Benzenecarboximidamide, 2-ethoxy-, hydrochloride (1:1)

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

Salmonella/microsome test (Ames test): negative with strains TA 98, TA 100, TA 102 and TA 1535 and TA 1537 (+/- S9 mix)

Link to relevant study records

Reference

Endpoint:

in vitro gene mutation study in bacteria

Remarks:

Type of genotoxicity: gene mutation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2000

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Target gene:

Histidine gene locus

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 male rat liver S9 mix

Test concentrations with justification for top dose:

0, 50, 158, 500, 1581, 5000 µg/plate and µg/tube (+/-S9 mix, all strains)

Vehicle / solvent:

deionized water

Untreated negative controls:

yes

Negative solvent / vehicle controls:

no

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: sodium azide (only TA 1535), nitrofurantoin (only TA 100), 4-nitro-1,2-phenylene diamine (TA 1537 and TA 98), cumene hydroperoxide (only TA 102), 2-aminoanthracene.

Remarks:

The positive controls sodium azide, nitrofurantoin, 4-nitro-1,2-phenylene diamine and cumene hydroperoxide were only used without S9 mix; the positive control 2-aminoanthracene was only used with S9 mix.

Details on test system and experimental conditions:

METHOD: Standard plate test and preincubation test; each concentration including the controls was tested in triplicate.

Evaluation criteria:

A reproducible and dose-related increase in mutant counts of at least one strain is considered to be a positive result. For TA 1535, TA 100 and TA 98 this increase should be about twice that of negative controls, whereas for TA 1537 at least a threefold increase should be reached. For TA 102 an increase of about 100 mutants should be reached. Otherwise, the result is evaluated as negative. However, these criteria may be overruled by good scientific judgment. In case of questionable results, investigations should continue, possibly with modifications, until a final evaluation is possible.

Statistics:

not specified

Species / strain:

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

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

weak strain-specific bacteriotoxic effect at 5000 µg/plate, however, this dose could nevertheless be used for assessment purposes

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Table 1: Summary of results from the Salmonella mutagenicity assay with Ethoxyamidin without S9 mix (mean values of revertants per plate)

Dose (µg per plate)	Without metabolic activation
	TA 1535	TA 100	TA 1537	TA 98	TA 102
0	8	81	8	31	182
50	8	72	8	25	180
158	9	74	9	32	172
500	10	80	9	30	170
1581	7	75	8	34	154
5000	9	76	6	33	145
Positive control	704	198	145	173	346
Dose ( µg per tube)	Without metabolic activation
	TA 1535	TA 100	TA 1537	TA 98	TA 102
0	12	95	9	23	228
50	14	105	8	30	274
158	14	104	9	26	265
500	11	112	8	24	267
1581	12	99	7	31	237
5000	7	71	6	17	157
Positive control	818	255	163	189	592

Table 2: Summary of results from the Salmonella mutagenicity assay with Ethoxyamidin with S9 mix (mean values of revertants per plate)

Dose (µg per plate)	With metabolic activation (liver S9 mix)
	TA 1535	TA 100	TA 1537	TA 98	TA 102
0	8	81	8	31	182
50	8	72	8	25	180
158	9	74	9	32	162
500	10	80	9	30	170
1580	7	75	9	34	154
5000	9	76	8	33	145
Positive control	704	198	145	173	346
Dose ( µg per tube)	With metabolic activation (liver S9 mix)
	TA 1535	TA 100	TA 1537	TA 98	TA 102
0	12	95	9	23	258
50	14	105	8	30	274
158	14	104	9	26	265
500	11	112	8	24	267
1580	12	99	7	31	237
5000	7	71	6	17	157
Positive control	818	255	163	189	592

 

 

Doses up to and including 1580 µg per plate did not cause any bacteriotoxic effects. Total bacteria counts remained unchanged and no inhibition of growth was observed. At 5000 µg the substance had a weak strain-specific bacteriotoxic effect, not limiting evaluation.

No evidence of mutagenic activity of Ethoxyamidin was seen in any tester strain with and without metabolic activation.

The positive controls sodium azide, nitrofurantoin, 4-nitro-1,2-phenylene diamine, cumene hydroperoxide and 2-aminoanthracene had a marked mutagenic effect, as was seen by a biologically relevant increase in mutant colonies compared to the corresponding negative controls.

Conclusions:

Interpretation of results (migrated information):
negative

Executive summary:

The mutagenic potential of Ethoxyamidin was evaluated in a Salmonella/microsome test with the S. typhimurium strains TA 98, TA 100, TA 102, TA 1535 and TA 1537 in the presence and absence of S9 mix according to OECD TG 471. Doses up to and including 1580 µg per plate did not cause any bacteriotoxic effects. At 5000 µg/plate a weak strain-specific bacteriotoxic effect occurred, which however did not affect assessment purposes. No evidence of mutagenic activity of Ethoxyamindin was seen in the treated cultures with and without S9 -mix. Thus, the test item can be considered as non- mutagenic in the Ames Test.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Additional information

Additional information from genetic toxicity in vitro:

The mutagenic potential of Ethoxyamidin HCl was evaluated in a Salmonella/microsome test with the S. typhimurium strains TA 98, TA 100, TA 102, TA 1535 and TA 1537 in the presence and absence of S9 mix according to OECD TG 471. Doses up to and including 1580 µg per plate did not cause any bacteriotoxic effects. At 5000 µg/plate a weak strain-specific bacteriotoxic effect occurred, which however did not affect assessment purposes. No evidence of mutagenic activity of Ethoxyamindin HCl was seen in the treated cultures with and without S9 -mix. Thus, the test item can be considered as non- mutagenic in the Ames Test.

Justification for selection of genetic toxicity endpoint
Only one study available

Justification for classification or non-classification

Based on the study results a classification according to Directive 67/548/EEC or Regulation (EC) No. 1272/2008 (CLP) is not warranted.