Registration Dossier

Administrative data

Endpoint:
acute toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
study well documented, meets generally accepted scientific principles, acceptable for assessment
Remarks:
the number of deaths at each dose were not reported; the specific doses (mg/kg) were not provided; individual clinical observations, body weights, pathology were not reported; sex of the animals was not provided.

Data source

Referenceopen allclose all

Reference Type:
publication
Title:
Unnamed
Year:
1963
Reference Type:
secondary source
Title:
Toxicity
Author:
Haley T.J
Year:
1979
Bibliographic source:
Handbook on the Physics and Chemistry of Rare Earths, 553-585

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 401 (Acute Oral Toxicity)
GLP compliance:
no
Test type:
standard acute method
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: crystalline
Details on test material:
- Name of test material (as cited in study report): Terbium nitrate
- Purity > 98%
- Other: Terbium nitrate obtained from the Lindsay Chemical Company, West Chicago, Illinois, and the K and K Laboratories, Jamaica, New York. The six hydrate form was tested (6H2O).
No other information are available.

Test animals

Species:
rat
Strain:
Sprague-Dawley
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: No data
- Age at study initiation: adult
- Weight at study initiation: 190 g to 250 g
- Fasting period before study: no data
- Housing: Animals were housed in air-conditioned quarters
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: no data

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
water
Details on oral exposure:
Aqueous solutions (pH 4.0 - 5.9) of the rare earth nitrates were prepared immediately before injection.
The solutions were given in single doses as 50% aqueous solutions.
Doses:
Unknown
No. of animals per sex per dose:
5 or 10 animals per group
Control animals:
not specified
Details on study design:
- Duration of observation period following administration: 30 days
Statistics:
On the basis of the mortality that occurred during the 30-day observation period, the LD50 values with 95% confidence limits were calculated by the method of Litchfield and Wilcoxon (1949).

Results and discussion

Effect levelsopen allclose all
Key result
Sex:
female
Dose descriptor:
LD50
Effect level:
> 5 000 mg/kg bw
Based on:
test mat.
Sex:
female
Dose descriptor:
LD50
Effect level:
> 1 753 mg/kg bw
Based on:
element
Mortality:
The animals were observed for 30 days although no deaths occurred later than 4 days after administration of the nitrate salts.
Clinical signs:
Within 1 to 2 hours after oral administration of the rare earth nitrates, most of the rats were depressed, and animals that received lethal doses showed little activity during the survival period.
Body weight:
No data
Gross pathology:
Throughout the observation period no gross pathologic changes were noted.

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Conclusions:
The acute oral LD50 of terbium trinitrate in female rats was higher than 5000 mg/kg bw.
Executive summary:

In an acute oral toxicity study (Bruce DW et al., 1963), female Sprague-Dawley rats were given in single doses of terbium trinitrate as 50% aqueous solution and observed for 30 days.

Within 1 to 2 hours after oral administration of the rare earth nitrates, most of the rats were depressed, and animals that received lethal doses showed little activity during the survival period. The animals were observed for 30 days although no deaths occurred later than 4 days after administration of the nitrate salts. Throughout the observation period no gross pathologic changes were noted.

The acute oral LD50 of terbium trinitrate in female rats was higher than 5000 mg/kg bw.