Zorgol 48

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

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)

Version / remarks:

adopted July 21, 1997

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

adopted May 31, 2008

Deviations:

no

Principles of method if other than guideline:

Two experiments were performed:
- Experiment 1: five concentratiosn from 50 to 5000 µg/plate with and without metabolic activation (S9-mix), plate incorporation method
- Experiment 2: five concentratiosn from 312 to 5000 µg/plate with and without metabolic activation (S9-mix), pre-incubation method

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Reference substance 001

EC Number:

920-427-4

Details on test material:

- Name of test material (as cited in study report): Zorgol 48
- Substance type: UVCB substance
- Physical state: yellowish liquid
- Analytical purity: not applicable
- Lot/batch No.: 20100223161335
- Expiration date of the lot/batch: 2011-02-09
- Stability under test conditions: no data
- Storage condition of test material: in a closed vessel at room temperature

Method

Target gene:

his¯

Species / strain

Species / strain / cell type:

S. typhimurium, other: TA 97a, TA 98, TA 100, TA 102, and TA1535

Metabolic activation:

with and without

Metabolic activation system:

S9-mix from livers of Aroclor induced male Sprague-Dawlea rats

Test concentrations with justification for top dose:

Experiment 1: 50, 150, 500, 1501, and 5002 µg/plate
Experiment 2: 312, 624, 1248, 2496, and 4992 µg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: ethanol
- Justification for choice of solvent/vehicle: the test substance is completely soluble in ethanol and ethanol does not have any effect ont he viability of the bacteria or the number of spontaneous revertants.

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: Without metabolic activation: 4-nitro-1,2-phenylene diamine (20 µg/plate) for strains TA 97a, TA98, and TA102; sodium azide (1 µg/plate) for strains TA 100 and TA 1535; with metabolic activation: 2-amino-anthracene (1 µg/plate) for strains TA 97a, TA 100,

Details on test system and experimental conditions:

METHOD OF APPLICATION: experiment 1: in agar (plate incorporation);
experiment 2: preincubation
DURATION
- Preincubation period: experiment 2: 20 min at 37°C
- Exposure duration: both experiments: 48 hrs
- Expression time (cells in growth medium): both experiments: 48 hrs

NUMBER OF REPLICATES: four replicate plates were tested.

DETERMINATION OF CYTOTOXICITY
- Method: background lawn, number of revertant colonies in controls

Evaluation criteria:

A test item is considered to have mutagenic potential, if a significant, reproducible increase of revertant colonies per plate (increas factor ≥ 2) in at least one strain can be observed. A concentration-related increase over the range tested can also be taken as a sign of mutagenic activity.

Statistics:

Mean values and standard deviations were calculated for the four replicates of each treatment, solvent control and positive control.
The increase factor f(I) of revertant induction (mean revertants divided by mean spontaneous revertants) and the absolute number of revertants (mean revertants less mean spontaneous revertants) were also calculated.

Results and discussion

Test results

Species / strain:

S. typhimurium, other: TA 97a, TA 98, TA 100 TA 102, and TA1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS
- no effects reported

COMPARISON WITH HISTORICAL CONTROL DATA: numbers of spontaneous revertants of the negative controls were in the normal range of the test laboratory.

ADDITIONAL INFORMATION ON CYTOTOXICITY: no signs of toxicity toward the tester strains could be ob served.

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

Tables with detailed test results are included under "Attached background material".

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative

Zorgol 48 did not show any mutagenic potential in all strains tested in both experiments neither with nor without metabolic activation.

Executive summary:

In a reverse gene mutation assay in bacteria, (Ames test) under GLP conditions according to OECD test guideline 471, five strains of S. typhimurium (TA 97a, TA 98, TA 100, TA 102, and TA 1535) were exposed to the test substance Zorgol 48 (1-Hexanol, 2-ethyl-, manuf. of, by-products from, distn. residues) in ethanol at concentrations of 50, 150, 500, 1501, and 5002 µg/plate (experiment 1, plate incorporation assay) and at concentrations of 312, 624, 1248, 2496, and 4992 µg/plate (experiment 2: pre-incubation assay) in the presence and absence of mammalian metabolic activation (S9-mix from Aroclor induced male rat liver).

 

Zorgol 48 was tested up to a limit concentration of 5000 µg/plate. It did not show any cytotoxicity up to this concentration. Negative controls did not show a response above background and positive controls induced the appropriate responses in the corresponding strains.

 

Zorgol 48 did not increase the number of revertants in any of the tester strains in either experiment with and without metabolic activation. There was no evidence of induced mutant colonies over background. The test item is stated as not mutagenic under test conditions (Paulus/Laus, 2010).

 

This study is classified as acceptable. It satisfies the requirement of OECD TG 471 and EU Method B.13/14 for in vitro mutagenicity (bacterial reverse gene mutation) tests without restriction.