Cobalt dinitrate

Endpoint summary

Description of key information

Skin irritation: not irritating (OECD 404; GLP)
Eye irritation: irreversible effects on the eye (OECD 405; GLP)

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Endpoint:

skin irritation / corrosion, other

Remarks:

in vivo study

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2012-03-27 to 2012-04-03

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Version / remarks:

2002-04-24

Deviations:

no

GLP compliance:

yes

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: 2.79 to 2.91 kg
- Housing: individually housed in stainless steel cages
- Diet (ad libitum): Purina Laboratory Rabbit Chow
- Water (ad libitum)
- Acclimation period: at least five days

The rabbits were maintained according to the recommendations contained in the National Academy Press 1996: "Guide for the Care and Use of Laboratory Animals".

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

Type of coverage:

semiocclusive

Preparation of test site:

clipped

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 was slightly moistened with the vehicle

Duration of treatment / exposure:

Initial animal: 3 minutes, 1 hour and 4 hours
Confirmatory animals: 4 hours

Observation period:

30 minutes, 24, 48, 72 and 168 hours after removal of the test substance

Number of animals:

3 male rabbits

Details on study design:

INITIAL AND CONFIRMATORY TEST
One animal was screened by applying the test substance for a 3 minute and 1 hour topical exposure. No irritation was observed in either exposure; therefore the four hour exposure was conducted.

TEST SITE
- Area of exposure/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 slightly moistened with the vehicle and applied to an area approximately 6 square centimeters on the side of the test animal. The application site is located approximately 5-7 centimeters down from the backbone. The test substance was then covered with a 2.5 cm² - 2 layer gauze patch held in place with non-irritating Kendall Curity Standard Porous Tape and the patch was then covered with a occlusive plastic overwrap secured in place with Kendall Curity Standard Porous Tape for the duration of the exposure period.

REMOVAL OF TEST SUBSTANCE
- Time after start of exposure: at the end of the 4 hour contact period

SCORING SYSTEM: according to the Draize scale
Other adverse changes at the skin will be reocrded if present

Irritation parameter:

erythema score

Basis:

mean

Remarks:

animal #1

Time point:

24/48/72 h

Score:

2

Max. score:

4

Reversibility:

fully reversible within: 7 days

Irritation parameter:

edema score

Basis:

mean

Remarks:

animal #1

Time point:

24/48/72 h

Score:

0.67

Max. score:

4

Reversibility:

fully reversible within: 72 hours

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

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

Irritation parameter:

erythema score

Basis:

mean

Remarks:

animal #3

Time point:

24/48/72 h

Score:

1

Max. score:

4

Reversibility:

fully reversible within: 7 days

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 three the test subjects which cleared by the 168 hour observation.

Interpretation of results:

GHS criteria not met

Conclusions:

The test substance is not irritating to the skin.
According to the EC-Regulation 1272/2008 and subsequent regulations, the test item is not classified as skin irritant.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2012-12-03 to 2012-12-24

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Version / remarks:

2002-04-24

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

signed 2012-11-30

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

TEST ANIMALS - New Zealand White (Hsdlf:NZW) strain rabbit
- Source: Harlan Laboratories UK Ltd., Leicestershire, UK
- Age at study initiation: twelve to twenty weeks old
- Weight at study initiation: 2.47 kg
- Housing: the animal was housed in suspended cage.
- Diet (ad libitum): 2930C Teklad Global Rabbit diet supplied by Harlan Laboratories UK Ltd., Oxon, UK
- Water (ad libitum): mains drinking water
- Acclimation period: at least five days

The animal was 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.

ENVIRONMENTAL CONDITIONS
- Temperature: 17 to 23°C
- Relative humidity: 30 to 70%
- Air exchange: at least fifteen changes per hour
- Photoperiod (hrs dark / hrs light): 12/12

Vehicle:

unchanged (no vehicle)

Controls:

no

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): a volume of 0.1 mL of the test item, which was found to weigh approximately 96 mg (as measured by gently compacting the required volume into an adapted syringe) was placed into the conjunctival sac of the right eye, formed by gently pulling the lower lid away from the eyeball. The upper and lower eyelids were held together for about one second immediately after treatment, to prevent loss of the test item, and then released. The left eye remained untreated and was used for control purposes.
For the purpose of the study the test item was ground before use.

Duration of treatment / exposure:

not applicable

Observation period (in vivo):

approximately 1 hour and 24, 48 and 72 hours following treatment as well as on days 7, 14 and 21

Number of animals or in vitro replicates:

1 male rabbit

Details on study design:

Immediately before the start of the test, both eyes of the provisionally selected test rabbit were examined for evidence of ocular irritation or defect with the aid of a light source from a standard ophthalmoscope. An animal free of ocular damage was used.

One rabbit was treated. Immediately after administration of the test item, an assessment of the initial pain reaction was made according to the six point scale (please refer to table 2 in the field "Any other information on materials and methods incl. tables" below).
After consideration of the ocular responses produced in this animal, no additional animals were treated.

SCORING SYSTEM: according to the Draize scale
Any other ocular effects were also noted.
Any clinical signs of toxicity, if present, were also recorded.
The animal's body weight was recorded on Day 0 (the day of dosing) and at the end of the observation period.

TOOL USED TO ASSESS SCORE: examination of the eye was facilitated by the use of the light source from a standard ophthalmoscope. The presence of corneal opacity at the 21-Day observation was confirmed by fluorescein staining.

Irritation parameter:

cornea opacity score

Basis:

mean

Remarks:

animal #1

Time point:

24/48/72 h

Score:

1

Max. score:

4

Reversibility:

not fully reversible within: 21 days

Remarks on result:

other: Initial pain reaction was moderate initial pain. Slight corneal opacity was observed 1 hour after administration. One quarter to greater than half but less than three quarters of the corneal area showed opacity during the study.

Irritation parameter:

iris score

Basis:

mean

Remarks:

animal #1

Time point:

24/48/72 h

Score:

1

Max. score:

2

Reversibility:

fully reversible within: 14 days

Remarks on result:

other: Slight iridial inflammation was observed 1 hour after administration as well as 7 and 14 days after administration. Slight to severe discharge was observed throughout the study.

Irritation parameter:

conjunctivae score

Basis:

mean

Remarks:

animal #1

Time point:

24/48/72 h

Score:

2

Max. score:

3

Reversibility:

not fully reversible within: 21 days

Remarks on result:

other: Moderate conjunctival redness was observed throughout the whole observation period. Red coloured staining of fur around treated eye was observed throughout the observation period.

Irritation parameter:

chemosis score

Basis:

mean

Remarks:

animal #1

Time point:

24/48/72 h

Score:

3

Max. score:

4

Reversibility:

not fully reversible within: 21 days

Remarks on result:

other: Moderate chemosis was observed throughout the whole observation period. Vascularization, with localized ingrowth of vessels, approximately 3 mm onto the cornea along the top, left of the eye was observed 7 days after administration.

Remarks on result:

other: Vascularisation, with generalized ingrowth of vessels, approximately 6 mm onto the cornea was observed 14 days after administration.

Remarks on result:

other: Vascularisation, with a localized ingrowth of vessels, approx. 4 mm onto the cornea along the bottom of the eye was observed 21 days after administration. Alopecia around the treated eye was observed 7, 14 and 21 days after administration.

Irritant / corrosive response data:

Red coloured staining of the fur was noted around the treated eye throughout the study.
Diffuse corneal opacity was noted in the treated eye one hour after treatment, at the 24, 48 and 72-Hour observations with translucent corneal opacity at the 7 and 14-Day observations and diffuse corneal opacity at the 21-Day observation. Vascularisation, with a localized ingrowth of vessels approximately 3 mm onto the cornea along the top, left of the treated eye, was noted at the 7-Day observation. Vascularisation, with a generalized ingrowth of vessels approximately 6 mm onto the cornea, was noted in the treated eye at the 14-Day observation. Vascularisation, with a localized ingrowth of vessels approximately 4 mm onto the cornea and along the bottom of the treated eye, was noted at the 21-Day observation.
Iridial inflammation was noted in the treated eye one hour after treatment, at the 24, 48 and 72-Hour, 7 and 14-Day observations.
Moderate conjunctival irritation was noted in the treated eye one hour after treatment with severe conjunctival irritation noted at the 24, 48 and 72-Hour observations and moderate conjunctival irritation noted at the 7, 14 and 21-Day observations.
Alopecia around the treated eye was noted at the 7, 14 and 21-Day observations.
The persistence of reactions in the treated eye at the 21-Day observation was considered to be indicative of irreversible ocular damage.

Other effects:

- Body weight: the animal showed expected gain in body weight during the study.

Interpretation of results:

Category 1 (irreversible effects on the eye)

Conclusions:

The test material caused irreversible ocular damage.
According to the EC Regulation No. 1272/2008 and subsequent regulations, the substance is classified as Category 1.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Additional information

Skin irritation

One reliable in vivo study described by Kukulinski (2012) (OECD 404; GLP compliant) is considered to be reliable without restrictions. The substance was not determined to be a skin irritant.

One in vivo study described by Vinegar (1977)(non-GLP compliant) was disregarded for hazard assessment purposes, since the test item was applied as diluted aqueous solution supplemented with nitric acid as stabilising agent. Since this test result does not reflect the irritating propertied of the sure substance, this study result is not suitable for risk assessment purposes.

Eye irritation

One reliable in vivo study described by Sanders (2013) (OECD 405; GLP compliant) is considered to be reliable without restrictions. The substance was determined to cause irreversible effects on the eye.

Furthermore, a reliable in vitro study described by Heppenheimer (2013) (OECD 437; GLP compliant) is considered to be reliable without restrictions. The substance was determined to be neither corrosive nor severely irritating to the eye.

Justification for selection of skin irritation / corrosion endpoint:
Key study

Justification for selection of eye irritation endpoint:
Key study

Effects on eye irritation: corrosive

Justification for classification or non-classification

                         

Skin irritation

Reference Kukulinski (2012) is considered as the key study for in vivo skin irritation and will be used for classification. During the study the test item was applied to the skin of three rabbits and the skin irritation was scored according to the Draize scale. The following mean scores (24, 48 and 72 hours) were obtained for the animals:

Erythema: 2, 1.67 and 1

Oedema: 0.67, 0.33 and 0.33

The classification criteria acc. to regulation (EC) 1272/2008 as irritating to skin are not met, since the values of erythema and oedema were below the threshold of ≥ 2.3 as well as the effects were fully reversible within 7 days. No classification required. Furthermore, the substance has not to be classified as skin irritating according to Directive 67/548 EC.

 

Eye irritation

Reference Sanders (2013) is considered as the key study for in vivo eye irritation and will be used for classification. During the study the test item was applied to one eye of one animal and the eye irritation was scored according to the Draize scale. The following mean scores (24, 48 and 72 hours) were obtained for the animal:

cornea: 1

iris: 1

conjunctival redness: 2

chemosis: 3

The ocular effects were not fully reversible within 21 days.Thus, according to Regulation (EC) 1272/2008 and subsequent amendments the substance will be classified as causing irreversible effects on the eye (Category 1). Furthermore, the substance has to be classified as risk of serious damage to eyes according to Directive 67/548 EC.

 

Respiratory irritation

The justification for non classification as respiratory irritant is covered under the endpoint specific target organ toxicity- single exposure: inhalation as given in the acute toxicity section.