Cobalt hydroxide oxide

Eye irritation

Administrative data

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2010-11-04 to 2010-11-15

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

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Version / remarks:

2002-04-24

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.5 (Acute Toxicity: Eye Irritation / Corrosion)

Version / remarks:

2008

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Cobalt hydroxide oxide

EC Number:

234-614-7

EC Name:

Cobalt hydroxide oxide

Cas Number:

12016-80-7

Molecular formula:

CoHO2

IUPAC Name:

cobaltoylol

Details on test material:

- Name of test material (as cited in study report): Cobalt oxyhydroxide
- Substance type: Solid
- Storage condition of test material: At room temperature (20 ± 5 °C, provided by Harlan Laboratories Ltd.)

Test animals / tissue source

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Source: Harlan Laboratories U.K. Ltd., Hillcrest, Dodgeford Lane, Belton, Loughborough, Leics, LE12 9TE, UK
- Age at study initiation: 15 - 16 weeks
- Weight at study initiation: 2559 - 2671 g
- Housing: Individually in stainless steel cages equipped with feed hoppers and drinking water bowls
- Diet (ad libitum): Pelleted standard Teklad Global High Fiber Rabbit Diet 2031C (batch no. 25/10, Provimi Kliba AG, 4303 Kaiseraugst / Switzerland)
- Water (ad libitum): Community tap water from Füllinsdorf
- Acclimation period: 6 - 7 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 17-23
- Humidity (%): 30-70
- Air changes (per hr): Air-conditioned with 10-15 air changes
- Photoperiod (hrs dark / hrs light): automatically controlled light cycle of 12 hours light and 12 hours dark

The animals were provided with environmental enrichment items which were considered not to contain any contaminant of a level that might have affected the purpose or integrity of the study.

Test system

Vehicle:

unchanged (no vehicle)

Controls:

no

Amount / concentration applied:

TEST MATERIAL
- The test item was applied as a weight of 0.1 g/animal, the dose specified in the test guidelines for solid test items.
- On the day of treatment, the test item was applied with an eye glass to the conjunctival sac of the left eye of each animal after gently pulling the lower lid away from the eyeball. The lids were then gently held together for about one second to prevent loss of test item. The right eye remained untreated and served as the reference control.
- A single animal was treated first. As neither a corrosive effect nor a severe irritant effect was observed after the 1- and 24-hour examinations, the test was completed using the two remaining animals.

Duration of treatment / exposure:

not applicable

Observation period (in vivo):

approximately 1, 24, 48 and 72 hours after test item instillation

Number of animals or in vitro replicates:

3 (male rabbits)

Details on study design:

The eyes of the animals were examined one day prior to test item administration.

Observation and Scoring:
- The eye reactions were assessed according to the Draize scale. Scleral reddening and ocular discharge were also assessed according to following scale (See "Any other information on materials and methods incl. tables"). Eye examinations were made with a Varta Cliptrix diagnostic-lamp (Roth AG, 4153 Reinach / Switzerland).
- Viability / Mortality: Daily from acclimatization of the animals to termination of the test.
- Clinical signs (systemic): Daily from acclimatization of the animals to termination of the test.
- Body weights: At start of acclimatization, on the day of application and at termination of observation.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

cornea opacity score

Basis:

mean

Remarks:

(animal #1)

Time point:

24/48/72 h

Score:

0

Results 2

Irritation parameter:

iris score

Basis:

mean

Remarks:

(animal #1)

Time point:

24/48/72 h

Score:

0

Results 3

Irritation parameter:

conjunctivae score

Basis:

mean

Remarks:

(animal #1)

Time point:

24/48/72 h

Score:

0.67

Max. score:

1

Reversibility:

fully reversible within: 72 hours

Results 4

Irritation parameter:

chemosis score

Basis:

mean

Remarks:

(animal #1)

Time point:

24/48/72 h

Score:

0

Results 5

Irritation parameter:

cornea opacity score

Basis:

mean

Remarks:

(animal #2)

Time point:

24/48/72 h

Score:

0

Results 6

Irritation parameter:

iris score

Basis:

mean

Remarks:

(animal #2)

Time point:

24/48/72 h

Score:

0

Results 7

Irritation parameter:

conjunctivae score

Basis:

mean

Remarks:

(animal #2)

Time point:

24/48/72 h

Score:

0

Results 8

Irritation parameter:

chemosis score

Basis:

mean

Remarks:

(animal #2)

Time point:

24/48/72 h

Score:

0

Results 9

Irritation parameter:

cornea opacity score

Basis:

mean

Remarks:

(animal #3)

Time point:

24/48/72 h

Score:

0

Results 10

Irritation parameter:

iris score

Basis:

mean

Remarks:

(animal #3)

Time point:

24/48/72 h

Score:

0

Results 11

Irritation parameter:

conjunctivae score

Basis:

mean

Remarks:

(animal #3)

Time point:

24/48/72 h

Score:

0

Results 12

Irritation parameter:

chemosis score

Basis:

mean

Remarks:

(animal #3)

Time point:

24/48/72 h

Score:

0

Irritant / corrosive response data:

- The mean score was calculated across 3 scoring times (24, 48 and 72 hours after instillation) for each animal for corneal opacity, iris light reflex, redness and chemosis of the conjunctivae, separately. The individual mean scores for corneal opacity and iris light reflex were 0.00 for all three animals. The individual mean scores for the conjunctivae were 0.67, 0.00 and 0.00 for reddening, respectively and 0.00 for chemosis for all animals.
- Slight reddening of the conjunctivae and slight reddening of the sclera were noted in two animals (#1 and #2) one hour after instillation of the test item. The slight reddening of the conjunctivae persisted in one animal (#1) up to the 48-hour reading. Slight swelling (chemosis) of the conjunctivae was observed in one animal (#1) at the 1-hour reading. At the same observation point, slight ocular discharge was present in two animals (#1 and #2).
- No abnormal findings were observed in the treated eyes of any animals 72 hours after treatment, the end of the observation period for all animals.

Other effects:

- Viability / Mortality: No intercurrent deaths occurred during the course of the study.
- Clinical signs: No clinical signs were recorded throughout the entire observation period.
- Body weights: The body weight of the animals was within the range commonly recorded for this strain and age.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

According to Regulation (EC) No. 1272/2008 and subsequent regulations, cobalt hydroxide oxide is not classified as an eye irritant.