Registration Dossier

Administrative data

Description of key information

The key study was a Local Lymph Node Assay, indicating that Activated Carbon - High Density Skeleton has no sensitising potential up to the highest technically achievable concentration (25%) in propylene glycol. The stimulation index did not exceed 3 for all tested concentrations.


Local Lymph Node Assay: not sensitising (OECD 429)

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records
Reference
Endpoint:
skin sensitisation: in vivo (LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
23 February 2010 - 10 March 2010
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Remarks:
in accordance with GLP
Qualifier:
according to
Guideline:
OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)
GLP compliance:
yes
Type of study:
mouse local lymph node assay (LLNA)
Species:
mouse
Strain:
other: CBA/CaOlaHsd
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Harlan Laboratories B.V., Postbus 6174, 5960 AD Horst, The Netherlands
- Age at study initiation: 8-12 weeks
- Weight at study initiation: 19.0-22.8 g
- Housing: Individually, under standard laboratory conditions
- Diet (e.g. ad libitum): Ad libitum, pelleted standard diet
- Water (e.g. ad libitum): Ad libitum, tap water
- Acclimation period: At least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 2
- Humidity (%): 25-65
- Photoperiod (hrs dark / hrs light): 12/12
Vehicle:
propylene glycol
Concentration:
0, 5, 10 and 25%
No. of animals per dose:
4
Details on study design:
RANGE FINDING TESTS:
- Compound solubility: Highest concentration that can be technically used was 25% in propylene glycol
- Irritation: No severe irritant effects were tolerated choosing the test concentrations (time points: 1 hour and 24+/-4 hours after application, on day 7)

MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method: LLNA
- Criteria used to consider a positive response:
1. Exposure to at least one concentration of the test item resulted in an incorporation of 3HTdR at least 3-fold or greater than that recorded in control mice, as indicated by the stimulation index, and
2. Data are compatible with a conventional dose response, although allowance must be made (especially at high topical concentrations) for either local toxicity or immunological suppression

TREATMENT PREPARATION AND ADMINISTRATION:
Test item was placed into a volumetric flask on a tared balance and propylene glycol was quantitatively added. The different test item concentrations were prepared individually. Homogeneity of the test item in vehicle was maintained during treatment with stirring. The preparations were made freshly before each dosing occasion.
Application of test substance to the animal was performed according to guideline (proliferative capacity was determined by incorporation of 20.4 uCi 3H-methyl thymidine per mouse).
Positive control substance(s):
hexyl cinnamic aldehyde (CAS No 101-86-0)
Statistics:
Mean values and standard deviation were calculated for the body weights.
Positive control results:
The positive control was found to induce sensitisation in the test system, which was clear but not excessive as required by the OECD guideline: a Stimulation Index (SI) of 1, 1.78, 2.54 and 4.88 at concentrations of 0%, 5%, 10% and 25% was calculated.
Key result
Parameter:
SI
Value:
1.43
Test group / Remarks:
5%
Key result
Parameter:
SI
Value:
2.85
Test group / Remarks:
10%
Key result
Parameter:
SI
Value:
2.38
Test group / Remarks:
25%
Key result
Parameter:
EC3
Remarks on result:
other: An EC3 value could not be calculated or derived
Cellular proliferation data / Observations:
The amount of disintegration per minute that were measured by liquid scintillation counting were (after correction for background counts): 1292, 1853, 3685 and 3074 for the concentrations of 0%, 5%, 10% and 25%, respectively.

- No deaths were noted during study period

- No symptoms of local toxicity at the ears of the animals and no systemic findings were observed during the study period

- Body weight was within the range commonly recorded for animals of this stratin and age

- An EC3 value could not be calculated or derived for steam activated carbon

Interpretation of results:
GHS criteria not met
Conclusions:
Under the conditions of this study, steam activated carbon did not induce sensitisation in the mouse. The highest SI calculated was 2.85, which is below the threshold of 3 for classification. Therefore, the test substance does not need to be classified for sensitisation based on the criteria outlined in Annex I of 1272/2008/EC.
Executive summary:

This Local Lymph Node Assay (OECD 429) was performed to determine the sensitising potential of steam activated carbon in mice. Test concentrations of 5%, 10% and 25% in propylene glycol were used (highest technically achievable concentration). As a positive control alpha-hexylcinnamicaldehyde was used. Proliferative capacity was determined by incorporation of 20.4 uCi 3H-methyl thymidine per mouse and subsequent liquid scintillation counting. Mortality, clinical signs and body weight were recorded.

No mortality or clinical signs were noted and body weights were within the range commonly recorded for the test animals.

The amount of disintegration per minute that were measured by liquid scintillation counting were (after correction for background counts): 1292, 1853, 3685 and 3074 for the concentrations of 0%, 5%, 10% and 25%, respectively. Accompanying Stimulation Indices (SI) that were calculated: 1.43, 2.85 and 2.38 for 5%, 10% and 25%, respectively.

Under the conditions of this study, steam activated carbon did not induce sensitisation in the mouse. The highest SI calculated was 2.85, which is below the threshold of 3 for classification. Therefore, the test substance does not need to be classified for sensitisation based on the criteria outlined in Annex I of 1272/2008/EC.

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not sensitising)

Respiratory sensitisation

Endpoint conclusion
Endpoint conclusion:
no study available

Justification for classification or non-classification

Based on the results of the key study, steam-activated carbon does not need to be classified for sensitisation when considering the criteria outlined in Annex I of 1272/2008/EC .