Caesium iodide

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

no data

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: No GLP, equivalent or similar to OECD and EU guideline.

Data source

Reference

Reference 1

Reference Type:

publication

Title:

Acute Toxicity studies of cesium and rubidium compounds

Author:

Johnson, G.T.; Lewis, R.T. and Perone, V.P.

Year:

1975

Bibliographic source:

Toxicology and applied pharmacology 32, 239-245 (1975)

Reference 2

Reference Type:

publication

Title:

Unnamed

Year:

1972

Materials and methods

Test guideline

Test guideline 1

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Deviations:

not specified

Remarks:

, e.g. 9 instead of 10 animals

Test guideline 2

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method B.1 (Acute Toxicity (Oral))

Deviations:

not specified

Remarks:

, e.g. 9 instead of 10 animals

GLP compliance:

no

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Caesium iodide

EC Number:

232-145-2

EC Name:

Caesium iodide

Cas Number:

7789-17-5

Molecular formula:

CsI

IUPAC Name:

caesium iodide

Test material form:

solid: crystalline

Test animals

Species:

rat

Strain:

other: Charles River albino rats

Sex:

male

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River, cesarian-derived albino rats
- Weight at study initiation: 175 -250 g
- Fasting period before study: yes (overnight, 16 h)

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

VEHICLE
- Justification for choice of vehicle: good solubility in water

Doses:

First main test: 820, 1170, 1660, 2350, 3340, 4750 mg/kg
Second main test: 1890, 2120, 2515, 2680, 3010 mg/kg

No. of animals per sex per dose:

9 male rats

Control animals:

not specified

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: 1 and 4 h following administration and dayly thereafter for the 14-day period
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, histopathology, behavioral observations

Statistics:

The LD50 values and their 95% confidence limits were calculated by probit analysis of Finney (1971).

Results and discussion

Preliminary study:

not applicable; however, range finding study was performed:
The test material was administered as a single dose, orally by stomach tube, to caesarean-derived rats weighing between 175 and 250 grams. Eight test groups of three animals per group (24 total) were used. The animals were fasted from food for approximately 16 hours prior to dosing. The test material was dissolved in deionized and distilled water. Observations for morbidity and mortality were recorded at 1 and 4 hours following administration and daily thereafter for the 7-day period. Gross necropsy observations were made on all animals which died or were sacrificed at the end of the 7-day observation period.
Results: Doses (died animals/3): 180 (0/3 deaths), 301 (0/3), 502 (0/3), 838 (0/3), 1400 (0/3), 2338 (2/3), 3904 (3/3) and 6520 (3/3) mg/kg)

Effect levels

Sex:

male

Dose descriptor:

LD50

Effect level:

2 386 mg/kg bw

Based on:

test mat.

95% CL:

2 310 - 2 467

Mortality:

All deaths occured within the first 72 h after dosing.

Clinical signs:

other: Clinical signs: weakness and listlessness

Gross pathology:

congested, cyanotic lungs with petechial hemorrhages and a fluid-distended stamach which appeared to result from spasm of the pyloric sphincter
following the dosing

Other findings:

Behavioral effects noted for survivors: week, thin and some exhibited bloody nasal exudate and eye discharge at sacrifice

Applicant's summary and conclusion

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The acute oral LD50 of cesium iodide in albino rats was determined to be 2386 mg/kg bw.

Executive summary:

In an acute oral toxicity study, groups of 9 fasted male albino rats were given a single oral dose of cesium iodide (> 99 %) in water at 11 different doses and observed for 14 days.

Oral LD50 Males = 2386 mg/kg bw (95% C.L: 2310 - 2467 mg/kg)

Cesium iodide is not classified after oral administration based on the LD50 obtained in male rats.