copper sulphide and zinc chloride sulphate hydroxide, recovery products from copper and zinc dusts

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

24.06.2020-17.07.2020

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Report date:

2020

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 431 (In Vitro Skin Corrosion: Human Skin Model Test)

GLP compliance:

yes

Test material

Reference

Name:

Unnamed

Type:

Constituent

Type:

Constituent

Type:

Constituent

Test material form:

other: wet sticky solid

Specific details on test material used for the study:

Test Item Zinc chlorohydroxy sulphate and copper sulphide, precipitation Synonym: „Sulphide precipitate “
Lot No. 20190601
CAS No. Not provided
EINECS-No. 951-963-7
Molecular Formula Not provided
Molecular Weight Not provided
Purity 100 % (UVCB), Multi-constituent substance.
Main components
Zinc Chloride Sulphate Hydroxide Hydrate (Zn12(OH)15(SO4)3Cl3 x H2O)
Sodium Sulphate (Na2SO4)
Copper Sulfide (CuS)
Sodium Chloride (NaCl)
Appearance blackish-green, wet sticky solid
Solubility Water - poor
Homogeneity homogenous
Production Date Not known
Expiry Date 31st December 2025
Storage Room temperature 25±5°C
Test Item Handling and Storage Melting point: 120°C, Protect from light, protect from humidity

In vitro test system

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Justification for test system used:

The RhE-based skin corrosion test methods have shown to be predictive of in vivo skin corrosion effects assessed in rabbits according to the OECD guideline 404.

Vehicle:

unchanged (no vehicle)

Details on test system:

RECONSTRUCTED HUMAN EPIDERMIS (RHE) TISSUE
- Model used: The reconstructed human epidermal model EpiDerm™
- Tissue batch number(s): Lot No. 30880; strain 00267
- Production date: 5.7.2020
- Delivery date: 13.7.2020
- Date of initiation of testing: 13.7.2020

TEMPERATURE USED FOR TEST SYSTEM
- Temperature used during treatment / exposure: RT

REMOVAL OF TEST MATERIAL AND CONTROLS
-Volume and number of washing steps: 20 times

MTT DYE USED TO MEASURE TISSUE VIABILITY AFTER TREATMENT / EXPOSURE
- MTT concentration: 1mg/mL
- Incubation time: 3h
- Spectrophotometer: Spectrophotometer MRX Dynex, UK Spectra MRX / 1SPA0086
- Wavelength: 570 nm

FUNCTIONAL MODEL CONDITIONS WITH REFERENCE TO HISTORICAL DATA
- Viability:
- Barrier function:
- Morphology:
- Contamination:
- Reproducibility:

NUMBER OF REPLICATE TISSUES: 2

CONTROL TISSUES USED IN CASE OF MTT DIRECT INTERFERENCE
- Fresh tissues / killed tissues
- Procedure used to prepare the killed tissues (if applicable):
- N. of replicates :
- Method of calculation used:

NUMBER OF INDEPENDENT TEST SEQUENCES / EXPERIMENTS TO DERIVE FINAL PREDICTION: A single testing run composed of at least two tissue replicates should be sufficient for a test chemical when the resulting classification is unequivocal. However, in cases of borderline results, such as non-concordant replicate measurements, a second run may be considered, as well as the third one in case of discordant results between the first two runs.

PREDICTION MODEL / DECISION CRITERIA (choose relevant statement)
- The test substance is considered to be corrosive to skin if the viability after 3 minutes exposure is less than 50%, or if the viability after 3 minutes exposure is greater than or equal to 50 % and the viability after 1 hour exposure is less than 15%.
- The test substance is considered to be non-corrosive to skin if the viability after 3 minutes exposure is greater than or equal to 50% and the viability after 1 hour exposure is greater than or equal to 15%.

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 25 mg

NEGATIVE CONTROL
- Amount(s) applied (volume or weight): 50 μl

POSITIVE CONTROL
- Amount(s) applied (volume or weight): 50 μl
- Concentration (if solution): 8 N KOH

Duration of treatment / exposure:

3-minute and 1-hour time points.

Number of replicates:

2

Test system

Amount / concentration applied:

- Amount(s) applied (volume or weight): 25 μl

POSITIVE CONTROL
- Amount(s) applied (volume or weight): 25 μl
- Concentration (if solution): 5%

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

1-hour exposure

Value:

65

Negative controls validity:

valid

Remarks:

100

Positive controls validity:

valid

Remarks:

6.5

Results 2

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

3-min exposure

Value:

93.2

Negative controls validity:

valid

Remarks:

100

Positive controls validity:

valid

Remarks:

62.4

Other effects / acceptance of results:

- OTHER EFFECTS:
- Visible damage on test system: no
- Direct-MTT reduction: The test item was checked for possible direct MTT reduction before the study was started. No color change were observed.
- Colour interference with MTT: The test item was checked for possible color interference before the study was started. Some non-colored test items may change into colored items in aqueous conditions and thus stain the skin tissues during the exposure. No color changes were observed.

ACCEPTANCE OF RESULTS:
- Acceptance criteria met for negative control: The relative mean tissue viability obtained after 15 ± 0.5 minutes treatment with the test item compared to the negative control tissues was 6.8%. The absolute mean OD570(optical density at 570 nm) of the three tissues of the negative control should reasonably be within the laboratory historical control data range.
- Acceptance criteria met for positive control: the positive control had a mean cell viability of 16% after 15 ± 0.5 minutes exposure. The mean relative tissue viability of the positive control should be <=50% relative to the negative control.
- Acceptance criteria met for variability between replicate measurements: The standard deviation value of the percentage viability of three tissues treated identically was less than 12%. The SD calculated from individual % tissue viabilities of the three identically treated replicates should be <=18.

Any other information on results incl. tables

Results obtained with test item, PC and NC 

 

		3 min endpoint				1-hour endpoint				Diff [%]		Prediction
		Viability [%]		Diff [%]		CV  [%]		Viability [%]			CV  [%]			QC
NC		100.0		5.1		3.6		100.0		5.8	5.8	4.1		qualified		Not classified
PC		62.4		10.1		8.4		6.5		0.0	0.0	36.9		qualified		Cat 1B/1C
TA		93.2		7.4		7.7		65.0		3.4	3.4	0.0		qualified		Not classified

Diff – the difference between two identically treated tissues, CV – Coefficient of variation,QC – Quality criteria

NC – Negative control, PC – Positive Control, TA – Test article

Applicant's summary and conclusion

Interpretation of results:

other: does not require classification regarding the skin corrosivity.

Conclusions:

Based on the experimental data conducted according to the OECD TG 431, it can be concluded, that test item “Zinc chlorohydroxy sulphate and copper sulphide, precipitation” does not require classification regarding the skin corrosivity.

Executive summary:

The purpose of the study was to evaluate the skin corrosion potential of “Zinc chlorohydroxy sulphate and copper sulphide, precipitation” in In Vitro Skin Corrosion Test utilising the Reconstructed Human Epidermis (RhE) Test Method (OECD TG 431).

The skin corrosion potential of “Zinc chlorohydroxy sulphate and copper sulphide, precipitation” was examined in the in vitro skin corrosion test using the reconstructed human epidermal model EpiDerm^TM. Two tissue replicates were used for each treatment (exposure times 3 min and 60 minutes). Concurrent positive (8N KOH) and negative (UP H₂O) controls were used to ensure the adequate performance of the experimental model.

 

The Optical densities (ODs) of Negative controlt reated tissues were 2,630 at three min and 2,417 at 1 hour. The viability of the tissues exposed for 1 hour to the positive control (8N KOH) was 6.5%.The Positive and Negative controls met the acceptance criteria set by the OECD TG 431.

 

The viability of cultures treated by “Zinc chlorohydroxy sulphate and copper sulphide, precipitation” was 93.2 % after 3 min and 65.0% after 60 min. Since the material did not reduce MTT, nor it interacted with water, and was very easily removed from the tissue surface during the washing procedure, no additional steps were necessary to correct the result obtained on viable tissues in the main experiment

 

The Test Item is classified as non-corrosive on the basis of the 1-hour time-point.