[No public or meaningful name is available]

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

no details given

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Data source

Reference

Reference Type:

publication

Title:

Acute Toxicological Effects of Multi-Walled Carbon Nanotubes (MWCNT)

Author:

Murthy et al.

Year:

2011

Bibliographic source:

Carbon Nanotubes - Growth and Applications, Dr. Mohammad Naraghi (Ed.), InTech, DOI: 10.5772/18984

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

GLP compliance:

not specified

Remarks:

GLP compliance is not specified in this publication

Type of study:

Buehler test

Justification for non-LLNA method:

no details given

Test material

Test material information

Constituent 1

Reference substance name:

Reference substance 001

EC Number:

919-206-5

Test material form:

solid: nanoform

Details on test material:

MWCNT1: 5-8 microns in length with 3-8nm inside diameter and outside diameter of 140±30 nm; Product No. 659258, purchased from Sigma-Aldrich, USA.

Specific details on test material used for the study:

MWCNT1: 5-8 microns in length with 3-8 nm inside diameter and outside diameter of 140 ± 30 nm; Product No. 659258 purchased from Sigma-Aldrich, USA.
The multi-walled carbon nanotubes used in the study were produced by catalytic chemical vapor deposition (CCVD). MWCNT1 were composed of 99.9 % carbon with small amount (<0.1% Fe) of iron. The manufacturer specification for nanomaterial characterization was confirmed by the following techniques. MWCNT1 characteristics were assessed in the as-synthesized form prior to use for experiments or after dispersion in the vehicle (distilled water) for dosing. Solution characteristics were measured with dynamic light scattering (DLS).

In vivo test system

Test animals

Species:

guinea pig

Strain:

Dunkin-Hartley

Sex:

male

Details on test animals and environmental conditions:

TEST ANIMALS
- Weight at study initiation: 300 - 400 g
- Housing: individually in standard stainless steel cages and sterilized paddy husk as bedding. Bedding material was changed daily, whereas water bottles were changed on alternate days
- Diet (e.g. ad libitum): ad libitum standard rabbit pellet food (supplier: M/s. Amrut Laboratory Animal Feed, Pune). The diet was supplemented with ascorbic acid.
- Water (e.g. ad libitum): ad libitum supply of UV treated water. The food and water was routinely analyzed and are considered not to contain any contaminants that could reasonably be expected to affect the purpose or integrity of the study.
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 ± 3 °C
- Humidity (%): 50 ±20 %
- Photoperiod (hrs dark / hrs light): 12 h light/dark cycle

Study design: in vivo (non-LLNA)

Induction

Route:

epicutaneous, occlusive

Vehicle:

not specified

Remarks:

purified

Concentration / amount:

400 mg

Day(s)/duration:

induction (day 1), same treatment was repeated on days 7 and 14

Adequacy of induction:

not specified

Challenge

Route:

epicutaneous, occlusive

Vehicle:

not specified

Concentration / amount:

200 mg

Day(s)/duration:

challenge on day 28, observation 30 and 54 h after challenge

Adequacy of challenge:

not specified

No. of animals per dose:

20 (test group)
10 (control group)

Details on study design:

- Exposure period: day 0, day 7, day 14
- Test groups: 20 animals
- Control group: 10 animals
- Site: One flank of each animal was closely clipped free of hair, without any abrasion, 24 hours before the induction exposure
- Frequency of applications: 3 times
- Duration: 6h
- Concentrations: 400 mg

B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day(s) of challenge: day 28
- Test groups: 20 animals
- Control group: 10 animals
- Site: posterior flank of both treatment and control groups
- Concentrations: 200 mg
- Evaluation (hr after challenge): 30h and 54 h after application challenge

Positive control substance(s):

not specified

Results and discussion

In vivo (non-LLNA)

Results

Results 1

Reading:

1st reading

Hours after challenge:

30

Group:

test chemical

No. with + reactions:

0

Total no. in group:

20

Clinical observations:

None of the animals treated with MWCNT1 showed any dermal reactions

Remarks on result:

no indication of skin sensitisation

Results 2

Reading:

2nd reading

Hours after challenge:

54

Group:

test chemical

No. with + reactions:

0

Total no. in group:

20

Clinical observations:

None of the animals treated with MWCNT1 showed any dermal reactions

Remarks on result:

no indication of skin sensitisation

Results 3

Group:

negative control

Remarks on result:

no indication of skin sensitisation

Results 4

Group:

positive control

Remarks on result:

not measured/tested

Applicant's summary and conclusion

Conclusions:

None of the animals treated with MWCNT1 exhibited any dermal reactions. Hence MWCNT1 can be considered as non-sensitizer.

Executive summary:

In order to assess the skin sensitisation potential of MWCNT1, the Buehler Test was performed in 30 (20 test and 10 control) male Dunkin Hartley guinea pigs in accordance with OECD 406 and the Directive 96/54/EEC, B.6.

The test substance at a dose of 400 mg was applied to all animals of the treatment group for a period of 6 h. The same treatment was repeated on days 7 and 14. Similarly, the animals in the control group were treated with distilled water. On day 28, 200 mg of the test material was applied via a cotton pad to both treatment and control groups for 6 h.

The skin reactions were observed and scored at 30 h and 54 h after application. None of the animals treated with MWCNT1 exhibited any dermal reactions, hence MWCNT1 can be considered as non-sensitizer.