3A-Flux

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

An Ames study according to OECD 471 was performed with the substance in 2021. This study is regarded as key study and is used for classification.

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:

From 27 April 2021 to 14 May 2021

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

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

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

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:

S9-mix
Obtained by Trinova Biochem GmbH, Gießen, Batch no. 4344, produced from the livers of male Sprague-Dawley rats which were treated with Phenobarbital/5,6-Benzoflavone.

Test concentrations with justification for top dose:

Experiment 1: 5000, 1500, 500, 150 and 50 μg/plate.
Experiment 2 and 2b: 5000, 2500, 1250, 625, 313, 156, 78 μg/plate.
5000 µg/plate was used as top dose as this is the recommended maximum test concentration according to OECD 471 guideline.

Vehicle / solvent:

Based on these results of the non-GLP pre-test, demin. water was used as solvent in the experiments

Negative solvent / vehicle controls:

yes

Remarks:

Dimethylsulfoxide (DMSO), CAS No. 67-68-5, for the positive controls Demineralized water for the test item and the positive control Sodium chloride (0.9 % NaCl) for the positive control

Positive controls:

yes

Positive control substance:

sodium azide

benzo(a)pyrene

mitomycin C

other:

Details on test system and experimental conditions:

- Number of cultures per concentration: Triplicate
- Number of independent experiments: 2
- Experiment 1: Plate incorporation method
Experiment 2: Pre-incubation method
- Exposure duration/duration of treatment: 48 h

Evaluation criteria:

A result is considered as positive 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 concentrations occurs in at least one tested strain with or without metabolic activation.

A biologically relevant increase is described as follows:
- if in the bacteria strains S. typhimurium TA98, TA100, TA102 the number of revertants is at least twice as high than the reversion rate of the negative controls (increase factor of at least 2.0)
- if in the bacteria strains S. typhimurium TA1535 and TA1537 the number of revertants is at least three times higher than the reversion rate of the negative controls (increase factor of at least 3.0).

A substance is not mutagenic if it does not meet the criteria above.

Key result

Species / strain:

S. typhimurium TA 102

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

Positive controls validity:

valid

Key result

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

Positive controls validity:

valid

Key result

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

Positive controls validity:

valid

Key result

Species / strain:

S. typhimurium TA 1537

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

Positive controls validity:

valid

Key result

Species / strain:

S. typhimurium TA 1535

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

Positive controls validity:

valid

Conclusions:

Based on the results of this study it is concluded that 3A-Flux is not mutagenic in the Salmonella typhimurium test strains TA98, TA100, TA102, TA1535 and TA1537 in the absence and presence of metabolic activation under the experimental conditions of the present study.

Executive summary:

The study was performed with the plate incorporation (experiment 1) and pre-incubation method (experiments 2 and 2b) in the absence and presence of a metabolic activation system (S9). Under these conditions the influence of the test item on bacterial test strains was evaluated. The test item 3A-Flux showed no relevant or dose-related increase in the number of revertants in the Salmonella typhimurium test strains TA98, TA100, TA102, TA1535 and TA1537 in all evaluated experiments.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Genetic toxicity in vivo

Description of key information

An in vivo study equivalent or similar to OECD 474  is available for Boric acid. Read-across is justified on the basis detailed in the study entry.

Link to relevant study records

Reference

Endpoint:

in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus

Remarks:

Type of genotoxicity: chromosome aberration

Type of information:

experimental study

Adequacy of study:

key study

Study period:

No data

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Study conducted to GLP and in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do not effect the quality of the relevant results. This study is conducted on an analogue substance. Read-across is justified on the following basis: In aqueous solutions at physiological and acidic pH, low concentrations of simple inorganic borates such as boric acid, disodium tetraborate decahydrate, disodium tetraborate pentahydrate, boric oxide and disodium octaborate tetrahydrate will predominantly exist as undissociated boric acid. At about pH 10 the metaborate anion (B(OH)4-) becomes the main species in solution (WHO, 1998). This leads to the conclusion that the main species in the plasma of mammals and in the environment is un-dissociated boric acid. Since other borates dissociate to form boric acid in aqueous solutions, they too can be considered to exist as un-dissociated boric acid under the same conditions. For comparative purposes, exposures to borates are often expressed in terms of boron (B) equivalents based on the fraction of boron in the source substance on a molecular weight basis. Some studies express dose in terms of B, whereas other studies express the dose in units of boric acid. Since the systemic effects and some of the local effects can be traced back to boric acid, results from one substance can be transferred to also evaluate the another substance on the basis of boron equivalents. Therefore data obtained from studies with these borates can be read across in the human health assessment for each individual substance. Conversion factors are given in the table below. Conversion factor for equivalent dose of B Boric acid H3BO3 0.175 Boric Oxide B2O3 0.311 Disodium tetraborate anhydrous Na2B4O7 0.215 Disodium tetraborate pentahydrate Na2B4O7•5H2O 0.148 Disodium tetraborate decahydrate Na2B4O7•10H2O 0.113 Disodium octaborate tetrahydrate Na2B8O13•4H2O 0.210 Sodium metaborate (anhydrous) NaBO2 0.1643 Sodium metaborate (dihydrate) NaBO2•2H2O 0.1062 Sodium metaborate (tetrahydrate) NaBO2•4H2O 0.0784 Sodium pentaborate (anhydrous) NaB5O8 0.2636 Sodium pentaborate (pentahydrate) NaB5O8∙5H2O 0.1832 References: WHO. Guidelines for drinking-water quality, Addendum to Volume 1, 1998.

Qualifier:

according to guideline

Guideline:

other: US-EPA-FIFRA section 158.340 Guideline 84-2

Deviations:

no

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)

Deviations:

not specified

GLP compliance:

yes

Type of assay:

micronucleus assay

Species:

mouse

Strain:

Swiss Webster

Sex:

male/female

Route of administration:

oral: gavage

Vehicle:

Distilled water.

Details on exposure:

Mice given two doses (in 10 mL distilled water) by gavage.

Duration of treatment / exposure:

2 days.

Frequency of treatment:

Animals dosed once per day.

Post exposure period:

No data

Remarks:

Doses / Concentrations:
0, 225, 450, 900, 1800, 3500 mg/kg bw/day
Basis:
actual ingested

No. of animals per sex per dose:

No data

Control animals:

not specified

Tissues and cell types examined:

No data

Sex:

male/female

Genotoxicity:

negative

Toxicity:

no effects

Vehicle controls validity:

not specified

Negative controls validity:

not specified

Positive controls validity:

not specified

Additional information on results:

Clinical signs included rough fur and haunched position.

Conclusions:

Interpretation of results (migrated information): negative
The test substance was not genotoxic.
Read-across is justified on the basis detailed in the rationale for reliability above. This study is therefore considered to be of sufficient adequacy and reliability to be used as a supporting study and no further testing is justified.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Justification for classification or non-classification

Based on the results of the Ames study performed in 2021 with the substance it is concluded that the substance is not mutagenic in the Salmonella typhimurium test strains TA98, TA100, TA102, TA1535 and TA1537 in the absence and presence of metabolic activation under the experimental conditions of the present study. In addition no genotoxicity was observed in the in vivo study performed in 1991 with Boric acid, used as read-across substance.

Therefore no classification is required.