Metabolic activation:
with and without
Metabolic activation system:
S9
Species / strain:
E. coli WP2 uvr A
Details on mammalian cell lines (if applicable):
Properly maintained: yes
Metabolic activation:
with and without
Metabolic activation system:
S9
Test concentrations with justification for top dose:
The test item was tested at the following concentrations at both experiments :
3; 10; 33; 100; 333; 1000; 2500 and 5000 µg/plate
Controlsopen allclose all
Negative controls:
yes
Solvent controls:
yes
Positive controls:
yes
Positive control substance:
sodium azide
Remarks:
withour activation
Positive control substance:
other: 4-nitro-o-phenylene-diamine
Remarks:
without activation
Positive control substance:
methylmethanesulfonate
Remarks:
without activation
Positive control substance:
other: 2-aminoanthracene
Remarks:
with activation

Results and discussion

Test results
Species / strain:
S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity:
not determined
Vehicle controls valid:
yes
Negative controls valid:
yes
Positive controls valid:
yes

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative

In conclusion, it can be stated that during the described mutagenicity test and under the experimental conditions reported according to OECD 471, the PAC- Ethenenitrile did not induce gene mutations by base pair changes or frameshifts in the genome of the strains used.
Executive summary:

This study was performed to investigate the potential of PAC- Ethenenitrile (CAS Nr. 1219086-87-9) to induce gene mutations according to the plate incorporation test (experiment I) and the pre-incubation test (experiment II) using the Salmonella typhimurium strains TA 1535, TA 1537, TA 98, TA 100, and the Escherichia coli strain WP2 uvrA according to OECD 471.

The assay was performed in two independent experiments both with and without liver microsomal activation. Each concentration, including the controls, was tested in triplicate. The test item was tested at the following concentrations in both experiments: 3; 10; 33; 100; 333; 1000; 2500; and 5000 µg/plate.

The test item precipitated in the overlay agar in the test tubes from 333 to 5000 µg/plate in the absence of S9 mix and from 100 to 5000 µg/plate in the presence of S9 mix. Precipitation of the test item in the overlay agar on the incubated agar plates was observed from 333 to 5000 µg/plate in experiment I without S9 mix and in experiment II with and without S9 mix. In experiment I with S9 mix precipitation was observed from 100 to 5000 µg/plate. The undissolved particles had no influence on the data recording.

The plates incubated with the test item showed normal background growth up to 5000 µg/plate with and without S9 mix in all strains used.

Toxic effects, evident as a reduction in the number of revertants (below the indication factor of 0.5), occurred in nearly all strains.

No substantial increase in revertant colony numbers of any of the five tester strains was observed following treatment with PAC- Ethenenitrile at any dose level, neither in the presence nor absence of metabolic activation (S9 mix). There was also no dose dependent increase in the number of revertant colonies below the threshold.

Appropriate reference mutagens were used as positive controls. They showed a distinct increase of induced revertant colonies. Negative and solvent controls showed regular background growth and mean revertant colony numbers in the range of the historical data.

Therefore the test was considered valid.