Silver

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Publication, not a full study report, GLP. However, the study has apparently been conducted in accordance with OECD guideline 402 and relevant experimental details and results are reported.

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

2013

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Version / remarks:

adopted 1987-02-24

Deviations:

no

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Silver

EC Number:

231-131-3

EC Name:

Silver

Cas Number:

7440-22-4

Molecular formula:

Ag

IUPAC Name:

Silver

Test material form:

solid: nanoform

Details on test material:

- Name of test material (as cited in study report): Ag-NPs (silver nanoparticles)(obtained from ABC Nanotech Co., Ltd. (Daejeon, Korea))
- Product name: SARPU 200KW (nano-sized colloidal silver)
- Physical state: black colloid
- Concentration in stock solution: 20.48%
- Lot No.: SL-132B4DD01
- Viscosity (cps): <15
- Specific gravity (at 25°C): 1.2
- Average particle size: 10.0 nm
- Particle surface area (mean): 3.18 x 10^2 mm^2/particle; 54.88 m^2/g
- pH: 5.80

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Koatec Co. Ltd. (Pyeongtaek, Korea)
- Age at study initiation: 8-week-old
- Weight at study initiation: 0 mg/kg: 252.93 ± 4.07 (males) and 228.69 ± 3.70 (females); 2000 mg/kg: 256.82 ± 5.99 (males) and 228.36 ± 8.40 (females)
- Housing: three animals were housed per cage, plus during the administration and observation periods, no more than three animals were housed in a wire cage.
- Diet (ad libitum): commercial rodent chow (TEKLAD CERTIFIED GLOBAL 18% PROTEIN RODENT DIET, 2918C Harlan Co. Ltd., Indianapolis, IN, USA
- Water (ad libitum): tap water sterilised by ultra-violet irradiation
- Quarantine and acclimation period: 1 week

ENVIRONMENTAL CONDITIONS
- Temperature: 23 ± 3°C
- Relative humidity: 55 ± 15%
- Air changes: 10 - 20 air changes per hour
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Type of coverage:

not specified

Vehicle:

other: 1% citric acid

Details on dermal exposure:

An electric clipper was used to expose the skin, then the test substance was applied and covered with a dressing. The dressing was removed after 24 hours.

Duration of exposure:

24 hours

Doses:

0 and 2000 mg/kg

No. of animals per sex per dose:

5 males / 5 females

Control animals:

yes

Details on study design:

- Duration of observation period following administration: 15 days
- Frequency of observations and weighing: the animals were observed twice a day over 15 days for any irritation and toxicity. The mortality, clinical signs, body weights and necropsy findings were observed and the results compared with those for the vehicle control group. The body weights were recorded on day 1, 3, 7 and 24.
- Necropsy of survivors performed: yes

Statistics:

The statistical analyses were performed using SPSS 12.1, Chicago, IL, USA and the data expressed as the mean ± SD. A chi-square test and one-way analysis of variance (ANOVA) were applied to test all the data. A value of p < 0.05 indicated statistical significance.

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 other: mg/kg

Based on:

test mat.

Mortality:

The Ag-NPs did not induce any abnormal signs in this study.

Clinical signs:

other: The Ag-NPs did not induce any death in this study.

Gross pathology:

There were no abnormal gross findings for any of the treated groups at necropsy.

Applicant's summary and conclusion

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

LD50 > 2000 mg/kg
According to the EC-Commission directive 67/548/EEC and its subsequent amendments, the test substance is not classified as acute toxic via the dermal route.
According to the EC-Regulation 1272/2008 and subsequent regulations, the test item is not classified as acute toxic via the dermal route.