Phenol, 2,4-bis[(dodecylthio)methyl]-6-methyl-

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Link to relevant study records

Reference

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:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: OECD Guideline Study

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Version / remarks:

adopted July 21, 1997

Deviations:

yes

Remarks:

2-aminoanthracene is the sole positive control to proof the efficiacy of the S9-mix

GLP compliance:

yes (incl. QA statement)

Remarks:

RCC CYTOTEST CELL RESEARCH GMBH , Rossdorf, Germany

Type of assay:

bacterial reverse mutation assay

Target gene:

his, trp

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:

Phenobarbital induced rat liver S9-mix

Test concentrations with justification for top dose:

33; 100; 333; 1000; 2500; and 5000 µg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMSO
- Justification for choice of solvent/vehicle: The solvent was chosen because of its solubility properties and its relative non-toxicity to the bacteria.

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: see table 1

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (plate incorporation); preincubation

DURATION
- Preincubation period: 60 min
- Exposure duration: at least 48 hours

NUMBER OF REPLICATIONS: three plates

DETERMINATION OF CYTOTOXICITY
- Method: relative total growth

Evaluation criteria:

A test item is considered positive if a dose related increase in the number of revertants exceeding the threshold of twice or thrice the colony count of the corresponding solvent control is observed at more than one concentration. Furthermore, a biologically relevant and reproducible increase exceeding the threshold at one test concentration is considered as positive.
A test item producing neither a dose related increase in the number of revertants nor a biologically relevant positive response at any one of the test points is considered nonmutagenic in this system.
A biologically relevant response is described as follows:
An increase is considered relevant if in the strains TA98, TA 100, and WP2 uvrA the number of reversions will be at least twice as high and in the strains TA 1535 and TA 1537 at least three times higher as compared to the spontaneous reversion rate.
Also, a dose-dependent and reproducible increase in the number of revertants is regarded as an indication of possibly existing mutagenic potential of the test item regardless whether the highest dose induced the above described enhancement factors or not.

Statistics:

No statistical evaluation of the data is required.

Species / strain:

S. typhimurium TA 1535, TA 1537, TA 98 and TA 100

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

Species / strain:

E. coli WP2 uvr A

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

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

In experiment I (plate incorporation test), no toxic effects were observed with and without metabolic activation. In experiment II (pre-incubation test), a minor toxic effect was observed in the presence of metabolic activation in strain TA 98 at 5000 µg/plate. No toxic effects were observed in the remaining strains.

No precipitation of the test item occurred up to the highest investigated dose.

Conclusions:

Interpretation of results (migrated information):
negative

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Additional information

Additional information from genetic toxicity in vitro:

Justification for selection of genetic toxicity endpoint
There was no genotoxicity detected, with and without metabolic activation, in a bacterial gene mutation assay (Ames test) conducted on the substance (OECD471).

Justification for classification or non-classification

Not classified for genetic toxicity, according to the criteria of CLP regulation EC No.1272/2008.