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Administrative data

Description of key information

• Not irritating to skin (equivalent to OECD 404)
• Not irritating to eyes (OECD 437 and equivalent to OECD 405)

Key value for chemical safety assessment

Skin irritation / corrosion

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

Eye irritation

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

Additional information

Skin irritation:

A reliable, Klimisch score 2, in vivo skin irritation study was performed according to EC Method B.4 (Unilever Research Laboratory, 1988). 0.5 mL of the test material was applied to the skin of three New Zealand white rabbits using a semi-occlusive dressing. Animals were observed for signs of erythema and oedema and the responses were graded at 30-60 minutes, and then at 24, 48 and 72 hours after patch removal. One hour after patch removal, two animals showed slight erythema and one showed distinct erythema. Two also showed slight oedema. These effects intensified to show marked erythema, together with slight or marked oedema, in all three animals at 24 to 72 hours after patch removal. Based on the classification criteria according to Regulation (EC) No. 1272/2008, Patchouli oil is not considered a skin irritant based on the irritancy scores for individual animals.

This result is supported by reliable, Klimisch score 2 data from Leberco Laboratories, 1971 in which 0.5 mL of Patchouli oil was applied to the skin of three healthy albino rabbits. The treated skin was then evaluated at the end of the 24 h contact period and then again after 72 hours according to the method of Draize. All scores were zero which indicates that the test material was not a skin irritant.

Additional reliable Klimisch score 2 supporting information is available from two human repeat insult patch tests (Hill Top Research, Inc, 1971 and Harrison Research Laboratories, Inc, 1983) which demonstrate that the test material is not a skin irritant. In the Harrison Laboratories study (1983), a total of 51 subjects completed the study in which 0.2 mL of a 2% solution of Patchouli was applied to the skin in a series of nine induction patches for a period of three weeks. During both the induction and challenge phases, the test areas were observed and the reaction scored and recorded. The original patch sites exhibited no reactions during rest or at the challenge and no reactions were observed during the induction or challenge phases of the study. In the study performed at Hill Top Research (1971) 22 subjects were treated with 0.5 mL of a 9.25% solution of Patchouli oil, light. All 22 subjects showed little or no primary irritation. It is therefore considered that Patchouli oil is not an irritant to human skin.


Eye irritation:

A reliable in vitro Bovine Corneal Opacity and Permeability Assay (BCOP), Klimisch score 1, was performed in accordance with GLP and OECD Guideline 437 to assess the ocular irritancy potential of Patchouli Oil to the isolated bovine cornea (Harlan Laboratories Ltd., Report 41102451R, 2012). The undiluted test item was applied for 10 minutes followed by an incubation period of 120 minutes. The two endpoints, decreased light transmission through the cornea (opacity) and increased passage of sodium fluorescein dye through the cornea (permeability) were combined in an empirically derived formula to generate an In Vitro Irritancy Score (IVIS). The in vitro irritancy score for Patchouli Oil was 0.8 and hence the test material was considered not to be an ocular corrosive or severe irritant.

The in vitro result is supported by a reliable, Klimisch score 2 in vivo study from Leberco Laboratories, 1971 in which 0.1 mL of Patchouli oil was applied to the eyes of three healthy albino rabbits. Both the treated and control eyes were examined every 24 hours for four days and then again on the seventh day. The scores were recorded according to the Draize scale for scoring ocular lesions. A mild to moderate conjunctival reaction was observed which had disappeared by the fourth day of observation. Based on the individual animal scores and the reversibility of the observed effects, the test material is not considered to be an eye irritant.

Justification for classification or non-classification

Patchouli was not irritating in the in vivo skin, in vitro eye and in vivo eye irritation studies and therefore requires no classification according to CLP Regulation (EC) No 1272/2008.