Neodecanoic acid, iron salt

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Remarks:

Bacterial Reverse Mutation Assay

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Experimental Start Date: 31 August 2017 Experimental Completion Date: 17 September 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Version / remarks:

OECD Guideline 471 (OECD, 1997).

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Neodecanoic acid, iron salt

EC Number:

257-446-6

EC Name:

Neodecanoic acid, iron salt

Cas Number:

51818-55-4

Molecular formula:

C10H20O2.xFe

IUPAC Name:

λ²-iron(2+) bis(2-ethyl-2,5-dimethylhexanoate)

Test material form:

solid

Details on test material:

CAS Number: 51818-55-4
EC Number 257-446-6
Molecular formula: C30H57FeO6
Molecular weight: 569.6
Purity: 100%
Storage conditions: Refrigerated under Nitrogen ( 2-8 °C )

Specific details on test material used for the study:

Batch number: E01133-065
Purity: 100%
Date received: 19 July 2017
Retest date: 31 July 2019
Storage conditions: 15-25°C, protected from light

Method

Target gene:

The test item was assayed for mutation in five histidine-requiring strains (TA98, TA100, TA1535, TA1537 and TA102) of Salmonella typhimurium, both in the absence and in the presence of metabolic activation using an Aroclor 1254-induced rat liver post-mitochondrial fraction (S-9), in two separate experiments

Species / strain

Species / strain / cell type:

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

Additional strain / cell type characteristics:

not applicable

Metabolic activation:

with and without

Metabolic activation system:

Aroclor 1254-induced rat liver post-mitochondrial fraction (S-9)

Test concentrations with justification for top dose:

Mutation Experiment 1 treatments of all the tester strains were performed in the absence and in the presence of S-9, using final concentrations of the test item at 5, 16, 50, 160, 500, 1600 and 5000 µg/plate, plus vehicle and positive controls. Following these treatments, no evidence of toxicity was observed except in strain TA1537 at a concentration of 5000 µg/plate in the absence of S-9.

Mutation Experiment 2 treatments of all the tester strains were performed in the absence and in the presence of S-9. The maximum test concentration of 5000 µg/plate was retained for all strains. Narrowed concentration intervals were employed covering the range 160-5000 µg/plate, in order to examine more closely those concentrations of the test item approaching the maximum test concentration and considered therefore most likely to provide evidence of any mutagenic activity. In addition, all treatments in the presence of S-9 were further modified by the inclusion of a pre-incubation step. In this way, it was hoped to increase the range of mutagenic chemicals that could be detected using this assay system. Following these treatments, no evidence of toxicity was observed.

Vehicle / solvent:

All the test item treatments in this study were performed using formulations prepared in dimethylformamide (DMF).

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: 2-nitrofluorene (2NF), Sodium azide (NaN3), 9-aminoacridine (AAC), Mitomycin C (MMC), Benzo[a]pyrene (B[a]P), 2-aminoanthracene (AAN)

Details on test system and experimental conditions:

The test item was assayed for mutation in five histidine-requiring strains (TA98, TA100, TA1535, TA1537 and TA102) of Salmonella typhimurium, both in the absence and in the presence of metabolic activation using an Aroclor 1254-induced rat liver post-mitochondrial fraction (S-9), in two separate experiments.

Rationale for test conditions:

OECD guidline

Evaluation criteria:

For valid data, the test article was considered to be mutagenic if:

1. A concentration related increase in revertant numbers was =1.5-fold (in strain TA102), =2-fold (in strains TA98 or TA100) or =3-fold (in strains TA1535 or TA1537) the concurrent vehicle control values

2. The positive trend/effects described above were reproducible.
The test article was considered positive in this assay if both of the above criteria were met.
The test article was considered negative in this assay if neither of the above criteria were met.

Results and discussion

Test results

Key result

Species / strain:

other: TA98, TA100, TA1535, TA1537 and TA102 of Salmonella typhimurium

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: It was concluded that the test item did not induce mutation

Any other information on results incl. tables

Details of all treatment solution concentrations and final test item concentrations are provided in the Test Article.

Mutation Experiment 1 treatments of all the tester strains were performed in the absence and in the presence of S-9, using final concentrations of the test item at 5, 16, 50, 160, 500, 1600 and 5000 µg/plate, plus vehicle and positive controls. Following these treatments, no evidence of toxicity was observed, except for a marked reduction in revertant numbers noted in strain TA1537 at a concentration of 5000µg/plate.

Mutation Experiment 2 treatments of all the tester strains were performed in the absence and in the presence of S-9. The maximum test concentration of 5000 µg/plate was retained for all strains. Narrowed concentration intervals were employed covering the range 160-5000 µg/plate, in order to examine more closely those concentrations of the test item approaching the maximum test concentration and considered therefore most likely to provide evidence of any mutagenic activity. In addition, all treatments in the presence of S-9 were further modified by the inclusion of a pre-incubation step. In this way, it was hoped to increase the range of mutagenic chemicals that could be detected using this assay system. Following these treatments no evidence of toxicity was observed.

In Mutation Experiment 1, precipitation of the test article was observed on the test plates at concentrations of 5000 µg/plate in all strains in the absence and presence of S-9.

In Mutation Experiment 2, precipitation of the test article was observed on the test plates at concentrations of 2500 µg/plate and above in all strains in the absence of S-9 and at 1250 µg/plate and above in all strains in the presence of S-9.

The individual mutagenicity plate counts were averaged to give mean values.From the data it can be seen that vehicle control counts fell within the laboratory’s historical ranges.The positive control chemicals all induced increases in revertant numbers of=1.5-fold (in strain TA102), =2-fold (in strains TA98 and TA100) or =3-fold (in strains TA1535 and TA1537) the concurrent vehicle controlsconfirming discrimination between different strains, and an active S-9 preparation. The study therefore demonstrated correct strain and assay functioning and was accepted as valid.

Following the test item treatments of all the test strains in the absence and presence of S-9, no increases in revertant numbers were observed that were =1.5-fold (in strain TA102), =2-fold (in strains TA98 and TA100) or =3-fold (in strains TA1535 and TA1537) the concurrent vehicle control. This study was considered therefore to have provided no evidence of any test item mutagenic activity in this assay system.

Applicant's summary and conclusion

Conclusions:

It was concluded that the test item did not induce mutation in five histidine-requiring strains (TA98, TA100, TA1535, TA1537 and TA102) of Salmonella typhimurium when tested under the conditions of this study. These conditions included treatments at concentrations up to 5000 µg/plate (the maximum recommended concentration according to current regulatory guidelines), in the absence and in the presence of a rat liver metabolic activation system (S-9).

Executive summary:

The test item was assayed for mutation in five histidine-requiring strains (TA98, TA100, TA1535, TA1537 and TA102) of Salmonella typhimurium, both in the absence and in the presence of metabolic activation using an Aroclor 1254-induced rat liver post-mitochondrial fraction (S-9), in two separate experiments.

All test item treatments in this study were performed using formulations prepared in dimethylformamide (DMF).

Mutation Experiment 1 treatments of all the tester strains were performed in the absence and in the presence of S-9, using final concentrations of the test item at 5, 16, 50, 160, 500, 1600 and 5000 µg/plate, plus vehicle and positive controls. Following these treatments, no evidence of toxicity was observed except in strain TA1537 at a concentration of 5000µg/plate in the absence of S-9.

Mutation Experiment 2 treatments of all the tester strains were performed in the absence and in the presence of S-9. The maximum test concentration of 5000 µg/plate was retained for all strains. Narrowed concentration intervals were employed covering the range 160-5000 µg/plate, in order to examine more closely those concentrations of the test item approaching the maximum test concentration and considered therefore most likely to provide evidence of any mutagenic activity. In addition, all treatments in the presence of S-9 were further modified by the inclusion of a pre-incubation step. In this way, it was hoped to increase the range of mutagenic chemicals that could be detected using this assay system. Following these treatments, no evidence of toxicity was observed.

In Mutation Experiment 1, precipitation was observed on the test plates at concentrations of 5000 µg/plate in all strains in the absence and presence of S-9.

In Mutation Experiment 2, precipitation was observed on the test plates at concentrations of 2500 µg/plate and above in all strains in the absence of S-9 and at 1250 µg/plate and above in all strains in the presence of S-9.

Vehicle and positive control treatments were included for all strains in both experiments. The mean numbers of revertant colonies fell withinacceptable ranges for vehicle control treatments, and were within historical control range of the positive control treatments.

It was concluded that the test item did not induce mutation in five histidine-requiring strains (TA98, TA100, TA1535, TA1537 and TA102) of Salmonella typhimurium when tested under the conditions of this study. These conditions included treatments at concentrations up to 5000 µg/plate (the maximum recommended concentration according to current regulatory guidelines),in the absence and in the presence of a rat

liver metabolic activation system (S-9).