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Administrative data

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

The test material was considered to be non-mutagenic under the conditions of the AMES test performed.

Link to relevant study records
Reference
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:
comparable to guideline study with acceptable restrictions
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
GLP compliance:
not specified
Type of assay:
bacterial reverse mutation assay
Species / strain / cell type:
S. typhimurium, other: TA 98, TA 100, TA 1535, TA 1537 and TA 1538
Metabolic activation:
with and without
Metabolic activation system:
rat liver metabolic activation system (S-9)
Test concentrations with justification for top dose:
Range Finder Experiment and Experiment 1: 1.6, 8, 40, 200, 1000 and 5000 µg/plate, with and without metabolic activation
Vehicle / solvent:
- Vehicle: sterile purified water.
Untreated negative controls:
yes
Positive controls:
yes
Positive control substance:
9-aminoacridine
2-nitrofluorene
sodium azide
benzo(a)pyrene
other: 2-Aminoanthracene
Species / strain:
S. typhimurium, other: TA 98, TA 100, TA 1535, TA 1537 and TA 1538
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Additional information on results:
When the data from the Range-Finder Experiment were analysed at the 1 % level using Dunnett's test a statistically significant increase in revertant numbers was observed following TA 100 treatments in the presence of S-9. As this increase was small in magnitude and was observed at the lowest dose treatment, this was not considered to be indicative of test item mutagenic activity in this strain under this treatment condition. No other test item treatments induced statistically significant increases in revertant numbers, when the data were analysed at the 1 % level using Dunnett's test.

TOXICITY
No clear evidence of toxicity, as manifest by a marked decrease in revertant numbers or a thinning of the background bacterial lawn was observed following the any of the dose treatments in any of the strains in the presence or the absence of S-9.

PRECIPITATION
No precipitation of test agent was observed following any of the treatments in either the presence or absence of S-9.

Summary of mean revertant colonies (-S9) - Experiment 1

Dose Level µg/plate TA 98 TA 100 TA 1535 TA 1537 TA 1538
Water 36± 5 117± 12 13± 1 15± 2 19± 6
Test item 1.6 41± 9 118± 7 10± 5 13± 4 18± 5
Test item 8 32± 10 132± 12 9± 1 16± 2 17± 7
Test item 40 39± 4 122± 1 13± 1 9± 1 17± 2
Test item 200 42± 7 (M) 116± 3 13± 3 (M) 12± 5 (M) 14± 4 (M)
Test item 1000 43± 7 (M) 110± 11 (M) 8± 2 (M) 12± 4 (M) 20± 3 (M)
Test item 5000 36± 2 (M) 94± 9 (M) 11± 6 (M) 12± 2 (M) 18± 7 (M)
2-Nitrofluorene 5 664± 35 338± 25
Sodium azide 2 763± 22 443± 18
9-Aminoacridine 50 136± 23

(M) Plates counted manually

Summary of mean revertant colonies (+S9) - Experiment 1

Dose Level µg/plate TA 98 TA 100 TA 1535 TA 1537 TA 1538
Water 40± 5 171± 15 14± 3 13± 4 27± 4
Test item 1.6 39± 5 209± 17 10± 2 15± 2 32± 3
Test item 8 49± 6 168± 20 18± 1 17± 6 22± 6
Test item 40 49± 7 185± 4 22± 7 12± 2 24± 8
Test item 200 40± 6 156± 8 17± 2 15± 2 (M) 25± 6 (M)
Test item 1000 44± 2 (M) 118± 12 (M) 16± 4 (M) 13± 6 (M) 23± 6 (M)
Test item 5000 37± 4 (M) 107± 14 (M) 9± 5 (M) 17± 1 (M) 26± 1 (M)
Benzo[a]pyrene 10 247± 35
2-Aminoanthracene 5 1831± 55 164± 17 358± 44 961± 46

(M) Plates counted manually

Conclusions:
It was concluded that test item did not induce mutation in Salmonella typhimurium strains TA 98, TA l00, TA l535, TA 1537 and TA 1538 under the conditions employed in the screening study.
Executive summary:

A screening study was conducted on test substance to determine reverse mutation in five histidine-requiring strains of Salmonella typhimuium. The strains tested were TA 98, TA 100, TA 1535, TA 1537 and TA 1538. Both the range finder experiment and experiment 1 were conducted at the concentrations of 1.6, 8, 40, 200, 1000 and 5000 µg/plate, with and without metabolic activation.

When the data from the Range-Finder Experiment were analysed at the 1 % level using Dunnett's test a statistically significant increase in revertant numbers was observed following TA 100 treatments in the presence of S9. As this increase was small in magnitude and was observed at the lowest dose treatment, this was not considered to be indicative of test item mutagenic activity in this strain under this treatment condition. No other test item treatments induced statistically significant increases in revertant numbers, when the data were analysed at the 1 % level using Dunnett's test.

No clear evidence of toxicity, as manifest by a marked decrease in revertant numbers or a thinning of the background bacterial lawn was observed following the any of the dose treatments in any of the strains in the presence or the absence of S9.

No precipitation of test agent was observed following any of the treatments in either the presence or absence of S9.

Conclusion

It was concluded that test item did not induce mutation in Salmonella typhimurium strains TA 98, TA l00, TA l535, TA 1537 and TA 1538 under the conditions employed in the screening study.

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

Additional information

IN VITRO GENE MUTATION IN BACTERIA

A screening study was conducted on Acid red 143 to determine reverse mutation in five histidine-requiring strains of Salmonella typhimuium. The strains tested were TA 98, TA 100, TA 1535, TA 1537 and TA 1538. Both the range finder experiment and experiment 1 were conducted at the concentrations of 1.6, 8, 40, 200, 1000 and 5000 µg/plate, with and without metabolic activation.

When the data from the Range-Finder Experiment were analysed at the 1 % level using Dunnett's test a statistically significant increase in revertant numbers was observed following TA 100 treatments in the presence of S9. As this increase was small in magnitude and was observed at the lowest dose treatment, this was not considered to be indicative of test item mutagenic activity in this strain under this treatment condition. No other test item treatments induced statistically significant increases in revertant numbers, when the data were analysed at the 1 % level using Dunnett's test.

No clear evidence of toxicity, as manifest by a marked decrease in revertant numbers or a thinning of the background bacterial lawn was observed following the any of the dose treatments in any of the strains in the presence or the absence of S9.

No precipitation of test agent was observed following any of the treatments in either the presence or absence of S9.

It was concluded that test item did not induce mutation in Salmonella typhimurium strains TA 98, TA l00, TA l535, TA 1537 and TA 1538 under the conditions employed in the screening study.

Justification for classification or non-classification

According to the CLP Regulation (EC) No 1272/2008, for the purpose of the classification for germ cell mutagenicity, substances are allocated in one of two categories in consideration of the fact that they are:

- substances known to induce heritable mutations or to be regarded as if they induce heritable mutations in the germ cells of humans or substances known to induce heritable mutations in the germ cells of humans or

- substances which cause concern for humans owing to the possibility that they may induce heritable mutations in the germ cells of humans.

The available information suggest that test substance did not show any reasons of concern from the genotoxicity point of view.

 

In conclusion, on the basis of the available information, the substance does not meet the criteria to be classified for genetic toxicity according to the CLP Regulation (EC) No 1272/2008.