Magnesium diniobate

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2009-09-01 to 2009-09-29

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2009

Report date:

2009

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Version / remarks:

1987-02-24

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.3 (Acute Toxicity (Dermal))

Version / remarks:

2008-05-30

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

signed 2009-04-06

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

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

Test material form:

solid

Details on test material:

- State of aggregation: pale yellow solid
- Density: ~4.5 g/cm³

Specific details on test material used for the study:

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: at room temperature

Test animals

Species:

rat

Strain:

other: Crl:WI(Han)

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River, 97633 Sulzfeld, Germany
- Females nulliparous and non-pregnant: yes
- Age at study initiation: males: 6 - 7 weeks old; females: 9 - 10 weeks
- Weight at study initiation: males: 216 - 225 g; females: 201 - 205 g
- Housing: kept individually in IVC cages, type III H, polysulphone cages on Altromin saw fibre bedding
- Diet (ad libitum): Altromin 1324 maintenance diet for rats and mice
- Water (ad libitum): tap water, sulfur acidified to a pH value of approx. 2.8
- Acclimation period: males: 6 days; females: 19 days

ENVIRONMENTAL CONDITIONS
- Temperature: 22 ± 3 °C
- Relative humidity: 55 ± 10 %
- Air changes: 10 x/hour
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Type of coverage:

other: occlusive or semi-occlusive dressing (not clearly stated)

Vehicle:

water

Details on dermal exposure:

TEST SITE
- Area of exposure: approx. 24 hours before test, the fur was removed from the dorsal area of the trunk by using an electric clipper.
The test item was applied uniformly over an area of approx 10 % of the total body surface.
- Type of wrap if used: the test item was held in contact with the skin by a dressing. The dressing consisted of a gauze-dressing and non-irritating tape and was fixed with an additional dressing.

REMOVAL OF TEST SUBSTANCE
- Washing / Time after start of exposure:
females: at the end of the exposure period residual test item was removed by using tap water
males: the application sites were not washed

Duration of exposure:

24 hours

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

5 males / 5 females

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: animals were weighed on day 0 (prior to the application) and on days 7 and 14. Clinical examination was made several times on the day of dosing (at least once during the first 30 minutes and with special attention given during the first 4 hours post dose) as well as once daily until the end of the observation period.
- Necropsy of survivors performed: yes, all animals were subjected to gross necropsy at the end of the observation period.
- Skin irritation was examined according to the Draize scale

Statistics:

not applicable

Results and discussion

Preliminary study:

none

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Remarks on result:

no indication of skin irritation up to the relevant limit dose level

Mortality:

No mortality occurred during the study.

Clinical signs:

No treatment-related effects were observed.
1/5 male animals showed slight scratches on the left side of application 2 to 7 days after dosing. 1/5 male animals showed slight scratches on the right side day 2 after dosing. No other signs of irritation were recorded within the observation period for any of the animals.

Body weight:

The body weight development of all male and female animals was within the expected range.
A slight weight loss of 2 g was recorded for 1/5 female animals during the first week, whereas all females gained weight during the second week. Toxicological relevance of this finding cannot clearly be concluded.
The male animals showed weight gain during the first and second week of the observation period.

Gross pathology:

With the exception of acute injection of blood vessels in the abdominal region, which is due to the euthanasia injection, no specific gross pathological changes were recorded for any animal.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

LD50 (male and female rats) > 2000 mg/kg bw
According to the Regulation (EC) No 1272/2008 and subsequent adaptations, the substance is not acutely toxic via the dermal route.