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Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

Bromhydrin-valerate is not mutagenic based on bacterial reverse mutation assays with the read-across substance diflucortolone-21-valerate (negative +/- S9 mix in S. typhimurium strains TA 98, TA 100, TA 1535, TA 1537 and TA 1538 (Lang and Sprenger-Semik, 1993; Lang and Schmitt, 1984).

Link to relevant study records

Referenceopen allclose all

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:
June to July 1992
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: comparable to guideline study with acceptable restrictions: E.coli WP2 strain or S. typhimurium TA 102 were not tested
Reference:
Composition 0
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
yes
Remarks:
no plate incorporation procedure performed
Principles of method if other than guideline:
Preincubation modification was performed
GLP compliance:
yes
Type of assay:
bacterial reverse mutation assay
Test material information:
Composition 1
Specific details on test material used for the study:
- Name of test material (as cited in study report): Diflucortolone-21-valerate (ZK 22612)
- Lot/batch No.: 41054493
Target gene:
Histidine gene locus
Species / strain:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Additional strain characteristics:
not specified
Metabolic activation:
with and without
Metabolic activation system:
Aroclor 1254 induced male rat liver S9 mix
Species / strain:
S. typhimurium TA 1538
Additional strain characteristics:
not specified
Metabolic activation:
with and without
Metabolic activation system:
Aroclor 1254 induced male rat liver S9 mix
Test concentrations with justification for top dose:
All strains: 0.05, 0.1, 0.25, 0.5, 1.0, 2.0 mg/plate
Vehicle:
DMSO
Negative controls:
yes
Solvent controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: without metabolic activation: 9-AA, 2-NF, NaN3; with metabolic activation: 2-AA, BP, CP, DMNA.
Key result
Species / strain:
other: S. typhimurium TA 1535, TA 1537, TA 1538, TA 98 and TA 100
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity:
no
Vehicle controls valid:
yes
Negative controls valid:
yes
Positive controls valid:
yes

None of the five tester strains showed increased reversion to prototrophy with diflucortolone-21-valerate at the concentrations tested, either in the absence or presence of S9 mix.

Precipitates in the agar were found starting at 0.25 or 0.50 mg diflucortolone-21-valerate/plate without S9 mix and 2 mg diflucortolone-21-valerate /plate with S9 mix.

Growth inhibition of the background lawn was not observed.

Negative controls and positive controls with known mutagens (9-acridinamine, hydrochloride; anthracen-2-amine; benzo[a]pyrene; cyclophosphamide; 2-nitro-9H-fluorene; sodium azide; N-nitrosodimethylamine) produced the expected numbers of revertant colonies.

Conclusions:
negative

Executive summary:

The purpose of the Ames test was to investigate whether diflucortolone-21-valerate can induce point mutations using the preincubation modification. The five histidine-dependent strains of S. typhimurium TA1535, TA100, TA1537, TA1538 and TA98 were tested. The study was performed with and without metabolic activation, employed a range of diflucortolone-21-valerate concentrations from 0.05 to 2.0 mg per plate. No increased reversion to prototrophy were seen neither without nor with metabolic activation. Precipitates in the agar were found starting at 0.25 or 0.50 mg diflucortolone-21-valerate/plate without S9 mix and 2 mg diflucortolone-21-valerate /plate with S9 mix. Growth inhibition of the background lawn was not observed.

Endpoint:
in vitro gene mutation study in bacteria
Remarks:
Type of genotoxicity: gene mutation
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Justification for type of information:
JUSTIFICATION FOR READ-ACROSS FROM SUPPORTING SUBSTANCE (STRUCTURAL ANALOGUE OR SURROGATE)
For bromhydrin-valerate (CAS No. 54605-02-6) no genetic toxicity data are available. Therefore, genetic toxicity in vitro data of diflucortolone-21-valerate (CAS No. 59198-70-8) were used since these data are regarded as representative. In diflucortolone-21-valerate the bromine atom in position 9 of the target molecule (bromhydrin-valerate) is replaced by a fluorine atom. No other changes in the molecule occured. No relevant toxicological effects are expected by the change of a halogen atom (Br) versus another (F). A search for structure-analogue substances using the QSAR OECD Toolbox 3.4 recommended diflucortolone-21-valerate as one out of 8 category substances for a read-across approach (for additional information see QSAR OECD Toolbox Report on Bromhydrin-valerat in "Attached justification").
Reason / purpose:
read-across source
Related information:
Composition 1
Principles of method if other than guideline:
Preincubation modification was performed
Test material information:
Composition 1
Target gene:
Histidine gene locus
Key result
Species / strain:
other: S. typhimurium TA 1535, TA 1537, TA 1538, TA 98 and TA 100
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity:
no
Vehicle controls valid:
yes
Negative controls valid:
yes
Positive controls valid:
yes

None of the five tester strains showed increased reversion to prototrophy with diflucortolone-21-valerate at the concentrations tested, either in the absence or presence of S9 mix.

Precipitates in the agar were found starting at 0.25 or 0.50 mg diflucortolone-21-valerate/plate without S9 mix and 2 mg diflucortolone-21-valerate /plate with S9 mix.

Growth inhibition of the background lawn was not observed.

Negative controls and positive controls with known mutagens (9-acridinamine, hydrochloride; anthracen-2-amine; benzo[a]pyrene; cyclophosphamide; 2-nitro-9H-fluorene; sodium azide; N-nitrosodimethylamine) produced the expected numbers of revertant colonies.

Conclusions:
negative

Executive summary:

The purpose of the Ames test was to investigate whether diflucortolone-21-valerate can induce point mutations using the preincubation modification. The five histidine-dependent strains of S. typhimurium TA1535, TA100, TA1537, TA1538 and TA98 were tested. The study was performed with and without metabolic activation, employed a range of diflucortolone-21-valerate concentrations from 0.05 to 2.0 mg per plate. No increased reversion to prototrophy were seen neither without nor with metabolic activation. Precipitates in the agar were found starting at 0.25 or 0.50 mg diflucortolone-21-valerate/plate without S9 mix and 2 mg diflucortolone-21-valerate /plate with S9 mix. Growth inhibition of the background lawn was not observed.

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:
June to Aug 1984
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: comparable to guideline study with acceptable restrictions: E.coli WP2 strain or S. typhimurium TA 102 were not tested
Reference:
Composition 0
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
yes
Remarks:
preincubation modification performed only with strain TA 100
GLP compliance:
yes
Type of assay:
bacterial reverse mutation assay
Test material information:
Composition 1
Specific details on test material used for the study:
- Name of test material (as cited in study report): ZK 22612 (Diflucortolone-21-valerate)
- Lot/batch No.: 23034436
Target gene:
Histidine gene locus
Species / strain:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Additional strain characteristics:
not specified
Metabolic activation:
with and without
Metabolic activation system:
Aroclor 1254 induced male rat liver S9 mix
Species / strain:
S. typhimurium TA 1538
Additional strain characteristics:
not specified
Metabolic activation:
with and without
Metabolic activation system:
Aroclor 1254 induced male rat liver S9 mix
Test concentrations with justification for top dose:
without preincubation: 0.1, 0.25, 0.5, 1.0, 2.5, 5.0 mg/plate
with preincubation: 0.1, 0.25, 0.5, 0.75, 1.0, 2.0, 4.0, 6.0 mg/plate (only S. typhymurium TA100)
Vehicle:
DMSO
Negative controls:
yes
Solvent controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: without metabolic activation: 9-AA, 2-NF, NaN3, with metabolic activation: 2-AA, BP, CP; in test with preincubation additionally DMNA was used as positive control
Key result
Species / strain:
other: S. typhimurium TA 1535, TA 1537, TA 1538, TA 98 and TA 100
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity:
no
Vehicle controls valid:
yes
Negative controls valid:
yes
Positive controls valid:
yes

None of the five tester strains showed increased reversion to prototrophy with ZK 22612 (diflucortolone-21-valerate) at the concentrations tested, either in the presence or absence of S9 mix. Also in an additionally performed test with TA 100 using the preincubation procedure ZK 22612 did not show a mutagenic effect.

Growth inhibition of the background lawn was not observed.

Precipitates in the agar were found generally in all concentrations without S9 mix, at 2.5 and 5 mg per plate with S9 mix and in the preincubation test starting at 1 mg per plate with S9 mix.

Negative controls and positive controls with known mutagens (9-aminoacridine, anthracene-2-amine, benzo(a)pyrene, cyclophosphamide, 2-nitrofluorene, sodium azide) produced the expected numbers of revertant colonies.

Conclusions:
negative

Executive summary:

ZK 22612 (diflucortolone-21-valerate) was examined for mutagenic activity in five histidine-dependent strains of S. typhimurium (TA1535, TA100, TA1537, TA1538, TA98) using the direct plate incorporation procedure. The study was performed with and without metabolic activation, employed a range of concentrations from 0.1 to 5.0 mg per plate. No increased reversion to prototrophy were seen neither without nor with metabolic activation. Also an additionally performed test with strain TA 100 using the preincubation procedure did not show a mutagenic effect of the test item. Precipitates in the agar were found generally in all concentrations without S9 mix, at 2.5 and 5 mg per plate with S9 mix and in the preincubation test starting at 1 mg per plate with S9 mix. Growth inhibition of the background lawn was not observed.

Endpoint:
in vitro gene mutation study in bacteria
Remarks:
Type of genotoxicity: gene mutation
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Justification for type of information:
JUSTIFICATION FOR READ-ACROSS FROM SUPPORTING SUBSTANCE (STRUCTURAL ANALOGUE OR SURROGATE)
For bromhydrin-valerate (CAS No. 54605-02-6) no genetic toxicity data are available. Therefore, genetic toxicity in vitro data of diflucortolone-21-valerate (CAS No. 59198-70-8) were used since these data are regarded as representative. In diflucortolone-21-valerate the bromine atom in position 9 of the target molecule (bromhydrin-valerate) is replaced by a fluorine atom. No other changes in the molecule occured. No relevant toxicological effects are expected by the change of a halogen atom (Br) versus another (F). A search for structure-analogue substances using the QSAR OECD Toolbox 3.4 recommended diflucortolone-21-valerate as one out of 8 category substances for a read-across approach (for additional information see QSAR OECD Toolbox Report on Bromhydrin-valerat in "Attached justification").
Reason / purpose:
read-across source
Related information:
Composition 1
Test material information:
Composition 1
Key result
Species / strain:
other: S. typhimurium TA 1535, TA 1537, TA 1538, TA 98 and TA 100
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity:
no
Vehicle controls valid:
yes
Negative controls valid:
yes
Positive controls valid:
yes

None of the five tester strains showed increased reversion to prototrophy with ZK 22612 (diflucortolone-21-valerate) at the concentrations tested, either in the presence or absence of S9 mix. Also in an additionally performed test with TA 100 using the preincubation procedure ZK 22612 did not show a mutagenic effect.

Growth inhibition of the background lawn was not observed.

Precipitates in the agar were found generally in all concentrations without S9 mix, at 2.5 and 5 mg per plate with S9 mix and in the preincubation test starting at 1 mg per plate with S9 mix.

Negative controls and positive controls with known mutagens (9-aminoacridine, anthracene-2-amine, benzo(a)pyrene, cyclophosphamide, 2-nitrofluorene, sodium azide) produced the expected numbers of revertant colonies.

Conclusions:
negative

Executive summary:

ZK 22612 (diflucortolone-21-valerate) was examined for mutagenic activity in five histidine-dependent strains of S. typhimurium (TA1535, TA100, TA1537, TA1538, TA98) using the direct plate incorporation procedure. The study was performed with and without metabolic activation, employed a range of concentrations from 0.1 to 5.0 mg per plate. No increased reversion to prototrophy were seen neither without nor with metabolic activation. Also an additionally performed test with strain TA 100 using the preincubation procedure did not show a mutagenic effect of the test item. Precipitates in the agar were found generally in all concentrations without S9 mix, at 2.5 and 5 mg per plate with S9 mix and in the preincubation test starting at 1 mg per plate with S9 mix. Growth inhibition of the background lawn was not observed.

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (negative)

Additional information

For bromhydrin-valerate (CAS No. 54605-02-6) no genetic toxicity data are available. Therefore, genetic toxicity in vitro data of diflucortolone-21-valerate (CAS No. 59198-70-8) were used since these data are regarded as representative. In diflucortolone-21-valerate the bromine atom in position 9 of the target molecule (bromhydrin-valerate) is replaced by a fluorine atom. No other changes in the molecule occured. No relevant toxicological effects are expected by the change of a halogen atom (Br) versus another (F). A search for structure-analogue substances using the QSAR OECD Toolbox 3.4 recommended diflucortolone-21-valerate as one out of 8 category substances for a read-across approach (for additional information see QSAR OECD Toolbox Report on Bromhydrin-valerat in "Attached justification").

Diflucortolone-21-valerate (ZK 22612) was examined for mutagenic activity in five histidine-dependent strains of S. typhimurium (TA1535, TA100, TA1537, TA1538, TA98) using the direct plate incorporation procedure (Lang and Schmitt, 1984). The study was performed with and without metabolic activation, employed a range of concentrations from 0.1 to 5.0 mg per plate. No increased reversion to prototrophy were seen neither without nor with metabolic activation. Also an additionally performed test with strain TA 100 using the preincubation procedure did not show a mutagenic effect of the test item. Precipitates in the agar were found generally in all concentrations without S9 mix, at 2.5 and 5 mg per plate with S9 mix and in the preincubation test starting at 1 mg per plate with S9 mix. Growth inhibition of the background lawn was not observed.

In a second Ames test diflucortolone-21-valerate was investigated for the induction on point mutations using the preincubation modification (Lang and Sprenger-Semik, 1993). The five histidine-dependent strains of S. typhimurium TA1535, TA100, TA1537, TA1538 and TA98 were tested. The study was performed with and without metabolic activation, employed a range of diflucortolone-21-valerate concentrations from 0.05 to 2.0 mg per plate. No increased reversion to prototrophy were seen neither without nor with metabolic activation. Precipitates in the agar were found starting at 0.25 or 0.50 mg diflucortolone-21-valerate/plate without S9 mix and 2 mg diflucortolone-21-valerate /plate with S9 mix. Growth inhibition of the background lawn was not observed.

Justification for classification or non-classification

Based on the study results of genetic toxicity in vitro tests with the read-across substance diflucortolone-21-valerate classification of bromhydrin-valerate is not required according to Regulation (EC) No. 1272/2008 (CLP).