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Administrative data

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

In vitro according to OECD guideline 471.

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:
weight of evidence
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Justification for type of information:
The read-across source zirconium tetrabutanolate and the target substance belong to simple alkoxides of metals of the same group (titanium and zirconium). Due to rapid hydrolysis, the intrinsic properties/toxicities lie in the organic part of the hydrolysis products. The main organic hydrolysis product is 1-butanol and therefore the properties are considered similar.
Reason / purpose for cross-reference:
read-across source
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)
Qualifier:
according to guideline
Guideline:
EPA OPPTS 870.5100 - Bacterial Reverse Mutation Test (August 1998)
Principles of method if other than guideline:
No deviation from guideline.
GLP compliance:
yes (incl. QA statement)
Type of assay:
bacterial reverse mutation assay
Key result
Species / strain:
S. typhimurium TA 1535
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
Key result
Species / strain:
S. typhimurium TA 1537
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
Key result
Species / strain:
S. typhimurium TA 98
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
Key result
Species / strain:
S. typhimurium TA 100
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
Key result
Species / strain:
E. coli WP2 uvr A
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
Executive summary:

The targe substance is not mutagenic, read-across from study of structure analogue, zirconium tetrapropanolate.

Endpoint:
in vitro gene mutation study in bacteria
Type of information:
experimental study
Adequacy of study:
key study
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)
Qualifier:
according to guideline
Guideline:
EPA OPPTS 870.5100 - Bacterial Reverse Mutation Test (August 1998)
Principles of method if other than guideline:
No deviation from guideline.
GLP compliance:
yes (incl. QA statement)
Type of assay:
bacterial reverse mutation assay
Specific details on test material used for the study:
SOURCE OF TEST MATERIAL
- Supplier: Borica Co., Ltd.
- Lot number: 000577Z
- Expiration date of the lot/batch: 2018-Jul-07
- CAS number: 23519-77-9
Target gene:
Gene of histidine in Salmonella typhimurium and gene of tryptophan in Escherichia coli.
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Additional strain / cell type characteristics:
other: all with rfa- and deletion of uvr B gene. In strain TA98 and TA100, presence of R factor plasmid pKM101 enhances chemical and UV-induced mutagenesis via an increase in the error-prone repair pathway.
Species / strain / cell type:
E. coli WP2 uvr A
Metabolic activation:
with and without
Metabolic activation system:
rat-liver homogenate activation system (S9)
Test concentrations with justification for top dose:
Eight concentrations of the test item (1.5, 5, 15, 50, 150, 500, 1500 and 5000 µg/plate) were assayed in triplicate against each tester strain, using the direct plate incorporation method.

The maximum concentration used for testing was 5000 µg/plate as the toxicity in Experiment 1 was not severe enough to preclude testing up to
the maximum recommended dose level.
Vehicle / solvent:
Vehicle(s)/solvent(s) used: THF (Tetrahydrofuran)
Supplier: Sigma-Aldrich
Batch number (purity) STBG9857 (99.9%)
Justification for choice of solvent/vehicle: the test substance was immiscible in sterile distilled water, dimethylformamide and dimethyl sulphoxide but was fully miscible in THF at 200 mg/mL. THF therefore was selected as the vehicle.
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
4-nitroquinoline-N-oxide
9-aminoacridine
N-ethyl-N-nitro-N-nitrosoguanidine
benzo(a)pyrene
other: 2-Aminoanthracene (2AA)
Details on test system and experimental conditions:
METHOD OF APPLICATION: in medium; in agar (plate incorporation); preincubation;

DURATION
- Preincubation period: 37 +/-3°C for 20 minutes with shaking
- Exposure duration: 37 +/-3°C for 48 hours.

NUMBER OF REPLICATIONS: 3

Evaluation criteria:
There are several criteria for determining a positive result. Any, one, or all of the following can be used to determine the overall result of the study:
1. A dose-related increase in mutant frequency over the dose range tested (De Serres and Shelby, 1979).
2. A reproducible increase at one or more concentrations.
3. Biological relevance against in-house historical control ranges.
4. Statistical analysis of data as determined by UKEMS (Mahon et al., 1989).
5. Fold increase greater than two times the concurrent solvent control for any tester strain (especially if accompanied by an out-of-historical range response (Cariello and Piegorsch, 1996)).

A test item will be considered non-mutagenic (negative) in the test system if the above
criteria are not met.
Statistics:
Statistical significance was confirmed by using Dunnetts Regression Analysis (* = p < 0.05) for those values that indicate statistically significant increases in the frequency of revertant colonies compared to the concurrent solvent control. Values that the program concluded as statistically significant but were within the in-house historical profile were not reported.
Key result
Species / strain:
S. typhimurium TA 1535
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
Key result
Species / strain:
S. typhimurium TA 1537
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
Key result
Species / strain:
S. typhimurium TA 98
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
Key result
Species / strain:
S. typhimurium TA 100
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
Key result
Species / strain:
E. coli WP2 uvr A
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
Conclusions:
The test substance was considered to be non-mutagenic under the conditions of this test.
Executive summary:

The test substance was tested according to OECD guideline 471 "Bacterial Reverse Mutation Test". Salmonella typhimurium strains TA1535, TA1537, TA98 and TA100 and Escherichia coli strain WP2 uvrA were treated with the test item using both the Ames plate incorporation and pre-incubation methods at up to eight dose levels (1.5, 5, 15, 50, 150, 500, 1500 and 5000 µg/plate), in triplicate, both with and without the addition of a rat liver homogenate metabolizing system (10% liver S9 in standard co-factors).

The test substance was not mutagenic either with or without metabolic activation.

Endpoint:
in vitro DNA damage and/or repair study
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
test procedure in accordance with generally accepted scientific standards and described in sufficient detail
Justification for type of information:
1-butanol is the main hydrolysis prodcut of the target substance. Properties of the the two substance are used for read-across.
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 479 (Genetic Toxicology: In Vitro Sister Chromatid Exchange Assay in Mammalian Cells)
GLP compliance:
not specified
Type of assay:
sister chromatid exchange assay in mammalian cells
Species / strain / cell type:
Chinese hamster Ovary (CHO)
Details on mammalian cell type (if applicable):
minimal essential medium complemented with 10 % (v/v) fetal bovine serum
Additional strain / cell type characteristics:
not specified
Metabolic activation:
without
Test concentrations with justification for top dose:
up to 0.1% (v/v) final concentration in the cell culture
Vehicle / solvent:
no vehicle
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
yes
Positive controls:
yes
Positive control substance:
other: acetaldehyde
Key result
Species / strain:
Chinese hamster Ovary (CHO)
Metabolic activation:
without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
not specified
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid

Lowest Concentration producing cell toxicity: without metabolic activation: >0.1% 

No evidence of DNA damage in an in vitro SCE assay in CHO cells up to a concentration of 0.1%.control: 5.49 (number of SCE per mitosis); butan-1-ol (0.1 % v/v): 5.66 (number of SCE per mitosis); acetaldehyde (0.0005 % v/v): 13.56 (number of SCE per mitosis); acetaldehyde (0.001 % v/v): 28.35 (number of SCE per mitosis)

Conclusions:
1-butanol did not induce mutation in the strains tested in vitro (without metabolic activation) .
Executive summary:

As the target substance hydrolyses rapidly (half-life < 5 minutes) the intrinsic properties are related to hydrolysis products of the target substance. This information is used as a supporting evidence on the toxicity of the target substance in CSA.

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

Genetic toxicity in vivo

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

Additional information

No study was conducted on the target substance titanium tetrabutanolate. The AMES study of zirconium tetraproanolate was used for read-across based on structure similarity.

AMES test on the Zirconium tetraproanolate showed no mutagenic effect either with or without metabolic activation.

As the target substance hydrolyses rapidly (half-life < 5 minutes) the intrinsic properties are related to hydrolysis products of the target substance. The hydrolysis products include 1 -butanol and non-hazardous zirconium dioxide.

In vitro studies of 1 -butanol

1-butanol was not mutagenic in bacteria (Salmonella typhimurium) (McCann et al., 1975; Kier et al., 1986). No mutagenic effects were observed in experiments on cultured Chinese hamster lung (V79) cells at concentrations up to 50 microliters/milliliter (Lasne et al., 1984) or Chinese hamster ovary (CHO) cells at concentrations up to 0.1% (Obe and Ristow, 1997). (Adapted from UNEP 2004)

Based on these findings, the target substance was considered no mutagenic potential.

Justification for classification or non-classification

Based on AMES study on the strucrual surrogate and the weight of evidence approach of in vitro studies on the hydrolysis products, there is no need for classification of the substance for mutagenic effects in accordance with the criteria of CLP Regulation