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Acute Toxicity: dermal

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Administrative data

Endpoint:
acute toxicity: dermal
Type of information:
experimental study
Adequacy of study:
key study
Study period:
july 2007
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP guideline study (OECD 402)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2008
Report date:
2008

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 402 (Acute Dermal Toxicity)
Deviations:
yes
Remarks:
acclimatation: 4 days
GLP compliance:
yes (incl. QA statement)
Test type:
standard acute method
Limit test:
yes

Test material

Constituent 1
Chemical structure
Reference substance name:
Tangled Multi-Walled Carbon Nanotubes
EC Number:
701-160-0
Cas Number:
7782-42-5
Molecular formula:
Hollow tubular carbon, 1-dimensional nano structures with hexagonal arrangement of carbon atoms
IUPAC Name:
Tangled Multi-Walled Carbon Nanotubes
Constituent 2
Reference substance name:
GRAPHISTRENGTH C100
IUPAC Name:
GRAPHISTRENGTH C100
Test material form:
solid: nanoform

Test animals

Species:
rat
Strain:
Sprague-Dawley
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source:Janvier, Le Genest-Saint-Isle, France
- Age at study initiation:approximately 8 weeks old
- Weight at study initiation:287+/- 6g for the males and 214+/- 5g for the females
- Fasting period before study:no
- Housing:During the acclimatation period, 1 to 7 animals of the same sex were housed in polycarbonate cages with stainless steel lid (48cm x 27cm x 20cm). During the treatment period, the animals were housed individually in polycarbonate cages with stainless steel lid (35.5cm x 23.5cm x 19.3cm). Each cage contained autoclaved sawdust, sawdust is analyzed by the supplier for composition and contaminant levels.
- Diet:SsniffR/M-H pelleted diet, ad libitum
- Water:filtered by a FG Millipore membrane (0.22 micron), ad libitum
- Acclimation period:4 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C):22+/-2
- Humidity (%):30 to 70
- Air changes (per hr):approximately 12 cycles/hour of filtered, non-recycled air
- Photoperiod (hrs dark / hrs light):12h/12h

Administration / exposure

Type of coverage:
semiocclusive
Vehicle:
unchanged (no vehicle)
Details on dermal exposure:
Purified water was used in order to to moisten the test item and ensure a good contact with a skin.
TEST SITE
- Area of exposure:dorsal area (5cm x 7cm for the males and 5cm x 6cm for the females)
- % coverage:approximately 10%
- Type of wrap if used:a hydrophilic gauze pad (pre-moistened with 2mL of purified water) held in contact with the skin for 24 hours by means of an adhesive hypoallergenic aerated semi-occlusive dressing and a restraining bandage. The dressing prevented from ingestion of the test item by the animal.

REMOVAL OF TEST SUBSTANCE
- Washing (if done):no
- Time after start of exposure:24 hours
- For solids, paste formed: yes
Duration of exposure:
24 hours
Doses:
2000 mg/Kg
No. of animals per sex per dose:
5 animals/sex/dose
Control animals:
not required
Details on study design:
- Duration of observation period following administration: 14 days
- Frequency of observations: frequently during the hours following administration of the test item; thereafter at least once a day until day 15.
-Frequency of weighing:individually, just before administration of the test item on day 1 and then on days 8 and 15.
- Necropsy of survivors performed: yes
Statistics:
no

Results and discussion

Preliminary study:
no
Effect levels
Key result
Sex:
male/female
Dose descriptor:
LD0
Effect level:
>= 2 000 mg/kg bw
Based on:
test mat.
Remarks on result:
other: no mortality
Mortality:
no deaths occured during the study
Clinical signs:
no clinical signs were observed during the study.
A black coloration of the skin was noted in all the animals from day 2 until day 10, in all the males and in one female between day 11 and day 15.
This coloration masked the evaluation of cutaneous reactions in all the animals from day 2 until day 6.
Crusts were observed in 1/5 males and 2/5 females between day 11 and day 15.
Body weight:
not affected by the treatment
Gross pathology:
macroscopic examination of the main organs of the animals (digestive tract, heart, kidneys, liver, lungs, pancreas, spleen and any other organs with obvious abnormalities) revealed no apparent abnormalities.
Other findings:
no

Applicant's summary and conclusion

Interpretation of results:
not classified
Remarks:
Migrated information Criteria used for interpretation of results: other: Regulation n°1272/2008
Conclusions:
Under the experimental conditions of this study, the dermal LD0 of the test item GRAPHISTRENGTH C100 micronised was equal to or higher than 2000mg/Kg in rats.
Executive summary:

The acute dermal toxicity of the test item GRAPHISTRENGTH C100 micronised was evaluated in rats according to OECD 402 and Good Laboratory Practice Regulations. The test item was applied to the skin of one group of ten Sprague-Dawley rats (five males and five females). The application was performed with the test item in its original form at the dose-level of 2000 mg/Kg.

The test site was then covered by a semi-occlusive dressing for 24 hours. Clinical signs, mortality and body weight gain were checked for a period of 14 days following the single application of the test item. All animals were subjected to necropsy.

No deaths and no clinical signs were observed during the study. A black coloration of the skin was noted in all the animals from day 2 until day 10, in all the males and in one female between day 11 and day 15. This coloration masked the evaluation of cutaneous reactionsin all the animals from day 2 until day 6. Crusts were observed in 1/5 males and 2/5 females between day 11 and day 15.

No apparent abnormalities were observed at necropsy in any animal.

The dermal LD0 of the test item GRAPHISTRENGTH C100 micronised was equal to or higher than 2000 mg/Kg in rats.