(+)-menthol

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

August 1st, 1989 - August 15th, 1989

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: According to OECD Guideline No 404, "Acute dermal Irritation/Corrosion", 1981 GLP performed

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1989

Report date:

1989

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Version / remarks:

1981's version

Deviations:

yes

Remarks:

extended to investigate 5 different concentrations of the test article and a vehicle control on each animal

GLP compliance:

yes (incl. QA statement)

Remarks:

(16-08-1989)

Test material

Test material information

Constituent 1

Reference substance name:

HR 89/620005

IUPAC Name:

HR 89/620005

Constituent 2

Reference substance name:

(+)-menthol

EC Number:

239-387-8

EC Name:

(+)-menthol

Cas Number:

15356-60-2

Molecular formula:

C10H20O

IUPAC Name:

2-isopropyl-5-methylcyclohexanol

Constituent 3

Reference substance name:

Cyclohexanol, 5-methyl-2 (1-methylethyl)- [1S-(1α,2β, 5α)]

IUPAC Name:

Cyclohexanol, 5-methyl-2 (1-methylethyl)- [1S-(1α,2β, 5α)]

Details on test material:

- Name of test material (as cited in study report): L-menthol, H&R 89/620005
- Physical state: white crystalline powder (large crystals, up to 1 cm)

Test animals

Species:

rabbit

Strain:

other: SPF albino female rabbits

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Chbb:HM, C.H.Boehringer/Biberach:Himalaya strain from Dr Karl Thomae GmbH, D-7950 Biberach an der Riss 1
- Weight at study initiation: between 2200 and 2900 g
- Housing: single PPL cages, 45 x 55 cm, with perforated floor
- Diet (e.g. ad libitum): ad libitum, pellets "Altromin 2123"
- Water (e.g. ad libitum): ad libitum fresh water
- Acclimation period: one week

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21 +/- 2°C
- Humidity (%): 55 +/- 15%
- Air changes (per hr): 6 time an hour
- Photoperiod (hrs dark / hrs light): from 6 to 18 hours

Test system

Type of coverage:

semiocclusive

Preparation of test site:

other: clipped

Vehicle:

other: Diethyl phthalate (DEP)

Controls:

other: each animalt was concurrently tested with a vehicle control

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 ml
- Concentration (if solution): 100%, 50%, 25%, 5% and 1% (w/w) of test material concentrations were tested
and vehicle control (0% test material, 100% DEP)
All 5 concentrations and vehicle control were applied to each rabbit.

Duration of treatment / exposure:

Test material was held in place for 4 hours and then the skin was cleaned with soap and lukewarm water.

Observation period:

First reading took place 30 minutes after removing of substance, and then at 24 hours, 48 hours, 72 hours, on day 7 and on day 14.

Number of animals:

4 rabbits were tested

Details on study design:

TEST SITE
- 6 distinct areas on the trunk of each rabbit was used to apply the different concentrations
- Type of wrap if used: test area was covered with gauze packs, 2.5 x 2.5 cm which were secured with a cross of 1 cm wide adhesive tape and fixed with Scanpor tape, 7.5 cm width, loosely wound round the trunk

REMOVAL OF TEST SUBSTANCE
- Washing (if done): with soap and lukewarm water
- Time after start of exposure: after 4 hours exposure

SCORING SYSTEM: see table below

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Remarks:

test material at 100%

Basis:

mean

Time point:

other: average score over all time points

Score:

2.5

Max. score:

3

Reversibility:

not fully reversible within: 14 days

Remarks on result:

other: underlying skin intact despite white to white-brown scales

Results 2

Irritation parameter:

erythema score

Remarks:

test material at 50%

Basis:

mean

Time point:

other: average score over all time points

Score:

1.9

Max. score:

3

Reversibility:

not fully reversible within: 14 days for 3 animals

Remarks on result:

other: scattered scale formation on intact skin on 3 of the animals

Results 3

Irritation parameter:

erythema score

Remarks:

test material at 25%

Basis:

mean

Time point:

other: average score over all time points

Score:

0.7

Max. score:

1

Reversibility:

not fully reversible within: 7 days

Remarks on result:

other: thin layer of white scales on one rabbit (No. 4290) and scattered white scales on another one (No. 4288)

Results 4

Irritation parameter:

erythema score

Remarks:

test material at 5%

Basis:

mean

Time point:

other: average score over all time points

Score:

0.2

Max. score:

1

Reversibility:

fully reversible within: 7 days

Results 5

Irritation parameter:

erythema score

Remarks:

test material at 1%

Basis:

mean

Time point:

other: average score over all time points

Score:

0

Max. score:

0

Reversibility:

fully reversible within: 24 hours

Results 6

Irritation parameter:

erythema score

Remarks:

vehicle control

Basis:

mean

Time point:

other: average score over all time points

Score:

0

Max. score:

0

Results 7

Irritation parameter:

edema score

Remarks:

test material at 100%

Basis:

mean

Time point:

other: average score over all time points

Score:

2.4

Max. score:

3

Reversibility:

not fully reversible within: 14 days

Remarks on result:

other: underlying skin intact despite white to white-brown scales

Results 8

Irritation parameter:

edema score

Remarks:

test material at 50%

Basis:

mean

Time point:

other: average score over all time points

Score:

1.3

Max. score:

2

Reversibility:

fully reversible within: 14 days for 3 animals

Remarks on result:

other: scattered scale formation on intact skin on 3 of the animals

Results 9

Irritation parameter:

edema score

Remarks:

test material at 25%

Basis:

mean

Time point:

other: average score over all time points

Score:

0

Max. score:

0

Results 10

Irritation parameter:

edema score

Remarks:

test material at 5%

Basis:

mean

Time point:

other: average score over all time points

Score:

0

Max. score:

0

Results 11

Irritation parameter:

edema score

Remarks:

test material at 1%

Basis:

mean

Time point:

other: average score over all time points

Score:

0

Max. score:

0

Applicant's summary and conclusion

Interpretation of results:

irritating

Remarks:

Migrated information at 100% Criteria used for interpretation of results: EU

Conclusions:

The test article "HR 891620005" (100%) shall be classified as skin irritant, whereas "HR 89/620005" in concentrations of 50%, 25%, 5% and 1% shall not be classified as skin irritant.

Executive summary:

The primary skin irritant effect of “HR 89/620005’ was investigated according to the method recommended in the OECD Guideline No. 404, “Acute Dermal Irritation/Corrosion”, 1981. The study design was extended to investigate 5 different concentrations of the test article and a vehicle control on each animal.

Under the experimental conditions described in the authorized report, the mean scores for erythema in the four rabbits used were as follows:

Test substance concentration	100%	50%	25%	5%	1%	Vehicle
Erythema	2.5	1.9	0.7	0.2	0.0	0.0
Oedema	2.4	1.3	0.0	0.0	0.0	0.0

According to the Official Journal of the European Communities, L 257, 1983, “HR 89/620005” shall be classified as skin irritant, whereas “HR 89/620005” in concentrations of 50%,25%,5%and 1% shall not be classified as skin irritant.