Selenious acid

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Adequacy of study:

supporting study

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

other: Not reliable, due to lack of information on method, e.g. no doses and no observation time was stated, only 5 animals were dosed (sex ratio unknown).

Data source

Reference

Reference Type:

publication

Title:

Behavioral and toxic profile of some essential trace metal salts in mice and rats.

Author:

Singh, PP

Year:

1991

Bibliographic source:

Ind. J. Pharmacol. 23, 153-159

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

Rats and mice were administered selenium dioxide dissolved in water by perioral route. According to ATSDR for oral exposure selenium dioxide dissolved in water is selenious acid. In one experiment the LD50 was determined and in another test 1/10 of the LD50 was administered to examine the gross behavioural effects. Selenium dioxide was dissolved in de-ionized triple glass distilled water and were administered by p.o. It is not sure if the LD50 is for selenium dioxide or for selenious acid, since selenium dioxide changes into selenious acid when dissolved in water.

GLP compliance:

not specified

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Selenium dioxide

EC Number:

231-194-7

EC Name:

Selenium dioxide

Cas Number:

7446-08-4

Molecular formula:

O2Se

IUPAC Name:

oxoselane oxide

Details on test material:

- Name of test material (as cited in study report): selenium dioxide
According to ATSDR for oral exposure selenium dioxide dissolved in water is selenious acid.

Test animals

Species:

other: rats and mice

Strain:

other: wistar rats and swiss mice

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- albino rats and mice
- Weight at study initiation: 100 - 125 g (rats); 20-22 g (mice)
- Housing: polycarbonate cages
- Diet (ad libitum): Gold Mohur Hind Lever diet
- Water (ad libitum): water

ENVIRONMENTAL CONDITIONS
- Temperature (°C): ambient temperature of 24±0.5°C
- Photoperiod (hrs dark / hrs light): 12 h dark and 12 h light cycle

Administration / exposure

Route of administration:

oral: unspecified

Vehicle:

water

Remarks:

de-ionized, distilled

Details on oral exposure:

VEHICLE
- The trace metal salts were dissolved in de-ionized triple glass distilled water.

Doses:

1/10 of the LD50 dose was administered for examination of the behavioural effect.
no doses used were stated for the LD50 determination

No. of animals per sex per dose:

5 animals per group

Control animals:

yes

Details on study design:

- The experiments were conducted between 10-15 h.
- Duration of observation period following administration: no data
- Frequency of observations and weighing: The gross behavioural changes were recorded at 30, 60, 120 and 240 min using method of Irwin (1959).
- Necropsy of survivors performed: no data
- Other examinations performed: clinical signs, body weight, organ weights, histopathology, other: The changes in rectal temperature were recorded by using the thermocouple probes on Digital precision thermometer-DU-3S (ELLAB, DENMARK). Behavioural effects were scored on a scale 0-8 where 4 was taken as normal. Score below 4 indicates decrease in activity and above 4 increase in activity. For body temperature the normal score was 0.

Statistics:

LD50 was calculated using the method of Horn.

Results and discussion

Effect levels

Effect levels 1

Sex:

male/female

Dose descriptor:

LD50

Effect level:

68.1 mg/kg bw

Based on:

not specified

Remarks on result:

other: rats

Effect levels 2

Sex:

male/female

Dose descriptor:

LD50

Effect level:

23.3 mg/kg bw

Based on:

not specified

Remarks on result:

other: mice); study not reliable, due to lack of information on method, e.g. no doses and no observation time was stated, only 5 animals were dosed (sex ratio unknown).

Mortality:

Salt of selenium showed marked depression of central nervous system followed by anoxic convulsions and death.

Clinical signs:

other: - In toxic doses the selenium salt exhibited marked depression of CNS in mice and rats evidenced by decrease in spontaneous motor activity, body and limb tone and impairments like pinnal and cornea1 reflexes. - In later stages animals showed anoxic convu

Other findings:

- Toxic effects were observed in mice and rats.
- In rats the trace metals used in 1/10 of their LD50 doses exhibited behavioural changes: selenium dioxide showed moderate reduction in spontaneous activity, muscle tone, touch response and respiration.
- Selenium dioxide showed moderate hypothermic effect which lasted up to 240 min
- Gross behavioural effects in mice: Alertness/spontaneous activity: 2; touch response/muscle tone: 2; respiration: 2; paio: 4; pinnal reflex/corneal Reflex/righting reflex:4; urination: 4; hypothermic: 2 (-1.48 °C)

Applicant's summary and conclusion

Interpretation of results:

other: The LD50 was found to be 68.1 mg/kg bw for rats . It is not sure if the LD50 is for selenium dioxide or for selenious acid, since selenium dioxide changes into selenious acid when dissolved in water.

Conclusions:

The LD50 was found to be 68.1 mg/kg bw for rats . Selenium dioxide was dissolved in de-ionized triple glass distilled water and the solution was administered p.o. It is not clear if the LD50 is for selenium dioxide or for selenious acid, since selenium dioxide changes into selenious acid when dissolved in water.