Caesium chloride

Endpoint summary

Description of key information

According to the results of an acute oral toxicity study with cesium chloride and acute dermal toxicity studies with two structural analogous read-across substances cesium chloride is not classified according to Regulation (EC) No 1272/2008 (CLP/GHS).

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:

weight of evidence

Study period:

no data

Reliability:

4 (not assignable)

Qualifier:

according to guideline

Guideline:

other: no data

GLP compliance:

not specified

Test type:

other: no data

Species:

rat

Strain:

not specified

Sex:

not specified

Route of administration:

other: oral

Sex:

not specified

Dose descriptor:

LD50

Effect level:

2 600 mg/kg bw

Based on:

test mat.

Interpretation of results:

Toxicity Category V

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The acute oral LD50 of cesium chloride in rats was determined to be 2600 mg/kg bw.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 600 mg/kg bw

Quality of whole database:

WoE approach with different studies in mice and rats which reveal values within the same range

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:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

2012-01-24 to 2012-02-22

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: CLP, guideline and GLP compliant study. An experimental study was performed with a structural analogous read-across substance.

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Version / remarks:

, adopted 1987

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

, adopted 1992

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1200 (Acute Dermal Toxicity)

Version / remarks:

,adopted 1998

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

fixed dose procedure

Species:

rat

Strain:

Wistar

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, 11 /12 weeks old
- Weight at study initiation: Male 272-300 g, Female 217-242 g
- Fasting period before study: food but not water was withheld overnight
- Housing: 5 animals/sex/cage
- Diet: ad libitum (ssniff® SM R/M-Z+H complete diet )
- Water: ad libitum
- Acclimation period: 5 days for the pre-study, 19 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: approximately 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.

Remarks:

cesium nitrate

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 1 727.6 mg/kg bw

Based on:

other: calculated for cesium chloride

Mortality:

no mortality occured

Clinical signs:

other: In males treated with 2000 mg/kg bw, blood around the nose (4 cases of 80 observations) was observed. This symptom (score +2) was found in two animals. It was detected between 1 and 5 hours after the treatment. However, this effect cannot be related to th

Gross pathology:

All animals survived until the scheduled necropsy on Day 15. Slight hydrometra was observed in one female and moderate hydrometra was found in a second female. Hydrometra was an indication for the sexual cycle of female animals and is a frequent observation in experimental rats with no toxicological meaning.
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:

An acute dermal toxicity study with cesium chloride is not available. Consequently, read-across was applied using study data from cesium nitrate. The acute dermal LD50 value of the test item cesium nitrate was greater than 2000 mg/kg bw in male and female Crl:(WI)BRrats.
Since cesium nitrate has a higher molecular weight due to the molecular weight of the counter ion the calculated value for cesium chloride is > 1728 mg/kg bw. Due to the fact that no test item related toxic effects or other changes occurred in this limit test of the structural analogous read-across substance cesium chloride was not classified as harmful category 4.

Executive summary:

An acute dermal toxicity study with cesium chloride is not available. Consequently, read-across was applied using study data from cesium nitrate.

An acute dermal toxicity study was performed with the test item cesium nitrate 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 nitrate 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. The test item did not cause dermal irritation symptoms as erythema, oedema or other signs.

In this acute dermal toxicity study with the test item cesium nitrate, the obtained acute dermal LD50 value was greater than 2000 mg/kg bw in male and female Crl:(WI)BRrats. Since cesium nitrate has a higher molecular weight due to the molecular weight of the counter ion the calculated value for cesium chloride is > 1728 mg/kg bw. Due to the fact that no test item related toxic effects or other changes occurred in this limit test of the structural analogous read-across substance cesium chloride was not classified as harmful category 4.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Quality of whole database:

An acute dermal toxicity study with cesium chloride is not available. Consequently, data from two structural analogous read-across substances, cesium nitrate and cesium iodide, were used. Both substances were tested up to the limit concentration. No test item related toxic effects or other changes were observed. Since both substances have a higher molecular weight due to the molecular weight of the counter ion the calculated value for cesium chloride is e.g. > 1728 mg/kg bw. Due to the fact that no test item related toxic effects or other changes occurred in limit tests of two structural analogous read-across substance the cesium chloride was not classified as harmful category 4.
Please refer to IUCLID section 13 for read-across justification.

Additional information

Oral:

A weight-of-evidence approach was used with different studies in mice and rats which reveal values within the same range and demonstrate the low oral toxicity of cesium chloride. An oral LD50 value of 2600 mg/kg bw in rats was used for the risk assessment.

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: 188 µm, d50: 344 µm, d90: 556 µm) no inhalable particles are expected. Inhalation exposure is thus expected to be negligible.

Dermal:

Key Study:

An acute dermal toxicity study with cesium chloride is not available. Consequently, read-across was applied using study data from cesium nitrate.

An acute dermal toxicity study was performed with the test item cesium nitrate 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 nitrate 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. The test item did not cause dermal irritation symptoms as erythema, oedema or other signs.

In this acute dermal toxicity study with the test item cesium nitrate, the obtained acute dermal LD50 value was greater than 2000 mg/kg bw in male and female Crl:(WI)BRrats. Since cesium nitrate has a higher molecular weight due to the molecular weight of the counter ion the calculated value for cesium chloride is > 1728 mg/kg bw. Due to the fact that no test item related toxic effects or other changes occurred in this limit test of the structural analogous read-across substance cesium chloride was not classified as harmful category 4.

Supporting Study:

An acute dermal toxicity study with cesium chloride is not available. Consequently, read-across was applied using study data from cesium iodide.

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.

Since cesium iodide has a higher molecular weight due to the molecular weight of the counter ion the calculated value for cesium chloride is > 1296 mg/kg bw. Due to the fact that no test item related toxic effects or other changes occurred in this limit test of the structural analogous read-across substance cesium chloride was not classified as harmful category 4.

Justification for selection of acute toxicity – oral endpoint
Data in rats

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: 188 µm, d50: 344 µm, d90: 556 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 with a structural analogous read-across substance

Justification for classification or non-classification

According to the results of an acute oral toxicity study with cesium chloride and acute dermal toxicity studies with two structural analogous read-across substances cesium chloride is not classified according to Regulation (EC) No 1272/2008 (CLP/GHS).