3,3,5-trimethylcyclohexyl methacrylate

Endpoint summary

Description of key information

To evaluate the skin irritation potential of 3,3,5 -trimethylcyclohexyl-methacrylate, two studies are available.The in vitro skin corrosion study was negative indicating that the substance is not skin corrosive. However, the substance is considered to be skin irritating based on the rabbit study.

To evaluate the eye irritation potential of 3,3,5 -trimethylcyclohexyl-methacrylate, a rabbit study is available and showed that the substance is not eye irritating.

No data is available to evaluate the respitratory irritation potential of 3,3,5 -trimethylcyclohexyl-methacrylate.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Reference 1

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

April / June 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 431 (In Vitro Skin Corrosion: Human Skin Model Test)

Version / remarks:

2016

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Cell source:

other: epiCS, cell systems

Details on animal used as source of test system:

Human skin model: The 0.6 cm2 reconstitued epidermis (epiCS, cell systems, batch No.100-AG0648-1) were received on 19 April 2017. The insert (filter + epidermis) was gently removed from the agarose while avoiding leaving agarose on the polycarbonate filter. The same day, the insert was placed in a 6 wells culture plate which had been previously filled with 1ml of culture medium. The culture dishes were incubated at 37+/-2°C, 5% CO2, 19 hours and 55 minutes before treatment. Just before the treatment, the culture medium was replaced by a new culture medium.

Vehicle:

unchanged (no vehicle)

Details on test system:

Grading of reactions:
3 minutes and 1 hour after the test item application, the human epidermis was mashed 20 times with 1ml of DPBS. The rinsed tissue were checked for any coloration and noted to be whitish, comparable coloration to that of the negetive control tissues.
The cell viability was quantified by measurement of the cell succinate deshydrogenase activity. This enzyme was responsible for the MTT reduction into blue formazan crystal. The skin sample was placed in MTT solution of 1 mg/ml concentration for 3 hours between 37°C and 37.7°C, 5% CO2. The precipitated blue formazan product was then extracted using isopropanol during 2 hours under agitation in the dark, and the concentration of formazan was measured by determing the optical density (OD) at 570 nm, just after dilution of the extraction in isopropanol (1:3).
The absorbance was measured in triplicate of MTT extract. The ùeasured absorbances were proportional to the number of living cells.

Treatment of the results : The results were expressed as a viability percentage compared with the negative control.

Evaluation and interpretation of the results :
The OD values obtained for the test item were used to calculate a percentage of viability relative to the negative control, which was arbitrarily set at 100%. The cut-off values for the prediction of corrosion associated with the epiSC model were as follows :
-Viability < 50% after 3 min exposure: Corrosive (1A)
-Viability > or = 50% after 3 min exposure AND < 15% after 60 min exposure: Corrosive (1B/1C)
-Viability > or = 50% after 3 min exposure AND > or = 15% after 60 min exposure: Non-Corrosive

Acceptability criteria :
-Negative control: mean OD of the tissue replicates should be > or = 0.8 and < or = 2.8 for epiSC model for every exposure time
-Positive control: mean viability of the tissue replicates expsed for 1 hour, expressed as % of the negative control, should be < 20% for epiCS model
-Test item: in the range 20-100% viability, and for ODs < or = 0.3, difference of viability between the two tissue replicates should not exceed 30%

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

The test item was applied, as supplied, at the dose of 50 µl at room temperature

Duration of treatment / exposure:

3 min, 1 hour

Number of replicates:

2

Irritation / corrosion parameter:

% tissue viability

Remarks:

3 min

Run / experiment:

treated

Value:

101.47

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Remarks:

100%

Positive controls validity:

valid

Remarks:

4.11%

Irritation / corrosion parameter:

% tissue viability

Remarks:

1 hour

Run / experiment:

treated

Value:

122.61

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Remarks:

100%

Positive controls validity:

valid

Remarks:

0.83%

Other effects / acceptance of results:

ACCEPTANCE OF RESULTS:
- Acceptance criteria met for negative control: yes
- Acceptance criteria met for positive control: yes

Interpretation of results:

other: not corrosive

Conclusions:

Based on these results, 3,3,5 -trimethylcyclohexylmethacrylate is not classified as skin corrosive.

Executive summary:

The aim of the study was to evaluate the possible corrosive effects of the test item after topical administratin on in vitro human reconstituted epidermis (epiCS, CellSystems).

The test item 3,3,5 -trimethylcyclohexylmethacrylate was applied as supplied, at the dose of 50 µl, to 2 Human skin modekl surfaces (epiCS, CellSystems) during 3 minutes and 1 hour, followed by a rinse with 20 ml of DPBS. Cell viability was then measured by enzymatic conversion of the vital dye MTT into a blue formazan salt that was quantitatively measured after extraction from tissues. The experimental protocol was established in accordance with the OECD TG 431.

Three minutes and 1 hour after the test item application, the mean percent viability of the epidermis skins treated with the test item were 101.47% and 122.61% when compared with the negative control (considered as 100%), versus 4.11% and 0.83%, respectively, with the positive control item (potassium hydroxide 8N).

All the acceptability criteria were met. This study is validated.

Based on these results, 3,3,5 -trimethylcyclohexylmethacrylate is not classified as skin corrosive.

Reference 2

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

May 1984

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

observation period of 7 days instead of 14 days

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Version / remarks:

1981

Deviations:

yes

Remarks:

observation period of 7 days instead of 14 days

GLP compliance:

yes

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Kleintierfarm Madoerin AG, Fuellinsdorf / Switzerland
- Age at study initiation: 11-12 week
- Weight at study initiation: 2-2.4 kg
- Housing: individually
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 4 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22+/-2
- Humidity (%): 55+/-10
- Air changes (per hr): 10-15
- Photoperiod (hrs dark / hrs light): 12/12

Type of coverage:

occlusive

Preparation of test site:

shaved

Vehicle:

unchanged (no vehicle)

Controls:

not required

Amount / concentration applied:

0.5 ml

Duration of treatment / exposure:

4 hr

Observation period:

1hr, 24, 48, 72 after removal of the dressing

Number of animals:

1 male and 2 females

Details on study design:

Approximately 24 hours before treatment, the dorsal fur was shaved with an electric clipper, exposing an area of approximately 100 square centimeters ( 10 x 10 cm).
On test day 1, 0.5 ml of the test article was applied to the intact skin of the shaved area. It was covered with a 3 x 3 cm patch of surgical gauze. The gauze was covered with aluminium foil and then covered with an occlusive dressing. The dressing was wrapped around the abdomen and anchored with an elastic bandage.
Observations : viability/mortality (daily), bodyweight (pre-test, day 1, at termination), symptoms (1hr, 24, 48, 72 after removal of the dressing).
The corrosive properties of the test artcile and the color to the treated skin area were described and recorded.
The study was terminated 7 days after application of the test article. All rabbits were killed at the end of the observation period by intraveneous injection of T61 into the ear vein. No necropsies were performed.

Irritation parameter:

erythema score

Basis:

mean

Remarks:

3 rabbits

Time point:

24/48/72 h

Score:

1.8

Max. score:

4

Reversibility:

not fully reversible within: 7 days

Irritation parameter:

edema score

Basis:

mean

Remarks:

3 rabbits

Time point:

24/48/72 h

Score:

0.67

Max. score:

4

Reversibility:

not fully reversible within: 7 days

Irritant / corrosive response data:

The test article was found to cause a primary irritation score of 2.5 when applied to intact rabbit skin.
In the area of application, no discoloration of the skin was observed which could be related to effects of the test article.
Scar formations were observed on the skin of 2 rabbits at 72 hours and/or 7 days.
The mean value of the scores for each types de lesion, calculated for each animal separately is : 1.7 -1.7 -2.0 for erythema, 1.0 -0.0 -1.0 for edema.

Other effects:

The bodyweight gain of all rabbits was similar.
No acute toxic symptoms were observed in the animals during the test period, and no mortality occurred.
Due to the results obtained, no macroscopic organ examination was indicated.

Interpretation of results:

Category 2 (irritant) based on GHS criteria

Conclusions:

Under the conditions of this experiment, 3,3,5-trimethylcyclohexylmethacrylate induce a mild skin irritation when applied to intact rabbit skin (4 -hour of occlusive exposure).

Executive summary:

The purpose of this primary skin irritation study was to assess possible irritation potential when single doses of 3,3,5-trimethylcyclohexylmethacrylate are placed in the skin of rabbits.

Under the conditions of this experiment, 3,3,5-trimethylcyclohexylmethacrylate was found to cause a primary irritation score of 2.5 when applied to intact rabbit skin (4 -hour of occlusive exposure).

In the area of application, no discoloration of the skin was observed which could be related to effects of the test article. Scar formations were observed on the skin of 2 rabbits at 72 hours and/or 7 days.

The mean value of the scores for each types de lesion, calculated for each animal separately is : 1.7 -1.7 -2.0 for erythema, 1.0 -0.0 -1.0 for edema.

Under the conditions of this experiment, 3,3,5-trimethylcyclohexylmethacrylate induce a mild skin irritation when applied to intact rabbit skin (4 -hour of occlusive exposure).

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

June 1984

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Version / remarks:

1981

Deviations:

no

GLP compliance:

yes

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Source: Kleintierfarm Madoerin AG, CH-4414 Fuellinsdorf, Switzerland
- Age at study initiation: 12/13 weeks
- Weight at study initiation: 2.1-2.5 kg
- Housing: individually
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum):ad libitum
- Acclimation period: 4 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22+/-2
- Humidity (%): 55+/-10
- Air changes (per hr): 10/15
- Photoperiod (hrs dark / hrs light): 12/12

Vehicle:

unchanged (no vehicle)

Controls:

not required

Amount / concentration applied:

0.1 ml

Duration of treatment / exposure:

single exposure

Observation period (in vivo):

1, 24, 48 and 72 hours after administration

Number of animals or in vitro replicates:

2 females and 1 male

Details on study design:

A single dose was administered to the left eye of each animal. The right eye remained untreated and was used as the reference control. The application volume was 0.1 ml per animal.
For observation, the eye were not rinsed.

OBSERVATIONS :
-viability : daily
-Body weight : pre-test, day 1 and at the termination of test
-Eye reaction: 1h, 24h, 48h and 72h after administration

The study was terminated 72 hours after administration of the test article.
All rabbits were killed at the end of the observation period.
No macroscopic organ examination was performed.

Irritation parameter:

cornea opacity score

Basis:

mean

Remarks:

3 rabbits

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Irritation parameter:

iris score

Basis:

mean

Remarks:

3 rabbits

Time point:

24/48/72 h

Score:

0

Max. score:

2

Remarks on result:

no indication of irritation

Irritation parameter:

conjunctivae score

Remarks:

redness

Basis:

mean

Remarks:

3 rabbits

Time point:

24/48/72 h

Score:

0

Max. score:

3

Remarks on result:

no indication of irritation

Irritation parameter:

chemosis score

Basis:

mean

Remarks:

3 rabbits

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Irritant / corrosive response data:

No corrosion of the cornea was observed at each of the measuring intervals.
After 1h of administration, some effects were observed on the conjunctivae (slight reddened) in 3 rabbits and on the slera (clear visible vessels) on 2 rabbits.
No effect on cornea opacity, iris, conjunctivae (redness and chemosis) were observed in all the rabbits after 24h of administration.
In the area of application, no discoloration of the corea and conjunctivae which could be related to effects of the test article was observed.

Other effects:

No acute toxic symptoms were observed in the animals during the test period, and no mortality occurred.
The body weight gain of all rabbits was similar.

Interpretation of results:

GHS criteria not met

Remarks:

not eye irritating

Conclusions:

Based on these results, 3,3,5 -trimethylcyclohexyl-methacrylate is considered to be not irritating to the eye of rabbit.

Executive summary:

The purpose of this primary eye irritation study was to assess possible irritation potential when single doses of 3,3,5 -trimethylcyclohexyl methacrylate are placed in the conjunctival sac of rabbit eyes.

Under the conditions of this experiment, 3,3,5 -trimethylcyclohexyl methacrylate was found to cause a primary irritation score of 0.3 when applied to the rabbit eye mucosa.

In the area of application, no discoloration of the cornea and conjunctivae was observed which could be related to effects of the test article. No corrosion was observed a each measuring intervals. Mean individual score at 24, 48 and 72h after administration was 0 for cornea opacity, iris, conjunctivae (redness and chemosis) in all the rabbits.

Based on these results, 3,3,5 -trimethylcyclohexyl methacrylate is considered to be not irritating to the eye of rabbit.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

In vitro skin corrosion study (2017) :

The aim of the study was to evaluate the possible corrosive effects of the test item after topical administration on in vitro human reconstituted epidermis (epiCS, CellSystems).

The test item 3,3,5 -trimethylcyclohexylmethacrylate was applied as supplied, at the dose of 50 µl, to 2 Human skin modekl surfaces (epiCS, CellSystems) during 3 minutes and 1 hour, followed by a rinse with 20 ml of DPBS. Cell viability was then measured by enzymatic conversion of the vital dye MTT into a blue formazan salt that was quantitatively measured after extraction from tissues. The experimental protocol was established in accordance with the OECD TG 431.

Three minutes and 1 hour after the test item application, the mean percent viability of the epidermis skins treated with the test item were 101.47% and 122.61% when compared with the negative control (considered as 100%), versus 4.11% and 0.83%, respectively, with the positive control item (potassium hydroxide 8N).

Based on these results, 3,3,5 -trimethylcyclohexylmethacrylate is not classified as skin corrosive.

In vivo skin irritation study (Ullmann 1984b) :

The purpose of this primary skin irritation study was to assess possible irritation potential when single doses of 3,3,5-trimethylcyclohexylmethacrylate are placed in the skin of rabbits.

Under the conditions of this experiment, 3,3,5-trimethylcyclohexylmethacrylate was found to cause a primary irritation score of 2.5 when applied to intact rabbit skin (4 -hour of occlusive exposure).

In the area of application, no discoloration of the skin was observed which could be related to effects of the test article. Scar formations were observed on the skin of 2 rabbits at 72 hours and/or 7 days.

The mean value of the scores for each types of lesion, calculated for each animal separately is : 1.7 -1.7 -2.0 for erythema, 1.0 -0.0 -1.0 for edema.

Under the conditions of this experiment, 3,3,5-trimethylcyclohexylmethacrylate induce a mild skin irritation when applied to intact rabbit skin (4 -hour of occlusive exposure).

In vivo eye irritation study (Ullmann 1984c) :

The purpose of this primary eye irritation study was to assess possible irritation potential when single doses of 3,3,5 -trimethylcyclohexyl-metahcrylate are placed in the conjunctival sac of rabbit eyes.

Under the conditions of this experiment, 3,3,5 -trimethylcyclohexyl-methacrylate was found to cause a primary irritation score of 0.3 when applied to the rabbit eye mucosa.

In the area of application, no discoloration of the cornea and conjunctivae was observed which could be related to effects of the test article. No corrosion was observed a each measuring intervals. Mean individual score at 24, 48 and 72h after administration was 0 for cornea opacity, iris, conjunctivae (redness and chemosis) in all the rabbits.

Based on these results, 3,3,5 -trimethylcyclohexyl-methacrylate is considered to be not irritating to the eye of rabbit.

Justification for classification or non-classification

Based on the available data, a classification for skin irritation is required for 3,3,5 -trimethylcyclohexyl-methacrylate according to the Regulation EC n°1272/2008 : skin Irrit.2 (H315).

However, no classification is required for eye irritation for 3,3,5 -trimethylcyclohexyl-methacrylate according to the Regulation EC n°1272/2008.