lithium nickel dioxide

Endpoint summary

Description of key information

Based on the results of the EpiDerm™ in vitro skin irritation and corrosion test strategy including transport classification, it was concluded that Lithium nickel dioxide shows a corrosive potential.

Based on the results of the BCOP and EpiOcular Tests, it was concluded that the test material shows serious eye damage in the in vitro eye irritation test strategy.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

OECD Guideline 435 (In Vitro Membrane Barrier Test Method for Skin Corrosion)

Version / remarks:

28 July 2015

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source (i.e. manufacturer or supplier): BASF SE, Batch: 8800315
- Purity: approx. 99.8 g/100 g
- Expiration date of the batch: 12 Aug 2021

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: room temperature
- Stability under test conditions: guaranteed by the sponsor

FORM AS APPLIED IN THE TEST: undiluted solid test substance

OTHER SPECIFICS:
- Pysical state/color: solid/anthracite
- pH: ca. 12 (undiluted test substance moistened with deionized water, determined in the lab prior to start of the GLP study)

Test system:

artificial membrane barrier model

Vehicle:

unchanged (no vehicle)

Details on test system:

MATERIAL:

Corrositex® kit:
InVitro International, Irvine CA, USA, containing: reagents required for qualification and categorization screen, biobarrier matrix powder and diluent, membrane discs and vials containing the Chemical Detection System.

Controls:
Negative control (NC): 10% citric acid
Positive control (PC): Sodium hydroxide (solid)

EXPERIMENTAL PROCEDURE:
- Test substance compatibility with the assay (qualification screen):
For the qualification screen, 100 mg test substance were added to the CDS screening tube. If the test substance failed to produce a color change in the CDS within one minute, the test substance could not be analyzed in this system, and no further testing was required.
- Categorization screen:
The categorization screen was used to assess the appropriate scoring scale for the test substance. The categorization screen was performed by adding 100 mg test substance to tube A and B each. Each tube was mixed, and the resulting color was observed. If required, 2 drops of the "confirm" reagent were added to tube B, the tube was mixed and the resulting color observed. The categorization kit and color chart provided by InVitro International were used to determine
the category. The test substance was scored as category 1 (high acid/alkaline reserve) or category 2 (low acid/alkaline reserve) as described in section 3.9.3.
- Bio barrier preparation:
The entire content of the biobarrier diluent vial was added slowly to the vial containing the bio barrier matrix powder. The vial containing the mixture was placed in a water bath at 64 – 68°C with a magnetic stirrer. The stir bar rotated slowly enough to avoid foaming until complete and uniform solubilisation. 200 μL solubilized matrix were pipetted into each of the membrane discs.
The membrane discs were then refrigerated for at least 2 hours at 2 – 8°C.
The bio barriers were wrapped and stored at 2 – 8°C for a maximum of 7 days.
Any remaining matrix solution was stored at 2 – 8°C for up to 30 days for preparation of additional bio barrier membrane discs.
- Corrositex® assay:
Following the acceptance of the positive control, the Corrositex® assay was performed for the test substance. Four vials containing the CDS were used for the test substance. In addition, one vial was used for the PC, the NC and the color control (blank) each. A membrane disc coated with the bio barrier matrix was placed into one vial containing the CDS, and approximately 500 mg test substance were added onto the membrane disc. An electronic time clock was started with the application. The vial was observed for three minutes for any change in the CDS. If no color change was observed within three minutes, the membranes remaining were treated with the test substance. An electronic time clock was started with each application. The vials were observed continuously for the first ten minutes. Thereafter, the vials were observed for
approximately ten minutes around the time points relevant for evaluation or until breakthrough of the test substance. The elapsed time between test substance
application and the first change in the indicator solution (i.e. barrier penetration) was recorded.
The positive control vial was prepared as described above and contained one pellet of sodium hydroxide on top of the membrane disc. This vial was monitored continuously until breakthrough.
The negative control vial was prepared as described above and contained 500 μL 10% citric acid monohydrate. This vial was observed for 60 minutes and evaluated as “non-corrosive” if no reaction had been observed.

ACCEPTANCE CRITERIA:
The Corrositex® assay was accepted if the breakthrough time for the positive control substance was in the historic control range (mean ± 2-3x standard deviations). The expected breakthrough time of the concurrent positive control (Sodium Hydroxide solid) should be between 8 - 16 min. In order to demonstrate the functional integrity of the membrane barrier, the acceptance criterium for the negative control was not to induce membrance breakthrough within a 60- minute observation period.

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

500 mg test substance

Duration of treatment / exposure:

max. 3 minutes

Number of replicates:

4

Irritation / corrosion parameter:

other: mean breakthrough time through Corrositex® Biobarrier Membrane in minutes

Run / experiment:

Mean of 4 vials

Value:

58.39

Vehicle controls validity:

not examined

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: corrosive subcategory 1C

The qualification screen demonstrated that the test substance is able to react with the CDS and produce a visible color change. Therefore, the membrane barrier test method was determined to be suitable for the evaluation of the corrosive potential of the test substance.
A timescale category test was carried out to distinguish between weak and strong acids or bases. The test substance was assigned to timescale category 2 (having a low acid/alkaline reserve).
The mean breakthrough time of the test substance determined in the actual Corrositex® assay was 58 minutes and 39 seconds (single break through times of the four vials [min:s]: 59:59, 67:301, 59:22 and 56:37). The second vial treated with the test substance showed a breakthrough time above 60 minutes, indicating no corrosive potential. However, break through times below 60 minutes were noted in the other three vials, thus, the test material is classified as corrosive.
The breakthrough times of three vials, indicated that the test substance has a weak corrosive potential and should be assigned to UN GHS skin corrosivity subcategories 1C or UN Transport Packing Group III as specified in the cited OECD TG 435 and Instruction Manual.

The negative control, 10% citric acid monohydrate, did not produce any reaction within 60 minutes after application. Sodium hydroxide (solid) applied as positive control showed a breakthrough time of 15 minutes and 55 seconds and was assigned accordingly. Thus, the controls fulfill the acceptance criteria and demonstrate the validity of the assay.

Interpretation of results:

Category 1B (corrosive) based on GHS criteria

Remarks:

Migrated information Criteria used for interpretation of results: EU

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (corrosive)

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

other: part of a testing strategy

Qualifier:

according to guideline

Guideline:

OECD Guideline 437 (Bovine Corneal Opacity and Permeability Test Method for Identifying i) Chemicals Inducing Serious Eye Damage and ii) Chemicals Not Requiring Classification for Eye Irritation or Serious Eye Damage)

Version / remarks:

26 July 2013

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU method B.47 (Bovine corneal opacity and permeability test method for identifying ocular corrosives and severe irritants)

Version / remarks:

09.12.2010

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Batch No. of test material: 8800315
- Content: approx. 99.8 g/100 g
- Homogeneity: the test item appeared to be homogeneous
- Appearance: solid, anthracite
- Expiry Date: 12 August 2021

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: room temperature, under N2

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing: The test item (non-surfactant) was tested as suspension in deionised water using sonication for 10 minutes. Before each removal the test item was resuspended.
- Form of application: 20% (w/v) suspention in deionized water

Species:

cattle

Details on test animals or tissues and environmental conditions:

SOURCE OF COLLECTED EYES
- Source: Freshly isolated bovine cornea; supplier: AB Schlachthof GmbH & Co. KG, 63739 Aschaffenburg, Germany
- Characteristics of donor animals: age of the animals: 14 month old
- indication of any existing defects or lesions in ocular tissue samples: Corneas free of defects (opacity, scratches, pigmentation etc.)

Vehicle:

water

Remarks:

deionized

Controls:

yes, concurrent positive control

yes, concurrent negative control

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 750 µL
- Concentration (if solution): 20% (w/v) solution in de-ionized water

NEGATIVE CONTROL
- Amount(s) applied (volume or weight with unit): 750 µL of de-ionized water

POSITIVE CONTROL
- Amount(s) applied (volume or weight with unit): 750 μL of 20% (w/v) solution of imidazole in deionized wateror

Duration of treatment / exposure:

4 hours

Number of animals or in vitro replicates:

3

Details on study design:

SELECTION AND PREPARATION OF CORNEAS: Corneas free of defects (opacity, scratches, pigmentation etc.) were dissected with a 2 to 3 mm rim of sclera. Isolated corneas were mounted in cornea holders that consists of anterior and posterior chambers. Both chambers were filled to excess with pre-warmed Eagle’s MEM (without phenol red) and then equilibrated in a vertical position at about 32°C for at least 1 hour. After the equilibration period, the medium in both chambers was replaced by fresh pre-warmed medium and initial corneal opacity readings were taken for each cornea with an opacitometer.

QUALITY CHECK OF THE ISOLATED CORNEAS: Any corneas that showed macroscopic tissue damage or an opacity value < 550 opacity units were discarded. The remaining corneas were then distributed into negative control, positive control and treatment groups.(According to OECD TG 437, corneas that have an opacity value >7 or equivalent for the opacitometer and cornea holders used after an initial one-hour equilibration period are to be discarded. In the test facility´s opacitometer in combination with the used cornea holder set 2013-22 and 2013-24, the maximal initial opacity of >7 arises from I= 550 lux with Io= 641 lux).

NUMBER OF REPLICATES: 3

NEGATIVE CONTROL USED: Yes

POSITIVE CONTROL USED: Yes

APPLICATION DOSE AND EXPOSURE TIME: Application of 750 µL of the 20% (w/v) test-substance preparation, 4 hours exposure time

REMOVAL OF TEST SUBSTANCE
- Number of washing steps after exposure period: at least 3 times.

- POST-EXPOSURE INCUBATION: no

METHODS FOR MEASURED ENDPOINTS:
- Corneal opacity: Yes.
- Corneal permeability: passage of sodium fluorescein dye measured with the aid of microtiter plate reader: Yes, OD490, OP_KiT opacitometer (Electro Design, 63-Riom France).

SCORING SYSTEM: In Vitro Irritancy Score (IVIS)

DECISION CRITERIA:
IVIS ≤ 3, Prediction: No Category
IVIS > 3; ≤ 55, Prediction: No prediction can be made
IVIS > 55, Prediction: Category 1

Irritation parameter:

in vitro irritation score

Remarks:

IVIS

Run / experiment:

Run 1, mean of three single corneas

Value:

355.13

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: Cathegory 1, serious eye damage

Other effects / acceptance of results:

OTHER EFFECTS:
- Visible damage on test system: No.

DEMONSTRATION OF TECHNICAL PROFICIENCY: Proficiency given

ACCEPTANCE OF RESULTS:
- Acceptance criteria met for negative control: yes
- Acceptance criteria met for positive control: yes

Table 1: Results of the BCOP Test, in vitro irritancy score (IVIS) of the test substance, the NC and the PC.

	Opacity value per cornea	Permeability at 490 nm (OD490)		IVIS
substance identification			per cornea	per group
				mean	SD
	400.00*	0.889*	413.34
Test substance	326.00*	1.201*	344.02	355.13	53.52
	291.00*	1.136*	308.04
	0	0.066	0.99
NC (Saline)	0	0.078	1.17	1.08	0.09
	0	0.072	1.08
	**	**	**
NC (deionised water)	2.00	0.078*	2.00	1.00	1.41
	0.00	0.061*	0.00
	81.00*	0.605*	90.08
PC (10% (w/v) Benzalkonium chloride in saline)	68.00*	0.471*	75.07	80.11	8.63
	67.00*	0.545*	75.18
	88.00*	0.771*	99.57
PC (20 % Imidazole in saline)	97.00*	1.239*	115.59	97.04	19.93
	65.00*	0.731*	75.97

*Correction was performed with the values of the Negative Control Saline.
** not taken into the evaluation since this value is declared as an outlier.

 

Interpretation of results:

Category 1 (irreversible effects on the eye) based on GHS criteria

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irreversible damage)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Skin irritation/corrosion:

The objective was to assess the skin corrosion and irritation potential of the test substance. Using the currently available methods a single in vitro assay is not sufficient to cover the full range of skin irritating/corrosion potential including transport classification. Therefore, three in vitro assays were proposed for this in vitro skin irritation and corrosion test strategy including transport classification: The Skin Corrosion Test (SCT), Skin Irritation Test (SIT) and In vitro Membrane Barrier Test (Corrositex®).

Based on the results observed it was concluded that Lithium nickel dioxide shows a corrosive potential in the EpiDerm™ in vitro skin irritation and corrosion test strategy including transport classification under the test conditions chosen.
The mean breakthrough time determined in the In vitro Membrane Barrier Test (Corrositex®) was 58 minutes and 39 seconds. The breakthrough times of three vials of the category 2 chemical, indicated that the test substance has a weak corrosive potential and should be assigned to UN GHS skin corrosivity  subcategories 1C or UN Transport Packing Group III as specified in the cited OECD TG 435 and Instruction Manual.

 

Eye irritation:

The objective was to assess the eye irritating potential of the test material. By using the methods currently available a single in vitro assay is not sufficient to cover the full range of eye irritating potential. Therefore, two in vitro assays conducted under GLP conditions were part of this in vitro eye irritation test strategy: The Bovine Corneal Opacity and Permeability Test (BCOP Test) (according to OECD guideline 437) and EpiOcular Eye Irritation Test (according to OECD guideline 492).
In the EpiOcular Test, the test substance was assessed to have an eye irritating potential (relative mean viability of the tissues treated with the test substances was 1.3%). However, no prediction can be made between GHS categories 1 and 2.
In the following BCOP Test the mean IVIS of the corneas treated with the test substance was 355.13, indicationg serious eye damage.
Based on the results of the BCOP and EpiOcular Tests, it was concluded that Lithium nickel dioxide shows serious eye damage in the in vitro irritation test strategy under the test conditions chosen.

Justification for classification or non-classification

The available experimental test data are reliable and suitable for classification purposes under Regulation (EC) No 1272/2008 (CLP Regulation).

To assess the skin corrosion and irritation potential of Lithium nickel dioxide, three in vitro assays were proposed for this in vitro skin irritation and corrosion test strategy including transport classification: The Skin Corrosion Test (SCT), the Skin Irritation Test (SIT) and the In vitro Membrane Barrier Test (Corrositex®). The test results indicated that the test substance has a weak corrosive potential and should be assigned to UN GHS skin corrosivity subcategories 1C or UN Transport Packing Group III as specified in the cited OECD TG 435 and Instruction Manual.

According to OECD 437 Lithium nickel dioxide showed serious eye damage.

 

As a result the substance Lithium nickel dioxide is considered to be classified for skin corrosion (Cat. 1C) and eye damage (Cat. 1) under Regulation (EC) No 1272/2008.