Phosphonium, triphenyl(3,7,11-trimethyl-2,4,6,10-dodecatetraenyl)-

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

In an OECD 471 bacterial reverse mutational assay no mutagenic potential was found in the absence and the presence of metabolic activation.

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:

1999-200

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:

21 Jul 1997

Deviations:

no

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Manufacturing date: August 1998

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: room temperature, exclusion of oxygen (under nitrogen)
- Solubility and stability of the test substance in the solvent: proven good solubility

FORM AS APPLIED IN THE TEST: solution

Target gene:

his, trp

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:

S9 mix (supplemented with cofactors) derived from Arocolor 1254 (i.p.) induced rat liver

Test concentrations with justification for top dose:

0; 1.25; 2.5; 5; 10; 20; 100; 500; 2500 and 5000 μg/plate (SPT)
0; 0.625; 1.25; 2.5; 5; 10 and 20 μg/plate (PIT)
3 test plates per dose or per control

In agreement with the recommendations of current guidelines 5 mg/plate or 5 μL/plate were generally selected as maximum test dose at least in the 1st Experiment.

Vehicle / solvent:

- Vehicle used: water
- Justification for choice of solvent/vehicle: Due to the good solubility of the test substance in water, water was used as vehicle.

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

4-nitroquinoline-N-oxide

9-aminoacridine

other: 2-aminoanthracene (E.coli: 60 μg/plate and TA1535, TA1537, TA100, TA98: 2.5 μg/plate; with S9 mix); N-methyl-N'-nitro-N-nitrosoguanidine (5 μg/plate; without S9 mix); 4-nitro-o-phenylenediamine (10 μg/plate; without S9 mix)

Remarks:

Sterility control: Additional plates were treated with soft agar, S9 mix, buffer, vehicle and the test substance but without the addition of tester strains.

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (plate incorporation); preincubation
- Cell density at testing: approx. 10^9 cells per mL

DURATION
- Preincubation period: 20 min
- Exposure duration: 48 – 72 hours

DETERMINATION OF CYTOTOXICITY
- Toxicity detected by a
• decrease in the number of revertants
• clearing or diminution of the background lawn (= reduced his- or trp- background growth)
was recorded for all test groups both with and without S9 mix in all experiments.

Evaluation criteria:

Acceptance criteria
The experiment was considered valid if the following criteria were met:
• The number of revertant colonies in the negative controls was within the range of the historical negative control data for each tester strain.
• The sterility controls revealed no indication of bacterial contamination.
• The positive control substances both with and without S9 mix induced a distinct increase in the number of revertant colonies within the range of the historical positive control data or above.
• Fresh bacterial culture containing approximately 10^9 cells per mL were used.

Assessment criteria
The test substance was considered positive in this assay if the following criteria were met:
• A dose-related and reproducible increase in the number of revertant colonies, i.e. about doubling of the spontaneous mutation rate in at least one tester strain either without S-9 mix or after adding a metabolizing system.

A test substance was generally considered non-mutagenic in this test if:
• The number of revertants far all tester strains were within the historical negative control range under all experimental conditions in two experiments carried out independently of each ather.

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

slight decrease in the number of his+ revertants in the preincubation assay with S9 mix at a conc. of 5000 µg/plate

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity nor precipitates, but tested up to recommended limit concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

slight decrease in the number of his+ revertants in the standard plate test and the preincubation assay with S9 mix at a conc. of 5000 µg/plate

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity nor precipitates, but tested up to recommended limit concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

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 nor precipitates, but tested up to recommended limit concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Additional information on results:

STUDY RESULTS
A bacteriotoxic effect (reduced background growth, decrease in the number of revertants, reduction in the titer) was observed in the standard plate test depending on the strain and test conditions from about 20 µg/plate onward.
In the preincubation assay bacteriotoxicity was observed depending on the strain and test conditions from about 2.5 µg - 5 µg/plate onward.

Conclusions:

Under the experimental conditions of this study, the test substance is not mutagenic in the Salmonella typhimurium/Escherichia coli reverse mutation assay in the absence and the presence of metabolic activation.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Additional information

In vitro

The test substance was tested for its mutagenic potential based on the ability to induce point mutations in selected loci of several bacterial strains, i.e. Salmonella typhimurium and Escherichia coli, in a reverse mutation

assay.

The used strains TA 1535, TA 100, TA 153-7, TA 98 and E. coli WP2 uvrA were tested at dose ranges of 20.0 µg -5,000.0 µg/plate (SPT; TA 100, TA 98), 1.25 µg - 20.0 µg/plate (SPT; all tester strains), 0.625 µg - 10.0 µg/plate (PIT; Salmonella strains) and 1.25 µg - 20.0 µg/plate (PIT; E. coli WP2 uvrA).

The standard plate test (SPT) and the preincubation test (PIT), both were performed with and without metabolic activation (Aroclor-induced rat liver S-9 mix).

No precipitation of the test substance was found together with a bacteriotoxic effect, observed under all test conditions.

An increase in the number of his+ or trp+ revertants was not observed in the standard plate test or in the preincubation test either without S-9 mix or after the addition of a metabolizing system.

According to the results of the present study, the test substance was not mutagenic in the Salmonella typhimurium/Escherichia coli reverse mutation assay under the experimental conditions chosen here.

Justification for classification or non-classification

The available experimental test data are reliable and suitable for classification purposes under Regulation 1272/2008, as amended for the thirteenth time in Regulation (EU) No 2018/1480. As a result the substance is not considered to be classified for genotoxicity under Regulation (EC) No. 1272/2008.