Niobium oxide

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

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

Qualifier:

according to guideline

Guideline:

OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method)

GLP compliance:

yes (incl. QA statement)

Test type:

acute toxic class method

Limit test:

yes

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 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 suspended in dimethylsulfoxide prior to use after crushing with a pestle and mortar to a fine dust, because there is no other suitable solvent. The suspension was carefully mixed immediately before administration. The homogeneity was proved visually.

Test animals

Species:

rat

Strain:

Wistar

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles RIver Wiga GmbH, 9730 Sulzfeld, Germany
- Females (if applicable) nulliparous and non-pregnant: yes
- Age at study initiation: approx. 7 weeks
- Weight at study initiation: 214.0 ± 13.3 g
- Fasting period before study: over night before oral administration
- Housing: groups of up to 3 per cage (Makrolon type 3)
- Bedding: ALTROMIN Type S8/15, granulated soft wood bedding
- Diet (e.g. ad libitum): ad libitum, ALTROMIN 1324, pelleted standard diet
- Water (e.g. ad libitum): ad libitum, tap water
- Acclimation period: 6 days before randomisation

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21.0 - 21.5
- Humidity (%): 30 - 40 %, with a shortly falling below 25 %
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

other: 0.5 % (m/v) solution of Tylose MH 1000 in deionised water

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 3 g test item filled up to 15 mL using 0.5 % (m/v) solution of Tylose MH 100 in deionised water
- Amount of vehicle (if gavage):

MAXIMUM DOSE VOLUME APPLIED: 10 mL/kg bw

CLASS METHOD (if applicable)
- Rationale for the selection of the starting dose: according to the mentioned regulatory guideline the limit test should be done at one dose level of 2000 mg/kg bw

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

6 female rats

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing:
- Clinical signs and mortality: continuously on administration day, once daily thereafter
- Weighing: On the day of administration and on days 7 and 14.
- Necropsy of survivors performed: yes, all animals were examined externally. The cranial, thoracic and abdominal cavities were then opened and examined macroscopically.

Statistics:

Group mean values and standard deviations for body weights and body weight gain.

Results and discussion

Effect levels

Effect levels 1

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Effect levels 2

Sex:

female

Dose descriptor:

LD0

Effect level:

2 000 mg/kg bw

Based on:

test mat.

Mortality:

None

Clinical signs:

No signs observed

Gross pathology:

No findings observed

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

In conclusion, the oral LD50 in rats after treatment with niobium oxide is considered to be greater than 2000 mg/kg bw.

Executive summary:

In an acute oral toxicity study according to OECD guideline 423, six fasted female Wistar rats were given a single oral dose of niobium oxide (>99% purity), suspended in a 0.5% (m/v) solution of Tylose MH 1000 in deionised water, at a dose of 2000 mg/kg bw (limit test) and were observed for 14 days. Neither mortality nor adverse clinical signs were recorded during the observation period. Based on the results from this study, the oral LD50 in rats is considered to be greater than 2000 mg/kg bw.