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Description of key information

The dermal sensitization potential of the test chemical was assessed in mice according to LLNA method. The study was conducted as per OECD Guidelines 429.

The Stimulations Indices[SI] were 1.2, 2.7, 3.6, 7.9 and 11.4 for the concentrations 1%,5%,10%,25%, 50% respectively.

The calculated EC3 value for the test chemical was 6.7% w/v and 12.96% for the positive control, α- hexylcinnamaldehyde.

Based on the above findings the test chemical can be considered to be sensitizing to skin.

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
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
data from handbook or collection of data
Justification for type of information:
data is from peer reviewed journals
Qualifier:
according to
Guideline:
OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)
Principles of method if other than guideline:
To determine the dermal sensitization potential of the test chemical in mice according to LLNA method
GLP compliance:
not specified
Type of study:
mouse local lymph node assay (LLNA)
Species:
mouse
Strain:
other: CBA/CaOlaHsd
Sex:
female
Details on test animals and environmental conditions:
mice, CBA/CaOlaHsd (nulliparous and non-pregnant)
Vehicle:
dimethyl sulphoxide
Concentration:
0, 1, 5, 10, 25 and 50% w/v
No. of animals per dose:
24 females (4 per group)
Details on study design:
Sodium picramate (1%,
5%, 10%, 25%, or 50% test chemical in DMSO) was applied to both ears of the mice (n ¼ 4) for 3 consecutive days. The control group was administered the vehicle only. Two days after the last application,
the mice were injected with radiolabeled thymidine (methyl-3H-thymidine). The mice were killed approximately 5 hours after the injection, and the draining auricular lymph nodes were excised and pooled per group. The concentration of the radiolabel was measured.

EC3 is the estimated concentration of a chemical necessary to cause a 3-fold increase in lymph node cell proliferative activity. Chemicals that at 1 or more test concentrations provoke a 3-fold or greater in lymphnode cell proliferation compared with vehicle controls are classified as potential contact allergens.
Positive control substance(s):
hexyl cinnamic aldehyde (CAS No 101-86-0)
Statistics:
EC3 is the estimated concentration of a chemical necessary to cause a 3-fold increase in lymph node cell proliferative activity. Chemicals that at 1 or more test concentrations provoke a 3-fold or greater in lymphnode cell proliferation compared with vehicle controls are classified as potential contact allergens.
Positive control results:
The calculated EC3 value for the test chemical was 6.7% w/v. For the positive control, α- hexylcinnamaldehyde was 12.96%.
Key result
Parameter:
EC3
Value:
6.7
Test group / Remarks:
test group
Remarks on result:
other: positive sensitizer
Cellular proliferation data / Observations:
The Stimulations Indices[SI] were 1.2, 2.7, 3.6, 7.9 and 11.4 for the concentrations 1%,5%,10%,25%, 50% respectively.
The calculated EC3 value for the test chemical was 6.7% w/v

Results of the LLNA study

Concentration

Stimulation Index

Test item

 

1%

1.2

5%

2.7

10%

3.6

25%

7.9

50%

11.4

Alpha-hexylcinnamaldehyde

 

5%

0.87

10%

2.26

25%

6.01

Interpretation of results:
other: sensitizing
Conclusions:
The Stimulations Indices[SI] were 1.2, 2.7, 3.6, 7.9 and 11.4 for the concentrations 1%,5%,10%,25%, 50% respectively.
The calculated EC3 value for the test chemical was 6.7% w/v. For the positive control, α- hexylcinnamaldehyde was 12.96%.
Based on the above findings the test chemical can be considered to be sensitiziing to skin.
Executive summary:

The dermal sensitization potential of the test chemical was assessed in mice according to LLNA method. The study was conducted as per OECD Guidelines 429.

5%, 10%, 25%, or 50% test chemical in DMSO) was applied to both ears of female non pregnant, nulliparous CBA/CaOlaHsd mice (n= 4) for 3 consecutive days. The control group was administered the vehicle only. Two days after the last application, the mice were injected with radiolabeled thymidine (methyl-3H-thymidine). The mice were killed approximately 5 hours after the injection, and the draining auricular lymph nodes were excised and pooled per group. The concentration of the radiolabel was measured.

EC3 is the estimated concentration of a chemical necessary to cause a 3 -fold increase in lymph node cell proliferative activity. Chemicals that at 1 or more test concentrations provoke a 3-fold or greater in lymphnode cell proliferation compared with vehicle controls are classified as potential contact allergens.

The Stimulations Indices[SI] were 1.2, 2.7, 3.6, 7.9 and 11.4 for the concentrations 1%,5%,10%,25%, 50% respectively.

The calculated EC3 value for the test chemical was 6.7% w/v and 12.96% for the positive control, α- hexylcinnamaldehyde.

Based on the above findings the test chemical can be considered to be sensitiziing to skin.

Endpoint conclusion
Endpoint conclusion:
adverse effect observed (sensitising)
Additional information:

Skin Sensitization

The dermal sensitization potential of the test chemical was assessed in mice according to LLNA method. The study was conducted as per OECD Guidelines 429.

5%, 10%, 25%, or 50% test chemical in DMSO) was applied to both ears of female non pregnant, nulliparous CBA/CaOlaHsd mice (n= 4) for 3 consecutive days. The control group was administered the vehicle only. Two days after the last application, the mice were injected with radiolabeled thymidine (methyl-3H-thymidine). The mice were killed approximately 5 hours after the injection, and the draining auricular lymph nodes were excised and pooled per group. The concentration of the radiolabel was measured.

EC3 is the estimated concentration of a chemical necessary to cause a 3 -fold increase in lymph node cell proliferative activity. Chemicals that at 1 or more test concentrations provoke a 3-fold or greater in lymphnode cell proliferation compared with vehicle controls are classified as potential contact allergens.

The Stimulations Indices[SI] were 1.2, 2.7, 3.6, 7.9 and 11.4 for the concentrations 1%,5%,10%,25%, 50% respectively.

The calculated EC3 value for the test chemical was 6.7% w/v and 12.96% for the positive control, α- hexylcinnamaldehyde.

Based on the above findings the test chemical can be considered to be sensitizing to skin.

Respiratory sensitisation

Endpoint conclusion
Endpoint conclusion:
no study available

Justification for classification or non-classification

Available studies for the test chemical indicate a very strong possibility that the test chemical has the potential to cause moderate sensitization to skin. Hence, the test chemical can be considered to be a skin sensitizer.