Docosan-1-ol

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 2022-03-22 to 2022-04-22

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2022

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Version / remarks:

2020

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Docosan-1-ol

EC Number:

211-546-6

EC Name:

Docosan-1-ol

Cas Number:

661-19-8

Molecular formula:

C22H46O

IUPAC Name:

docosan-1-ol

Test material form:

solid

Method

Target gene:

Tryptophan locus (E.coli)

Species / strain

Species / strain / cell type:

E. coli WP2 uvr A

Metabolic activation:

with and without

Metabolic activation system:

Type and composition of metabolic activation system:
- source of S9 : Trinova Biochem GmbH, Giessen, Germany
- method of preparation of S9 mix : prepared from male Sprague Dawley rats that had been injected intraperitoneally with Arochlor 1254 (500 mg/kg bw).
- concentration or volume of S9 mix and S9 in the final culture medium : 0.5 mL S9 mix in final culture medium (5% v/v in first experiment and 10% v/v in second experiment)
- quality controls of S9 (e.g., enzymatic activity, sterility, metabolic capability): not specified

Test concentrations with justification for top dose:

1.7, 5.4, 17, 52, 164, 512, 1600 and 5000 µg/plate (first experiment)
8.5, 15, 27, 48, 154, 492 μg/plate (second experiment)

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: tetrahydrofuran (THF)

- Justification for choice of solvent/vehicle: A solubility test was performed based on visual assessment. The test material formed a clear colourless solution in THF.

Controls

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

Remarks:

THF

Positive controls:

yes

Positive control substance:

4-nitroquinoline-N-oxide

other: 2-aminoanthracene (2AA), 15 µg, solvent DMSO

Details on test system and experimental conditions:

NUMBER OF REPLICATIONS:
- Number of cultures per concentration (single, duplicate, triplicate) : triplicate
- Number of independent experiments : Two experiments

METHOD OF TREATMENT/ EXPOSURE:
- Cell density at seeding (if applicable): 10^9 cells/mL
- Test substance added in medium; in agar (plate incorporation)

TREATMENT AND HARVEST SCHEDULE:
- Preincubation period, if applicable: not applicable
- Exposure duration/duration of treatment: 48 hours
- Harvest time after the end of treatment (sampling/recovery times): not applicable

METHODS FOR MEASUREMENT OF CYTOTOXICITY
- Method, e.g.: background growth inhibition, increase in the size of microcolonies, reduction of the revertant colonies

Rationale for test conditions:

Test Guidelines conditions

Evaluation criteria:

a) The vehicle control and positive control plates (with or without S9-mix) must exhibit a characteristic number of revertant colonies when compared against relevant historical control data generated at the laboratory
b) The selected dose-range should include a clearly toxic concentration or should exhibit limited solubility as demonstrated by the preliminary toxicity range-finding test or should extend to 5 mg/plate.
c) No more than 5% of the plates are lost through contamination or some other unforeseen event. If the results are considered invalid due to contamination, the experiment will be repeated.
A test material is considered negative (not mutagenic) in the test if:
a)The total number of revertants in the tester strain TA100 or WP2 uvrA is not greater than two times the concurrent vehicle control, and the total number of revertants in tester strains TA1535, TA1537 or TA98 is not greater than three times the concurrent vehicle control.
b)The negative response should be reproducible in at least one follow-up experiment.
A test material is considered positive (mutagenic) in the test if:
a)The total number of revertants in the tester strain TA100 or WP2 uvrA is greater than two times the concurrent vehicle control, or the total number of revertants in tester strains TA1535, TA1537, TA98 is greater than three times the concurrent vehicle control.
b)In case a follow-up experiment is performed when a positive response is observed in one of the tester strains, the positive response should be reproducible in at least one follow-up experiment.

Statistics:

Not specified

Results and discussion

Test results

Key result

Species / strain:

E. coli WP2 uvr A

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Remarks:

precipitation from 52 µg/plate

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

True negative controls validity:

not applicable

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS
- Data on pH: not examined
- Data on osmolality: not examined
- Possibility of evaporation from medium: not examined
- Water solubility: not examined
- Precipitation and time of the determination: not examined
- Definition of acceptable cells for analysis: not examined


RANGE-FINDING/SCREENING STUDIES (if applicable): not examined

STUDY RESULTS
- Concurrent vehicle negative and positive control data : see in tables attached

Ames test:
- Signs of toxicity : None
- Individual plate counts : See in tables attached
- Mean number of revertant colonies per plate and standard deviation : See in tables attached


HISTORICAL CONTROL DATA (with ranges, means and standard deviation, and 95% control limits for the distribution as well as the number of data)
- Positive historical control data: Range (89-2027: without S9; 109-1642: with S9); Mean (1312: without S9; 424: with S9); SD (369: without S9; 189: with S9); 95% upper limit (2035: without S9; 795: with S9); 95% lower limit (589: without S9; 53: with S9)
- Negative (solvent/vehicle) historical control data: Range (9-61: without S9; 9-68: with S9); Mean (21: without S9; 25: with S9); SD (8: without S9; 10: with S9); 95% upper limit (37: without S9; 44: with S9); 95% lower limit (5: without S9; 6: with S9)

Applicant's summary and conclusion

Conclusions:

Docosan-1-ol (CAS 661-19-8, EC 211-546-6) has been tested in a reliable 5th-strain test conducted according to OECD Test Guideline 471 and in compliance with GLP, using Escherichia Coli (E.coli) strain WP2 uvrA via the plate incorporation methodology. No dose-related increase in the number of revertant colonies in the tester strain WP2 uvrA was observed, both in the absence and presence of metabolic activation in the first experiment. These results were confirmed in the follow up experiment. Appropriate positive and solvent controls were added and gave expected results. It is concluded that the test substance is negative for mutagenicity to bacteria under the conditions of the test.