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
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Comparable to guideline study with acceptable restrictions. Only 4 strains tested.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1988
Report Date:
1988

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
yes
Remarks:
Only 4 strains tested
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): omega-chloro-para-fluoracetophenone (Test substance No.: 87/675)
- Physical state: no data
- Analytical purity: 98 %
- Impurities (identity and concentrations): not reported
- Storage condition of test material: 4°C

Method

Target gene:
histidine auxotrophy
Species / strain
Species / strain:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Metabolic activation:
with and without
Metabolic activation system:
Aroclor 1254-treated rat liver S-9 mix
Test concentrations with justification for top dose:
Experiment 1: 20, 100, 500, 2500, 5000 µg/plate (SPT±S9); Experiment 2: 1, 5, 25, 125, 250 µg/plate (SPT+S9); 0.2, 1, 5, 25, 50 µg/plate (SPT-S9); Experiment 3: 1.5, 5, 15, 50, 150 µg/plate (PIT+S9); 0.1, 0.3, 1, 3, 10 µg (PIT-S9)
Vehicle:
- Vehicle(s)/solvent(s) used: DMSO
- Justification for choice of solvent/vehicle: complete solubility of the test substance in DMSO.
Controlsopen allclose all
Negative controls:
yes
Remarks:
Sterility control
Solvent controls:
yes
Positive controls:
yes
Positive control substance:
other: 2-aminoanthracene 10 µg
Remarks:
With S-9, strains TA100, TA98, TA1537, TA1535
Negative controls:
yes
Remarks:
Sterility control
Solvent controls:
yes
Positive controls:
yes
Positive control substance:
other: N-methyl-N´-nitro-N-nitrosoguanidine (MNNG) 5 µg
Remarks:
Without S-9, strains TA100 and TA1535
Negative controls:
yes
Remarks:
Sterility control
Solvent controls:
yes
Positive controls:
yes
Positive control substance:
other: 4-nitro-o-phenylendiamine 10 µg
Remarks:
Without S-9, strain TA98
Negative controls:
yes
Remarks:
Sterility control
Solvent controls:
yes
Positive controls:
yes
Positive control substance:
other: 9-aminoacridine chloride monohydrate 100 µg
Remarks:
Without S-9, strain TA1537
Details on test system and conditions:
METHOD OF APPLICATION: in agar (plate incorporation) and preincubation

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

NUMBER OF REPLICATIONS: 3 plates

DETERMINATION OF CYTOTOXICITY
- Method: relative total growth, other: reduction of his- background growth, decrease in the number of his+ revertants
Evaluation criteria:
A test substance is characterized as positive in the Ames test if the following requirements are fulfilled:
- doubling of the spontaneous mutation rate (control)
- dose-response relationship
- reproducibility of the results

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:
Bacteriotoxic effect depending on strain without S-9 from about 10 µg - 20 µg/plate onward and with S-9 from about 100 - 150 µg/plate onward.
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

Experiment 1:

Standard plate test, maximum number of revertants (mean ± SD):

      Control     Test substance
 Strain  -S9  +S9  -S9  +S9
 TA1535  17 ± 2  24 ± 2  14 ± 1 (20 µg)  18 ± 3 (20 µg)
 TA100  112 ± 8  123 ± 8  103 ± 5 (20 µg)  134 ± 4 (20 µg)
 TA1537  7 ± 1  9 ± 1  5 ± 2 (20 µg)  7 ± 1 (20 µg)
 TA98  21 ± 2  35 ± 3  contamination (20 µg)  32 ± 0 (20 µg)

Experiment 2:

Standard plate test, maximum number of revertants (mean ± SD):

      Control     Test substance
 Strain  -S9  +S9  -S9  +S9
 TA1535  15 ± 2  19 ± 3  16 ± 3 (5 µg)  17 ± 1 (25 µg)
 TA100  108 ± 2  115 ± 9  109 ± 8 (1µg)  113 ± 5 (5 µg)
 TA1537  8 ± 1  9 ± 2  7 ± 1 (1 µg)  12 ±1 (25 µg)
 TA98  22 ± 1  32 ± 1  23 ± 2 (0.2 µg)  33 ± 1 (5 µg)

Experiment 3:

Preincubation test, maximum number of revertants (mean ± SD):

      Control     Test substance
 Strain  -S9  +S9  -S9  +S9
 TA1535  18 ± 5  17 ± 3  19 ± 3 (1.0 µg)  17 ± 5 (15 µg)
 TA100  116 ± 9  116 ± 3  116 ± 7 (1.0 µg)  113 ± 4 (5.0 µg)
 TA1537  10 ± 2  9 ± 2  9 ± 2 (0.3 µg)  11 ± 2 (5.0 µg)
 TA98  21 ± 2  31 ± 3  21 ± 2 (0.1 µg)  38 ± 4 (50 µg)

Applicant's summary and conclusion