Registration Dossier

Data platform availability banner - registered substances factsheets

Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Toxicological information

Acute Toxicity: oral

Currently viewing:

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:
comparable to guideline study with acceptable restrictions

Data source

Reference
Reference Type:
publication
Title:
Organ biodistribution, clearance, and genotoxicity of orally administered zinc oxide nanoparticles in mice
Author:
Li C-H, Shen C-C, Cheng Y-W, Huang S-H, Wu C-C, Kao C-C, Liao,J-W and Kang J-J
Year:
2012
Bibliographic source:
Nanotoxicology, 6(7):746-56

Materials and methods

Test guideline
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method)
Deviations:
no
GLP compliance:
not specified
Remarks:
the publication does not specify GLP compliance
Test type:
other: limit test
Limit test:
yes

Test material

Constituent 1
Chemical structure
Reference substance name:
Zinc oxide
EC Number:
215-222-5
EC Name:
Zinc oxide
Cas Number:
1314-13-2
Molecular formula:
ZnO
IUPAC Name:
oxozinc
Test material form:
other: nano- and micromaterial
Details on test material:
uncoated ZnO nanoparticle:
- Diameter: 50 nm approximately
- Hydrodynamic diameter: 93.35 ± 14.53 nm

ZnO microparticles:
- Diameter: >100 nm
- Hydrodynamic diameter 1226.2 ± 120.4 nm

Other information: The suspensions of ZnO particles (stock concentration: 50 mg/mL) were prepared using anhydrous dimethyl sulfoxide (DMSO). ZnO-nanoparticle and ZnO microparticle were diluted with sterile water plus 1% hydroxypropyl methyl cellulose (HPMC) or culture medium, then mixed vigorously, sonicated, and then immediately applied to mice or human cells to minimize agglomeration. Finally, the DMSO concentration was less than 1% (in vivo study).

Test animals

Species:
mouse
Strain:
not specified
Sex:
male/female
Details on test animals or test system and environmental conditions:
No data

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
DMSO
Details on oral exposure:
- Rationale for the selection of the starting dose: Based on the result of another study (Yamaki & Yoshino 2009).
Doses:
5,000 mg/kg bw for both ZnO nanoparticle and microparticle
No. of animals per sex per dose:
5/sex/dose
Control animals:
yes
Details on study design:
Thirty mice were divided into three groups (five males and five females per group). Mice were fed with vehicle (control group), 5,000 mg/kg bw ZnO-nanoparticle suspension or 5,000 mg/kg bw ZnO-microparticles suspension. Dosed mice were conditioned for 14 d. The mortality and clinical behaviour were observed daily. Body weights were recorded twice weekly. At the end of the study (on Day 14), the mice were anaesthetised with isoflurane and blood (for serum biochemistry analysis) was collected from the orbital sinus, followed by gross necropsy. Tissue samples (for histopathologic examination) were taken and fixed in 10% neutral buffered formalin
Statistics:
All data were expressed as the mean ± SD from at least three independent experiments (N ‡ 3). The significance of the difference between the control and each experimental test condition was analysed by Student’s t-test. Statistically significant differences among groups were determined using one-way analysis of variance (ANOVA). A value of p < 0.05 was taken as statistically significant.

Results and discussion

Effect levels
Sex:
male/female
Dose descriptor:
LD50
Effect level:
> 5 000 mg/kg bw
Based on:
test mat.
Mortality:
Not observed
Clinical signs:
other: Not observed
Body weight:
other body weight observations
Remarks:
In comparison with vehicle control group, ZnO microparticles treated group showed a body weight reduction in both males (Days 5 and 10) and females (Days 5, 10, and 14); the body weight changes were unobvious in ZnO nanoparticle treated groups.
Gross pathology:
Decreased wet weights of the spleen, kidney, and liver were observed in ZnO microparticles treated females but not in ZnO nanoparticle treated males. However, no obvious gross pathological signs were found in the study.
Other findings:
All serum biochemistry measures were without any significant alternation except for marginal variations in certain parameters.

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Conclusions:
Based on the study details, the LD50 value of both the ZnO nanoparticles and ZnO microparticles can be established at >5,000 mg/kg bw in mice.
Executive summary:

The study was conducted to examine the acute toxicity of both ZnO nanoparticles and ZnO microparticles in mice.

Thirty mice were divided into three groups (five males and five females per group). Mice were fed with vehicle (control group), 5,000 mg/kg bw ZnO-nanoparticle suspension or 5,000 mg/kg bw ZnO-microparticles suspension. Dosed mice were conditioned for 14 d.

All the mice survived throughout the testing period without exhibiting any abnormalities related to the test substances. In comparison with the vehicle control group, ZnO-microparticles treated group showed a body weight reduction in both males (Days 5 and 10) and females (Days 5, 10, and 14); the body weight changes were not obvious in ZnO-nanoparticle treated groups. All serum biochemistry measures were without any significant alterations except for marginal variations in certain parameters.

Based on the study details, the LD50 value of both the ZnO nanoparticles and ZnO microparticles can be established at >5,000 mg/kg bw in mice.