Niobium dioxide

Endpoint summary

Description of key information

No data is available for Niobium dioxide (target substance). Thus, Niobium oxide (source substance) is used to assess the skin and eye irritating/corrosive potential of Niobium dioxide in a read-across approach.

Niobium oxide was tested negative in an acute skin and in an acute eye irritation/corrosion study (EU methods B.4 & B.5).

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Endpoint:

skin irritation: in vivo

Type of information:

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

Adequacy of study:

key study

Justification for type of information:

For justification of read-across please refer to the read-across report attached to IUCLID section 13.

Reason / purpose for cross-reference:

read-across source

Irritation parameter:

erythema score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

0

Remarks on result:

no indication of irritation

Irritation parameter:

edema score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

0

Remarks on result:

no indication of irritation

Irritant / corrosive response data:

The treated and also the control skin area did not show any irritations at any observation time. After one hour the administration area was discoloured slightly black in all animals. This discolouration did not interfere with the evaluation of a possible erythema.
For detailed information on the individual results, please see Table 1 in box "Any other information on results".

Other effects:

None of the animals died during the course of investigation and no clinical signs were observed.

Table 1: Evaluation of alterations of the skin area after administration of the test item

Alteration	Animal No.	Observed grades of skin alteratioons of each observation time
		Hours after administration
		1		24		48		72
		Control	Test Item	Control	Test Item	Control	Test Item	Control	Test Item
Erythema	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
Oedema	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

* The administration area was discoloured slight black; this discolouring did not interfere with the evaluation of a possible erythema.

Interpretation of results:

GHS criteria not met

Conclusions:

In the acute dermal irritation/corrosion study according to Directive 67/548/EEC, Annex V, B.4, Niobium oxide is considered to be non-irritating to the skin.

Executive summary:

In a primary dermal irritation study (EU method B.4), young adult male New Zealand White rabbits (3/sex) were dermally exposed to 0.5 g of Niobium oxide (>99% purity), moistened with 0.5% (m/v) solution of Tylose MH100 in deionised water, for 4 hours to a body surface area of 2 x 3 cm. Animals then were observed for 1, 24, 48 and 72 hours. Irritation was scored by the method of Draize.

Neither mortality nor any adverse clinical signs of toxicity were observed during the study. The treated and also the control skin areas did not show any irritations at any observation time. In this study, Niobium oxide is not a dermal irritant.

This information is used in a read-across approach in the assessment of the target substance.

For justification of read-across please refer to the attached read-across report (see IUCLID section 13).

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:

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

Adequacy of study:

key study

Justification for type of information:

For justification of read-across please refer to the read-across report attached to IUCLID section 13.

Reason / purpose for cross-reference:

read-across source

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

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

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

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 serous 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.

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

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 serous 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.

This information is used in a read-across approach in the assessment of the target substance.

For justification of read-across please refer to the attached read-across report (see IUCLID section 13).

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

No data is available for Niobium dioxide (target substance). Thus, Niobium oxide (source substance) is used to assess the skin and eye irritating/corrosive potential of Niobium dioxide in a read-across approach.

For justification of read-across please refer to the read-across report attached to IUCLID section 13.

The source substance Niobium oxide (>99% purity) was tested negative for acute dermal irritating properties in a study conducted according to EU method B.4. After a dermal exposure period of 4 hours no skin effects were observed in rabbits.

In an acute eye irritation study (EU method B.5) a slight redness of the conjunctivae and a serous lacrimation was observed in all animals on the day of instillation after treatment with the source substance. The cornea and iris were not affected. After 24 hours no signs of irritation were observed anymore. Thus, Niobium oxide is not considered to be an eye irritant.

Justification for classification or non-classification

The read across partner Niobium oxide did not cause any skin and eye effects in an acute dermal and eye irritating study in accordance to EU method B.4 and EU method B.5. Based on these results, the target substance Niobium dioxide does not warrant classification for skin and eye irritation in accordance to CLP regulation (EC) No 1272/2008.