Dicerium trioxide

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2017

Reliability:

1 (reliable without restriction)

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)

GLP compliance:

yes (incl. QA statement)

Test type:

acute toxic class method

Test material

Test material information

Constituent 1

Reference substance name:

Dicerium trioxide

EC Number:

215-718-1

EC Name:

Dicerium trioxide

Cas Number:

1345-13-7

Molecular formula:

Ce2O3

IUPAC Name:

dicerium trioxide

Test material form:

solid: particulate/powder

Details on test material:

Fine Light Yellow Powder

Test animals

Species:

rat

Strain:

Wistar

Sex:

female

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

olive oil

Doses:

The starting dose could be selected from the fixed dose levels of 5, 50, 300, and 2000 mg/kg body weight. A limit dose of 2000 mg/kg body weight was used as a starting dose. One group of 3 females was dosed. Test item-related mortality was not observed during 24 hours and therefore, in a second step, another 3 females were treated at the same dose.

No. of animals per sex per dose:

The starting dose could be selected from the fixed dose levels of 5, 50, 300, and 2000 mg/kg body weight. A limit dose of 2000 mg/kg body weight was used as a starting dose. One group of 3 females was dosed. Test item-related mortality was not observed during 24 hours and therefore, in a second step, another 3 females were treated at the same dose.

Results and discussion

Preliminary study:

The test item Cerium Oxideadministered to 6 females ata limit dose of 2000 mg/kg body weight did not caused death. No signs of toxicity were observed during the first 4 hours in females or the 14-day observation period thereafter.The body weights of all animals increased during the study. A stagnation and a slight decrease of body weights in two animals wereobserved between the first and second week after administration of the test item. During necropsy, no macroscopic findings were observed.

Effect levels

Sex:

female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Mortality:

0

Body weight:

The body weights of all animals increased during the study. A stagnation of body weights in animals No 5 and 6 and a slight decrease of body weights in animals No 3 and No 4were observed between the first and second week after administration of the test item. Summary results of body weights are presented in Table 3.

Any other information on results incl. tables

All (6/6 females) animals survived the limit dose of 2000 mg/kg body weight

Table1Administration Results

Sex	Dose	ID	Result	Sex	Dose	ID	Result
♀	2000 mg/kg	1	alive	♀	2000  mg/kg	4	alive
		2	alive			5	alive
		3	alive			6	alive

No mortality was observed during the study. During the follow up period, no animals displayed signs of intoxication, change of health, nor any other adverse reaction.

Table3Body Weight

Sex	Dose	ID	Body Weight (g)			Body Weight Difference (g)
			Initial	Week 1	Week 2	Week 1 - Initial	Week 2 - Initial	Week 2 - Week 1
♀	2000 mg/kg	1	190	210	220	20	30	10
		2	185	200	205	15	20	5
		3	180	200	195	20	15	-5
		4	190	200	195	10	5	-5
		5	190	210	210	20	20	0
		6	190	200	200	10	10	0

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

Table4NecropsyResults

Sex	Dose	ID	Result	Sex	Dose	ID	Result
♀	2000 mg/kg	1	no finding	♀	2000 mg/kg	4	no finding
		2	no finding			5	no finding
		3	no finding			6	no finding

Applicant's summary and conclusion

Interpretation of results:

Category 5 based on GHS criteria

Conclusions:

The LD50 of the test item Cerium Oxideisgreater than 2000 mg/kg body weight after single oral administration to Wistar rats.

Executive summary:

Based onAnnex 2d Test Procedure with a Starting Dose of 2000 mg/kg body weight of OECD Guideline 423itcan be concluded that thetest itemCerium Oxideis according to UNGlobally Harmonized System of Classification, Labelling and Packaging of Chemicalsclassified Category 5/Unclassified with a LD₅₀cutoff value equal to or greater than5000 mg/kgbody weight according to Regulation (EU) Nr. 1272/2008 (CLP),after single oral administration to Wistar rats.