Potassium dicyanoargentate

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

the study does not need to be conducted because the available information indicates that the substance should be classified for respiratory sensitisation or corrosivity

Justification for type of information:

JUSTIFICATION FOR DATA WAIVING
According to GHS and EU CLP 1272/2008, potassium dicyanoargentate is classified as category 1A for skin corrosion, as an adverse effect was observed within an hour with 3 minutes of exposure to the substance.

Cross-reference

Reason / purpose for cross-reference:

data waiving: supporting information

Reference

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Reliable without restriction - GLP-compliant and conducted according to guideline.

Qualifier:

according to guideline

Guideline:

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

Qualifier:

according to guideline

Guideline:

EU Method B.40 (In Vitro Skin Corrosion: Transcutaneous Electrical Resistance Test (TER))

GLP compliance:

yes

Species:

human

Strain:

other: EpiDerm EPI-200 Skin Model

Details on test animals or test system and environmental conditions:

- Source: MatTek Corporation, Ashland MA, USA
- Lot no.: 21902 kit P
- Culture substrate: Polycarbonate membranes of 10 mm cell culture inserts

Type of coverage:

open

Preparation of test site:

other: Skin tissue

Vehicle:

unchanged (no vehicle)

Controls:

yes

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 30.0 to 38.1 mg

Duration of treatment / exposure:

3 minutes and 1 hour exposures

Observation period:

3 hours

Number of animals:

2 replicates per exposure duration

Details on study design:

The test substance was checked for colour interference in aqueous conditions and possible direct MTT (3-4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) reduction by adding the test substance to MTT medium. The tissues were treated with test substance for 3 minutes and 1-hour and incubated in Dulbecco's Modified Eagle's Medium (DMEM). The level of the DMEM medium was just beneath the tissue. Skin was moistened with 25 μl Milli-Q water and 30.0 to 38.1 mg of Potassium dicyanoargentate 54.2% was applied directly on top of the skin tissue, spread to match the size of the tissue. 50 μl Milli-Q water was used as a negative contol and 50 μl 8.0 N potassium hydroxide was used as the positive control. All exposures were carried out in a humid atmosphere of 80 - 100% (actual range 63 - 91%), containing 5.0 ± 0.5% CO2 in air in the dark at 37.0 ± 1.0°C (actual range 36.6 – 37.2°C), apart from the 3 minute incubation which was maintained at room temperature. After the exposure period, the tissues were washed with phosphate buffered saline (PBS) to remove residual test substance and kept in DMEM until 6 tissues (= one application time) were dosed and rinsed. The DMEM medium was replaced by 300 μl MTT-medium and tissues were incubated for 3 hours at 37°C in air containing 5% CO2. After incubation the tissues were washed with PBS and formazan was extracted with isopropanol over night at room temperature. The amount of extracted formazan was determined spectrophotometrically at 570 nm. Cell viability was calculated for each tissue as percentage of the mean of the negative control tissues. Skin corrosion potential of the test substance was classified according to remaining cell viability following exposure of the test substance with either of the two exposure times.

Irritation / corrosion parameter:

other: other: Relative tissue viability

Value:

12

Remarks on result:

other:

Remarks:

Basis: mean. Time point: 3 minutes. Max. score: 100.0. Reversibility: no data. (migrated information)

Irritation / corrosion parameter:

other: other: Relative tissue viability

Value:

3

Remarks on result:

other:

Remarks:

Basis: mean. Time point: 1 hour. Max. score: 100.0. Reversibility: no data. (migrated information)

Other effects / acceptance of results:

The maximum inter-tissue variability in viability between two tissues treated identically was up to 16.5%. Both viabilities at the 3 minute exposure were below 50% (15.9 and 8.7%) and therefore the outcome of both tissues was clearly positive. In addition at the 1 hour exposure both viabilities were below 15% (2.5 and 2.9%) and clearly positive.

The in vitro skin corrosion test is considered acceptable if it meets the following criteria:
a) The absolute mean OD570 of the two tissues of the negative control should reasonably be within the laboratory historical control data range.
b) The mean relative tissue viability following 3-minute exposure to the positive control should be ≤ 30%.
c) The maximum inter-tissue variability (in viability) is ≤ 30% between two tissues treated identically.
d) The maximum difference in percentage between the mean viability of two tissues and one of the two tissues is ≤ 15%.

All validity criteria were met. Although, the maximum inter-tissue variability in viability between two tissues treated identically and the maximum difference in percentage between the mean viability of two tissues and one of the two tissues treated with Potassium dicyanoargentate 54.2% were above the acceptability criteria at the 3 minute exposure period (up to 45.5 and 29.4% respectively), both viabilities were below 50% (15.9 and 8.7%) and therefore the outcome of both tissues was clearly positive. In addition at the 1 hour exposure both viabilities were below 15% (2.5 and 2.9%) and clearly positive. Therefore this deviation does not affect the study integrity.

Interpretation of results:

Category 1A (corrosive) based on GHS criteria

Remarks:

Criteria used for interpretation of results: OECD GHS

Conclusions:

Potassium dicyanoargentate 54.2% is corrosive in the in vitro skin corrosion test at 3 minute and 1 hour exposures.

Executive summary:

The potential of potassium dicyanoargentate 54.2% to induce skin corrosion was tested on a human three dimensional epidermal model. Potassium dicyanoargentate 54.2% was applied directly on top of the skin tissue, spread to match the size of the tissue. Milli-Q water was used as the negative control and 8.0N potassium hydroxide served as the positive control. Tissues were incubated for 3 minutes at room temperature and for 1 hour at biological temperature (37.0 ± 1.0°C). The amount of extracted formazan was determined spectrophotometrically and results were used to calculate cell viability as percentage of the mean of the negative control tissues. Potassium dicyanoargentate 54.2% was determined to be corrosive at both exposure times. This study is reliable without restriction as it was GLP-compliant and was performed according to guideline.