5-butoxy-2-[4-(4-butoxy-2-hydroxyphenyl)-6-(2,4-dibutoxyphenyl)-1,3,5-triazin-2-yl]phenol

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:

1999

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1999

Report date:

1999

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Method

Target gene:

His: Salmonella
Trp: E. coli

Species / strain

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:

Phenobarbital and beta-Naphthoflavone-induced liver S9 mix from rats

Test concentrations with justification for top dose:

incorporation test (experiment I) and the preincubation test (experiment II) (with and without metabolic activation): 33; 100; 333; 1000; 2500; and 5000 µg/plate

Vehicle / solvent:

DMSO

Controls

Controls 1

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: TA 1535, TA 100: sodium azide, NaN3, TA1537, TA98: 4-nitro-o-phenylene-diamine, 4-NOPD, WP2 uvrA: methyl methane sulfonate, MMS

Remarks:

without metabolic activation

Controls 2

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: 2-aminoanthracene

Remarks:

with metabolic activation

Details on test system and experimental conditions:

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

DURATION
- Preincubation period: 60min
- Exposure duration: 48h

NUMBER OF REPLICATIONS: two

NUMBER OF CELLS EVALUATED: all colonies counted

DETERMINATION OF CYTOTOXICITY
- Method: mitotic index

Evaluation criteria:

The Salmonella typhimurium and Escherichia coli reverse mutation assay is considered acceptable if it meets the following criteria:
- regular background growth in the negative and solvent control
- the spontaneous reversion rates in the negative and solvent control are in the range of our historical data
- the positive control substances should produce a significant increase in mutant colony frequencies

Evaluation of Results:
A test item is considered positive if either a dose related and reproducible increase in the number of revertants or a biologically relevant and reproducible increase for at least one test concentration is induced.
A test item producing neither a reproducible and dose related increase in the number of revertants, nor a biologically relevant and reproducibly positive response at any one of the test points is considered non-mutagenic in this system.
A mutagenic response is described as follows:
A test item is considered mutagenic if in the strains TA 98, 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.

Results and discussion

Test results

Species / strain:

other: TA 1535, TA 1537, TA 98, and TA 100, WP2 uvrA.

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

(5000 µg/plate)

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

True negative controls validity:

not applicable

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS
- Precipitation: yes, at higher concentrations

RANGE-FINDING/SCREENING STUDIES:
In the pre-experiment the concentration range of the test item was 3 - 5000 ug/plate. The pre-experiment is reported as experiment I since no relevant toxic effects were observed and 5000 ug/plate were chosen as maximal concentration. The concentration range included two logarithmic decades. The following concentrations were tested.

COMPARISON WITH HISTORICAL CONTROL DATA: yes, for negative control without metabolic activation, solvent control wihtout metabolic activation, positive control without metabolic activation

Applicant's summary and conclusion

Conclusions:

The reverse bacterial mutation test did not reveal a genotoxicity potential.