Reaction mass of aluminium and magnesium oxide and spinel (Mg(AlO2)2)

Skin irritation / corrosion

Administrative data

Endpoint:

skin corrosion: in vitro / ex vivo

Remarks:

in vitro

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP - guideline study with only minor deviations

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Deviations:

yes

Remarks:

no concurrent positive control was conducted

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: OECD Guideline 431

Deviations:

yes

Remarks:

no concurrent positive control was conducted

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

dioxo-2,4-dioxa-1,5-dialumina-3-magnesapentane oxomagnesium alumane

EC Number:

701-289-2

Molecular formula:

Al, MgO, Mg(AlO2)2

IUPAC Name:

dioxo-2,4-dioxa-1,5-dialumina-3-magnesapentane oxomagnesium alumane

Details on test material:

- Name of test material (as cited in study report): Aluminium-Skimmings
- Physical state: grey solid
- Analytical purity: Aluminium: 708.0 g/kg
Ammonium(NH4): 22.0 g/kg
Magnesium: 68.0 g/kg
- Lot/batch No.: Lieferung vom 21.04.2009
- Stability under test conditions: until August 21, 2011
- Storage condition of test material: room temperature

Test animals

Species:

other: not applicable, in-vitro test

Strain:

other: not applicable, in-vitro test

Test system

Type of coverage:

other: not applicable, in-vitro test

Preparation of test site:

other: not applicable, in-vitro test

Vehicle:

physiological saline

Controls:

other: not applicable, in-vitro test

Amount / concentration applied:

The test item was applied at a 100% concentration, i.e. 25 mg per insert. (plus 50 µL 0.9% NaCl to moisten and ensure good contact with the skin)

Duration of treatment / exposure:

3 + 60 min

Observation period:

not applicable

Number of animals:

not applicable, in-vitro test

Details on study design:

The experiment was carried out on a reconstructed human epidermis EST-1000 (CellSystems, St. Katharinen, Germany) for detection of topically applied skin corrosives.
A 100% concentration was tested on the skin/epidermal equivalents in triplets. For the determination of time related cytotoxic effects the incubation periods were 3 min. and 60 min., respectively.
To check the reliability of this test procedure a blinded positive/negative control study is conducted at regular intervals in the lab. This reliability check is always performed by two technicians, two laboratories in parallel using the same batches of the control test items.
The test item was applied at a 100% concentration, i.e. 25 mg per insert. (plus 50 µL 0.9% NaCl to moisten and ensure good contact with the skin).

After the incubation period the inserts were washed carefully in PBS and MTT reduction was performed. For viability testing the inserts were placed in new 24 well plates containing 300µl of MTT solution (37°C, 1mg/mL in MTT-assay medium, delivered by Cell Systems®). The tissues were incubated for about 2 hours under cell culture conditions (5% CO2, 37°C, max humidity). The extraction of blue formazan was performed in Isopropanol (24 well plates, 2ml / insert) on a vertical shaker (at least 60 min.). For determination of cell viability the absorption of the Isopropanol-extracts were measured in duplicates at 570 nm in an automatic reader (EL808, Bio-Tek; 96 well format, 200 µL).

Substances are classified as „corrosive (R34)“, if the cell viability of the EST 1000 is decreased by more than 50% after 3 min. of incubation to the test item, or if the cell viability is less than 15% after 60 min. of exposure to the test item

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

other: % viability

Basis:

mean

Time point:

other: 3 min

Score:

102.99

Max. score:

100

Results 2

Irritation parameter:

other: % viability

Basis:

mean

Time point:

other: 60 min

Score:

91.69

Max. score:

100

Any other information on results incl. tables

Sample No.	Test item	Time [min.]	OD mean*	StdDev	% Viability
1-3	control NaCl 0.9%	60	1.83	0.05	100.00
7-9	Aluminium-Skimmings	60	1.68	0.12	91.69
10-12	control NaCl 0.9%	3	1.80	0.09	100.00
16-18	Aluminium-Skimmings	3	1.86	0.16	102.99

Applicant's summary and conclusion

Interpretation of results:

other: not corrosive

Remarks:

Criteria used for interpretation of results: EU

Conclusions:

The test item is not corrosive in a reconstructed human skin model.