Dimanganese trioxide

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2009-10-28 to 2009-12-24

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2009

Report date:

2009

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.4 (Acute Toxicity: Dermal Irritation / Corrosion)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

manganese oxide

IUPAC Name:

manganese oxide

Constituent 2

Reference substance name:

1344-43-0

Cas Number:

1344-43-0

IUPAC Name:

1344-43-0

Constituent 3

Reference substance name:

Manganese oxide

EC Number:

215-695-8

EC Name:

Manganese oxide

IUPAC Name:

215-695-8

Details on test material:

- Name of test material: MnO
- Substance type: Green powder
- Physical state: Solid
- Impurities (identity and concentrations): MnO2 0.46%, Fe 56 ppm, Ins. ac. 15 %, H2O at 105 °C 0.01%
- Composition of test material, percentage of components: Mn 77.8%
- Purity test date: 24/09/08
- Lot/batch No.: 104833-06
- Storage condition of test material: Room temperature in the dark

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Harlan Laboratories UK Limited, Hillcrest, Belton, Loughborough, UK
- Age at study initiation: 12 to 20 weeks old
- Weight at study initiation: 2.31 to 2.79 kg
- Housing: Individually housed in suspended cages.
- Diet: 2030 Teklad Global Rabbit diet (Harlan Teklad, Blackthorn, Bicester, Oxon, UK) available ad libitum.
- Water: Mains drinking water available ad libitum.
- Acclimation period: Minimum of 5 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 17 to 23 °C
- Humidity (%): 30 to 70 %
- Air changes (per hr): A minimum of 15 changes per hour.
- Photoperiod (hrs dark / hrs light): 12 hour cycle

Test system

Type of coverage:

semiocclusive

Preparation of test site:

shaved

Vehicle:

unchanged (no vehicle)

Controls:

no

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 g (moistened sufficiently with 0.5 mL of distilled water to achieve a paste).

Duration of treatment / exposure:

Animal were exposed for 4 hours.

Observation period:

Animals were observed for 72 hours for skin reactions.

Number of animals:

3 animals in total (1 animal used in the initial test, with further 2 animals in the main test)

Details on study design:

TEST SITE
- Area of exposure: The test material was introduced a 2.5 cm x 2.5 cm cotton gauze patch
- Type of wrap if used: The trunk of each rabbit was wrapped in an elasticated corset.


REMOVAL OF TEST SUBSTANCE
- Washing: Any residual test material was removed by gentle swabbing with cotton wool soaked in distilled water.
- Time after start of exposure: 4 hours post administration of test material.


SCORING SYSTEM: Draize J.H. (1959) “Dermal Toxicity” In: Appraisal of the Safety of Chemicals in Foods, Drugs and Cosmetics. Associations of Food and Drug Officials of the United States, Austin, Texas p.46-59; see Table 1 in box 'Any other information on materials & methods incl. tables'.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Results 2

Irritation parameter:

edema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Results 3

Irritation parameter:

erythema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Results 4

Irritation parameter:

edema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Results 5

Irritation parameter:

erythema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Results 6

Irritation parameter:

edema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Irritant / corrosive response data:

No irritation was observed in any of the animals.

For individual results see Table 2 in box 'Any other information on results incl. tables'.

Any other information on results incl. tables

Table 2: Individual Skin Reactions 

Skin Reaction	Observation Time (Following Patch Removal)	Individual Scores – Rabbit Number and Sex			Total
		68627 Male	68626 Male	68662 Male
Erythema/Eschar Formation	Immediately	0	0	0	0
	1 Hour	0	0	0	0
	24 Hours	0	0	0	0
	48 Hours	0	0	0	0
	72 Hours	0	0*	0*	0
Oedema Formation	Immediately	0	0	0	0
	1 Hour	0	0	0	0
	24 Hours	0	0	0	0
	48 Hours	0	0	0	0
	72 Hours	0	0*	0*	0

 * = measurement performed at approximately 68 hours post dosing.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Under the conditions of the test, the test material was found to be a non-irritant to rabbit skin.

Executive summary:

In a primary dermal irritation study according to guideline OECD 404, three young adult New Zealand White rabbits were dermally exposed to 0.5% manganese oxide (77% Mn content) in water for 4 hours to 2.5 x 2.5 cm of the body surface area. Animals then were observed for 72 hours. Irritation was scored by the method of Draize. No irritation was observed in any of the animals. In this study, manganese oxide is not a dermal irritant.