Caesium iodide

Endpoint summary

Description of key information

The acute oral LD50 value and the acute dermal LD50 value of the test item was greater than 2000 mg/kg bw in rats. Therefore, the test item has not to be classified according to Regulation (EC) No 1272/2008 (CLP/GHS).
According to REACH Regulation (EC) No 1907/2006, Annex VIII, 8.5 data for a maximum of two routes of exposure need to be provided. Testing for acute toxicity via the inhalation route was not applicable as data on acute oral and acute dermal toxicity were available. Based on the results of the particle size distribution study (d10: 125 µm, d50: 226 µm, d90: 391 µm) no inhalable particles are expected. Inhalation exposure is thus expected to be negligible.

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

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.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Deviations:

not specified

Remarks:

, e.g. 9 instead of 10 animals

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

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)

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).

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)

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

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.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

2 386 mg/kg bw

Quality of whole database:

CLP and Guideline compliant study

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Link to relevant study records

Reference

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2011-01-24 to 2011-02-23

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP and guideline compliant

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Version / remarks:

adopted 24 February 1987

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.3 (Acute Toxicity (Dermal))

Version / remarks:

Regulation (EC) 440/2008 of 30 May 2008

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

fixed dose procedure

Limit test:

yes

Species:

rat

Strain:

other: Crl(WI)Br

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Toxi-Coop Zrt. 1103 Budapest, Cserkesz u. 90.
- Age at study initiation: Young adult rats, femles were nulliparous and non-pregnant
- Weight at study initiation: Preliminary study: 202-222 g, Male 274-300 g, Female 220-244 g
- Fasting period before study: food but not water was withheld overnight
- Housing: during acclimatisation: 3 animals/sex/cage, during the study: individually
- Diet: ad libitum (ssniff® SM R/M-Z+H complete diet )
- Water: ad libitum
- Acclimation period: 5 days for the pre-study, 20 days for the main study

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 3 °C
- Humidity (%): 30 - 70 %
- Air changes (per hr): 8-12 air exchanges/hour by central air-condition system.
- Photoperiod: Artificial light, from 6 a.m. to 6 p.m.

Type of coverage:

semiocclusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

TEST SITE
- Area of exposure: at least 10 % of the total body surface
- Type of wrap if used: sterile gauze pad below a semi-occlusive plastic wrap

REMOVAL OF TEST SUBSTANCE
- Washing: water pre-warmed to body temperature
- Time after start of exposure: 24 hours

TEST MATERIAL
- Amount applied: Main-tests: 2000 mg/kg bw; pre-test: Pre-test: 5 mg/kg bw, 50 mg/kg bw, 300 mg/kg bw, 2000 mg/kg bw
- Constant volume or concentration used: yes

Duration of exposure:

single administration for 24 hours

Doses:

Main-test
2000 mg/kg bw

No. of animals per sex per dose:

Main-test: 5 males and 5 females
Pre-tests: 2 females per dose

Control animals:

not required

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: For the main study, the body weight of all animals were recorded on day 0 (shortly before the treatment), on day 7 and on day 15 (with a precision of 1 g)
- Necropsy of survivors performed: yes
- Other examinations performed: Animals were observed individually 1 h and 5 h after dosing, and once each day for 14 days thereafter. Observations included the skin and fur, eyes and mucous membranes, and also respiratory, circulatory, autonomic and central nervous system, and somatomotor activity and behaviour pattern. Particular attention was directed to observation of tremors, convulsions, salivation, diarrhoea, lethargy, sleep and coma.
All animals were subjected to gross pathology. All animals were exsanguinated under isoflurane anaesthesia. After examination of the external appearance the cranial, thoracic and abdominal cavities were opened and the appearance of the tissues and organs were observed. All gross pathological changes were recorded for each animal on the post mortem record sheets. The animals of preliminary study were humanely sacrificed on day 7.

Statistics:

not applicable

Preliminary study:

No mortalities occured during the preliminary study

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

No mortalities occured

Clinical signs:

other: In one male treated with 2000 mg/kg bw dose porphyrin excretion (1 cases of 80 observations) was observed. This symptom (score +1) was found on right eye on Day 1. Four animals were free of symptoms during the study. All male animals were free of symptoms

Gross pathology:

All animals survived until the scheduled necropsy on Day 15.
No macroscopic alterations due to the systemic toxic effects of the test item were found.

Other findings:

none

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The acute dermal LD50 value of the test item was greater than 2000 mg/kg bw in male and female Crl(WI)Br rats.

Executive summary:

An acute dermal toxicity study was performed with the test item cesium iodide in Crl(WI)Br rats, in compliance with OECD Guideline No. 402 and EU Method B.3. A limit test was carried out. A single group of male and female animals (n=5 animals/sex) was exposed to the test item at 2000 mg/kg bw by dermal route. The test item was applied in its original form and left in contact with the skin for 24 hours, followed by a 14-day observation period.

No mortality occurred after the single dermal administration of cesium iodide at a dose of level 2000 mg/kg bw with an exposure period of 24 h. No test item related systemic toxic clinical signs were observed and no test item related effects on the animal’s body weights were established throughout the study. The general symptoms observed could not be connected to a toxic effect of the test item but may be related to the induced stress during the treatment procedure (for example due to the presence of the bandage etc.). Autopsy revealed no treatment related pathological changes.

In this acute dermal toxicity study with the test item cesium iodide, the obtained acute dermal LD50 valuewas greater than 2000 mg/kg bw in male and female Crl(WI)Br rats.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

discriminating dose

Value:

2 000 mg/kg bw

Quality of whole database:

CLP and Guideline compliant study

Additional information

Oral:

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

The oral LD50 Males was 2386 mg/kg bw (95% C.L: 2310 - 2467 mg/kg)

Inhalation:

According to REACH Regulation (EC) No 1907/2006, Annex VIII, 8.5 data for a maximum of two routes of exposure need to be provided. Testing for acute toxicity via the inhalation route was not applicable as data on acute oral and acute dermal toxicity were available. Based on the results of the particle size distribution study (d10: 125 µm, d50: 226 µm, d90: 391 µm) no inhalable particles are expected. Inhalation exposure is thus expected to be negligible.

Dermal:

An acute dermal toxicity study was performed with the test item cesium iodide in Crl(WI)Br rats, in compliance with OECD Guideline No. 402 and EU Method B.3. A limit test was carried out. A single group of male and female animals (n=5 animals/sex) was exposed to the test item at 2000 mg/kg bw by dermal route. The test item was applied in its original form and left in contact with the skin for 24 hours, followed by a 14-day observation period.

No mortality occurred after the single dermal administration of cesium iodide at a dose of level 2000 mg/kg bw with an exposure period of 24 h. No test item related systemic toxic clinical signs were observed and no test item related effects on the animal’s body weights were established throughout the study. The general symptoms observed could not be connected to a toxic effect of the test item but may be related to the induced stress during the treatment procedure (for example due to the presence of the bandage etc.). Autopsy revealed no treatment related pathological changes.

In this acute dermal toxicity study with the test item cesium iodide, the obtained acute dermal LD50 value was greater than 2000 mg/kg bw in male and female Crl(WI)Br rats.

Justification for selection of acute toxicity – oral endpoint
Most reliable study

Justification for selection of acute toxicity – inhalation endpoint
According to REACH Regulation (EC) No 1907/2006, Annex VIII, 8.5 data for a maximum of two routes of exposure need to be provided. Testing for acute toxicity via the inhalation route was not applicable as data on acute oral and acute dermal toxicity were available. Based on the results of the particle size distribution study (d10: 125 µm, d50: 226 µm, d90: 391 µm) no inhalable particles are expected. Inhalation exposure is thus expected to be negligible.

Justification for selection of acute toxicity – dermal endpoint
Most reliable study

Justification for classification or non-classification

According to the resutls from the acute oral toxicity study, no classification and labelling is required according to Regulation No (EC) 1272/2008 (CLP) criteria.

According to the resutls from the acute dermal toxicity study, no classification and labelling is required according to Regulation No (EC) 1272/2008 (CLP) criteria.