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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:
migrated information: read-across based on grouping of substances (category approach)
Adequacy of study:
weight of evidence
Study period:
12 May - 22 Jun 1987
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Comparable to guideline study with acceptable restrictions (only three Salmonella typhimurium strains tested)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1987
Report Date:
1987

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
yes
Remarks:
(only 3 strains tested)
GLP compliance:
yes
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): [trade name]
- Substance type: product
- Physical state: liquid
- Analytical purity: no data
- Storage condition of test material: placed in a sealed secondary container, and stored desiccated at room temperature in the dark

Method

Target gene:
his operon
Species / strainopen allclose all
Species / strain / cell type:
S. typhimurium TA 97
Additional strain / cell type characteristics:
other: histidine auxotrophe
Species / strain / cell type:
S. typhimurium TA 98
Additional strain / cell type characteristics:
other: histidine auxotroph
Species / strain / cell type:
S. typhimurium TA 100
Additional strain / cell type characteristics:
other: histidine auxotroph
Metabolic activation:
with and without
Metabolic activation system:
rat liver post-mitochondrial fraction (S9) from Arochlor-1254 induced male Wistar rats
Test concentrations with justification for top dose:
0, 8, 40, 200, 1000 and 5000 µg/plate
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: dimethylsulfoxide (DMSO)
- Justification for choice of solvent/vehicle: not stated
Controlsopen allclose all
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
Remarks:
DMSO
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: 2-nitrofluorene (50 µg/plate) for TA 98; sodium azide (2 µg/plate) for TA 100; 9-aminoacridine (50 µg/plate) for TA 97
Remarks:
without metabolic activation
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
Remarks:
DMSO
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: 2-aminoanthracene (5 µg/plate) with all strains
not specified
Remarks:
with metabolic activation
Details on test system and experimental conditions:
METHOD OF APPLICATION: in medium; in agar (plate incorporation)

DURATION
- Preincubation period: not applicable
- Exposure duration: 2 days


NUMBER OF REPLICATIONS: 3 (test substance), 5 (controls)


DETERMINATION OF CYTOTOXICITY
- Method: other: the background lawn was inspected for signs of toxicity (no further details mentioned)


OTHER:
- Colony counting: Colonies were counted electronically using a 40-10 image analyser (Analytical Measuring Systems).
Evaluation criteria:
- Validity criteria: a) negative control within the normal range, b) clear induced increase in revertant numbers by the positive control confirming discrimination between different strains and an active S9 preparation and c) no more than 5% loss of the plates due to contamination or unforeseen event
- Evaluation criteria: the test compound is considered mutagenic if a) the assay is valid and b) if it induces a two-fold and significant increase in revertant numbers, accompanied by dose response correlations
Statistics:
Analysis of variance (the F-test) and regression analysis were performed

Results and discussion

Test resultsopen allclose all
Species / strain:
S. typhimurium TA 97
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
not examined
Positive controls validity:
valid
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
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 100
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
not examined
Positive controls validity:
valid
Additional information on results:
TEST-SPECIFIC CONFOUNDING FACTORS
- Effects of pH: not measured
- Effects of osmolality: not applicable
- Evaporation from medium: not applicable
- Water solubility: not mentioned
- Precipitation: at 5000 µg/plate, this did not affect scoring of mutant colonies
- Other confounding effects: none


RANGE-FINDING/SCREENING STUDIES: An initial toxicity range-finding experiment was carried out in TA 100 only, using final concentrations at 8, 40, 200, 1000 and 5000 µg/plate plus a solvent and positive control. From these test results the highest test dose were chosen for the main mutation assay. There were no signs of toxicity up to 5000 µg/plate either in the absence and presence of S9.


COMPARISON WITH HISTORICAL CONTROL DATA: yes, the mean solvent control counts fell within the normal historical range.


ADDITIONAL INFORMATION ON CYTOTOXICITY: no cytotoxicity up to 5000 µg/plate in all strains
Remarks on result:
other: strain/cell type: Salmonella typhimurium
Remarks:
Migrated from field 'Test system'.

Any other information on results incl. tables

Table #: Number of revertants per plate (mean of 3 (test substance) resp. 5 (control) plates)

 

[Strain TA 97]

[Strain TA 98]

[Strain TA 100]

Conc.
[µg/plate]

¿ MA

+ MA

Cytotoxic
(yes/no)

¿ MA

+ MA

Cytotoxic
(yes/no)

¿ MA

+ MA

Cytotoxic
(yes/no)

0*

 85.4

 157.4

no 

 19.8

 23.0

 no

 90.2

 126.6

 no

8

 76.7

 143.7

 no

 15.7

 22.7

 no

 82.3

 125.3

 no

40

 83.0

 137.7

 no

 24.3

 33.0

 no

 97.0

 140.0

 no

200

 80.0

 159.0

 no

 22.3

 29.7

 no

 93.0

 136.7

 no

1000

 79.7

 154.3

 no

 19.0

 28.7

 no

 93.0

 126.7

 no

5000

 86.7**

 140.3**

 no

 15.7**

 32.7**

 no

 95.0**

 120.7**

 no

Positive control

 484.6

 520.6

 no

 1224.2

 940.8

 no

 536.0

 675.8

 no

*solvent control with DMSO ** precipitate observed

 

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative