Cinnamaldehyde

Endpoint summary

Description of key information

Skin Sensitization:

Based on all the available observations and results, it was concluded that the test chemical gave positive reactions of skin sensitization when applied at higher concentrations in humans as well as animals. Therefore, as per CLP criteria of classification and labelling the test chemical was classified as a positive sensitizer.

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

supporting 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 a peer-reviewed journal.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Principles of method if other than guideline:

Equivalent or similar to OECD Guideline 406 (Skin Sensitisation)

GLP compliance:

not specified

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

No Data Available

Species:

guinea pig

Strain:

not specified

Sex:

not specified

Details on test animals and environmental conditions:

No Data Available

Route:

other:

Vehicle:

unchanged (no vehicle)

Concentration / amount:

2% test chemical

Route:

other:

Vehicle:

unchanged (no vehicle)

Concentration / amount:

2% test chemical

No. of animals per dose:

6 guinea pigs

Details on study design:

No Data Available

Challenge controls:

No Data Available

Positive control substance(s):

not specified

Positive control results:

No Data Available

Reading:

1st reading

Group:

test chemical

Dose level:

2%

No. with + reactions:

6

Total no. in group:

6

Clinical observations:

Sensitisation reactions were produced

Remarks on result:

positive indication of skin sensitisation

Interpretation of results:

other: The test chemical was observed to be sensitizing.

Conclusions:

Based on all the available data, it was concluded that the test chemical was observed to be sensitizing as the test chemical at 2% produced sensitization reactions in all six guinea-pigs tested.

Executive summary:

A guinea pig maximisation test, equivalent or similar to OECD test guideline 406 was performed using 6 guinea pigs. The test chemical was tested at 2 % concentration. A patch containg 2% of the test chemical was applied to all the 6 guinea pigs which resuled in positive sensitizing of all the tested animal. Therefore, based on all the available data, it was concluded that the test chemical was observed to be sensitizing as the test chemical  at 2% produced sensitization reactions in all six guinea-pigs tested.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (sensitising)

Additional information:

Skin Sensitization:

The studies of the test chemical on human and animals (guinea pigs) are as follows:

Study 1:

A modified Draize procedure was used to identify, the test chemical for its potential to induce allergic contact dermatitis in guinea pigs. Induction exposure included intradermal injections at 4 sites with 0.1 mL aliquots of test substance at 2.5 times the ICC. Challenge exposure included intradermal induction (ICC) at a dose of 0.25% and topical application (ACC) at a concentration of 20%. In the absence of sensitization reactions at first challenge the induction and challenge procedures were repeated, but this time a comfirmatory challenge with controls was included irrespective of any apparent sensitization reactions at the previous challenge. Based on all the available data, it was concluded that the test chemical was observed to be a skin sensitizer to guinea pigs at the challenge concentrations tested.

Study 2:

A guinea pig maximisation test, equivalent or similar to OECD test guideline 406 was performed using 6 guinea pigs. The test chemical was tested at 2 % concentration. A patch containg 2% of the test chemical was applied to all the 6 guinea pigs which resuled in positive sensitizing of all the tested animal. Therefore, based on all the available data, it was concluded that the test chemical was observed to be sensitizing as the test chemical  at 2% produced sensitization reactions in all six guinea-pigs tested.

Study 3:

A cumulative contact enhancement test was carried out for the test chemical to examine skin sensitization potential in Guinea Pigs.A 24-h closed patch is attached to the skin every other day over a period of 2 weeks (a total of 4 applications) at a concentration of 0, 5, 1, 0.2 %. The challenge step is performed by directly applying the test material at a concentration of 0, 5, 1, 0.2 %.For the induction phase, an area on the back of the animals was shaved with electric clippers and then with an electric razor. To the shaved part a patch of lint cloth (2 X 4 cm) containing 0.2 ml of the test chemical solution was applied for 24 h under closed conditions. The patch test unit consisted of a 2 X 4 cm lint cloth attached to 2 inch wide Blendenn. After the application of the unit, it was covered with two layers of Silky Tex. Both edges of the tape were then secured to the skin with Elatex in order to prevent the unit from peeling off.For the challenge exposure, a lateral part of the body of the animals was shaved.To the shaved part, the newly prepared test solution (about 0.01 ml) was applied on a circular 2 cm cotton patch. The reaction was evaluated at 24, 48, and 72 h.The test chemical revealed a higher positive ratio when 3 to 4 contacts of highly concentrated solution were used both for induction, and challenge. The test chemical gave a high ratio of 9/10 when a 5% solution was applied 4 times for induction and when the same concentration was used for challenge. Thus, based on all the observations, it was concluded that the a higher positive sensitization ratio was obtained for the test chemical if an appropriate concentration is applied more frequently, and therefore the test chemical was considered to be skin sensitization.

Study 4:

A study was conducted on 26 human female workers to identify the potential of the test chemical for skin sensitization in a patch test.

The test chemical was applied at a concentration of 1% in petrolatum and the reactions were noted. Allergic contact dermatitis of the hands, fore arms and the face of the female workers was observed. Therefore, based on all the available data, it was concluded that the test chemical was sensitizing to the skin of 26 female workers working at perfume industry.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Based on all the observations and results, it was concluded that the test chemical was a positive sensitizer when tested in human subjects as well as animals. Therefore, as per the CLP criteria of classificationa and labelling, the test chemical was classified as a 'skin sensitizer'.