Essential oil obtained from the leaves of Cymbopogon flexuosus, gramineae by distillation

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Study period:

No data

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Test performed according to the Modified Draize Test, not performed in accordance with CLP. Klimisch 2 reliability has been assigned in accordance with ECHA Practical Guide #6, based on the fact that the study was read-across.

Data source

Reference

Reference Type:

publication

Title:

The sensitization potential of some perfume ingredients tested using a modified Draize procedure

Author:

D. Sharp

Year:

1978

Bibliographic source:

Toxicology, 9, 261-271

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

Modified Draize test: In comparison to the original Draize test, this test includes control animals at every challenge and was performed over a shorter time period as a result of combining the series of 10 intradermal injections.

GLP compliance:

no

Type of study:

Draize test

Test material

Test material information

Constituent 1

Reference substance name:

Lemongrass oil Guatemala

IUPAC Name:

Lemongrass oil Guatemala

Details on test material:

- Name of test material (as cited in study report): Lemongrass oil Guatemala
- Substance type: natural perfume ingredient

In vivo test system

Test animals

Species:

guinea pig

Strain:

Dunkin-Hartley

Sex:

male/female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: bred in test laboratories colony
- Weight at study initiation: 450 g (preliminary irritation tests) 350 g (sensitization test)
- Housing: wire mesh cages in pairs of the same sex
- Diet (e.g. ad libitum): pelleted guinea pig diet, cabbage and hay ad libitum
- Water (e.g. ad libitum): ad libitum

ENVIRONMENTAL CONDITIONS
no information available

IN-LIFE DATES: No information available

Study design: in vivo (non-LLNA)

Induction

Induction 1

Route:

intradermal

Vehicle:

no data

Induction 2

Concentration / amount:

Induction injections: 0.1 mL aliquots of 0.5% Lemongrass oil Guatemala
Challenge injections: 0.1 mL aliquots of 0.2% Lemongrass oil Guatemala
Challenge applications: 0.1 mL aliquots of 20% Lemongrass oil Guatemala

Challenge

Challenge 1

Route:

intradermal and epicutaneous

Vehicle:

no data

Challenge 2

Concentration / amount:

Induction injections: 0.1 mL aliquots of 0.5% Lemongrass oil Guatemala
Challenge injections: 0.1 mL aliquots of 0.2% Lemongrass oil Guatemala
Challenge applications: 0.1 mL aliquots of 20% Lemongrass oil Guatemala

No. of animals per dose:

4 (Preliminary irritation test: Intradermal injections)
4 (Preliminary irritation test: Topical applications)
10 (sensitization test)

Details on study design:

RANGE FINDING TESTS:
Prior to the sensitization test, preliminary irritation tests were performed in order to select suitable concentrations of test substance for the sensitization test; a preliminary intradermal injection test and a topical application test.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 4 (intradermal injections at once on 4 sites)
- Exposure period: The challenge followed 14 days after the induction.
- Test groups: 10 guinea pigs weighing about 350g.
- Control group: no controls used in the induction exposure.
- Site: 4 sites per animal: the two inguinal and the two auxillary areas of each animal.
- Frequency of applications: the intradermal injections were performed once per animal.
- Duration: 14 days.
- Concentrations: 0.1 mL aliquots of 0.5% Lemongrass oil Guatemala

B. CHALLENGE EXPOSURE
- No. of exposures: 2 (intradermal injections on 1 flank, topical exposure on the other).
- Day(s) of challenge: The challenge followed 14 days after induction.
- Exposure period: The treatment sites were examined for evidence of sensitization 24 hours after the challenge.
- Test groups: 10 guinea pigs weighing about 350g.
- Control group: At every challenge 4 previously untreated control animals were treated in exactly the way as the test animals.
- Site: the two inguinal and the two axillary areas of each animal (same sites as the induction exposure).
- Concentrations: 0.1 mL aliquots of 0.2% Lemongrass oil Guatemala (injections) and 0.1 mL aliquots of 20% Lemongrass oil Guatemala (topical application)
- Evaluation (hr after challenge): 24 hours after challenge.

OTHER:
If there was evidence of sensitization at the first challenge a rechallenge, similar to the first challenge, was performed to confirm the effect 7 days after the first challenge (controls included). If there was no evidence of sensitization at the first challenge, the induction and challenge procedures were repeated, including the original controls.

Assessment of skin response:
The treatment sites were examined using a Philips colour-matching unit with 3 Philips 40W Actinic Blue 05 fluorescent tubes and 3 Philips 40W White 35 fluorescent tubes. Treatment sites were scored for size, erythema and oedema. Scores ranged from 0 to +++.
A sensitization response was defined as a reaction with a significantly greater total score than in control animals.

Challenge controls:

At every challenge, 4 previously untreated controls of the same sex and similar weight were treated similar to the test animals.

Positive control substance(s):

no

Results and discussion

Positive control results:

Not applicable

Any other information on results incl. tables

No individual or mean scores provided in the article. Only the overall result is reported, which is that Lemongrass oil Guatemala was found to be not sensitizing.

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Under the conditions of the Modified Draize test as reported in this publication, Lemongrass oil appeared to be not sensitizing. Therefore, Lemongrass oil does not need to be classified as sensitizing to skin according to the criteria as outlined in Annex I of 1272/2008/EC (CLP).

Executive summary:

In this Modified Draize test the sensitizing potential of Lemongrass oil was determined. Prior to the sensitization test, preliminary intradermal and topical irritation test were performed in order to determine suitable concentrations for the sensitization test.

For the main test, 10 Dunkin-Hartley guinea pigs were first induced by intradermal injections which was followed after 14 days by a challenge consisting of intradermal and topical exposure. At every challenge 4 previously untreated controls were treated in exactly the same way as the test animals. At 24 hours after the challenge, the treatment sites were examined for erythema, edema and necrosis.

The grade of ertythema, edema and necrosis determine the possible sensitization properties of the test substance. Based on this study, Lemongrass oil does not trigger a sensitization reaction in albino Dunkin-Hartley guinea pigs. Therefore, Lemongrass oil does not need to be classified as sensitizing to skin according to the criteria as outlined in Annex I of 1272/2008/EC (CLP).