Caesium carbonate

Endpoint summary

Description of key information

Two studies (in vitro and in vivo) are available for skin irritation and one in vitro study for eye irritation.

OECD Guideline 431: the conclusion of the study was that the test item is considered to be not corrosive to the skin.

OECD Guideline 404: the conclusion of the study was that the test item (50 % solution) is considered as a negligible irritant to the skin.

OECD Guideline 437: the conclusion of the study was that the test item is considered as eye damaging.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Reference 1

Endpoint:

skin irritation: in vivo

Type of information:

not specified

Adequacy of study:

weight of evidence

Study period:

Final report : Dec. 17th, 2003

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Main deficiency: Test material was Cesium carbonate 50% solution

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

GLP compliance:

yes

Specific details on test material used for the study:

Cesium carbonate 50% solution

Irritation parameter:

edema score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Irritation parameter:

erythema score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Interpretation of results:

GHS criteria not met

Executive summary:

The test article, cesium carbonate 50% solution, was evaluated for its potential to produce primary dermal irritation or corrosion after a single topical 4 hour application to the skin of New Zealand White rabbits. The test article is considered a negligeable irritant.

Reference 2

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

2010-07-02 to 2010-07-03

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 431 (In Vitro Skin Corrosion: Human Skin Model Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Justification for test system used:

The EPISKIN model has been validated for corrosivity testing in an international trial; it is considered to be suitable for this study (STATEMENT ON THE SCIENTIFIC VALIDITY OF THE EPISKINTM TEST (AN IN VITRO TEST FOR SKIN CORROSIVITY); ECVAM JRC Environment Institute, European Commission; Ispra; 03 April 1998).

Details on test system:

RECONSTRUCTED HUMAN EPIDERMIS (RHE) TISSUE
- Model used: EpiDerm ™
- Tissue batch number(s): 13657
- Delivery date: 01. Jul. 2010
- Date of initiation of testing: 02. Jul. 2010

TEMPERATURE USED FOR TEST SYSTEM
- Temperature used during treatment / exposure: 37 °C

MTT DYE USED TO MEASURE TISSUE VIABILITY AFTER TREATMENT / EXPOSURE
- Incubation time: 3 hours
- Spectrophotometer: plate spectral photometer Dynatech MRX
- Wavelength: 570 nm

NUMBER OF REPLICATE TISSUES: 2

NUMBER OF INDEPENDENT TEST SEQUENCES / EXPERIMENTS TO DERIVE FINAL PREDICTION:

PREDICTION MODEL / DECISION CRITERIA (choose relevant statement)
- The test substance is considered to be corrosive to skin if the viability after 3 minutes exposure is less than 50%, or if the viability after 3 minutes exposure is greater than or equal to 50 % and the viability after 1 hour exposure is less than 15%.
- The test substance is considered to be non-corrosive to skin if the viability after 3 minutes exposure is greater than 50% and the viability after 1 hour exposure is greater than 15%.

Control samples:

yes, concurrent vehicle

yes, concurrent positive control

Amount/concentration applied:

59 mg

Duration of treatment / exposure:

3 min, 1 h

Number of replicates:

2

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

Negative control (3 min and 1 h)

Value:

100

Vehicle controls validity:

valid

Negative controls validity:

not examined

Positive controls validity:

valid

Remarks on result:

no indication of irritation

Remarks:

(OD570 = 1.598)

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

Positive control (1 h)

Value:

20.3

Vehicle controls validity:

valid

Negative controls validity:

not examined

Positive controls validity:

valid

Remarks on result:

positive indication of irritation

Remarks:

(OD570 = 0.325)

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

Test item (1 h)

Value:

47.4

Vehicle controls validity:

valid

Negative controls validity:

not examined

Positive controls validity:

valid

Remarks on result:

no indication of irritation

Remarks:

(OD570 = 0.757)

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

Test item (3 min)

Value:

102.6

Vehicle controls validity:

valid

Negative controls validity:

not examined

Positive controls validity:

valid

Remarks on result:

no indication of irritation

Remarks:

(OD570 = 1.656)

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

Positive control (3 min)

Value:

25.5

Vehicle controls validity:

valid

Negative controls validity:

not examined

Positive controls validity:

valid

Remarks on result:

positive indication of irritation

Remarks:

(OD570 = 0.411)

Interpretation of results:

GHS criteria not met

Conclusions:

According to OECD Guideline 431 study the test item is considered to be not corrosive.

Executive summary:

The test item is considered to be not corrosive. After three minutes treatment, the relative absorbance values were decreased to 102.6 %. This value is well above the threshold for corrosivity (50 %). After one hour treatment relative absorbance values were reduced to 47.4 %. This value is well above the threshold for corrosivity (15 %). The values of the negative control were well above the required acceptability criterion of mean OD > 0.8 for both treatment interval thus showing the quality of the tissues. The value of the positive control induced a decrease in the relative absorbance as compared to the negative control to 25.5 % for the three minutes treatment interval and 20.3 % for the one hour treatment interval thus ensuring the validity of the test system. Although the value of the one-hour-experiment was 20.3 % and therefore higher than the threshold for corrosivity, this is considered as not relevant, as a clear corrosive effect was determined and values above 15 % have been measured for the positive control before: Values for the positive control were within the range of historical data of the test facility.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2015-02-12 to 2015-02-12

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP and guideline compliant study

Qualifier:

according to guideline

Guideline:

OECD Guideline 437 (Bovine Corneal Opacity and Permeability Test Method for Identifying Ocular Corrosives and Severe Irritants)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Species:

other: bovine

Details on test animals or tissues and environmental conditions:

Isolated corneas obtained as a by-product from a slaughterhouse were used after examination for defects. They were mounted in corneal holders with endothelial side against the O-ring of the posterior chamber. After treatment with RPMI an opacity measurement was performed using an opacitometer to discarded corneas that have an initial opacity reading above 7 units. Three corneas with opacity readings approximately equivalent to the median opacity were selected as negative-controll. For testing 750 µL of test item or control substance were used (closed-chamber method). After incubation time substances were removed and the epithelium was washed with MEM (RPMI was used for the controll group). The anterior chamber was refilled with complete RPMI and the opacity measurement was performed. In addition optical density at 490 nm was determined using a spectrophometer. Therefore the poserior chamber was refilled with complete RPMI and the anterior chamber with 1 ml of 5 mg/ml sodium fluorescein solution. After the incubation time of 90 min at 32 +- 1°C the optical density was measured. After that the in vitro irritation score (IVIS) was determined with following formula: mean opacity value + (15 x mean permeabiltiy optical densitiy at 490 nm.

Vehicle:

physiological saline

Amount / concentration applied:

The test item was suspended with physiological saline 0.9% NaCl (see 10.3) to gain a
20% concentration.

Duration of treatment / exposure:

4 hours +- 5 min to measure the opacity.
90min to measure the optical density at 490 nm.

Irritation parameter:

in vitro irritation score

Run / experiment:

Mean

Value:

183.05

Vehicle controls validity:

valid

Negative controls validity:

not examined

Positive controls validity:

valid

Remarks on result:

positive indication of irritation

Interpretation of results:

Category 1 (irreversible effects on the eye) based on GHS criteria

Remarks:

Migrated information

Conclusions:

According to the evaluation criteria the test item cesium carbonate is classified into UN GHS Category 1.

Executive summary:

The eye irritancy potential of cesium carbonate was investigated in the bovine corneal opacity and permeability assay.The study followed the procedures indicated by OECD Guideline for the Testing of Chemicals, number 437 “Bovine Corneal Opacity and Permeability Test Method for Identifying i) Chemicals Inducing Serious Eye Damage and ii) Chemicals Not Requiring Classification for Eye Irritation or Serious Eye Damage”. Therefore the test item cesium cabonate was suspended with physiological saline 0.9% NaCl to gain a 20% concentration. The mean in vitro irritation score was calculated at 183.05. Therefore the test item was classified into UN GHS Category 1. The in vitro irritation score obtained with the positive control fell within the two standard deviations of the current historical mean and therefore this assay is considered to be valid.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irreversible damage)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Skin irritation

in vitro

One valid experiment was performed in accordance with OECD guideline 431. Two tissues of the human skin model EpiDerm™ were treated with Cesium Carbonate for three minutes and one hour, respectively. ln average 59 mg of the solid test item were applied to each tissue and spread to match the tissue size. Deionised water was used as negative control, Sm KOH was used as positive control. After treatment with the negative control the absorbance values were weil above the required acceptability criterion of mean 00 > 0.8 for both treatment intervals thus showing the quality of the tissues. The positive control showed clear corrosive effects for both treatment intervals. After three minutes treatment with the test item, the relative absorbance values were increased to 102.6 %. This value is weil above the threshold for corrosion potential (50 %). After one hour treatment, relative absorbance values were reduced to 47.4 %. This value, too, is weil above the threshold for corrosion potential (15 %). Therefore, cesium carbonate is considered as not corrosive in the Human Skin Model
Test.

 

in vivo

The test article, cesium carbonate 50% solution, was evaluated for its potential to produce primary dermal irritation or corrosion after a single topical 4 hour application to the skin of New Zealand White rabbits. The test article is considered a negligable irritant.

 

Eye irritation

The eye irritancy potential of cesium carbonate was investigated in the bovine corneal opacity and permeability assay according to OECD guideline 437. The test item was suspended with physiological saline 0.9% NaCl to gain a 20% concentration. The mean in vitro irritation score was 185.05. The in vitro irritation score obtained with the positive control fell within the two standard deviations of the current historical mean and therefore this assay is considered to be valid. According to the evaluation criteria the test item cesium carbonate is regarded as eye damaging (cat 1 if IVIS scorre is above 55).

Justification for classification or non-classification

 

The test item was not corrosive in an in vitro skin corrosion study according to OECD 431. In addition, an in vivo study performed according the OECD guideline 404 concluded that Cesium carbonate 50% solution was considered as a negligible irritant. Therefore, cesium carbonate was not classified as skin irritant.

 

The test item was corrosive in an in vitro eye corrosion study according to OECD 437 “Bovine Corneal Opacity and Permeability Test" and was classified with Cat. 1 for serious eye damage according to Regulation (EC) No 1272/2008 (CLP/GHS).