Caesium hydroxide

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1974

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Cross-reference

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference 1

Reference Type:

publication

Title:

Acute toxicity of cesium and rubidium compounds

Author:

Johnson, G.T.; Lewis, R.T. and Wagner, W.D.

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

Test guideline 2

Qualifier:

equivalent or similar to guideline

Guideline:

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

Deviations:

not specified

GLP compliance:

no

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Caesium hydroxide

EC Number:

244-344-1

EC Name:

Caesium hydroxide

Cas Number:

21351-79-1

Molecular formula:

CsHO

IUPAC Name:

caesium hydroxide

Constituent 2

Reference substance name:

Cesium hydroxide

IUPAC Name:

Cesium hydroxide

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

CsOH was dissolved in deionized-distilled water on a weight-to-weight basis prior to administration.

Doses:

500, 625, 781, 976, 1220, 1525 mg/kg bw.

No. of animals per sex per dose:

10 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:

no preliminary results.

Effect levels

Sex:

male

Dose descriptor:

LD50

Effect level:

1 026 mg/kg bw

Based on:

test mat.

Remarks:

Caesium hydroxide

95% CL:

929 - 1 133

Mortality:

All deaths occured within the first 72 h after dosing.

Clinical signs:

other: Clinical signs were increased respiration rate, ruffled fur, eye closing and huddling together. A bloody nasal exudate was noted in several animals receiving the higher doses.

Gross pathology:

Lethal and certain sublethal doses induced stomach and intestinal haemorrhage and adhesions of abdominal organs (stomach, pancreas, spleen, liver and small intestines). In the higher dose range, death was related to the degree of blockage of the gastrointestinal tract from the resultant adhesions and/or the leakage of the bloody fluid exudate into the peritoneal cavity.

Other findings:

Behavioral effects noted for survivors were initial hyperexcitability followed by apathy and weakness which persited the 14-day observation period.

Applicant's summary and conclusion

Interpretation of results:

Toxicity Category IV

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The acute oral LD50 of cesium hydroxide in albino rats was determined to be 1026 mg/kg bw.

Executive summary:

In an acute oral toxicity study, groups of 10 fasted male albino rats were given a single oral dose of cesium hydroxide in water at 6 different doses and observed for 14 days.

All deaths occurred within the first 72 h after dosing. Clinical signs were increased respiration rate, ruffled fur, eye closing and huddling together. A bloody nasal exudate was noted in several animals receiving the higher doses. Lethal and certain sublethal doses induced stomach and intestinal haemorrhage and adhesions of abdominal organs (stomach, pancreas, spleen, liver and small intestines). In the higher dose range, death was related to the degree of blockage of the gastrointestinal tract from the resultant adhesions and/or the leakage of the bloody fluid exudate into the peritoneal cavity.

Oral LD50 for males for cesium hydroxide = 1026 mg/kg bw (95% C.L: 929 - 1133).