2-methoxy-4-(methoxymethyl)phenol

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

Ames test (OECD TG 471): negative

Link to relevant study records

Reference

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

The study was performed between 4 and 21 December 2007.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Version / remarks:

(1997)

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Target gene:

- S. typhimurium: Histidine gene
- Escherichia coli: Tryptophan gene

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2

Metabolic activation:

with and without

Metabolic activation system:

Rat liver S9-mix induced by a combination of phenobarbitone and beta-naphthoflavone

Test concentrations with justification for top dose:

- Dose range finding test:
TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2 (without and with S9): doses of 0, 0.15, 0.5, 1.5, 5, 15, 50, 150 and 500, 1500 and 5000 µg/plate

- Experiments 1 and 2:
The following dose levels were used for all the strains (with and without S9 activation): 50, 150, 500, 1500 and 5000 µg/plate

Vehicle / solvent:

- Solvent used: DMSO
- Justification for choice of solvent: the test substance was found to be soluble in DMSO up to 50 mg/ml, which provided a final concentration of 5000 µg/plate.

Negative solvent / vehicle controls:

yes

Remarks:

DMSO

Positive controls:

yes

Positive control substance:

4-nitroquinoline-N-oxide

9-aminoacridine

N-ethyl-N-nitro-N-nitrosoguanidine

benzo(a)pyrene

other: 2-aminoanthracene

Details on test system and experimental conditions:

METHOD OF APPLICATION:
- Experiment 1: direct plate incorporation method (measured aliquotes of 0.1 ml of one of the bacterial cultures were dispensed into sets of test tubes followed by 2.0 ml of molten, trace histidine or tryptophan supplemented, top aga, 0.1 ml of the test material formulation, vehicle or positive control and either 0.5 ml of S9-mix or phosphate buffer. The contents of each test tube were mixed and equally distributed onto the surface of Vogel-Bonner Minimal agar plates (one tube per test).
- Experiment 2: Methodology as described for Exp.1

DURATION
- Exposure duration: 48 hours

NUMBER OF REPLICATIONS:
- Doses of the test substance were tested in triplicate in each strain (in all experiments).

DETERMINATION OF EFFECTS
- After the incubation time, the plates were assessed for the number of revertant colonies using a Domino colony counter and examined for effects on the growth of the bacterial background lawn.

Some of the positive controls used in this study were not the combination with the used strains that is recommended in the guidelines, but they fulfilled the purpose with which they were used- they evoked the positive results in the tested strains.

Evaluation criteria:

If exposure to a test substance produces a dose-related and reproducible increase in revertant colony numbers at one or more concentrations in at least one bacterial strain with or without metabolic activation.
If exposure to a test substance does not produce a reproducible increase in revertant colony numbers, it is considered to show no evidence of mutagenic activity in this test system.

Key result

Species / strain:

S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Positive controls validity:

valid

Additional information on results:

RANGE-FINDING/SCREENING STUDIES:
- No toxicity.

Conclusions:

The substance is not mutagenic in the reverse mutation assay performed with Salmonella typhimurium and Escherichia coli strains according to OECD 471 (1997).

Executive summary:

The mutagenic activity of the substance was evaluated in accordance with OECD 471 (1997) and according to GLP principles. The test was performed in two independent experiments, both being direct plate incorporation method, both in the absence and presence of S9-mix. The dose levels were selected based on the preliminary toxicity test. The test material caused no visible reduction in the growth of the bacterial background lawn at any dose level. Therefore, it was tested up to the maximum recommended dose level of 5000 ug/plate. Adequate negative and positive controls were included. The substance did not induce a significant dose-related increase in the number of revertant (His+) colonies in any of the four S. typhimurium tested strains (TA1535, TA1537, TA98 and TA100), neither in the tested E.coli strain (WP2), both in the absence and presence of S9-metabolic activation. These results were confirmed in independently repeated experiments. Based on the results of this study, it is concluded that the substance is not mutagenic in the reverse mutation assay.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Additional information

The mutagenic activity of the substance was evaluated in accordance with OECD 471 (1997) and according to GLP principles. The test was performed in two independent experiments, both being direct plate incorporation method, both in the absence and presence of S9-mix. The dose levels were selected based on the preliminary toxicity test. The test material caused no visible reduction in the growth of the bacterial background lawn at any dose level. Therefore, it was tested up to the maximum recommended dose level of 5000 ug/plate. Adequate negative and positive controls were included. The substance did not induce a significant dose-related increase in the number of revertant (His+) colonies in any of the four S. typhimurium tested strains (TA1535, TA1537, TA98 and TA100), neither in the tested E.coli strain (WP2), both in the absence and presence of S9-metabolic activation. These results were confirmed in independently repeated experiments. Based on the results of this study, it is concluded that the substance is not mutagenic in the reverse mutation assay.

Justification for classification or non-classification

Based on the results of the Ames test, the substance does not have to be classified for genotoxicity in accordance with Regulation (EC) Np 1272/2008 and its amendments.