Cobalt sulphate

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:

Spanish article translated into english. - The stability of the test item was missing. - According to the guideline, at least 5 rodents of the same sex should be used at each dose level and later at least one group of the other sex should be tested to establish that animals of this sex are not markedly more sensitive to the test substance. In the publication it was not clear how many animals were used at each dose level and it was also not clear how many males and females were used at the different dose levels. - Observation period was only 7 days instead of the recommended 14 days by the guideline. In the publication it was stated that animals rarely died after 48 hours, but it was not clear at which time point for certain animals did not die anymore. According to the guideline, the time of death should be recorded as precisely as possible. In addition, it was not mentioned how many animals showed signs of toxicity. - According to the guideline, the animals should be weighed, but nothing was stated about weighing the animals. - According to the guideline, clinical examination should be made at certain time intervals. In the publication was nothing stated about the time points at which observations were made. - According to the guideline, animals which die during the test are necropsied, and at the conclusion of the test the surviving animals are sacrificed and necropsied. In the publication it was only stated that surviving animals were sacrificed after 7 days. - According to the guideline, the volume administered to rodents should not exceed 1 ml/100g body weight, except in the cases of aqueous solutions where 2 ml/ 100 g may be used. Variability in the test volume should be minimised by adjusting the concentration to ensure a constant volume at all dose levels. There was no indication on what volume was administered to the rats and if it was at a constant volume.

Data source

Reference

Reference Type:

publication

Title:

Toxicidad aguda y alteraciones hematológicas y séricas por algunas sales de cobalto en ratas

Author:

Llobet, J.M. & Domingo, J.L.

Year:

1983

Bibliographic source:

Revista Española de Fisiologia, 39: 291 - 298.

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

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 sulphate

EC Number:

233-334-2

EC Name:

Cobalt sulphate

Cas Number:

10124-43-3

Molecular formula:

Co.H2O4S

IUPAC Name:

λ²-cobalt(2+) sulfate

Details on test material:

- Name of test material (as cited in study report): Cobalt sulphate heptahydrate
- Molecular formula (if other than submission substance): CoSO4*7H2O
- Analytical purity: The salt was analytically pure
No further information on the test material was stated.

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Weight at study initiation: Mean weight 192.5 +/- 22.3 g
- Diet: ad libitum
- Water:ad libitum
- Fasting period before study: Fasted for 24 hours before administration
No further information on the test animals was stated.

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

Rationale for the selection of the dose levels: They chose the dose levels based on pre-tests with a small number of rats. It was tested at which dose no deaths occurred and at which dose all test animals died.
No further information on the oral exposure was stated.

Doses:

1000 mg/kh, 1110 mg/kg, 1232 mg/kg, 1368 mg/kg, 1520 mg/kg, 1685 mg/kg

No. of animals per sex per dose:

8 or 10 animals (It was not clearly stated in the publication how many males and females were used per dose and if the genders were equally distributed.)

Control animals:

yes

Details on study design:

- Duration of observation period following administration: 7 days
- Frequency of observations and weighing: No data
- Necropsy of survivors performed: Yes
No further information on the study design was stated.

Statistics:

Method for determination of LD50, and confidence limit according to Litchfield and Wilcoxon (1949).

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LD50

Effect level:

1 330 mg/kg bw

95% CL:

>= 1 220 - <= 1 450

Mortality:

Death occurred in 95 % of animals within the first 24 hours after administration. Most animals even died within the first 6 hours. Rats rarely died after 48 hours.
The following percentage of animals died at the different dose levels:
1000 mg/kg: 0 %
1110 mg/kg: 10 %
1232 mg/kg: 30 %
1368 mg/kg: 50 %
1520 mg/kg: 80 %
1685 mg/kg: 100 %

Clinical signs:

other: Intoxication symptoms: (occurred shortly after intoxication) decrease of general activity and especially exploiting behaviour, frequency of "getting up"; increase of water consumption; deficit in motivity of hind legs, less pain sensitivity Clinical signs

Gross pathology:

No marcoscopic alterations were observed at the most significant organs.

Applicant's summary and conclusion

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

Cobalt sulphate heptahydrate is moderately toxic if administered orally.
LD50: 1330 mg/kg (Confidence interval: 1220 - 1450)
According to the EC Regulation No. 1272/2008 and subsequent regulations, the test item is classified as Category 4.