Charcoal

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2010-06-18 to 2010-08-09

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study was conducted as per OECD 429 and EU B.42 test method guidelines

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)

Deviations:

no

Principles of method if other than guideline:

no aplica

GLP compliance:

no

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

Reference substance name:

Charcoal

EC Number:

240-383-3

EC Name:

Charcoal

Cas Number:

16291-96-6

Molecular formula:

C

IUPAC Name:

Carbón vegetal

Details on test material:

Identity: Charcoal (Probe 1: C-Fix = 73.3%)
CAS No.: 16291-96-6
Batch No.: 19062009 1PP
Purity: C-Fix: 73.3%; dose calculation not adjusted to purity
Storage: At room temperature, moisture protected
Expiration Date: December 2030

In vivo test system

Test animals

Species:

mouse

Strain:

other: CBA/CaOlaHsd

Sex:

female

Details on test animals and environmental conditions:

Animals: Female mice of 8-12 weeks of age and with 19-23 g of body weight were included in the study; Housing: Animals were individually housed; Lighting: 12 h light/12 h dark; Temperature: 22 ± 2°C; Relative humidity: 35 to 85%; Food: Animals had access to pelleted standard diet, ad libitum; Water: Tap water, ad libitum; Bedding: Granulated soft wood bedding; Acclimatisation: Study animals were acclimated to their housing for 5 days prior to their first day of dosing.

Study design: in vivo (LLNA)

Vehicle:

propylene glycol

Remarks:

99% pureza

Concentration:

3 groups of 4 female mice were treated on the dorsal surface of both ears once per day for 3 days with the test article, charcoal (Probe 1: C-Fix = 73.3%) at 2.5, 5, and 10% (w/w) in the vehicle propylene glycol.

No. of animals per dose:

4 ratas hembra

Details on study design:

ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method: Local Lymph Node Assay
- Criteria used to consider a positive response: A 3-fold or greater increase in proliferative activity relative to the concurrent vehicle control is considered a positive response.

TREATMENT PREPARATION AND ADMINISTRATION:
On each day of dosing, the test article was prepared at the appropriate concentrations (w/w) by suspending the appropriate amount of test article in propylene glycol. The application volume of 25 µL was used.

4 groups of 4 female mice were treated on the dorsal surface of both ears once per day for 3 consecutive days as follows:
Group 1: vehicle, propylene glycol; Group 2: Charcoal, 2.5% (w/w); Group 3: Charcoal, 5% (w/w); and Group 4: Charcoal 10% (w/w)

On day 6, the mice were injected, i.v., with 20.4 µCi of 3H-Methyl thymidine (3HTdR) per mouse. Five hours later, the mice were euthanized and the draining auricular lymph nodes were removed. The lymph node cells were treated with 5% trichloroacetic acid (TCA) to precipitate the DNA. The resulting pellets were counted in a β-scintillation counter to determine incorporation of 3HTdR.

Positive control substance(s):

hexyl cinnamic aldehyde (CAS No 101-86-0)

Statistics:

The mean values and standard deviations were calculated for the body weight parameter.

Results and discussion

Positive control results:

The positive control, HCA at 10% and 25% resulted in a stimulation index (SI) of 3.41 and 6.14, respectively. A 3-fold or greater increase in proliferative activity relative to the concurrent vehicle control is considered a positive response.

In vivo (LLNA)

Results

Results 1

Parameter:

SI

Remarks on result:

other: SI: Vehicle control = 1.00; Charcoal (2.5% w/v) = 0.65; Charcoal (5% w/v) = 0.72; and Charcoal (10% w/v) = 1.11

Results 2

Parameter:

other: disintegrations per minute (DPM)

Remarks on result:

other: DPM per lymph node: Vehicle control = 295.6; Charcoal (2.5% w/v) = 192.7; Charcoal (5% w/v) = 211.4; and Charcoal (10% w/v) = 329.3

Any other information on results incl. tables

 

% Concentración elemento de prueba la (w/w)	Grupo	Medición DPM	Cálculo			Resultado
			DPM-Guna)	Nº de ganglios linfáticos	DPM por los ganglios linfáticos b)	SI
---	BG I	20	---	---	---	---
---	BG II	17	---	---	---	---
0	1	2383	2365	8	295,6	1,00
2.5	2	1560	1542	8	192,7	0,65
5	3	1710	1692	8	211,4	0,72
10	4	2653	2635	8	329,3	1,11

Bg =    Antecedentes (1 ml 5% de ácido tricloroacético) por duplicado

1      =    Grupo de Control

2-4 =    Grupos de prueba

IE =    Índice de Estimulación

a)     =    El valor medio fue tomado de la I y II cifras BG

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information up to 10% (w/w) of charcoal Criteria used for interpretation of results: EU

Conclusions:

no sensibilizante bajo condiciones de estudio