Ethyltriphenylphosphonium iodide

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

Negative in reverse gene mutation assay in bacteria (Salmonella typhimurium TA 98, TA 100, TA 1535, TA 1537 and TA 102 with and without metabolic acitvation, OECD 471/EU B.13/14, GLP)

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:

2017-04-21 to 2017-05-19

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:

21st July, 1997

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

May 30, 2008

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.5100 - Bacterial Reverse Mutation Test (August 1998)

Version / remarks:

August, 1998

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Target gene:

his operon

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and TA 102

Metabolic activation:

with and without

Metabolic activation system:

rat liver S9 mix

Test concentrations with justification for top dose:

Experiment I:
3.16, 10.0, 31.6, 100, 316, 1000, 2500 and 5000 μg/plate
Experiment II:
1.00, 3.16, 10.0, 31.6, 100, 316, 1000 and 2500 μg/plate
based on the results of a preliminary test.

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMSO
- Justification for choice of solvent/vehicle: The vehicle was diluted prior to the experiment and the solvent was compatible with the survival of the bacteria and the S9 activity.

Untreated negative controls:

yes

Remarks:

A.dest.

Negative solvent / vehicle controls:

yes

Remarks:

DMSO

True negative controls:

no

Positive controls:

yes

Positive control substance:

sodium azide

methylmethanesulfonate

other: 4-nitro-o-phenylene-diamine (without metabolic activation, strains TA 98, TA1537), 2-aminoanthracene (with metabolic activation, strains TA 98, TA 100, TA 1535, TA 1537 and TA 102)

Details on test system and experimental conditions:

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

DURATION
- Preincubation period: 60 min at 37°C
- Exposure duration: 48 h at 37°C

NUMBER OF REPLICATIONS: 3

DETERMINATION OF CYTOTOXICITY
- Method: other: Cytotoxicity can be detected by a clearing or rather diminution of the background lawn or a reduction in the number of revertants down to a mutation factor of approximately ± 0.5 in relation to the solvent control.

Rationale for test conditions:

The test was performed as recommended in the respective guidelines.

Evaluation criteria:

The Mutation Factor is calculated by dividing the mean value of the revertant counts by the mean values of the solvent control (the exact and not the rounded values are used for calculation).
A test item is considered as mutagenic if:
- a clear and dose-related increase in the number of revertants occurs and/or
- a biologically relevant positive response for at least one of the dose groups occurs
in at least one tester strain with or without metabolic activation.

A biologically relevant increase is described as follows:
- if in tester strains TA 98, TA 100 and TA 102 the number of reversions is at least twice as high
- if in tester strains TA 1535 and TA 1537 the number of reversions is at least three times higher
than the reversion rate of the solvent control.

Key result

Species / strain:

other: TA 98, 100, 102, 1535, 1537

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS
- Precipitation: No precipitation of the test item was observed in any tester strain used in experiment I and II (with and without metabolic activation).

RANGE-FINDING/SCREENING STUDIES: Preliminary study performed with 3.16, 10.0, 31.6, 100,316, 1000, 2500 and 5000 µg/plate test substance

CYTOTOXICITY: Toxic effects of the test item were noted in all tester strains evaluated in experiment I and II.
In experiment I toxic effects of the test item were observed in tester strains TA 98, TA 1535 and TA 102 at concentrations of 1000 μg/plate and higher (without metabolic activation) and at concentrations of 2500 μg/plate and higher (with metabolic activation). In tester strain TA 100 toxic effects of the test item were noted at concentrations of 316 μg/plate and higher (without metabolic activation) and at concentrations of 1000 μg/plate (with metabolic activation). In tester strain TA 1537 toxic effects of the test item were observed at concentrations of 1000 μg/plate and higher (with and without metabolic activation).
In experiment II toxic effects of the test item were noted in tester strain TA 98 at concentrations of 1000 μg/plate and higher (without metabolic activation) and at concentrations of 316 μg/plate and higher (with metabolic activation). In tester strain TA 100 toxic effects of the test item were noted at concentrations of 316 μg/plate and higher (without metabolic activation) and at concentrations of 1000 μg/plate and higher (with metabolic activation). In tester strain TA 1535 toxic effects of the test item were observed at concentrations of 1000 μg/plate and higher (with and without metabolic activation). In tester strain TA 1537 toxic effects of the test item were noted at concentrations of 100 μg/plate and higher (without metabolic activation) and at concentrations of 316 μg/plate and higher (with metabolic activation). In tester strain TA 102 toxic effects of the test item were noted at concentrations of 100 μg/plate and higher (without metabolic activation) and at concentrations of 1000 μg/plate and higher (with metabolic activation).

HISTORICAL CONTROL DATA (with ranges, means and standard deviation and confidence interval (e.g. 95%)
- Positive historical control data:

Historical Laboratory Control Data of the Positive Control (in 2014 - 2016) without S9 ( - S9)
TA 99 TA 100 TA 1535 TA 1537 TA 102
Substance 4-NOPD NaN3 NaN3 4-NOPD MMS
Canc./plate 10µg 10µg 10µg 40µg 1µg
Mean 430.7 612.1 792.0 94.5 1729.2
SD 155.5 220.0 299.5 22.7 518.8
Min 141 132 38 35 272
Max 1830 1423 1854 273 3321
RSD [%] 36.1 35.9 37.8 24.0 30.0
n 971 1188 931 929 682

Historical Laboratory Control Data of the Positive Control (in 2014 - 2016) with S9 ( - S9)
TA 98 TA 100 TA 1535 TA 1537 TA 102
Substance 2-AA 2-AA 2-AA 2-AA 2-AA
Canc./plate 2.5 µg 2.5 µg 2.5 µg 2.5 µg 10 µg
Mean 1880.5 1727.7 133.9 234.1 801.2
SD 708.5 522.0 134.9 101.4 223.7
Min 70 169 22 26 137
Max 3606 3132 1954 682 3588
RSD [%] 37.7 30.2 100.8 43.3 27.9
n 966 1184 927 925 678


- Negative (solvent/vehicle) historical control data:
Historical Laboratory Control Data of the Negative Control (in 2014 - 2016) without S9 ( - S9)
TA 98 TA 100 TA 1535 TA 1537 TA 102
Mean 24.2 90.7 13.8 8.2 270.4
SD 6.7 15.6 6.7 2.9 55.0
Min 11 49 4 3 141
Max 58 155 41 35 472
RSD [%] 27.7 17.2 48.6 35.3 20.3
n 972 1191 929 931 682

Historical Laboratory Control Data of the Negative Control (in 2014 - 2016) with S9 ( - S9)
TA 98 TA 100 TA 1535 TA 1537 TA 102
Mean 29.0 96.4 10.5 8.3 339.7
SD 6.8 14.1 4.5 3.1 71.3
Min 15 62 3 3 157
Max 59 160 38 36 586
RSD [%] 23.4 14.6 42.7 37.4 21.0
n 967 1189 925 926 676

S9: metabolic activation
Conc.: concentration
Mean: mean of revertants/plate
Min.: minimum of revertants/plate
Max.: maximum of revertants/plate
SD: Standard Deviation
RSD: Relative Standard Deviation
n: Number of control values
NaN3: sodium azide
4-NOPD: 4-nitro-o-phenylene-diamine
MMS: methylmethanesulfonate
2-AA: 2-aminoanthracene

Conclusions:

Ethyltriphenylfphosphonium iodide was not mutagenic (negative) in the reverse gene mutation assay in bacteria according to OECD guideline 471 (adopted 21 July 1997) and EU method B.14 (dated May 30, 2008) with Salmonella typhimurium strains TA 98, TA 100, TA 1535, TA 1537 and TA 102 with and without metabolic acitvation.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Genetic toxicity in vivo

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

In a reverse gene mutation assay in bacteria according to OECD guideline 471 (adopted 21 July 1997) and EU method B.13/14 (dated May 30, 2008), Salmonella typhimurium strains TA 98, TA 100, TA 1535, TA 1537 and TA 102 were exposed to Ethyltriphenylphosphonium iodide in the absence and in the presence of mammalian metabolic activation (rat liver S9 mix). The assay was performed using the plate incorporation method (experiment I) and the preincubation method (experiment II). In the dose range finding test, performed as plate incorporation test, the test substance was tested formulated in DMSO up to concentrations of 5000 µg/plate in the absence and presence of S9-mix in the strains TA98 and TA100. In experiment I, concentrations up to 5000 µg/plate and in experiment II, concentrations up to 2500 µg/plate were tested in the absence and presence of S9-mix. Toxic effects of the test item were noted in all tester strains.

No biologically relevant increases in revertant colony numbers of any of the five tester strains were observed following treatment with Ethyltriphenylphosphonium iodide at any concentration level, neither in the presence nor absence of metabolic activation in experiment I and II.

Based on the results of this study it is concluded that Ethyltriphenylphosphonium iodide is not mutagenic in the bacterial reverse mutation assay.

Justification for classification or non-classification

Ethyltriphenylfphosphonium iodide is not mutagenic in the bacterial reverse mutation assay.

According to the criteria of REGULATION (EC) No 1272/2008, Ethyltriphenylphosphonium iodide does not have to be classified and has no obligatory labelling requirement for mutagenicity. According to the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) of the United Nations (2004), Ethyltriphenylphosphonium iodide does not have to be classified for mutagenicity.