2-[(1-methylpropyl)amino]ethanol

Genetic toxicity: in vitro

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:

13 May 2009 to 12 January 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: compliant to GLP and testing guideline; adequate coherence between data, comments and conclusions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)

Deviations:

no

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

2-[(1-methylpropyl)amino]ethanol

EC Number:

252-471-9

EC Name:

2-[(1-methylpropyl)amino]ethanol

Cas Number:

35265-04-4

Molecular formula:

C6H15NO

IUPAC Name:

2-[(butan-2-yl)amino]ethan-1-ol

Details on test material:

Name of test material (as cited in study report):2-[(1-methylpropyl)amino]ethanol
Physical state: colorless to yellow liquid
Purity: 99.73%
Impurities (identity and concentrations): not indicated
Purity test date: April 2009
Lot/Batch No.: A1V68M010101
Expiration date of the lot/batch: January 2011
Stability under test conditions: not indicated
Storage condition of test material: at room temperature and protected from humidity

Method

Target gene:

histidine operon

Species / strain

Species / strain / cell type:

S. typhimurium, other: TA 1535, TA 1537, TA 98, TA 100 and TA 102

Metabolic activation:

with and without

Metabolic activation system:

S9 mix

Test concentrations with justification for top dose:

Experiments without S9 mix:
. 312.5, 625, 1250, 2500 and 5000 µg/plate for both mutagenicity experiments.
Experiments with S9 mix:
. 312.5, 625, 1250, 2500 and 5000 µg/plate for the first and second experiments,
. 625, 1250, 1875, 2500, 3750 and 5000 µg/plate for the third experiment.

Vehicle / solvent:

- Vehicle used: water for injection

Controls

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

sodium azide

Remarks:

Migrated to IUCLID6: 9-aminoacridine; 2-nitrofluorene; mitomycin C; 2-anthramine; benzo(a)pyrene

Details on test system and experimental conditions:

METHOD OF APPLICATION:
The test item was tested in a preliminary test and three mutagenicity experiments.
The preliminary test, all experiments without S9 mix and the first experiment with S9 mix were performed according to the direct plate incorporation method. The second and third experiments with S9 mix were performed according to the preincubation method.

DURATION
- Preincubation period: 60 min
- Exposure duration: 48 to 72 hours

Evaluation criteria:

A reproducible 2-fold increase (for the TA 98, TA 100 and TA 102 strains) or 3-fold increase (for the TA 1535 and TA 1537 strains) in the number of revertants compared with the vehicle controls, in any strain at any dose-level and/or evidence of a dose-relationship was considered as a positive result. Reference to historical data, or other considerations of biological relevance may also be taken into account in the evaluation of the data obtained.

Statistics:

Not applicable

Results and discussion

Test results

Species / strain:

S. typhimurium, other: TA 1535, TA 1537, TA 98, TA 100 and TA 102

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative

The test item did not show any mutagenic activity in the bacterial reverse mutation test with Salmonella typhimurium.

Executive summary:

The potential of 2-[(1-methylpropyl)amino]ethanol to induce reverse mutation in Salmonella typhimurium was evaluated according to the international guidelines (OECD 471 and Commission Directive No. B13/14) and in compliance with the principles of Good Laboratory Practice. A preliminary toxicity test was performed to define the dose-levels of 2-[(1-methylpropyl)amino]ethanol to be used for the mutagenicity study. The test item was then tested in three independent experiments, without and/or with a metabolic activation system, the S9 mix, prepared from a liver post‑mitochondrial fraction (S9 fraction) of rats induced with Aroclor 1254. All experiments were performed according to the direct plate incorporation method except for the second and third tests with S9 mix, which were performed according to the preincubation method (60 minutes, 37°C).

Five strains of bacteria Salmonella typhimurium: TA 1535, TA 1537, TA 98, TA 100 and TA 102 were used. Each strain was exposed to at least five dose-levels of the test item (three plates/dose‑level). After 48 to 72 hours of incubation at 37°C, the revertant colonies were scored. The evaluation of the toxicity was performed on the basis of the observation of the decrease in the number of revertant colonies and/or a thinning of the bacterial lawn. 2-[(1-methylpropyl)amino]ethanol was dissolved in water for injections.

The dose-levels of the positive controls were as follows:

without S9 mix

.           1 µg/plate of sodium azide (NaN₃): TA 1535 and TA 100 strains,

.           50 µg/plate of 9-Aminoacridine (9AA): TA 1537 strain,

.           0.5 µg/plate of 2-Nitrofluorene (2NF): TA 98 strain,

.           0.5 µg/plate of Mitomycin C (MMC): TA 102 strain.

 

with S9 mix

.           2 µg/plate of 2-Anthramine (2AM): TA 1535, TA 1537 and TA 98 strains,

.           5 µg/plate of Benzo(a)pyrene (BAP): TA 100 strain,

.           10 µg/plate of 2-Anthramine (2AM): TA 102 strain.

The number of revertants for the vehicle and positive controls was as specified in the acceptance criteria. The study was therefore considered valid.

Since the test item was freely soluble and non-severely toxic, the highest dose-level selected was 5000 µg/plate, according to the criteria specified in the international guidelines.

Experiments without S9 mix

The selected treatment-levels were: 312.5, 625, 1250, 2500 and 5000 µg/plate for both mutagenicity experiments.

No precipitate was observed in the Petri plates when scoring the revertants at any dose-levels.

A moderate toxicity was noted at 5000 µg/plate in the TA 100 strain. No noteworthy toxicity was observed at any dose-levels, in the other tester strains.

The test item did not induce any noteworthy increase in the number of revertants in any of the five strains.

 

Experiments with S9 mix

The selected treatment-levels were:

.           312.5, 625, 1250, 2500 and 5000 µg/plate for the first and second experiments,

.           625, 1250, 1875, 2500, 3750 and 5000 µg/plate for the third experiment.

No precipitate was observed in the Petri plates when scoring the revertants at any dose-levels.

No noteworthy toxicity was observed in any tester strains in the first experiment (direct plate incorporation method). In the second and third experiments (preincubation method), a moderate to strong toxicity was induced at dose-levels > 2500 µg/plate in all tester strains.

Noteworthy increases in the number of revertants in comparison to the vehicle control were noted in the second experiment in the TA 98 strain (up to 2.0-fold the vehicle control value) and in the TA 102 strain (up to 2.2-fold the vehicle control value). Since these slight increases were not observed in the first experiment (using the direct plate incorporation method) and were not reproduced in the third confirmatory experiment (using the preincubation method), despite the closer range of dose-levels used, they were not considered as biologically relevant.

The test item did not induce any noteworthy increase in the number of revertants in any of the other tester strains.

2-[(1-methylpropyl)amino]ethanoldid not show any mutagenic activity in the bacterial reverse mutation test with Salmonella typhimurium.