Potassium titanium oxide (K1.88-2.13Ti8O16.94-17.07)

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

Ames test

A study was performed to OECD and EC test guidelines. Terracess TF-L, was evaluated using Salmonella typhimurium tester strains TA98, TAlOO, TA1535 and TA1537 and Escherichia coli tester strain WP2uvrA with and without metabolic activation. In an initial toxicity-mutation test, the maximum dose of the test substance evaluated was 5000 µg per plate. No appreciable toxicity and no positive mutagenic response was observed with any of the tester strains in either the presence or absence of S9 activation. Based on these findings a confirmatory mutagenicity test was determined using five dose levels, 333, 667, 1000, 3333, and 5000 µg per plate. Precipitate was observed beginning at 667 µg per plate. No appreciable toxicity was observed. No positive mutagenic responses were observed for all tester strains at any dose level in either the presence or absence of S9 activation. Terracess TF-L showed no evidence of mutagenicity in the Bacterial Reverse Mutation Test either in the presence or absence of metabolic activation and the test substance was concluded to be negative in this study.

Chromosome Aberration

A study was performed to OECD and EC test guidelines. Teracess TF was tested without S9 mix with 3 hours treatment and 12 hours recovery at concentrations of 39.06, 78.13 and 156.25 µg/mL With S9 mix, Terrracess TF was tested for 3 hours treatment and 12 hours recovery at concentrations of 156.25, 312.5 and 625 µg/mL. In a second assay Terracess TF was tested without S9 mix with 5 hours continuous treatment at concentrations of 12.5, 25 and 50 µg/mL. In the first test, in both the absence and presence of S9 mix, Terracess TF-S caused no statistically significant increases in the proportion of metaphase figures containing chromosomal aberrations. Following continuous treatment, in the absence of S9 mix, Terracess TF-S caused a statistically significant increase in the proportion of metaphase figures containing chromosomal aberrations, at 12.5 µg/mL including gap-type aberrations only. This increase is not thought to be of significance as the observed response was not dose related and the biological significance of gap-type aberrations is questionable. Due to the level of precipitate on the slides in both tests, some metaphases were unscorable and as such there was selectivity in the metaphases that were analysed. No increases in the proportion of polyploid cells were seen in either test. It is concluded that Terracess P is not mutagenic in the mouse lymphoma L5178Y test system under the experimental conditions described.

Mouse Lymphoma Assay

According to OECD and EC test guidelines, Terracess P was tested up to concentrations of 100 μg/ml (dose range finding test) and 33 μg/ml in the absence and presence of 8% (v/v) S9 -mix with a 3 h incubation time in the first experiment. In the second experiment, Terracess P was again tested up to concentrations of 33 µg/mL but in the absence and presence of 12% (v/v) S9 -mix. Incubation times were 24 and 3 hours in the absence and presence of S9 -mix, respectively. No toxicity was observed, but at the highest dose levels precipitation occurred. In the presence and absence of S9-mix, Terracess P did not induce a significant increase in the mutation frequency in the presence and absence of S9 -mix, in the first experiment and confirmed in the independent repeat experiment. It is concluded that Terracess P is not mutagenic in the mouse lymphoma L5178Y test system under the experimental conditions described.

Justification for selection of genetic toxicity endpoint

No single endpoint can be selected all three tests (Ames, chromosome aberration and mouse lymphoma) are to be considered together to reach a conclusion on genotoxicity.

Short description of key information:

Negative in the Ames test (EC B13/14/OECD 471) performed with Terracess TF

Negative in the in vitro mammalian chromosome aberration test (EC B.10/OECD 473) performed with Terracess TF

Negative in the in vitro mammalian gene mutation test (EC B.7/OECD 476) performed with Terracess P

The mouse lymphoma assay was performed with Terracess P, a compound which has been demonstrated to be very similar in structure, physicochemical properties and toxicological profile to Terracess TF in the read across justification document for reprotoxicity, mutagenicity (see section 13). Due to the fact Terracess TF and Terracess P have nearly the same chemical structure, the same interaction with bio-molecules, living cells and tissue is expected. Therefore, a read across from Terracess TF to data obtained with Terracess P is scientifically justified.

Link to relevant study records

Reference

Reference 1

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:

18th August 2004 - 31st August 2004

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)

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Target gene:

histidine locus (salmonella)
tyryptophan locus (Ecoli)

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2

Details on mammalian cell type (if applicable):

Tester strain cultures were checked for the following genetic markers on the day of the preparation of master plates.

The histidine requirement was tested by comparing the growth of each Salmonella tester strain on a histidine/biotin-supplemented minimum glucose agar plate with their growth on a biotin-only minimum glucose agar plate.

The tryptophan requirement was tested by comparing the growth of WP2uvrA strain on a tryptophan-supplemented minimum glucose agar plate with their growth on a minimum glucose agar plate.

For the Salmonella tester strains the presence of the rfa wall mutation was confirmed by demonstration of the sensitivity of the cultures to crystal violet.

The presence of uvrA and uvrB mutation was demonstrated by their sensitivity to ultraviolet light of the tester strains.

The presence of the pKM101 plasmid was confirmed for cultures of tester strains TA98 and TA 100 by demonstration of resistance to ampicillin.

Metabolic activation:

with and without

Metabolic activation system:

Aroclor induced rat liver (S-9 mix).

Test concentrations with justification for top dose:

Initial toxicity mutation test: 33.3, 66.7, 100, 333, 667, 1000, 3333, and 5000 µg per plate.
Confirmatory mutagenicity test: 333, 667, 1000, 3333, and 5000 µg per plate.

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMSO (dimethyl sulfoxide)

- Justification for choice of solvent/vehicle: DMSO was chosen as the dosing vehicle based on the solubility of the test substance and compatibility with the target cells. Terracess TF-L was a homogeneous suspension in DMSO at the highest concentration, 50 mg/ml, tested in the study.

Untreated negative controls:

yes

Remarks:

DMSO

Negative solvent / vehicle controls:

yes

Remarks:

DMSO

True negative controls:

no

Positive controls:

yes

Positive control substance:

benzo(a)pyrene

Remarks:

Others used: benzo[a]pyrene 2-nitrofluorene; 2-arninoanthracene; sodium azide and ICR-191

Details on test system and experimental conditions:

Concentration of the test substance resulting in precipitation: 667 µg/plate

Evaluation criteria:

Strains TA1535 and TA1537: Data will be judged positive if the increase in mean revertants at the highest numerical dose response is ? 3.0-fold the mean concurrent negative control value (vehicle control). This increase in the mean number of revertants per plate must be accompanied by a dose response
associated with increasing concentrations of the test substance.
2. Strains TA98, TAl00 and WP2uvrA: Data sets will be judged positive if the increase in mean revertants at the highest numerical dose
response is ? 2.0-fold the mean concurrent negative control value (vehicle control). This increase in the mean number of revertants per plate must be accompanied by a dose response to increasing concentrations of the test substance.

Statistics:

For each tester strain, the mean of the number of revertants and the standard deviation were calculated.

Key result

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

(> 5000 µg/plate)

Vehicle 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

Remarks:

(> 5000 µg/plate)

Vehicle 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

Remarks:

(> 5000 µg/plate)

Vehicle 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

Remarks:

(> 5000 µg/plate)

Vehicle 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

Remarks:

(> 5000 µg/plate)

Vehicle controls validity:

valid

Positive controls validity:

valid

Additional information on results:

No appreciable toxicity was observed in any of the tester strains.
No positive mutagenic responses were observed in any of the tester strains at any dose level in either the presence or absence of the metabolic activation.

The S9 was thawed and the 10% S9 mix prepared immediately prior to its use. The S9 mix was held on ice at all times before use. The S9 mix contained the following components:

 

dd-H20	2.4 mL
0.825 M KCI/0.2 M MgCl2	0.4 mL
0.2 M phosphate buffer, pH 7.4	5.0 mL
10 mL	0.2 mL
0.04MNADP	l.0 mL
S9	l.0 mL
Total Volume	10 mL

 

 No contaminant colonies were observed on the sterility plates for the most concentrated test substance dilution (50 mg/mL) and the S9 and sham mixes (100 mM phosphate buffer at pH 7.4)

Conclusions:

All criteria for a valid study were met. Under the conditions of this study, Terracess TF-L showed no evidence of mutagenicity in the Bacterial Reverse Mutation Test either in the presence or absence of Aroclor-induced rat liver S9. The test substance was concluded to be negative in this study.

Reference 2

Endpoint:

in vitro cytogenicity / chromosome aberration study in mammalian cells

Remarks:

Type of genotoxicity: chromosome aberration

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

OECD Guideline 473 (In Vitro Mammalian Chromosome Aberration Test)

Qualifier:

according to guideline

Guideline:

EU Method B.10 (Mutagenicity - In Vitro Mammalian Chromosome Aberration Test)

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.5375 - In vitro Mammalian Chromosome Aberration Test

Qualifier:

according to guideline

Guideline:

other: Official notice of J MHLW, METI and ME (21 November 2003)

GLP compliance:

yes

Type of assay:

in vitro mammalian chromosome aberration test

Species / strain / cell type:

mammalian cell line, other: Chinese Hamster Lung (CHL) cells

Details on mammalian cell type (if applicable):

- Type and identity of media: the cells were routinely grown and subcultured in Minimal Essential medium supplemented with 10% heat-inactivated foetal calf serum, non-essential amino acids solution, L-glutamine and gentamycin solution. The cells were grown at 37°C in a humid atmosphere containing 5%carbon dioxide 75 cm2 tissue culture flasks.
- Properly maintained: yes
- Periodically checked for Mycoplasma contamination: yes

Metabolic activation:

with and without

Metabolic activation system:

S9 mix

Test concentrations with justification for top dose:

Concentration range in the main test (with metabolic activation): 156.25 ... 625 µg/ml
Concentration range in the main test (without metabolic activation): 39.06 ... 300 µg/ml

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMSO
- Justification for choice of solvent/vehicle: Prior to commencing testing, the solubility of the test substance in solvents compatible with the test system was assessed. Terracess TF-S was found to be insoluble in all compatible solvents, however it formed a doseable suspension in culture medium at 10 mg/mL. On dosing at 50% v/v into aqueous tissue culture medium, giving a final concentration of 5000 µg/mL, precipitate was observed. Concentrations with high ionic strength and osmolality may cause chromosomal aberrations therefore concentrations greater than 5000 µg/mL or 10 M are not used in this test system. In this case, the highest final concentration used for subsequent testing was 5000 µg/mL.

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

Remarks:

DMSO

Positive controls:

yes

Remarks:

Mitomycin C in the absence of S9 mix and Cyclophosphamide in the presence of S9 mix.

Details on test system and experimental conditions:

First test:
Without S9 mix - 3 hours treatment, 12 hours recovery: 39.06, 78.13 and 156.25 µg/mL.
With S9 mix - 3 hours treatment, 12 hours recovery: 156.25, 312.5 and 625 µg/mL.

Second test:
Without S9 mix - 15 hours continuous treatment: 12.5, 25 and 50 µg/mL.

Evaluation criteria:

The test substance is considered to cause a positive response if the following conditions are met:

1) Statistically significant increases (P<0.01) in the frequency of metaphases with aberrant chromosomes (excluding gaps) are observed at one or more test concentration.
2) The increases exceed the negative control range of this laboratory, taken at the 99% confidence limit.
3) The increases are reproducible between replicate cultures.
4) The increases are not associated with large changes in pH, osmolality of the treatment medium or extreme toxicity.
5) Evidence of a dose-relationship is considered to support the conclusion.

A negative response is claimed if no statistically significant increases in the number of aberrant cells above concurrent control frequencies are observed, at any dose level.

Key result

Species / strain:

Chinese hamster lung (CHL/IU)

Metabolic activation:

with

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Remarks:

(156.25 µg/ml)

Vehicle controls validity:

valid

Positive controls validity:

valid

Key result

Species / strain:

Chinese hamster lung (CHL/IU)

Metabolic activation:

without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Remarks:

(625 µg/ml)

Vehicle controls validity:

valid

Positive controls validity:

valid

Additional information on results:

Observations:
Second main test:

Concentration range in the second main test was 3.13-300 microgram/ml(without metabolic activation). Exposure time was 15 hours. Due to the level of precipitate on the slides obscuring some cells and metaphases, the miotic index could not be established for some cultures. During chromosome aberration analysis, some metaphases were unscorable and as such there was some selectivity in the metaphases that were analysed.


The concentration producing toxicity was 100 microgram/ml with metabolic activation and 200 microgram/ml without metabolic activation.

First main test:

The level of precipitate on the slides obscured some metaphases and as such there was selectivity in the metaphases that were analysed.

First test

Toxicity data:

In the absence of S9 mix, Terracess TF-S caused a reduction in the cell count to 36% of the solvent control value at 156.25 µg/mL. Terracess TF-S caused a reduction in the mitotic index to 55% of the solvent control value at 156.25 µg/mL. The dose levels selected for the metaphase analysis were 39.06, 78.13 and 156.25 µg/mL.

In the presence of S9 mix, Terracess TF-S caused a reduction in the cell count to 66% of the solvent control value at 5000 µg/mL. Terracess TF-S caused a reduction in the mitotic index to 50% of the solvent control value at 625 µg/mL. The dose levels selected for the metaphase analysis were 156.25, 312.5 and 625 µg/mL.

Precipitated material was observed on the slides corresponding to all levels treated with Terracess TF-S, increasing with rising concentration, both in the absence and presence of S9 mix. The mitotic index could not be established for some cultures as the precipitate was obscuring some of the cells and metaphases.

Metaphase analysis:

In both the absence and the presence of S9 mix, Terracess TF-S caused no statistically significant increases in the proportion of cells with chromosomal aberrations at any dose level, when compared with the solvent control. Precipitate present on the slides obscured some of the metaphases and therefore these could not be scored for aberrations. Consequently, there was selectivity in the metaphases that were analysed. Both positive control compounds, Mitomycin C and Cyclophosphamide, caused statistically significant increases in the proportion of aberrant cells (P<0.001). This demonstrated the efficacy of the S9 mix and the sensitivity of the test system.

Second test

Toxicity data:

In the absence of S9 mix, Terracess TF-S caused a reduction in the cell count to 48% of the solvent control value at 300 µg/mL. Terracess TF-S caused a reduction in the mitotic index to 90% of the solvent control value at 50 µg/mL. A reduction in the mitotic index to 69% of the solvent control was observed at 100 µg/mL, however there was considerable precipitate present on these slides to enable analysis of chromosome aberrations. The dose levels selected for metaphase analysis were 12.5, 25 and 50 µg/mL.

Precipitated material was observed on the slides corresponding to all cultures treated with Terracess TF-S, increasing with rising concentration. The mitotic index could not be established for some cultures as the precipitate was obscuring some of the cells and metaphases.

Metaphase analysis:

The effects of Terracess TF-S on the chromosomes of CHL cells are shown in Table 7 and summarised in Table 1. In the absence of S9 mix, Terracess TF-S caused a statistically significant increase in the proportion of metaphase figures containing chromosomal aberrations, at 12.5 µg/mL including gap-type aberrations only, when compared with the solvent control (P<0.01. This increase is not thought to be of significance as the observed response was not dose related and the biological significance of gap-type aberrations is questionable.

No significant increases in polyploid metaphases were observed during metaphase analysis in either test.

Conclusions:

Interpretation of results:
negative with metabolic activation
negative without metabolic activation

Terracess TF-S has shown no evidence of clastogenic activity in this in vitro cytogenetic test system, under the experimental conditions described.
Some metaphases were obscured by precipitate; consequently there was selectivity in the metaphases that were scored for chromosome analysis and this should be taken into account when interpreting the results.

Reference 3

Endpoint:

in vitro gene mutation study in mammalian cells

Type of information:

experimental study

Adequacy of study:

key study

Study period:

16-feb-2009 to 24-mar-2009

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 476 (In Vitro Mammalian Cell Gene Mutation Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.17 (Mutagenicity - In Vitro Mammalian Cell Gene Mutation Test)

Deviations:

no

Principles of method if other than guideline:

- The recommendations of the “International Workshop on Genotoxicity Tests Workgroup” (the IWGT), published in the literature (Clive et al., 1995, Moore et al., 1999, 2000, 2002, 2003, 2006 and 2007).

GLP compliance:

yes (incl. QA statement)

Type of assay:

mammalian cell gene mutation assay

Target gene:

- Thymidine kinase (TK) locus in L5178Y mouse lymphoma cells

Species / strain / cell type:

mouse lymphoma L5178Y cells

Details on mammalian cell type (if applicable):

- Type and identity of media:
-RPMI 1640 Hepes buffered medium (Dutch modification) containing penicillin/streptomycin (50 U/ml and 50 μg/ml, respectively), 1 mM sodium pyruvate and 2 mM L-glutamin supplemented with 10% (v/v) heat-inactivated horse serum (=R10 medium).
- Properly maintained: yes
- Periodically checked for Mycoplasma contamination: yes
- Periodically checked for karyotype stability: no
- Periodically "cleansed" against high spontaneous background: yes

Metabolic activation:

with and without

Metabolic activation system:

Rat liver S9-mix induced by a combination of phenobarbital and ß-naphthoflavone

Test concentrations with justification for top dose:

Dose range finding test:
Without and with S9-mix, 3 hours treatment: 1, 3, 10, 33 and 100 µg/mL
Without S9-mix, 24 hours treatment: 1, 3, 10, 33 and 100 µg/mL
Experiment 1:
Without and with S9-mix, 3 hours treatment: 0.01, 0.03, 0.1, 0.3, 1, 3, 10 and 33 µg/mL
Experiment 2
Without S9-mix, 24 hours treatment: 00.01, 0.03, 0.1, 0.3, 1, 3, 10 and 33 µg/mL
With S9-mix, 3 hours treatment: 0.01, 0.03, 0.1, 0.3, 1, 3, 10 and 33 μg/mL

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMSO
- Justification for choice of solvent/vehicle: Accepted and approved by authorities and international guidelines

Negative solvent / vehicle controls:

yes

Remarks:

dimethylsulfoxide

Positive controls:

yes

Positive control substance:

methylmethanesulfonate

Remarks:

Without S9-mix Migrated to IUCLID6: 15 µg/mL for the 3 hours treatment period and 5 µg/mL for the 24 hours treatment period

Negative solvent / vehicle controls:

yes

Remarks:

dimethylsulfoxide

Positive controls:

yes

Positive control substance:

cyclophosphamide

Remarks:

With S9-mix Migrated to IUCLID6: 7.5 µg/ml

Details on test system and experimental conditions:

DURATION
- Exposure duration:
Short-term treatment
With and without S9-mix: 3 hours
Prolonged treatment period
Without S9-mix: 24 hours
- Expression time (cells in growth medium): 2 days
- Selection time (if incubation with a selection agent): 11 to 12 days

SELECTION AGENT (mutation assays): 5 µg/mL trifluorothymidine (TFT)

NUMBER OF REPLICATIONS:
- Solvent controls: Duplo cultures
- Treatment groups and positive control: Single cultures

NUMBER OF CELLS EVALUATED: 9.6 x 10E5 cells/concentration

DETERMINATION OF CYTOTOXICITY
- Method: relative suspension growth (dose range finding test) and relative total growth (mutation experiments)

RANGE-FINDING/SCREENING STUDIES:
-The suspension growth expressed as the reduction in cell growth after approximately 24 and 48 hours or only 24 hours cell growth, compared to the cell growth of the solvent control, was used to determine an appropriate dose range for the mutagenicity tests

Evaluation criteria:

The global evaluation factor (GEF) has been defined by the IWTG as the mean of the negative/solvent MF distribution plus one standard deviation. For the micro well version of the assay the GEF is 126.

A test substance is considered positive (mutagenic) in the mutation assay if:
a) It induces a MF of more than MF(controls) + 126 in a dose-dependent manner; or
b) In case a repeat experiment is performed when a positive response is observed in one of the tester strains, the positive response should be reproducible in at least one independently repeated experiment.
An observed increase should be biologically relevant and will be compared with the historical control data range.

A test substance is considered equivocal (questionable) in the mutation assay if no clear conclusion for positive or negative result can be made after an additional confirmation study.

A test substance is considered negative (not mutagenic) in the mutation assay if:
a) None of the tested concentrations reaches a mutation frequency of MF(controls) + 126.
b) The results are confirmed in an independently repeated test.

Key result

Species / strain:

mouse lymphoma L5178Y cells

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity, but tested up to precipitating concentrations

Vehicle controls validity:

valid

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS
- Effects of pH: No
- Effects of osmolality: No
- Precipitation: Precipitation in the exposure medium was observed at dose levels of 33 µg/mL and above

RANGE-FINDING/SCREENING STUDIES:
- No toxicity was observed up to and including the highest tested dose level of 100 µg/mL

COMPARISON WITH HISTORICAL CONTROL DATA:
The spontaneous mutation frequencies in the solvent-treated control cultures were between the minimum and maximum value of the historical control data range and within the acceptability criteria of this assay.

ADDITIONAL INFORMATION ON CYTOTOXICITY:
No toxicity was observed up to and including the highest tested dose level in both experiments.

Conclusions:

Interpretation of results:
negative

The spontaneous mutation frequencies in the solvent-treated control cultures were between the minimum and maximum value of the historical control data range

Positive control chemicals, methyl methane sulfonate and cyclophosphamide induced appropriate responses.

In conclusion, TERRACESS P is not mutagenic in the TK mutation test system.

Executive summary:

This test was performed with Terracess P, a compound which has been demonstrated to be very similar in structure, physicochemical properties and toxicological profile to Terracess TF in the Read across Justification document for reprotoxicity, mutagenicity document (see section 13). Due to the fact Terracess TF and Terracess P have nearly the same chemical structure, the same interaction with bio-molecules, living cells and tissue is expected. Therefore, a read across from Terracess TF to data obtained with Terracess P is scientifically justified.

Reference 4

Endpoint:

in vitro gene mutation study in mammalian cells

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
Please see attached justification.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
Please see attached justification.

3. ANALOGUE APPROACH JUSTIFICATION
Please see attached justification.

4. DATA MATRIX
Please see attached justification.

Reason / purpose for cross-reference:

read-across source

Key result

Species / strain:

mouse lymphoma L5178Y cells

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity, but tested up to precipitating concentrations

Vehicle controls validity:

valid

Positive controls validity:

valid

Executive summary:

This test was performed with Terracess P, a compound which has been demonstrated to be very similar in structure, physicochemical properties and toxicological profile to Terracess TF in the Read across Justification document for reprotoxicity, mutagenicity document (see section 13). Due to the fact Terracess TF and Terracess P have nearly the same chemical structure, the same interaction with bio-molecules, living cells and tissue is expected. Therefore, a read across from Terracess TF to data obtained with Terracess P is scientifically justified.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Justification for classification or non-classification

Three in-vitro studies examined aspects of the mutagenic potential of Terracess TF. The mouse lymphoma assay was performed with its analogue, Terracess P. None of these studies indicated any mutagenic potential and it is not necessary to classify Terracess TF as hazardous on the basis of mutagenic activity according to the CLP Regulation (Regulation (EC) 1272/2008).