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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Toxicological information

Repeated dose toxicity: other routes

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Administrative data

repeated dose toxicity: other route
Type of information:
experimental study
Adequacy of study:
other information
3 (not reliable)
Rationale for reliability incl. deficiencies:
unsuitable test system

Data source

Reference Type:
Nano-Sized Carbon Black Exposure Exacerbates Atherosclerosis in LDL-Receptor Knockout Mice
Niwa Y, Hiura Y, Murayama T, Yokode M, Iwai N
Bibliographic source:
Circulation Journal 71: 1157 – 1161

Materials and methods

Test guideline
no guideline followed
Principles of method if other than guideline:
Repeated intratracheal administration of an approximate total dose of 444 mg/kg carbon black within 10 weeks to investigate the effects of CB on the development of atherosclerosis
GLP compliance:
not specified

Test material

Constituent 1
Chemical structure
Reference substance name:
Carbon black
EC Number:
EC Name:
Carbon black
Cas Number:
Molecular formula:

Test animals

other: Low-density lipoprotein receptor knockout mice (LDLR/KO)

Administration / exposure

Route of administration:
other: intratracheal
Analytical verification of doses or concentrations:
not specified
Duration of treatment / exposure:
10 weeks
Frequency of treatment:
One instillation (1mg) per week
Doses / concentrations
Dose / conc.:
1 other: mg/animal per week
in the absence or presence of cholesterol
No. of animals per sex per dose:
5 male / group; 4 groups
Control animals:
Details on study design:
Two groups of mice were subjected to a 10-week endotracheal dispersion of autoclaved CB (1 mg per animal/week) and given isoenergy diets containing 0% or 0.51% Chol. Another 2 groups of mice underwent intratracheal dispersion of air only under isonergy diets with 0% or 0.51% Chol. Intratracheal dispersion of CB and air was performed once a week for 10 weeks under light ether anesthesia

Results and discussion

Applicant's summary and conclusion

No conclusions can be drawn on the repeated dose toxicity of carbon black. The relevance of the non-validated test system is unclear.
Executive summary:

The experiment was conducted with two groups of low-density lipoprotein receptor knockout mice (LDLR/KO) fed with isoenergetic diets in the absence of cholesterol or presence of 0.51% cholesterol.

Carbon black was not detected by electron microscopy in aortas, livers, kidneys, and spleen of LDLR/KO mice after repeated intratracheal administration.

An accelerated development of atherosclerosis in the mice was studied by examination of Oil red O stained aortic tissue. The stained plaque area was quantifi ed. Mice fed with cholesterol only and those treated with carbon black in addition had a statistically signifi cantly more extensive staining (7 and 13% area stained, respectively). Vehicle or carbon black treated mice showed both about 3% stained area in the absence of cholesterol. The authors interpreted these results that carbon black treatment accelerated development of atherosclerosis.