Niobium dioxide

Eye irritation

Administrative data

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2003-01-02 to 2003-03-20

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2003

Report date:

2003

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Test guideline 2

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Niobium oxide

EC Number:

234-808-1

EC Name:

Niobium oxide

Cas Number:

12034-57-0

Molecular formula:

NbO

IUPAC Name:

niobium(II) oxide

Test material form:

solid

Details on test material:

- Lot/batch No. of test material: SNB10OG200277M
- Expiration date of the lot/batch: 2003-12-31
- Purity: >99%
- Description: black, odourless powder
- Storage condition of test material: dry, room temperatue, closed container

Specific details on test material used for the study:

- Treatment of test material prior to testing: The test item was administered as the original substance after crushing with a pestlar and mortar.

Test animals / tissue source

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Source: Charles River Wiga GmbH, 97320 Sulzfeld, Germany
- Hygiene status upon supply: SPF
- Weight at study initiation: 2268 - 3105 g
- Housing: Cages of stainless steel with bottom grid of oval steel and with tub for faeces, dimensions of cages: 50 x 55 x 40 cm
- Diet (e.g. ad libitum): ad libitum, ALTROMIN 2123, standard diet for rabbits
- Water (e.g. ad libitum): ad libitum, tap water
- Bedding: ALTROMIN Type S8/15, granulated soft wood bedding
- Acclimation period: 2 - 4 weeks

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 - 21
- Humidity (%): 30 - 40
- Photoperiod (hrs dark / hrs light): 12/12

Test system

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent no treatment

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.1 g

Duration of treatment / exposure:

single treatment, after 24 hours the treated eye was washed

Observation period (in vivo):

1, 24, 48 and 72 hours after instillation

Number of animals or in vitro replicates:

3 male rabbits

Details on study design:

REMOVAL OF TEST SUBSTANCE
- Washing (if done): rinsing with deionised water
- Time after start of exposure: 24 h

SCORING SYSTEM: Draize method

EVALUATION CRITERIA
The evaluation of results was carried out according to Appendix 6 to Directive 2001/59/EU of August 06, 2001.
The following criteria should be fulfilled within 72 hours after instillation and persist for at least 24 hours in a test using three animals for classification of a substance as eye irritant and for the labelling with R36 (significant ocular lesions):
In at least two animals redness of conjunctivae ≥2.5, chemosis of conjunctivae ≥2.0, cornea opacity ≥2.0 < 3, iris lesion ≥1.0 < 2 and for labelling with R41 (severe ocular lesions) in at least two animals cornea opacity ≥3.0, iris lesions =2.0.
All responses scored at 24, 48 and 72 hours after instillation are used to calculate the mean value for each ocular lesion for each individual animal.
The classification as eye irritant and labelling with R41 (severe ocular lesions) is also necessary if a lower effect is not reversible in the 21 day observation period or an irreversible coloration of the cornea or iris are induced.

TOOL USED TO ASSESS SCORE: hand-slit lamp (Heine OPTOTECHNIK)

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

cornea opacity score

Basis:

mean

Remarks:

of three animals

Time point:

24/48/72 h

Score:

0

Max. score:

0

Remarks on result:

no indication of irritation

Results 2

Irritation parameter:

iris score

Basis:

mean

Remarks:

of three animals

Time point:

24/48/72 h

Score:

0

Max. score:

0

Remarks on result:

no indication of irritation

Results 3

Irritation parameter:

chemosis score

Basis:

mean

Remarks:

of three animals

Time point:

24/48/72 h

Score:

0

Max. score:

0

Remarks on result:

no indication of irritation

Results 4

Irritation parameter:

conjunctivae score

Basis:

mean

Remarks:

of three animals

Time point:

24/48/72 h

Score:

0

Max. score:

0

Remarks on result:

no indication of irritation

Irritant / corrosive response data:

The control eyes of the animals showed no alterations at any observation time. A slight redness of the conjunctivae and a serious lacrimation was observed in all animals on the day of instillation. The cornea and iris were not affected. After 24 hours no signs of irritation were observed. For details on the individual results please see Table 1 in box "Any other information on results".

Other effects:

None of the animals died or showed clinical signs during the course of testing.

Any other information on results incl. tables

Table 1: Evaluation of alterations of eyes after instillation of Niobium(II) oxide

Alteration	Animal No.	Observed grades of skin alterations of each observation time
		Hours after administration
		1		24		48		72
		Control	Test Item	Control	Test Item	Control	Test Item	Control	Test Item
Cornea	1	0	0	0	0*	0	0	0	0
	2	0	0	0	0	0	0	0	0
	3	0	0	0	0	0	0	0	0
Iris	1	0	0	0	0	0	0	0	0
	2	0	0	0	0	0	0	0	0
	3	0	0	0	0	0	0	0	0
Conjunctivae Redness	1	0	1*	0	0*	0	0	0	0
	2	0	1*	0	0	0	0	0	0
	3	0	1*	0	0	0	0	0	0
Conjunctivae Chemosis	1	0	0	0	0	0	0	0	0
	2	0	0	0	0	0	0	0	0
	3	0	0	0	0	0	0	0	0

* serous lacrimation

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

In conclusion, in a primary eye irritation study Niobium oxide was instilled into the conjunctival sac of the eye of three young adult New Zealand White rabbits for 24 hours. Based on the results, Niobium oxide can be considered as not eye irritating.

Executive summary:

In a primary eye irritation study (EU method B.5), 0.1 g of  Niobium oxide (> 99% purity) was instilled into the conjunctival sac of the eye of three young adult New Zealand White rabbits for 24 hours. After the exposure period the treated eyes were rinsed with deionised water. Animals were observed for 1, 24, 48 and 72 hours after instillation. Irritation was scored by the method of Draize. In this study, none of the animals died or showed clinical signs of toxicity. A slight redness of the conjunctivae and a serious lacrimation was observed in all animals on the day of instillation. The cornea and iris were not affected. After 24 hours no signs of irritation were observed anymore. Based on the results, niobium oxide is not an eye irritant to the eye.