Cobalt dinitrate

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Remarks:

Methodology well-documented Minor deviations from the guideline: - The stability of the test item was not stated. - According to the guideline, necropsy of all animals should be carried out. There was no information,if necropsy of the animals was carried out. - According to the guideline, the observation period should be at least 14 days. In this study only an observation period of 10 days was used. - According to the guideline, the number of animals that died or were killed during the test and the time of death after dosing should be stated. This information was missing in this publication. -According to the guideline, the LD50 values for the sex dosed determined at 14 days should be stated. The LD50 for combined sexes determined at 10 days was stated. - According to the guideline, the animals should be fasted before test item administration. There is no statement in the study, if this was done. - According to the guideline the individual weights of animals should be determined shortly before the test substance is administered, weekly thereafter and at death; changes in weight should be calculated and recorded when survival exceeds one day. At the end of the test surviving animals are weighed and then sacrificed. This information is missing in the report.

Data source

Reference

Reference Type:

publication

Title:

Acute oral toxicity of inorganic cobalt compounds in rats

Author:

Speijers, G.J.A. et al.

Year:

1982

Bibliographic source:

Fd Chem. Toxic, Vol. 20:311-314.

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Version / remarks:

1987-02-24

Deviations:

yes

Remarks:

, see "rational for reliability"

GLP compliance:

not specified

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Cobalt dinitrate

EC Number:

233-402-1

EC Name:

Cobalt dinitrate

Cas Number:

10141-05-6

Molecular formula:

Co.2NO3

IUPAC Name:

cobalt(2+) dinitrate

Details on test material:

- Name of test material (as cited in study report): Cobalt (II) nitrate hexahydrate
- Molecular formula: Co(NO3)2 * 6H2O
- Molecular weight: 291.1 g/mol
- Analytical purity: 99 % pure
No further information on the test material was stated.

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: The colony of the Animal Breeding Unit, National institute of Public Health, Bilthoven
- Weight at study initiation: approx. 100 g
- Housing: Caged singly or in pairs of the same sex and dose group, in wire cages.
- Diet (ad libitum): Semi-purified diet (Murneon-SSP Tox (Trouw Ltd. Putten)
- Water (ad libitum): Drinking water

ENVIRONMENTAL CONDITIONS
- Temperature: 22- 25 °C
- Relative humidity: 35 - 55 %
No further information on the test animals was statd.

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

VEHICLE
The compound was dissolved in in distilled water.
No further information about the oral exposure was stated.

Doses:

450 mg/kg bw, 675 mg/kg bw, 1000 mg/kg bw, 1500 mg/kg bw, 2250 mg/kg bw

No. of animals per sex per dose:

5 males / 5 females

Control animals:

not specified

Details on study design:

- Duration of observation period following administration: 10 days
- Frequency of observations and weighing: Signs of reaction and deaths were recorded for 10 days, and the rectal temperature was mesured in all survivng rats 1.5, 24 and 48 hr after administration of the cobalt compound.
- Necropsy of survivors performed: No data
No further information on the study design was stated.

Statistics:

The oral LD50 values for male and female combined, were calculated according to the method of mayximum likelihood of Finney (1971).

Results and discussion

Effect levels

Effect levels 1

Sex:

male/female

Dose descriptor:

LD50

Effect level:

691 mg/kg bw

Based on:

test mat.

95% CL:

526 - 907

Remarks on result:

other: This is the LD50 for the cobalt compound tested.

Effect levels 2

Sex:

male/female

Dose descriptor:

LD50

Effect level:

434 mg/kg bw

Remarks on result:

other: This is the LD50 for the anhydrous form of the test item. The LD50 of the anhydrous form of the cobalt compound was derived from the LD50 data of the cobalt compound tested.

Effect levels 3

Sex:

male/female

Dose descriptor:

LD50

Effect level:

140 mg/kg bw

Based on:

element

Remarks on result:

other: This is the LD50 for the cobalt (II) ion. The LD50 of the cobalt (II) ion was derived from the LD50 data of the cobalt compound tested.

Mortality:

No data

Clinical signs:

other: The highest dose caused sedation and diarrhoea. A decrease in body temperature was recorded. The temperature reductions were time- and dose-related.

Gross pathology:

No data

Applicant's summary and conclusion

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

The following LD50 value was determined for cobalt (II) nitrate hexahydrate:
LD50 (combined male and female rats): 691 mg/kg bw (95 % confidence interval: 526 - 907 mg/kg bw)
According to the EC Regulation No. 1272/2008 and subsequent regulations, the test item is classified as Category 4.