Graphite

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2010-02-24 to 2010-07-19

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Well performed GLP study according to recent OECD guideline

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:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Version / remarks:

2002

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

2008

GLP compliance:

yes (incl. QA statement)

Remarks:

Certificate attached to full study report

Test material

Test material information

1

Reference substance name:

Graphite

EC Number:

231-955-3

EC Name:

Graphite

Cas Number:

7782-42-5

Molecular formula:

C

IUPAC Name:

carbon

Test material form:

solid: particulate/powder

Test animals

Species:

rabbit

Strain:

other: Russian Crl:CHBB

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Deutschland GmbH
- Age at study initiation: approx. 15 - 21 months
- Weight at study initiation: 2.8 - 3.1kg
- Housing: Individually in PPO cages (floor area: 2576cm^2)
- Diet (e.g. ad libitum): Altromin 2123, ad libitum
- Water (e.g. ad libitum): ad libitum, acidified with hydrochloric acid to pH 2.5 in order to prevent microbial growth
- Acclimation period: 7d

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20°C +/- 3°C
- Humidity (%): 30% - 70%
- Air changes (per hr): 10
- Photoperiod (hrs dark / hrs light): 12hrs/12hrs

Test system

Type of coverage:

semiocclusive

Preparation of test site:

other: clipped as closely as possible with an electrical clipper

Vehicle:

unchanged (no vehicle)

Remarks:

moistened with water

Controls:

no

Amount / concentration applied:

0.5g

Duration of treatment / exposure:

3min, 1hr, 4hrs

Observation period:

24hrs, 48hrs, 72hrs

Number of animals:

3

Details on study design:

TEST SITE
- Area of exposure: 2.5cm x 2.5cm
- Type of wrap if used: 16-layer gauze patch; the patch was placed on the appropriate anterior test field moistened with water and secured semi-occlusively with adhesive Gothaplast tape (2.5cm)

REMOVAL OF TEST SUBSTANCE
- Washing (if done): mild soap and lukewarm water
- Time after start of exposure: 3min, 1hr and 4hrs

SCORING SYSTEM:
- According to OECD 404 and Regulation (EC) 440/2008 B.4, table 1 (see also section "Any other information on materials and methods incl. tables"

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

mean

Remarks:

animal 1

Time point:

24/48/72 h

Score:

0

Max. score:

0

Reversibility:

fully reversible

Remarks on result:

other: See section "Any other information on results incl. tables"

Results 2

Irritation parameter:

edema score

Basis:

mean

Remarks:

animal 1

Time point:

24/48/72 h

Score:

0

Max. score:

0

Reversibility:

fully reversible

Remarks on result:

other: See section "Any other information on results incl. tables"

Results 3

Irritation parameter:

erythema score

Basis:

mean

Remarks:

animal 2

Time point:

24/48/72 h

Score:

0

Max. score:

0

Reversibility:

fully reversible

Remarks on result:

other: See section "Any other information on results incl. tables"

Results 4

Irritation parameter:

edema score

Basis:

mean

Remarks:

animal 2

Time point:

24/48/72 h

Score:

0

Max. score:

0

Reversibility:

fully reversible

Remarks on result:

other: See section "Any other information on results incl. tables"

Results 5

Irritation parameter:

erythema score

Basis:

mean

Remarks:

animal 3

Time point:

24/48/72 h

Score:

0

Max. score:

0

Reversibility:

fully reversible

Remarks on result:

other: See section "Any other information on results incl. tables"

Results 6

Irritation parameter:

edema score

Basis:

mean

Remarks:

animal 3

Time point:

24/48/72 h

Score:

0

Max. score:

0

Reversibility:

fully reversible

Remarks on result:

other: See section "Any other information on results incl. tables"

Irritant / corrosive response data:

The animal No. 4240 used in the initial test showed no skin reactions on the left and right test fields immediately after the termination of exposure. Also 1 hr after the termination of exposure a formation of erythema or oedema was not observed in animal No. 4240. Animal No. 4302 and No. 4331 from the confirmatory test showed no signs of skin irritation, too. On the subsequent days, 24 hrs, 48 hrs and 72 hrs after the termination of exposure, the animals No. 4240, No. 4302 and No. 4331 were free of skin reactions. The mean individual erythema scores after 4-hour exposure were 0.00, 0.00, 0.00, respectively. The mean individual oedema scores after 4-hour exposure were 0.00, 0.00, 0.00, respectively.

Any other information on results incl. tables

TABLE: Assessment of the formation of erythema and oedema within the first 72hrs after the termination of the exposure including the mean values calculated from the results of observation

Animal No.	Weight in kg	Exposure time	Test field	Observation assessment of the formation of erythema after the termination of exposure [hrs]					Mean	Observation assessment of the formation of oedema after the termination of exposure [hrs]					Mean
				0	1	24	48	72		0	1	24	48	72
4240	2.9	3 min	al	0	0	0	0	0		0	0	0	0	0
		1 hr	ml	0	0	0	0	0		0	0	0	0	0
		4 hrs	pr	0	0	0	0	0	0.00	0	0	0	0	0	0.00
4302	2.8	4 hrs	al		0	0	0	0	0.00		0	0	0	0	0.00
4331	3.1	4 hrs	al		0	0	0	0	0.00		0	0	0	0	0.00

Only the scores for the 4hr exposure from the readings after 24hrs, 48hrs and 72hrs are included in the calculation of the individual mean values
al = anterior left

ml = middle left

pr = posterior right

Applicant's summary and conclusion

Interpretation of results:

not irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Based on the results of the study described in this report, EXPANDED GRAPHITE POWDER has to be classified neither as irritant nor as corrosive according to the provisions laid down in regulation (EC) No 1272/2008 (2008).

Executive summary:

The skin irritant effect of EXPANDED GRAPHITE POWDER was investigated according to the method recommended in the OECD Guideline 404 and the council regulation (EC) No. 440/2008 part B.4. Based on the critical analysis of all known data performed by the sponsor or monitor in his own responsibility the in vivo testing of the test item was considered to be justified. During an initial test using one female albino rabbit a sequential application (exposure time 3 min, 1 hr and 4 hrs) of EXPANDED GRAPHITE POWDER was carried out on one site of the left and right back area each. The skin was examined for signs of irritation straight after as well as 1 hr, 24 hrs, 48 hrs and 72 hrs after the termination of exposure. Since the animal did not show any signs of skin irritation within the observation period of 72 hours it was decided to carry out a confirmatory test with two additional animals in order to allow a categorization of the test item based on the classification criteria. Two female albino rabbits were exposed to the test item on one skin site of the back during the confirmatory test. After 4-hour exposure time the test item was removed and the skin was examined 1 hr, 24 hrs, 48 hrs and 72 hrs after the termination of exposure. These animals did not show any skin reactions, either. Under the experimental conditions described in this report the mean scores after the 4-hour exposure were:

Animal No.       Erythema          Oedema

4240                    0.00                     0.00

4302                    0.00                     0.00

4331                    0.00                     0.00

Based on the results of the study described in this report, EXPANDED GRAPHITE POWDER has to be classified neither as irritant nor as corrosive according to the provisions laid down in regulation (EC) No 1272/2008.