Multi-Walled Carbon Nanotubes (MWCNT), synthetic graphite in tubular shape

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2006

Report date:

2006

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.3 (Acute Toxicity (Dermal))

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1200 (Acute Dermal Toxicity)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

carbon

EC Number:

936-414-1

Molecular formula:

C

IUPAC Name:

carbon

Test material form:

solid: nanoform, no surface treatment

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Harlan-Winkelmann GmbH, Borchen, Germany
- Strain: HsdCpb:Wu
- Age at study initiation: approx. 9-13 weeks
- Weight at study initiation: 221-246 g for males and 205-220 g for females
- Fasting period before study: none
- Housing: individually in polycarbonate cages on low dust wood granulate bedding
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 2
- Humidity (%): 55 +/- 5
- Air changes (per hr): approx. 10
- Photoperiod (hrs dark / hrs light): 12 / 12

Administration / exposure

Type of coverage:

semiocclusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

TEST SITE
- Area of exposure: 20 cm2
- % coverage: approx. 10
- Type of wrap if used: gauze patch fixed with an elastic adhesive tape pervious to air

REMOVAL OF TEST SUBSTANCE
- Washing (if done): rinsed with tepid water using soap
- Time after start of exposure: approx. 24 hours


TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 22.1-24.6 mg/cm2 (males) and 20.5-22.0 mg/cm2 (females)

Duration of exposure:

24 hours

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: several times on the day of application as well as at least once daily during observation period (clinical signs, mortality); surviving animals were weighed individually at application, after one week and at the end of the 14-day observation period.
- Necropsy of survivors performed: yes

Statistics:

none (limit test)

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Mortality:

All male and female animals survived the treatment.

Clinical signs:

other: No clinical signs were observed.

Gross pathology:

No gross pathological findings were observed.

Other findings:

none

Applicant's summary and conclusion

Executive summary:

The acute dermal toxicity of the test substance was low with an LD50 value > 2000 mg/kg bw for male and female rats according to OECD TG 402. Single semiocclusive administration of 2000 mg/kg bw for 24 hours was tolerated by both sexes without mortalities, clinical signs, toxicological effects on weight development and gross pathological findings.