Charcoal

Genetic toxicity: in vivo

Administrative data

Endpoint:

in vivo mammalian cell study: DNA damage and/or repair

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Justification for type of information:

In-life exposure to fish for up to 14 days at sub-lethal concentrations.
After exposure, blood was taken from the fish and evaluated for DNA damage/repair on the lines of the COMET assay

Data source

Reference

Reference Type:

publication

Title:

Evaluation of multiwalled carbon nanotubes toxicity in two fish species

Author:

Giovani Valentin Cimbaluk et al

Year:

2018

Bibliographic source:

Ecotoxicology and Environmental Safety 150 (2018) 215–223Available online 04 January 2018

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 489 (In vivo Mammalian Alkaline Comet Assay)

Version / remarks:

Fish used

GLP compliance:

not specified

Type of assay:

mammalian comet assay

Test material

Test material information

Constituent 1

Reference substance name:

Carbon

EC Number:

231-153-3

EC Name:

Carbon

Cas Number:

7440-44-0

Molecular formula:

C

IUPAC Name:

carbon

Test material form:

solid: particulate/powder

Specific details on test material used for the study:

Multiwalled carbon nanotubes

Test animals

Species:

other: Fish; Danio rerio

Sex:

not specified

Administration / exposure

Route of administration:

other: Immersion

Details on exposure:

The fish were exposes orally, dermally and through gills. There was evidence of carbon in the gut.

Duration of treatment / exposure:

96 hours and 14 days

Doses / concentrations

Dose / conc.:

10 ppm

Remarks:

In water, semi-static exposure

No. of animals per sex per dose:

40 total

Control animals:

yes, concurrent vehicle

Positive control(s):

No

Examinations

Tissues and cell types examined:

Peripheral blood (erythrocytes)

Details of tissue and slide preparation:

Microscope slides were prepared with a blood cell suspension(10μL) in low melting point agarose (120μL) at 37 °C, followed byincubation in lysis solution at 4 °C for 24 h. After lysis incubation, theslides were placed in a NaOH (10 M) and EDTA (200 mM) solution at apH N 13 for 30 min for the DNA denaturation.

Results and discussion

Test results

Sex:

male/female

Genotoxicity:

negative

Toxicity:

no effects

Vehicle controls validity:

valid

Negative controls validity:

not applicable

Positive controls validity:

not applicable

Additional information on results:

The comet assay scores were higher than control group at 5 mg/L in the 96 hour test with one group, but there was no statistical significance

Applicant's summary and conclusion

Conclusions:

There was no significant difference in thefrequency of MN or other morphological nuclear abnormalities between the treatment and the control