Kieselguhr, soda ash flux-calcined

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

The study was performed between 23 March 2010 and 26 March 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study performed to GLP and internationally accepted guideline

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: OECD Guideline 431 (In vitro skin corrosion: Human skin model test)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Kieselguhr, soda ash flux-calcined

EC Number:

272-489-0

EC Name:

Kieselguhr, soda ash flux-calcined

Cas Number:

68855-54-9

Molecular formula:

SiO2

IUPAC Name:

silanedione

Details on test material:

- Name of test material (as cited in study report): Soda-ash flux calcined kieselguhr
- Physical state: Solid
- Purity: 100%
- Lot/batch No.: 211184
- Expiration date of the lot/batch: 31 December 2013
- Storage condition of test material: Room temperature in the dark

Test animals

Species:

other: EPISKIIN™ Reconstituted Human Epidermis model

Test system

Amount / concentration applied:

TEST MATERIAL
- Amount applied: 20 mg


VEHICLE
Test material was used as suppled

Duration of treatment / exposure:

Duplicate tissues were treated with the test material for exposure periods of 3, 60 and 240 minutes.

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

other: other: Relative mean viability %

Value:

102.8

Remarks on result:

other:

Remarks:

Basis: mean. Time point: 3 minutes. (migrated information)

Results 2

Irritation / corrosion parameter:

other: other: Relative mean viability %

Value:

111.3

Remarks on result:

other:

Remarks:

Basis: mean. Time point: 60 minutes. (migrated information)

Results 3

Irritation / corrosion parameter:

other: other: Relative tissue viability %

Value:

114.1

Remarks on result:

other:

Remarks:

Basis: mean. Time point: 240 minutes. (migrated information)

Any other information on results incl. tables

Direct MTT reduction

The MTT solution containing the test material did not turn blue/purple. This was taken to indicate the test material did not reduce MTT

Table 1: Mean OD₅₄₀ values and viabilities for the negative control, positive control material and test material

Material	Exposure period	Mean OD540of duplicate tissues	Relative mean % viability
Negative control material	240 minutes	0.142	100*
Positive control material	240 minutes	0.013	9.2
Test material	240 minutes	0.162	114.1
	60 minutes	0.158	111.3
	3 minutes	0.146	102.8

* = The mean viability of the negative control tissues is set at 100%

Table 2: Qualitative evaluation of tissue viability (MTT uptake visual evaluation)

Material	Exposure period	Tissue 1	Tissue 2
Negative control material	240 minutes	-	-
Positive control material	240 minutes	++	++
Test material	240 minutes	-	-
	60 minutes	-	-
	3 minutes	-	-

- = Blue tissue (viable)

++ = Tissue completely white (dead)

The relative mean tissue viability for the positive control treated tissues was 9.2% relative to the negative control treated tissues following the 240 -minute exposure period. The positive control acceptance criterion was therefore satisfied.

Applicant's summary and conclusion

Interpretation of results:

not irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The test material was considered to be non-corrosive to the skin