titanyl (IV) diascrobate

Endpoint summary

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Reference 1

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2019

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

OECD Guideline 439 (In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method)

GLP compliance:

yes (incl. QA statement)

Test system:

human skin model

Irritation / corrosion parameter:

% tissue viability

Value:

> 50

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

no indication of irritation

Interpretation of results:

GHS criteria not met

Conclusions:

Disks of EPISKIN (three units) were treated with test item and incubated for 15 minutes (± 0.5 min) at room temperature. Exposure of test material was terminated by rinsing with 1x PBS solution. Epidermis units were then incubated at 37 ± 1°C for 42 hours (± 1 h) in an incubator with 5 ± 1% CO2, ≥ 95 % humidified atmosphere. The viability of each disk was assessed by incubating the tissues for 3 hours (± 5 min) with MTT solution at 37 ± 1°C in 5 ± 1 % CO2 protected from light. The precipitated formazan was then extracted using acidified isopropanol and quantified spectrophotometrically.
The test item has an intrinsic colour (brownish), therefore two additional test item treated tissues were used for the non-specific OD evaluation (NSCliving).
The test item is a possible MTT-reducer, therefore additional controls (test item treated killed tissues and negative control treated killed tissues) were used to detect and correct for test substance interference with the viability measurement.
The test item is a possible MTT-reducer and has an intrinsic colour (brownish). To avoid a possible double correction [TODTT (MTT and NSCliving)] for colour interference, a third control for non-specific colour in killed tissues (NSCkilled) was performed. Two killed test item treated tissues were used to avoid a possible double correction for colour interference. However, the NSCliving % was 1.5 % (below 5 %), so the (NSCkilled) was not determined and used during the calculation of true MTT metabolic conversion.
SDS (5% aq.) and 1× PBS treated (three units / positive and negative control) epidermis were used as positive and negative controls respectively. For each treated tissue viability was expressed as a percentage relative to negative control.
The test chemical is identified as requiring classification and labelling according to UN GHS (Category 2 or Category 1), if the mean relative viability after 15 minutes exposure and 42 hours post incubation is less or equal (≤) to 50 % of the negative control.
In this in vitro skin irritation test using the EPISKIN model, the test item TITANIUM DIASCORBATE did not show significantly reduced cell viability in comparison to the negative control (mean value: 92 %). All obtained test item viability results were far above 50 % when compared to the viability values obtained from the negative control. Therefore the test item was considered to be non-irritant to skin.
Positive and negative controls showed the expected cell viability values within acceptable limits. The experiment was considered to be valid.
The results obtained from this in vitro skin irritation test, using the EPISKIN model, indicated that the test item reveals no skin irritation potential under the utilised testing conditions. The test item TITANIUM DIASCORBATE is considered to be non-irritant to skin and is therefore not classified (UN GHS No Category).

Executive summary:

The results obtained from this in vitro skin irritation test, using the EPISKIN model, indicated that the test item reveals no skin irritation potential under the utilised testing conditions. The test item TITANIUM DIASCORBATE is considered to be non-irritant to skin and is therefore not classified (UN GHS No Category).

Reference 2

Endpoint:

skin irritation / corrosion, other

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2019

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

OECD Guideline 431 (In Vitro Skin Corrosion: Reconstructed Human Epidermis (RHE) Test Method)

GLP compliance:

yes

Test system:

human skin model

Irritation / corrosion parameter:

% tissue viability

Remarks on result:

other: The experiment was invalid and the study was discontinued

Other effects / acceptance of results:

The mean NSMTT (non-specific MTT reduction) was above the threshold value (50%) in each run after 4 hours of exposure. It was 79.613% in the first gear, 62.501% in the second gear and 114.126% in the third gear. According to the INVITTOX protocol No. 118; "EPISKINTM Skin Corrosivity Test" updated December 2011 / February 2012 (ECVAM database service for alternatives to animal experiments): "If the non-specific reduction in MTT is> 50% relative to the negative control: take additional steps if possible or the chemical should be considered inconsistent with the test. " And based on OECD 431 (adopted: 29 July 2016): "However, results for test chemicals producing% NSMTT and / or% NSCliving ≥ 50% Negative Control should be handled with caution." The experiment was invalid and the study was discontinued. The Final Report will not be written.

Interpretation of results:

other: the experiment gave no result

Conclusions:

The Mean NSMTT (Non-Specific MTT reduction) was higher than the threshold value (50%) in each run after 4 hours of exposure. The first run it was 79.613%, the second run it was 62.501% and the third run it was 114.126%. According to the INVITTOX Protocol No. 118; “EPISKINTM Skin Corrosivity Test” updated December 2011 / February 2012 (ECVAM Database Service on Alternative Methods to Animal Experimentation).: “If non specific MTT reduction is > 50% relative to the negative control: additional steps must be undertaken if possible or the chemical must be considered as incompatible with the test.” And based on the OECD 431 (Adopted: 29 July 2016): “Nevertheless, results for test chemicals producing %NSMTT and/or %NSCliving ≥ 50% of the negative control should be taken with caution.” The experiment was invalid and the study was stopped.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2019

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

OECD Guideline 438 (Isolated Chicken Eye Test Method for Identifying i) Chemicals Inducing Serious Eye Damage and ii) Chemicals Not Requiring Classification for Eye Irritation or Serious Eye Damage)

GLP compliance:

yes

Irritation parameter:

cornea opacity score

Remarks:

Mean maximum corneal opacity

Value:

0.5

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

no indication of irritation

Irritation parameter:

corneal swelling 

Remarks:

Mean maximum corneal swelling at up to 75 min

Value:

3

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

no indication of irritation

Irritation parameter:

percent corneal swelling

Run / experiment:

Mean maximum corneal swelling at up to 240 min

Value:

4

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

no indication of irritation

Other effects / acceptance of results:

In this ICET, TITANIUM DIASCORBATE did not cause ocular corrosion or severe irritation in the enucleated chicken eyes in both cases. The overall ICE class was 2xI, 1xII in the first and 1xI, 2xII in the additional experiment.
Positive and negative controls showed the expected results. The experiment was considered to be valid.
In this in vitro eye irritation study, using the Isolated Chicken Eye model with TITANIUM DIASCORBATE, no ocular corrosion or severe irritation potential was observed. The overall ICE class was 2xI, 1xII in the first and 1xI, 2xII in the additional experiment.
According to the guideline OECD 438, TITANIUM DIASCORBATE is categorized as “No Category”.

Interpretation of results:

GHS criteria not met

Conclusions:

In this in vitro eye irritation study, using the Isolated Chicken Eye model with TITANIUM DIASCORBATE, no ocular corrosion or severe irritation potential was observed. The overall ICE class was 2xI, 1xII in the first and 1xI, 2xII in the additional experiment.
According to the guideline OECD 438, TITANIUM DIASCORBATE is categorized as “No Category”.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Justification for classification or non-classification

substance is not classified as irritating