Cobalt dichloride

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2011-11-17 to 2011-11-25

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2011

Report date:

2011

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Version / remarks:

2002-04-24

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Cobalt dichloride

EC Number:

231-589-4

EC Name:

Cobalt dichloride

Cas Number:

7646-79-9

Molecular formula:

Cl2Co

IUPAC Name:

cobalt(2+) dichloride

Details on test material:

- Name of test material (as cited in study report): Cobalt chloride Crystals Batch Number: NJ0Z 3950, Expiration Date: 10/2014
- Physical state: purple crystals
- Storage condition of test material: stable under the conditions of the test protocol (private communication sponsor)

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Kuiper Rabbitry, Gary, Indiana
- Age at study initiation: approximately ten to twelve weeks old
- Weight at study initiation: 2.97 to 3.28 kg
- Housing: the rabbits were individually housed in stainless steel cages.
- Diet (ad libitum): Purina Laboratory Rabbit Chow
- Water (ad libitum): water
- Acclimation period: at least five days prior to study initiation

The rabbits were maintained according to the recommendations contained in the National Academy Press 1996: "Guide for the Care and Use of Laboratory Animals".
All animals used in this study were considered to be in good health at study initiation.

ENVIRONMENTAL CONDITIONS
- Temperature: 20 ± 3°C
- Humidity: 30 - 70%
- Photoperiod (hrs dark / hrs light): 12/12

Test system

Type of coverage:

semiocclusive

Preparation of test site:

shaved

Vehicle:

water

Controls:

no

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 g aliquot of the test material

Duration of treatment / exposure:

4 hours

Observation period:

approximately 30 minutes after patches were removed, and 24, 48 and 72 and 168 hours after treatment

Number of animals:

3 male rabbits

Details on study design:

TEST SITE
- Area of exposure and type of wrap if used: the day before study initiation, electric clippers were used to remove the hair from the left side of the trunk, from the midline of the back to the abdomen. The following day an aliquot of the test material was then applied to an area approximately 6 square centimeters on the side of the test animal. The application site is slightly moistened with water to assure good skin contact, and is located approximately 5 - 7 centimeters down from the backbone. The test substance was then covered with a 2.5 cm^2 - 2 layer gauze patch held in place with non-irritating Kendall Curity Standard Porous Tape and the patch was then covered with a semi-occlusive plastic overwrap secured in place with Kendall Curity Standard Porous Tape for the duration of the exposure period.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): excess material was removed from the site
- Time after start of exposure: at the end of the 4 hour contact period

SCORING SYSTEM: the site was observed and scored according to the Draize scale
Other adverse changes at the skin sites will be recorded if present.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

mean

Remarks:

animal #1

Time point:

24/48/72 h

Score:

0.67

Max. score:

4

Reversibility:

fully reversible within: 72 hours

Results 2

Irritation parameter:

edema score

Basis:

mean

Remarks:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

4

Results 3

Irritation parameter:

erythema score

Basis:

mean

Remarks:

animal #2

Time point:

24/48/72 h

Score:

1.67

Max. score:

4

Reversibility:

fully reversible within: 7 days

Results 4

Irritation parameter:

edema score

Basis:

mean

Remarks:

animal #2

Time point:

24/48/72 h

Score:

0.33

Max. score:

4

Reversibility:

fully reversible within: 48 hours

Results 5

Irritation parameter:

erythema score

Basis:

mean

Remarks:

animal #3

Time point:

24/48/72 h

Score:

1.33

Max. score:

4

Reversibility:

fully reversible within: 7 days

Results 6

Irritation parameter:

edema score

Basis:

mean

Remarks:

animal #3

Time point:

24/48/72 h

Score:

0.33

Max. score:

4

Reversibility:

fully reversible within: 48 hours

Irritant / corrosive response data:

There were mild irritation reactions in all of the test subjects which clreared by the 168 hour observation.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The test material is non-irritating to the skin of rabbits.
According to the EC Regulation No. 1272/2008 and subsequent regulations, cobalt dichloride is not classified as a skin irritant.