Niobium carbide

Eye irritation

Administrative data

Endpoint:

eye irritation: in vivo

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

2000-07-24 to 2001-06-21

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP guideline study. Data are used in a read-across approach for the assessment of niobium carbide.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2001

Report date:

2001

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

niobium pentoxide

IUPAC Name:

niobium pentoxide

Constituent 2

Reference substance name:

Diniobium pentaoxide

EC Number:

215-213-6

EC Name:

Diniobium pentaoxide

Cas Number:

1313-96-8

Molecular formula:

Nb2O5

IUPAC Name:

diniobium pentaoxide

Details on test material:

- Name of test material (as cited in study report): Nb2O5 NIOBIUM PENTOXIDE GRADE LN
- Intended use: optical industry, electro ceramics, single crystals
- Physical state: A white powder
- Lot/batch No: 20000103
- Analytical purity: 99.99%

Test animals / tissue source

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Source: Harlan UK Ltd., Bicester, Oxon, England
- Age at study initiation: 11 weeks
- Weight at study initiation: 2.3 to 3.0kg
- Housing: metal cages with perforated floors
- Diet (e.g. ad libitum): standard laboratory rabbit diet (Special Diet Services STANRAB (P) SQC pellet)
- Water (e.g. ad libitum):ad libitum
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19+/-2
- Humidity (%): 30-70
- Photoperiod (hrs dark / hrs light): 12/12

Test system

Vehicle:

unchanged (no vehicle)

Controls:

other: untreated eyes of the animals served as control

Amount / concentration applied:

100 mg

Duration of treatment / exposure:

Single treatment

Observation period (in vivo):

72 h

Number of animals or in vitro replicates:

3

Details on study design:

Eyes were evaluated at 1, 24, 48 and 72 hours after instillation

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

cornea opacity score

Remarks:

- Corneal opacity

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

0

Reversibility:

other: not applicable

Results 2

Irritation parameter:

iris score

Remarks:

- Iridal lesions

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

0

Reversibility:

other: not applicable

Results 3

Irritation parameter:

conjunctivae score

Remarks:

- Conjuctival redness

Basis:

mean

Remarks:

(mean of three animals and of three time points)

Time point:

24/48/72 h

Score:

0.3

Max. score:

2

Reversibility:

fully reversible

Results 4

Irritation parameter:

chemosis score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

0

Reversibility:

other: not applicable

Irritant / corrosive response data:

No corneal damage or iridial inflammation was observed.
Transient hyperaemia of the blood vessels to a diffuse crimson colouration of teh conjunctivae was seen in all animals with above normal swelling in two animals. All reactions had resolved completely by one, two, or three days after isntallation.

Any other information on results incl. tables

Rabbit no. & sex	Region of eye		1h	24h	48h	72h
1391 Male	Cornea	Density	0	0	0	0
		Area	0	0	0	0
	Iris		0	0	0	0
	Conjuctiva	Redness	2	1	0	0
		Chemosis	1	0	0	0
1460 Male	Cornea	Density	0	0	0	0
		Area	0	0	0	0
	Iris		0	0	0	0
	Conjuctiva	Redness	1	1	1	0
		Chemosis	1	0	0	0
1461 Male	Cornea	Density	0	0	0	0
		Area	0	0	0	0
	Iris		0	0	0	0
	Conjuctiva	Redness	1	0	0	0
		Chemosis	0	0	0	0

Applicant's summary and conclusion

Interpretation of results:

not irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

In a primary eye irritation irritation study according to OECD Guideline 405 niobium pentoxide was tested as not irritating to the eye.

Executive summary:

In a primary eye irritation irritation study according to OECD Guideline 405, 100 mg niobium pentoxide (99.99%) was instilled to one eye of 3 male New Zealand White rabbits each (single instillation). Animals were observed 1, 24, 48 and 72 hours after instillation. Irritation was scored regarding corneal opacity, iridal lesions, conjunctival redness and chemosis. Except conjunctival redness all scores remained 0, giving no hint on eye irritation. 3 out of 3 animals showed conjunctival redness, which was fully reversible until 72 hours latest. Therefore, niobium pentoxide is not an eye irritant in this test.

The information is used in a read-across approach for the assessment of niobium carbide.