Tellurium dioxide

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2012-06-13 to 2012-06-15

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

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.46 (In Vitro Skin Irritation: Reconstructed Human Epidermis Model Test)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Tellurium dioxide

EC Number:

231-193-1

EC Name:

Tellurium dioxide

Cas Number:

7446-07-3

Molecular formula:

O2Te

IUPAC Name:

tellurium dioxide

Test material form:

solid: particulate/powder

Details on test material:

lot/batch No.of test material: EK1008F023

Test animals

Details on test animals or test system and environmental conditions:

Human Skin model:
EPISKIN-SM is a three-dimensional human epidermis model. Adult human-derived epidermal keratinocytes are seeded on a dermal substitute
consisting of a collagen type I matrix coated with type IV collagen. A highly differentiated and stratified epidermis model is obtained after 13-day
culture period comprising the main basal, supra basal, spinous and granular layers and a functional stratum corneum (Tinois et al., 1994). Its use
for skin irritation testing involves topical application of test materials to the surface of the epidermis, and the subsequent assessment of their
effects on cell viability.

Test system

Details on study design:

The irritation potential of a chemical may be predicted by measurement of its cytotoxic effect, as reflected in the MTT assay, on the EPISKIN reconstituted human epidermis. This method is approved by international regulatory agencies as a replacement for the identification of irritants / corrosives in the in vivo Rabbit skin assay (OECD 404).

Results and discussion

In vitro

Results

Irritation / corrosion parameter:

other: other: relative viability (%)

Value:

76

Remarks on result:

other:

Remarks:

Basis: mean. Time point: after 15 minutes incubation. Reversibility: no data. Remarks: The relative cell viability was 76 % of negative control; as this value is clearly above the threshold value of ≤ 50 % for classification, thus the test substance is considered to be not irritating.. (migrated information)

Any other information on results incl. tables

 

Substance	Optical Density (OD)		Viability (%)
Negative Control: PBS	1	0.669	88
	2	0.748	98
	3	0.874	114
	mean	0.764	100
	standard deviation (SD)		13.11
Positive Control: SDS 5%	1	0.112	15
	2	0.058	7.6
	3	0.066	8.6
	mean	0.079	10
	standard deviation (SD)		4.01
Test Item: Tellurium dioxide	1	0.609	80
	2	0.536	70
	3	0.599	78
	mean	0.581	76
	standard deviation (SD)		5.29

 

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Tellurium dioxide was considered to be not irritating in an in-vitro skin irritation study using the EPISKIN model.

Executive summary:

In a study conducted according to OECD guideline 439 in-vitro skin irritation of Tellurium dioxide was tested using the EPISKIN model.

Disks of EPISKIN (three units / chemical) were treated with Tellurium dioxide 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 Tellurium dioxide, the mean relative viability of epidermis was 76 %. All validity criteria were within acceptable limits and therefore the study can be considered as valid.

In conclusion results indicate that Tellurium dioxide can be considered to be non-irritating.

The reconstructed human epidermis model EPISKIN-SM is designed to predict and classify the skin irritant potential of chemicals, by measuring its cytotoxic effect, as reflected in the MTT assay, on the EPISKIN reconstituted human epidermis. This method is approved by international regulatory agencies as a replacement for the identification of irritants / corrosives in the in vivo Rabbit skin assay (OECD 404).