2,4,6-trimethylcyclohex-3-ene-1-methanol

Eye irritation

Administrative data

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

February 4, 1986 - February 19, 1986

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

The test was performed before the REACH regulation came into force requesting in vitro studies. The results are used for read across to Isocyclogeraniol.

Cross-reference

Reason / purpose for cross-reference:

read-across: supporting information

Reference

Skin corrosion: No corrosive effects are expected based structural grounds and the 100% application in the LLNA test, not showing corrosive effects.

Skin irritation (OECD TG 439): Irritating
Eye irritation and severe damage (OECD TG 405): Irritating

Endpoint conclusion:

adverse effect observed (irritating)

Endpoint conclusion:

adverse effect observed (irritating)

Skin corrosion:

The substance is not considered corrosive because no corrosive functional groups are present: the substance is an alkyl alcohol. The methyl group attached to the double bond is not a corrosive alert either. In addition, no corrosive effects were seen in the LLNA test up to 100%.

In vitro skin irritation test:

The possible skin irritation potential of the substance was tested in vitro using a human skin model through topical application for 15 minutes. The study procedures described in this report were according to OECD TG 439 guideline and GLP principles. Skin tissue was treated by topical application of 25 μL undiluted test substance. After 42 hours incubation period, determination of the cytotoxic (irritancy) effect was performed. Cytotoxicity is expressed as the reduction of mitochondrial dehydrogenase activity measured by formazan production from (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide) MTT at the end of treatment. Skin irritation is expressed as the remaining cell viability after exposure to the test substance. Reliable negative and positive controls were included. The positive control had a mean cell viability of 19% after 15 minutes exposure. The standard deviation value of the percentage viability of three tissues treated identically was less than 9%, indicating that the test system functioned properly. The relative mean tissue viability obtained after 15 minutes treatment with the substance compared to the negative control tissue was 12%. Since the mean relative tissue viability for Isocyclogeraniol was below 50% after 15 minutes treatment the substance is considered to be irritant and the substance shall be classified as a skinirritant.

Eye irritation OECD TG 405:

The substance was tested in an eye irritation test in rabbits according to OECD TG 405 test guideline and in compliance with GLP principles. The eyes of three rabbits were exposed to 0.1 mL of the test substance and observations were made up to 14 days after installation. All three animals showed conjunctivae redness ≥2 and in 2 of 3 animals conjunctivae oedema (chemosis) ≥2. Iridial inflammation (score = 1) was noted in two animals. All animals showed opacity ≥1. Observed effects were reversible in all animals within 7 to 14 days except for opacity effects in one animal (score 3 and circumcorneal vascularisation on day 14). Based on the test results, the substance is classified “irreversible effects on the eye.

Based on the positive result in the skin irritation test with the substance and the positive result in the eye irritation test with the read-across substance, the substance needs to be classified as a skin and eye irritant. According to EU Classification, Labeling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No. 1272/2008 and GHS this results in skin irritation category 2, H315: Causes skin irritation and serious eye damage category 1, H318: Causes serious eye damage.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1986

Report date:

1986

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Version / remarks:

1981

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

1

Reference substance name:

(2,4-Dimethylcyclohex-3-en-1-yl)methanol

Cas Number:

67634-17-7

Molecular formula:

C9H16O

IUPAC Name:

(2,4-Dimethylcyclohex-3-en-1-yl)methanol

Test animals / tissue source

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

- Source: Nottingham University, School of Agriculture, Sutton Bonington, Leicestershire, U.K.
- Age at study initiation: 12-16 weeks
- Weight at study initiation: Body weights were 2.65-3.14 kg
- Housing: Individually
- Diet: Free access to food (Rabbit Diet, A.W. Tindall Limited, Holbeach, Lincolnshire, U.K.)
- Water: Free access to drinking water
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS (set to maintain)
- Temperature (°C): 18-20
- Humidity (%): 45-55
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12/12

Test system

Vehicle:

unchanged (no vehicle)

Controls:

other: One eye of each animal remained untreated and served as the reference control.

Amount / concentration applied:

Amount applied: 0.1 mL

Duration of treatment / exposure:

Single instillation on Day 1

Observation period (in vivo):

14 days

Number of animals or in vitro replicates:

3 (sex unknown)

Details on study design:

STUDY DESIGN
The test material was applied undiluted in 3 animals.

TREATMENT
In accordance with OECD 405 (1981). The test substance is placed in the conjunctival sac of one eye of each animal after gently pulling the lower lid away from the eyeball. The lids are then gently held together for about one second. The other eye serves at control.

REMOVAL OF TEST SUBSTANCE
-Washing: No

OBSERVATIONS
- Irritation:
The eyes of each animal were examined approximately 1, 24, 48 and 72 hours and 7 and 14 days after instillation of the test substance.
The irritation scores and a description of all other (local) effects were recorded. The irritation was assessed according to OECD 405 (1981).
Examination of the eye was facilitated by use if a standard ophthalmoscope.

Results and discussion

In vitro

Results

Irritation parameter:

other:

Vehicle controls validity:

other: other information is presented

Remarks on result:

other: Other information is presented

In vivo

Results

Results 1

Irritation parameter:

cornea opacity score

Remarks:

Degree

Basis:

animal: #1 and #3 (mean)

Time point:

24/48/72 h

Score:

2

Max. score:

4

Reversibility:

fully reversible within: 14 days

Remarks:

But some circum corneal vacualisation was seen in animal 3

Results 2

Irritation parameter:

cornea opacity score

Remarks:

(opacity)

Basis:

animal: #2 (mean)

Time point:

24/48/72 h

Score:

2.33

Max. score:

4

Reversibility:

not fully reversible within: 14 days

Results 3

Irritation parameter:

iris score

Basis:

animal: #1 (mean)

Time point:

24/48/72 h

Score:

0

Max. score:

2

Reversibility:

fully reversible

Results 4

Irritation parameter:

iris score

Basis:

animal: #2 and #3 (mean)

Time point:

24/48/72 h

Score:

1

Max. score:

2

Reversibility:

fully reversible within: 14 days

Results 5

Irritation parameter:

conjunctivae score

Remarks:

(redness)

Basis:

animal: #1 and #3 (mean)

Time point:

24/48/72 h

Score:

2.33

Max. score:

3

Reversibility:

fully reversible within: 7 days

Results 6

Irritation parameter:

conjunctivae score

Remarks:

(redness)

Basis:

animal: #2 (mean)

Time point:

24/48/72 h

Score:

2.66

Max. score:

3

Reversibility:

fully reversible within: 14 days

Results 7

Irritation parameter:

chemosis score

Basis:

animal: #1 (mean)

Time point:

24/48/72 h

Score:

2

Max. score:

4

Reversibility:

fully reversible within: 7 days

Results 8

Irritation parameter:

chemosis score

Basis:

animal: #2 (mean)

Time point:

24/48/72 h

Score:

2.33

Max. score:

4

Reversibility:

fully reversible within: 14 days

Results 9

Irritation parameter:

chemosis score

Basis:

animal: #3 (mean)

Time point:

24/48/72 h

Score:

1.66

Max. score:

4

Reversibility:

fully reversible within: 7 days

Irritant / corrosive response data:

A dulling of the normal lustre of the corneal surface was noted in all treated eyes one hour after treatment. Circumcorneal vascularisation was noted in two of the three treated eyes on day 14 (animal 2 and 3); the remaining treated eye showed a dulling of the normal lustre of the corneal surface at day 7 (animal 1). A small area of opalescent opacity was noted in one treated eye on day 14.
Iridial inflammation was noted in all treated eyes one hour after treatment and in one treated eye on day 7.
Conjunctivitis was noted in all treated eyes one hour after treatment and in one eye on day 7.

Applicant's summary and conclusion

Interpretation of results:

other: Irreversible effects on the eye, cat. 1.

Remarks:

According to Regulation (EC) No. 1272/2008 and its amendments

Conclusions:

In an eye irritation study with rabbits, performed according to OECD TG 405 (1981) and GLP principles, irritation was observed in all animals resulting in scores that need classification.
Most test results indicated a Cat 2 classification: All three animals showed conjunctivae redness ≥2 and in 2 of 3 animals conjunctivae oedema (chemosis) ≥2. Iridial inflammation (score = 1) was noted in two animals. All animals showed opacity ≥1. Observed effects were reversible in all animals within 7 to 14 days
However, because in one animal cornea opacity effects (score 3 and circumcorneal vascularisation on day 14) was seen and the not expected reversibility the substance is classified “irreversible effects on the eye, cat. 1” according to Regulation (EC) No. 1272/2008 and Category 1 Serious eye damage according to GHS.

Executive summary:

The substance was tested in an eye irritation test in rabbits according to OECD TG 405 test guideline and in compliance with GLP principles. The eyes of three rabbits were exposed to 0.1 mL of the test substance and observations were made up to 14 days after installation. All three animals showed conjunctivae redness ≥2 and in 2 of 3 animals conjunctivae oedema (chemosis) ≥2. Iridial inflammation (score = 1) was noted in two animals. All animals showed opacity ≥1. Observed effects were reversible in all animals within 7 to 14 days except for opacity effects in one animal (score 3 and circumcorneal vascularisation on day 14). Based on the test results, the substance is classified “irreversible effects on the eye.