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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 from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2009
Report Date:
2009

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): N-Propanol
- Physical state: Liquid, colorless, clear
- Analytical purity: 99.95 area-%
- Lot/batch No.: TK504_20081022
- Storage condition of test material: Room temperature

Method

Target gene:
S. typhimurium: his-
E. coli: trp-
Species / strainopen allclose all
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Species / strain / cell type:
E. coli WP2 uvr A
Metabolic activation:
with and without
Metabolic activation system:
liver S9 mix from phenobarbital i.p. and β-naphthoflavone orally induced rats
Test concentrations with justification for top dose:
0; 20; 100; 500; 2500 and 5000 μg/plate (SPT)
0; 312.5; 625; 1250; 2500 and 5000 μg/plate (PIT)
Vehicle / solvent:
water
Controls
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: see "Details on test system"
Details on test system and experimental conditions:
Experiment 1: Standard plate test (SPT)
Test tubes containing 2 mL soft agar kept in a water bath at 45°C, and remaining components added in the following order:
0 .1 mL test solution or vehicle
0 .1 mL bacterial suspension
0 .5 mL S-9 mix (in tests with metabolic activation) or 0 .5 mL phosphate buffer (in tests without metabolic activation).
After mixing, the samples are poured onto Vogel-Bonner agar plates.

Experiment 2: Preincubation assay (PIT)
0.1 mL test solution or vehicle, 0.1 mL bacterial suspension and 0 .5 mL S-9 mix are
incubated at 37°C for the duration of 20 minutes. Subsequently, 2 mL of soft agar is added
and, after mixing, the samples are poured onto the Vogel-Bonner agar plates.

Experiment1&2
In each experiment 3 test plates per dose or per control used; after incubation at 37°C for 48 hours in the dark, the bacterial colonies ( his+/trp+ revertants) are counted.
Positive control:
with metabolic activation: 2-aminoanthracene: 2.5 μg/plate for each S. typhimurium strain; 60 μg/plate for E. coli WP2 uvrA
without metabolic activation: 5 μg/plate N-methyl-N'-nitro-N-nitrosoguanidine for TA 100 and TA 1535, 10 μg/plate 4-nitro-o-phenylendiamine
for TA 98, 100 μg/plate 9-aminoacridine chloride for TA 1537 and 5 µg/plate N-Ethyl-N-nitro-N-nitrosoguanidine for E. coli WP2 uvrA; all substances were dissolved in DMSO.
The titer was determined and in regularly measurements the strain characteristics were checked. Sterility control was performed.
Evaluation criteria:
Acceptance criteria
Generally, the experiment is considered valid if the following criteria are met:
• The number of revertant colonies in the negative controls was within the range of the historical negative control data for each tester strain.
• The sterility controls revealed no indication of bacterial contamination.
• The positive control substances both with and without S9 mix induced a distinct increase in the number of revertant colonies within the range of the historical positive control data or above.
• The titer of viable bacteria was ≥ 10e8/mL.

Assessment criteria
The test chemical is considered positive in this assay if the following criteria are met:
• A dose-related and reproducible increase in the number of revertant colonies, i.e. about doubling of the spontaneous mutation rate in at least one tester strain either without S9 mix or after adding a metabolizing system.
A test substance is generally considered non-mutagenic in this test if:
• The number of revertants for all tester strains were within the historical negative control range under all experimental conditions in at least two experiments carried out independently of each other.

Results and discussion

Test results
Species / strain:
other: S. typhimurium TA 1535, TA 100, TA 1537, TA 98 and E. coli WP2 uvrA
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity nor precipitates, but tested up to recommended limit concentrations
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Additional information on results:
No precipitation of the test substance was found with and without S9 mix.
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Any other information on results incl. tables

Mutagenicity

Standard plate test (20 - 5000 µg/plate)
Strain Metabolic activation system mean revertants in Controls maximum revertant factor dose dependency Assessment
TA 98 no 28 1.0 no negative
  yes 33 1.2 no negative
TA 100 no 100 1.1 no negative
  yes 99 1.3 no negative
TA 1535 no 17 1.0 no negative
  yes 15 1.0 no negative
TA 1537 no 11 1.3 no negative
  yes 9 1.4 no negative
WP2 uvr A no 34 1.1 no negative
  yes 39 1.1 no negative
Preincubation test (312.5 - 5000 µg/plate)
Strain Metabolic activation system mean revertants in Controls maximum revertant factor dose dependency Assessment
TA 98 no 26 1.1 no negative
  yes 32 1.0 no negative
TA 100 no 102 1.0 no negative
  yes 103 1.1 no negative
TA 1535 no 14 1.0 no negative
  yes 14 1.0 no negative
TA 1537 no 8 1.0 no negative
  yes 8 1.0 no negative
WP2 uvr A no 36 1.1 no negative
  yes 51 1.0 no negative

Applicant's summary and conclusion