By-product from Guanidinoacetic acid manufacturing

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

A GLP-Study according to OECD-Guideline 471 has been performed to determine the mutagenic potential of By-product from Guanindinoacetic acid manufacturing.

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:

2020-11-24 - 2021-05-11

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Specific details on test material used for the study:

Batch-No.: 201009MA2 solid

Target gene:

histidine operon

Metabolic activation:

with and without

Metabolic activation system:

Mammalian Microsomal Fraction S9 Mix

Test concentrations with justification for top dose:

31.6, 100, 316, 1000, 2500 and 5000 μg/plate
The recommended maximum test concentration for soluble
non-cytotoxic substances is 5 mg/plate or 5 μl/plate

Vehicle / solvent:

A. dest.

Negative solvent / vehicle controls:

yes

Positive controls:

yes

Positive control substance:

sodium azide

methylmethanesulfonate

other:

Details on test system and experimental conditions:

TA98: his D 3052; rfa-; uvrB-; R-factor: frame shift mutations
TA100: his G 46; rfa-; uvrB-; R-factor: base-pair substitutions
TA1535: his G 46; rfa-; uvrB-: base-pair substitutions
TA1537: his C 3076; rfa-; uvrB-: frame shift mutations
E. coli: WP2 uvrA (pKM101): trp-; uvrA-: base-pair substitutions

Incubation: 37 °C for at least 48 h in the dark

Evaluation criteria:

Cytotoxicity can be detected by a clearing or rather diminution of the background lawn (indicated as "N" or “B”, respectively in the result tables) or a reduction in the number of revertants down to a mutation factor of approximately ≤ 0.5 in relation to the solvent control.

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.

Statistics:

A statistical evaluation of the results is not regarded as necessary

Key result

Species / strain:

S. typhimurium TA 98

Remarks:

Plate-incorporation Test

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 examined

True negative controls validity:

not examined

Positive controls validity:

valid

Key result

Species / strain:

S. typhimurium TA 100

Remarks:

Plate-incorporation Test

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 examined

True negative controls validity:

not examined

Positive controls validity:

valid

Key result

Species / strain:

S. typhimurium TA 1535

Remarks:

Plate-incorporation Test

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 examined

True negative controls validity:

not examined

Positive controls validity:

valid

Key result

Species / strain:

S. typhimurium TA 1537

Remarks:

Plate-incorporation Test

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 examined

True negative controls validity:

not examined

Positive controls validity:

valid

Key result

Species / strain:

E. coli WP2 uvr A pKM 101

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 examined

True negative controls validity:

not examined

Positive controls validity:

valid

Key result

Species / strain:

S. typhimurium TA 98

Remarks:

Pre-incubation Test

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 examined

True negative controls validity:

not examined

Positive controls validity:

valid

Key result

Species / strain:

S. typhimurium TA 100

Remarks:

Pre-incubation Test

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 examined

True negative controls validity:

not examined

Positive controls validity:

valid

Key result

Species / strain:

S. typhimurium TA 1535

Remarks:

Pre-incubation Test

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 examined

True negative controls validity:

not examined

Positive controls validity:

valid

Key result

Species / strain:

S. typhimurium TA 1537

Remarks:

Pre-incubation Test

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 examined

True negative controls validity:

not examined

Positive controls validity:

valid

Key result

Species / strain:

E. coli WP2 uvr A pKM 101

Remarks:

Pre-incubation Test

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 examined

True negative controls validity:

not examined

Positive controls validity:

valid

Conclusions:

In conclusion, it can be stated that during the described mutagenicity test and under the experimental conditions reported, By-product from Guanidinoacetic acid manufacturing did not cause gene mutations by base pair changes or frameshifts in the genome of the tester strains used.
Therefore, By-product from Guanidinoacetic acid manufacturing is considered to be non-mutagenic in this bacterial reverse mutation assay.

Executive summary:

The test item By-product from Guanidinoacetic acid manufacturing was investigated for its potential to induce gene mutations according to the plate incorporation test (experiment I) and the pre-incubation test (experiment II) using Salmonella typhimurium strains TA98, TA100, TA1535, TA1537 and tester strain E. coli WP2 uvrA (pKM101).
In two independent experiments several concentrations of the test item were used. Each assay was conducted with and without metabolic activation. The concentrations, including the controls, were tested in triplicate. The following concentrations of the test item were prepared and used in the experiments:
31.6, 100, 316, 1000, 2500 and 5000 μg/plate
No precipitation of the test item was observed in any tester strain used in experiment I and II (with and without metabolic activation).
No toxic effects of the test item were noted in any of the five tester strains used up to the highest dose group evaluated with and without metabolic activation in experiment I and II.
No biologically relevant increases in revertant colony numbers of any of the five tester strains were observed following treatment with By-product from Guanidinoacetic acid manufacturing at any concentration level, neither in the presence nor absence of metabolic activation in experiment I and II.
All criteria of validity were met.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Justification for classification or non-classification

By-product from Guanidinoacetic acid manufacturing did not cause gene mutations by base pair changes or frameshifts in the genome of the tester strains used.