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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

Constituent 1
Chemical structure
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.

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