Caesium sulphate

Acute Toxicity: dermal

Administrative data

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.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2012

Report date:

2012

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Version / remarks:

, adopted 1987

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

, adopted 1992

Deviations:

no

Test guideline 3

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

Test material

Test material information

Constituent 1

Reference substance name:

Caesium nitrate

EC Number:

232-146-8

EC Name:

Caesium nitrate

Cas Number:

7789-18-6

Molecular formula:

Cs.HNO3

IUPAC Name:

cesium nitrate

Test material form:

solid: crystalline

Test animals

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.

Administration / exposure

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

Results and discussion

Preliminary study:

No mortalities occured during the preliminary study

Effect levels

Effect levels 1

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Remarks:

cesium nitrate

Effect levels 2

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 1 856.7 mg/kg bw

Based on:

other: calculated for cesium sulphate

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

Applicant's summary and conclusion

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

An acute dermal toxicity study with cesium sulphate 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 sulphate is > 1857 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 sulphate was not classified as harmful category 4.

Executive summary:

An acute dermal toxicity study with cesium sulphate 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 valuewas 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 sulphate is > 1857 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 sulphate was not classified as harmful category 4.