Registration Dossier

Administrative data

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

Gene mutation (Bacterial Reverse Mutation Assay/Ames test) - Read-across to UV123 (CAS No. 129757-67-1): the substance was considered to be non-mutagenic in S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2 in the presence and absence of Aroclor-induced rat-liver S9 metabolic activation (OECD 471/GLP).

Link to relevant study records

Referenceopen allclose all

Endpoint:
in vitro gene mutation study in bacteria
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Justification for type of information:
Read-across justification attached below.
Reason / purpose for cross-reference:
read-across source
Species / strain:
other: S.typhimurium TA 98, TA 100, TA 1535, TA 1537; Escherichia coli WP2uvrA
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
not applicable
Positive controls validity:
valid
Conclusions:
In the experiments performed without and with microsomal activation none of the tested concentrations of UV123 led to an increase in the incidence of both histidine- or tryptophan-prototrophic mutants by comparison with the negative control. The target substance is also predicted to be negative in the assay.
Endpoint:
in vitro gene mutation study in bacteria
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Read-across guideline study, GLP compliance
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 E. coli WP2
Metabolic activation:
with and without
Metabolic activation system:
Aroclor-induced rat-liver S9 mix
Test concentrations with justification for top dose:
preliminary toxicity test without metabolic activation: 20 - 5000 µg/plate
main test (with and without metabolic activation): 313, 625, 1250, 2500 and 5000 µg/plate
Vehicle / solvent:
Acetone
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: see "Details on test system"
Details on test system and experimental conditions:
NUMBER OF REPLICATIONS: 3

METHOD OF APPLICATION: in agar (plate incorporation)

DURATION
- Exposure duration: 48h

NUMBER OF REPLICATIONS: three Petri dishes are prepared per strain and per group

DETERMINATION OF CYTOTOXICITY
- Method: ; relative total growth

- POSITIVE CONTROLS
WITHOUT S9
1) for strain TA 98: 2-nitrofluorene, 10 µg/plate in dimethylsulfoxide
2) for strains TA 100 and TA 1535: sodium azide, 2.0 µg/plate in bidistilled water
3) for strain TA 1537: 9 (5)-aminoacridine hydrochloride monohydrate, 150 µg/plate in dimethylsulfoxide
4) for strain E. coli: 4-nitroquinoline-N-oxide, 1 µg/plate in dimethylsulfoxide.

WITH S9
1) for strains TA 98 and TA 100: 2-aminoanthracene, 2.5 µg/plate in dimethylsulfoxide
2) for strain TA 1535: cyclophosphamide monohydrate, 400 µg/plate in bidistilled water
3) for strain TA 1537: 2-aminoanthracene, 5µg/plate in dimethylsulfoxide;
4) for strain E. coli WP2uvrA: 2-aminoanthracene, 50 µg/plate in dimethylsulfoxide
.
Evaluation criteria:
Criteria for a positive response:
The test substance is considered to be positive in this test system if one or both of the following conditions are met:
- at least a reproducible doubling of the mean number of revertants per plate above that of the negative control at any concentration level for one or more of the following strains: TA 98, TA 1535, TA 1537 and E. coli
- a reproducible increase of the mean number of revertants per plate for any concentration above that of the negative control by at least a factor of 1.5 for strain TA 100.
Generally a concentration-related effect should be demonstrable.
Assay acceptance criteria:
A test is considered acceptable if the mean colony counts of the control values of all strains are within the acceptable ranges and if the results of the positive controls meet the criteria for a positive response.
In either case the final decision has to be based on scientific judgement.
Species / strain:
other: S.typhimurium TA 98, TA 100, TA 1535, TA 1537; Escherichia coli WP2uvrA
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
not applicable
Positive controls validity:
valid
Additional information on results:
RANGE-FINDING/SCREENING STUDIES:
Nine concentrations of the test item ranging from 20 to 5000 µg/0.1 ml were tested to determine the highest concentration to be used in the mutagenicity assay. From the results obtained, the highest concentration suitable for the mutagenicity test was found to be 5000 µg/0.1 ml.

EXPERIMENTAL RESULT

Experiment 1

TA 1535 TA 100 TA 1537 TA 98 WP2uvrA
Dose (µg/plate) -S9 +S9 -S9 +S9 -S9 +S9 -S9 +S9 -S9 +S9
0 20 13 116 130 12 11 29 35 26 33
313 13 16 108 121 8 13 23 52 22 31
625 13 17 114 124 9 12 18 43 13 33
1250 13 13 99 123 9 15 21 39 16 26
2500 17 15 114 115 10 13 18 43 26 37
5000 13 9 98 142 9 11 26 50 17 36
positive control 568 451 606 1781 1225 307 1225 815 443 1223

Experiment 2

TA 1535 TA 100 TA 1537 TA 98 WP2uvrA
Dose (µg/plate) -S9 +S9 -S9 +S9 -S9 +S9 -S9 +S9 -S9 +S9
0 8 12 138 120 8 11 23 34 16 23
312.5 9 11 132 147 8 13 18 40 23 27
625 12 6 162 148 10 12 24 36 17 24
1250 9 12 133 129 9 13 16 34 27 17
2500 11 8 148 128 10 11 20 46 16 27
5000 11 10 140 134 7 11 20 48 26 19
positive control 455 477 667 1481 1585 126 1520 1184 379 546
Conclusions:
In the experiments performed without and with microsomal activation none of the tested concentrations of the test item led to an increase in the incidence of both histidine- or tryptophan-prototrophic mutants by comparison with the negative control.
Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (negative)

Genetic toxicity in vivo

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

Additional information

Gene mutation (Bacterial Reverse Mutation Assay/Ames test)

There is one gene mutation supporting study (Bacterial Reverse Mutation Assay/Ames test) with the substance available. There is one gene mutation key study (Bacterial Reverse Mutation Assay/Ames test) available (read-across to UV123 (CAS No. 129757-67-1)).

In a reverse gene mutation study in bacteria (84/449/EWG, B.14/GLP), strains of S. typhimurium TA 98, 100, 1535, 1537 were exposed to the substance in acetone at concentrations of 20 - 5000 μg/plate with and without metabolic activation (Aroclor-induced rat-liver S9). As this study has only 4 strains, it is a supporting study. There was no increase in induced mutant colonies over background either with and without metabolic activation. Under the conditions of this study, the substance is considered non-mutagenic.

In a reverse gene mutation study in bacteria (OECD 471/GLP), strains of S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2 were exposed to UV123 in acetone at concentrations of 313, 625, 1250, 2500 and 5000 µg/plate (plate incorporation method for both experiments) with and without metabolic activation (Aroclor-induced rat-liver S9). As this study has 5 strains, it is the key study. There was no cytotoxicity noted up to the limit dose. The positive controls gave the appropriate response. There was no increase in induced mutant colonies over background either with and without metabolic activation. Under the conditions of this study, UV-123 is considered non-mutagenic.

The target substance is also predicted to be negative in this assay.

Justification for classification or non-classification

Based on the available information in the dossier, the substance does not need to be classified for germ cell mutagenicity when the criteria outlined in Annex I of 1272/2008/EC are applied, based on the read-across data from UV123 (CAS No.129757-67-1).