Indium

Skin irritation / corrosion

Administrative data

Endpoint:

skin 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

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2012

Report date:

2012

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

version 22 July 2010

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Zinc chloride

EC Number:

231-592-0

EC Name:

Zinc chloride

Cas Number:

7646-85-7

Molecular formula:

ZnCl2

IUPAC Name:

Zinc dichloride

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

Product name: Indium powder
Molecular formula: In
Batch number: In-05252012A1
CAS number: 7440-74-6
Appearance: silver grey, powder
Manufacture Date: 06 June 2012
Expiry date: 06 June 2014
Storage conditions: Controlled Room Temperature (15-25°C, below 70 RH%)
Safety Precautions: Routine safety precautions (gloves, goggles, face mask, lab coat) for unknown materials were applied to assure personnel health and safety.

In vitro test system

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Cell source:

skin obtained from plastic surgery from multiple donors

Vehicle:

unchanged (no vehicle)

Details on test system:

RECONSTRUCTED HUMAN EPIDERMIS (RHE) TISSUE
- Model used: EPISKINTM (SM) (Manufacturer: SkinEthic, France
- Tissue batch number(s):12-EKIN-028
- Expiry Date: 16 July 2012

TEMPERATURE USED FOR TEST SYSTEM
- Temperature used during treatment / exposure: 21.7-22.3°C
- Temperature of post-treatment incubation (if applicable): 37°C

REMOVAL OF TEST MATERIAL AND CONTROLS
-Volume and number of washing steps: 1wahsing step: rinsing thoroughly with PBS 1x solution (0.9%)

MTT DYE USED TO MEASURE TISSUE VIABILITY AFTER TREATMENT / EXPOSURE
- MTT concentration: 2 mL of 0.3 mg/mL MTT per well
- Incubation time: 3h
- Spectrophotometer: 96-well plate spectrophotometer
- Wavelength: 540nm

NUMBER OF REPLICATE TISSUES: 3

CONTROL TISSUES USED IN CASE OF MTT DIRECT INTERFERENCE (see any other info on mat and meth)

Control samples:

yes, concurrent negative control

yes, concurrent positive control

yes, concurrent MTT non-specific colour control

Amount/concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 20 mg

VEHICLE
- Amount(s) applied (volume or weight with unit): na; no formulation was required

NEGATIVE CONTROL: PBS
- Concentration (if solution): 50µl

POSITIVE CONTROL: SDS 5%
- Concentration (if solution): 50µl

Duration of treatment / exposure:

15 minutes (± 0.5 min)

Duration of post-treatment incubation (if applicable):

42h

Number of replicates:

3

Results and discussion

In vitro

Results

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

1

Value:

97

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

no indication of irritation

In vivo

Other effects:

none

Any other information on results incl. tables

The results of the optical density (OD) measured at 540 nm of each extract and the calculated % viability of the cells is presented below:

 

 

Table : Optical Density (OD) and the calculated % viability of the cells

Substance	Optical Density (OD)		Viability (%)
Negative Control:	1	0.797	104
PBS	2	0.744	97
	3	0.753	98
	mean	0.765	100
	standard deviation (SD)		3.79
Positive Control:	1	0.246	32
SDS 5%	2	0.207	27
	3	0.083	11
	mean	0.179	23
	standard deviation (SD)		10.97
Test Item:	1	0.718	94
Indium powder	2	0.683	89
	3	0.832	109
	mean	0.744	97
	standard deviation (SD)		10.41

 

 

 

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

In this in vitro skin irritation test in the EPISKIN model with indium powder the results indicated that the test item is Non Irritant (NI)
[UN GHS: No Category].

Executive summary:

Disks of EPISKIN (three units / chemical) were treated with Diindium trisulphide and incubated for 15 minutes at room temperature. Exposure of test material was terminated by rinsing with PBS. Epidermis units were then incubated at 37°C for 42 hours in an incubator with 5% CO₂. The viability of the epidermis on each disk was assessed by incubating the tissues for 3 hours with MTT solution at 37°C in 5% CO₂ protected from light. The formazan extract in acidified isopropanol was then spectrophotometrically evaluated for optical density (OD) and quantified.

SDS 5% and PBS treated epidermis were used as positive and negative controls, respectively. For each treated tissue viability was expressed as a % relative to negative control. If the mean relative viability after 15 minutes exposure and 42 hours post incubation is less or equal (≤) to 50% of the negative control, the test substance is considered to be irritant to skin.

Following exposure with indium powder, the mean treated skin value was 97% and therefore non irritant. All validity criteria were within acceptable limits and therefore the study can be considered as valid.

In this in vitro skin irritation test in the EPISKIN model with indium powder the results indicated that the test item is Non Irritant (NI) [UN GHS: No Category].