Tetraamminezinc(2+) carbonate

Skin irritation / corrosion

Administrative data

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

9 December 2016 - 17 November 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

29 July 2016

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: B.40 BIS.: Methods for the determination of toxicity and other health effects: In Vitro Skin Corrosion: Human Skin Model Test; Official Journal of the European Union, No. L 142

Version / remarks:

30 May 2008

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

other: IATA for skin corrosion and irritation, Series on Testing and Assessment No. 203

Version / remarks:

11 July 2014

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

BASF SE Experimental Toxicology and Ecology, 67056 Ludwigshafen, Germany

Test material

Test material information

Constituent 1

Reference substance name:

Tetraamminezinc(2+) carbonate

EC Number:

254-099-2

EC Name:

Tetraamminezinc(2+) carbonate

Cas Number:

38714-47-5

Molecular formula:

Zn(NH3)4 CO3

IUPAC Name:

Tetraamminezinc(2+) carbonate

Test material form:

liquid

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Kampagne 02/2014
- Expiration date of the lot/batch: February 18, 2017

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Room temperature

In vitro test system

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Vehicle:

unchanged (no vehicle)

Details on test system:

RECONSTRUCTED HUMAN EPIDERMIS (RHE) TISSUE
- Model used: EpiDerm™ 200 kit ( EPI-200 tissues with surface of 0.6 cm²), MatTek In Vitro Life Science Laboratories, Bratislava, Slovakia
- Tissue lot number: 23385

TEMPERATURE USED FOR TEST SYSTEM
- Temperature used during treatment / exposure: 3 min at room temperature or 1 hour in the incubator at 37°C

REMOVAL OF TEST MATERIAL AND CONTROLS
- Washing: with sterile PBS

MTT DYE USED TO MEASURE TISSUE VIABILITY AFTER TREATMENT / EXPOSURE
- MTT concentration: 1.0 mg / mL
- Incubation time: 3 hours
- Spectrophotometer: SunriseTM Absorbance Reader
- Wavelength: 570 nm

FUNCTIONAL MODEL CONDITIONS
- Viability: 1.404 ± 0.016
- Barrier function: ET-50 = 6.44 hours
(Lower acceptance limit: ET50 = 4.0 hours and Upper acceptance limit: ET50 = 8.7 hours)
- Morphology: functional stratum corneum, a viable basal cell layer, intermediate spinous and granular layers
- Contamination: no, sterile

NUMBER OF REPLICATE TISSUES: 2 per exposure time

CONTROL TISSUES USED IN CASE OF MTT DIRECT INTERFERENCE
- killed tissues
- Procedure used to prepare the killed tissues: EPI-200 tissue that is killed by freezing at –20°C
- N. of replicates : 2

NUMBER OF INDEPENDENT TEST SEQUENCES / EXPERIMENTS TO DERIVE FINAL PREDICTION: 2

PREDICTION MODEL / DECISION CRITERIA
Step 1: Identification of corrosives:
mean tissue viability
(% of negative control) Prediction
< 45 after 3 min exposure corrosive
>45 after 3 min exposure and < 10% after 1h exposure corrosive
45-55 after 3 min exposure borderline (inconclusive)1
> 55% after 3 min exposure and < 10-20% after 1h exposure borderline (inconclusive) 1
> 55% after 3 min exposure and > 20% after 1 hour exposure non-corrosive
1 The borderlines-evaluation (50 ± 5%, 25 ± 5% and 15 ± 5%) was determined statistically using historic BASF data and hence considers the variance of the test method. This evaluation is an amendment to the evaluation provided in OECD Guideline 431.

Step 2: Optional UN GHS subcategorization of corrosives identified in step 1:
% of negative control) Prediction
< 20 after 3 min exposure UN GSH Cat 1A
20-30% after 3min exposure borderline (inconclusive) for UN GHS subcategorization
> 30% after 3 min exposure UN GHS Cat 1B or 1C
According to the current OECD Guideline 431 differentiation of UN GHS categories 1A versus 1B/C is possible. However, the subcategorization into UN GHS Cat 1A is over-predictive (29% of 1B/C substances are over-predicted as 1A) as stated in the Guideline and differentiation between GHS sub-categories 1B or 1C is not possible. If the test substance is identified to be corrosive by SCT and a transport classification is needed an additional test appropriate for UN GHS subcategorization should be performed to confirm classification as UN GHS Cat 1A or to differentiate between UN GHS Cat 1B and 1C.

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 50 µL

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

POSITIVE CONTROL
- Amount(s) applied (volume or weight): 50 µL

Duration of treatment / exposure:

3 min or 1 hour

Number of replicates:

2

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

1st run (3 min)

Value:

91.6

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Remarks:

100%

Positive controls validity:

valid

Remarks:

12.4%

Results 2

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

1st run (1 h)

Value:

20.4

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Remarks:

100%

Positive controls validity:

valid

Remarks:

5.6%

Results 3

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

2nd run (1 h)

Value:

22.2

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Remarks:

100%

Positive controls validity:

valid

Remarks:

6.2%

Other effects / acceptance of results:

OTHER EFFECTS:
- Direct-MTT reduction: yes
- Colour interference with MTT: no

DEMONSTRATION OF TECHNICAL PROFICIENCY: yes

ACCEPTANCE OF RESULTS:
- Acceptance criteria met for negative control: yes
Tissue viability is acceptable if the mean OD570 of the NC is ≥ 0.8. The mean OD570 of the NC should not exceed 2.8.
- Acceptance criteria met for positive control: yes
A tissue viability of ≤ 30% is acceptable for the 3-minute exposure. Mean viability of the tissues exposed for 1 hour should be <15%.
- Acceptance criteria met for variability between replicate measurements: yes
In the range of 20% and 100% viability, variability between the tissues is considered to be acceptable if the coefficient of variation (CV) of %-viability is ≤ 30%.

Historic control data:
Historic Range of NC (Period Jan 2015- Jan 2017)
3 min exposure: Mean OD570 1.919 ± 0.177
60 min exposure: Mean OD570 1.936 ± 0.193

Historic Range of PC (Period Jan 2015- Jan 2017)
3 min exposure: Mean OD570 0.282 ± 0.073
60 min exposure: Mean OD570 0.121 ± 0.033

Viability % (Period Jan 2015- Jan 2017)
3 min exposure: Mean % 14.7 ± 3.8
60 min exposure: Mean % 6.2 ± 1.4

Applicant's summary and conclusion

Interpretation of results:

other: not skin corrosive (Cat. 1)