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Toxicological information

Acute Toxicity: oral

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Administrative data

Endpoint:
acute toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Study period:
25 January 2005 - 16 February 2005
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP compliant study conducted in accordance with international guidelines.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2002
Report Date:
2005

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method B.1 tris (Acute Oral Toxicity - Acute Toxic Class Method)
Deviations:
no
GLP compliance:
yes
Test type:
acute toxic class method

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): SILICON NITRIDE Si3N4
- Physical state: Grey powder
- Analytical purity: >97%
- Lot/batch No.: 2607/04-FS
- Storage condition of test material: In closed container: at least 1 year

Test animals

Species:
rat
Strain:
other: Crl:CD(SD)IGS BR
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS
- Age at study initiation: Approximately 8 weeks at the time of the administration.
- Housing: Single caging in Makrolon cages type III (39 cm x 23 cm bottom area, 18 cm height). Wire mesh lids. Sanitation of cages once a week.
- Diet (e.g. ad libitum): ad libitum. Exception: The feed was withdrawn the evening before the
administration of the test substance and was offered again about
three hours afterwards.
- Water (e.g. ad libitum): at libitum
- Acclimation period: At least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): Average of 21.9 °C (continuous control and recording)
- Humidity (%): Average of 49.9% (continuous control and recording)
- Air changes (per hr): 12
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
water
Remarks:
deionised
Details on oral exposure:
VEHICLE
- Justification for choice of vehicle: The test substance could be homogeneously suspended in water and water shall be used preferably, according to the guidelines.

MAXIMUM DOSE VOLUME APPLIED: The dose volume was 10ml per kg body weight for all groups
Doses:
300 and 2000 mg per kg
The dose volume was 10 mL per kg body weight for all groups.
No. of animals per sex per dose:
3
Control animals:
no
Details on study design:
- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Observations were performed within the periods 0 - 0.5, 0.5 - 1, 1 - 2, 2 - 4 and 4 - 6 hours
after administration (p.a.) of the test substance and then at least once a day for a total of 2 weeks. Observations included but were not limited to changes in skin, fur, eyes, the occurrence of secretions and excretions, autonomic activity, changes in gait, posture and the presence of convulsions.
Body weights were determined: before administration, 7 and 14 days after administration
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight.

Results and discussion

Effect levels
Sex:
female
Dose descriptor:
LD50
Effect level:
> 2 000 mg/kg bw
Based on:
test mat.
Mortality:
All animals survived until the scheduled termination of the study.
Clinical signs:
No toxic effects present.
Body weight:
One animal had a minimal body weight gain 7 - 14 d p.a. This was considered to be toxicologically unremarkable. Weight gains and body weights in the other animals were inconspicuous.
Mean body weight after 14 days of administration for the duplicate doses of 300 and 2000 mg/kg were accordingly: 26.0 g (SD = 4.6), 17.3g (SD = 1.5), 18.7g (SD = 4.0), 8.3g (SD = 6.4).
Gross pathology:
All animals were normal at the necropsy 14 d p.a.

Applicant's summary and conclusion

Interpretation of results:
not classified
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
No toxic effects of the test substance were noted by signs in life and post mortem at a dose of 2000 mg test substance per kg body weight. No mortality occurred.
According to Commission Directive 2001/59/EC "SILICON NITRIDE Si3N4" does not require classification for acute oral toxicity.