Mentha arvensis, ext.

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The study is performed according to an unspecified guideline unspecified, and provides acceptable basic data.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1983

Report date:

1983

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: no data on guideline available

Deviations:

not applicable

Principles of method if other than guideline:

The test substance was applied to the clipped dorsum of 8 rabbits for 4 hours under individual semi-occlusive patches. Reaction grades for erythema, oedema, cracking and scaling were assessed 4, 24, 48, and 72 hours after treatment by using grades ranging from "a"(very slight) to "h"(severe). An overall irritation score was assigned to each tested substance ranging from 0 (normal skin) to 7 (extreme).

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

cornmint oil

IUPAC Name:

cornmint oil

Details on test material:

- Name of test material (as cited in study report): Peppermint Flavour - Arvensis

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age at study initiation: 9-12 weeks

Test system

Type of coverage:

semiocclusive

Preparation of test site:

other: clipped 3-4 days before test start, animals in the telogen phase of hair growth were selected

Vehicle:

unchanged (no vehicle)

Controls:

yes

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 ml

Duration of treatment / exposure:

4 hours

Observation period:

0, 24, 48 and 72 hours after treatment, and occasionally up to 7 days after treatment.

Number of animals:

8

Details on study design:

TEST SITE
- Area of exposure: dorsal surface
- Type of wrap if used: 2.5 cm2 of cotton gauze (8 ply folded in two) laid on a piece of thin flexible polythene (3 cm x 3 cm) attached to a piece of zinc oxide plaster (9 cm x 2.5 cm)

REMOVAL OF TEST SUBSTANCE
- Washing (if done): treatment site wiped clean of excess material
- Time after start of exposure: upon patch removal (after 4 hrs)

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

mean

Time point:

24 h

Score:

1.6

Max. score:

4

Reversibility:

not fully reversible within: 72 hours

Results 2

Irritation parameter:

erythema score

Basis:

mean

Time point:

48 h

Score:

1.4

Max. score:

4

Reversibility:

not fully reversible within: 72 hours

Results 3

Irritation parameter:

erythema score

Basis:

mean

Time point:

72 h

Score:

1.4

Max. score:

4

Reversibility:

no data

Remarks:

after 72 hours

Results 4

Irritation parameter:

edema score

Basis:

mean

Time point:

24 h

Score:

1.7

Max. score:

4

Reversibility:

not fully reversible within: 72 hours

Results 5

Irritation parameter:

edema score

Basis:

mean

Time point:

48 h

Score:

1.6

Max. score:

4

Reversibility:

not fully reversible within: 72 hours

Results 6

Irritation parameter:

edema score

Basis:

mean

Time point:

72 h

Score:

1.7

Max. score:

4

Reversibility:

no data

Remarks:

after 72 hours

Irritant / corrosive response data:

no other data

Other effects:

no data

Any other information on results incl. tables

Overall Irritation score for each animal

Animal number	265	272	288	291	311	313	317	322	Total irritation score per group
Group
Diethyl Phtalate	1	1	1	-	1	1	1	0	6
Geraniol	3	3	3	-	2	4	4	3	22
Peppermint Flavour - Arvensis	2	3	3	-	3	3	4	3	21

Distribution of overall irritation scores (0 -7) within each treatment group

Overall Irritation Scores	0	1	2	3	4	5	6	7
Group
Diethyl Phtalate	1	6
Geraniol			1	4	2
Peppermint Flavour - Arvensis			1	5	1

In order to classify the test substance, the irritation scoring from "a" to "h" is converted to the grading of skin reactions as defined by OECD Guideline for the testing of chemicals No. 404: Acute Dermal Irritation/Corrosion.

The conversion for erythema:

Reaction Grades in this study	OECD grading of skin reactions
a (marginal/very slight)	1 (very slight)
b (slight)	1 (very slight)
c (fairly distinct)	2 (well defined)
d (quite distinct)	2 (well defined)
e (becoming well developed)	2 (well defined)
f (well developed)	3 (moderate to severe)
g (becoming severe)	3 (moderate to severe)
h (severe)	4 (severe)

The conversion for oedema:

Reaction Grades in this study	OECD grading of skin reactions
a (marginal/very slight)	1 (very slight)
b (slight)	2 (slight)
c (fairly distinct)	2 (slight)
d (quite distinct)	2 (slight)
e (becoming well developed)	3 (moderate)
f (well developed)	3 (moderate)
g (becoming severe)	4 (severe)
h (severe)	4 (severe)

Applicant's summary and conclusion

Interpretation of results:

other: not irritating

Remarks:

Based on CLP criteria

Conclusions:

The overall Irritation Score for cornmint oil (Peppermint Flavour - Arvensis) was slightly irritating towards rabbits under the conditions of this test. After conversion of the used irritation scores to the grading of skin reactions as defined by OECD Guideline for the testing of chemicals No. 404: Acute Dermal Irritation/Corrosion, it was concluded that cornmint oil does not have to be classified as irritating in accordance with the criteria outlined in Annex I of the CLP Regulation (1272/2008/EC).

Executive summary:

Cornmint oil (Peppermint Flavour - Arvensis), two control substances (Diethyl Phtalate and Geraniol), and Peppermint Flavour - Brazilian were applied to the clipped dorsum of 8 rabbits for 4 hours under individual semi-occlusive patches. Reaction grades for erythema, oedema, cracking and scaling were assessed 4, 24, 48, and 72 hours after treatment by using grades ranging from "a" (very slight) to "h" (severe). An overall irritation score was assigned to each tested substance ranging from 0 (normal skin) to 7 (extreme). The overall irritation score for Peppermint Flavour - Arvensis was 3 (Slight/moderate erythema and oedema at 24 hours. The reaction generally reduced to slight at 72 hours, but sometimes the slight/moderate reaction was maintained.

In order to classify Peppermint Flavour - Arvensis according to the current guidelines, the reaction grades wee converted to OECD grading of skin reactions. This resulted in an OECD grading for Peppermint Flavour - Arvensis of 1.5 for erythema (very slight - well defined) and 1.7 for oedema (very slight - slight). It is concluded that cornmint oil does not need to be classified as irritating to the skin based on the criteria outlined in Annex I of the CLP Regulation (1272/2008/EC).