CTO

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

18 January to 14 February 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Report date:

2018

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method)

Version / remarks:

2001

GLP compliance:

yes (incl. QA statement)

Test type:

acute toxic class method

Limit test:

yes

Test material

Test material information

1

Reference substance name:

Cesium tungstate (Cs0.33WO3)

Cas Number:

189619-69-0

Molecular formula:

Cs0.33WO3

IUPAC Name:

Cesium tungstate (Cs0.33WO3)

Test material form:

solid: particulate/powder

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No. of test material: Lot B0345
- Purity: >99%
- Appearance: dark blue powder

Test animals

Species:

rat

Strain:

Wistar

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Dobrá Voda, Slovak Republic
- Females nulliparous and non-pregnant: Yes
- Age at study initiation: 8-12 wks
- Weight at study initiation: 175-200 g
- Fasting period before study: overnight
- Housing: housed in plastic cages suspended on stainless steel racks, up to 3 animals per cage
- Diet: The laboratory food ssniff (Spezialdiäten GmbH, Germany) was offered at recommended doses each day approximately at the same time.
- Water: ad libitum
- Acclimation period: acclimated under the conditions identical to the conditions during the experiment 5 days prior to the start of treatment.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22.8 ± 0.5° C
- Humidity (%): 54.0 ± 2.0 %
- Photoperiod (hrs dark / hrs light): 12-hour light /12-hour dark cycle

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

olive oil

Details on oral exposure:

VEHICLE
- Justification for choice of vehicle: Olive oil is a standard vehicle according to OECD TG 423
- Lot/batch no.: L63417
- The required amount of the test item (according to the body weight and dose) was mixed with vehicle (olive oil) shortly before administration.

CLASS METHOD
- Rationale for the selection of the starting dose: The starting dose could be selected from the fixed dose levels of 5, 50, 300, and 2000 mg/kg body weight. Available information indicated that the test item is likely to be non-toxic with regard to acute toxicity. A limit dose of 2000 mg/kg body weight was therefore used as a starting dose.

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

6 females

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Animals were observed individually immediately after administration of the test item and 0.5, 1, 2, and 4 hours later.
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight, histopathology; Clinical observations included: changes in skin, fur, eyes, mucous membranes, respiratory, circulatory, autonomic and central nervous systems, somatomotor activity, and behavioural pattern. Particular attention was given to potential neurologic endpoints such as tremors, convulsions, salivation, diarrhoea, lethargy, sleep and coma.

Results and discussion

Effect levels

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

None

Clinical signs:

other: The limit dose of 2000 mg/kg body weight did not cause death or evident signs of toxicity. During the follow up period, no other signs of intoxication, change of health, nor any other adverse reactions were displayed.

Gross pathology:

All animals were necropsied. During necropsy, no macroscopic findings were observed.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The test item, Cesium Tungsten Oxide, was administered to 6 females Wistar rats at a limit dose of 2000 mg/kg. The limit dose did not cause death or evident signs of toxicity. During the follow up period, no other signs of intoxication, change of health, nor any other adverse reactions were displayed. The body weight of animals increased between week 1 and week 2, except 1 animal. The macroscopical examination of the animals at the end of the study did not reveal treatment-related changes. The LD50 of the test item was thus determined to be greater than 2000 mg/kg body weight after single oral administration to Wistar rats.

The test item Cesium Tungsten Oxide does not meet GHC classification criteria as based on study results the LD50 cut off value is equal to or greater than 5000 mg/kg body weight, after single oral administration to Wistar rats.

Executive summary:

The test item, Cesium Tungsten Oxide, was administered to 6 females Wistar rats at a limit dose of 2000 mg/kg. The limit dose did not cause death or evident signs of toxicity. During the follow up period, no other signs of intoxication, change of health, nor any other adverse reactions were displayed. The body weight of animals increased between week 1 and week 2, except 1 animal. The macroscopical examination of the animals at the end of the study did not reveal treatment-related changes. The LD50 of the test item was thus determined to be greater than 2000 mg/kg body weight after single oral administration to Wistar rats.

The test item Cesium Tungsten Oxide does not meet GHS classification criteria as based on study results the LD50 cut off value is equal to or greater than 5000 mg/kg body weight, after single oral administration to Wistar rats.