(octahydro-4,7-methano-1H-indenyl)methyl acrylate

Endpoint summary

Description of key information

Skin irritation : At first, an in vitro skin irritation study (OECD 439) was performed but the results are inconclusive. So, in a second step, an in vivo skin irritation study (OECD 404) was performed, and based on the results, Tricyclodecanemoonomethylol acrylate is considered as skin irritating.

Eye irritation: An in vitro eye irritation/corrosion study (OECD 437) was performed on Tricyclodecanemonomethylol acrylate. The results are conclusive and the substance is not considered as eye irritating.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

01 August 2018 - 12 September 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Version / remarks:

2015

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.2500 (Acute Dermal Irritation)

Version / remarks:

August 1998

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.4 (Acute Toxicity: Dermal Irritation / Corrosion)

Version / remarks:

May 2008

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: Appendix to Director General Notification, No. 12-Nousan-8, JMAFF

Version / remarks:

November 2000, including the most recent revisions

Deviations:

no

GLP compliance:

yes

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River France, L’Arbresle, France
- Age at study initiation: approx. 12-16 weeks old
- Weight at study initiation: 2868 - 3365 g
- Housing: individually in cages with perforated floors
- Diet: pelleted diet for rabbits (Global Diet 2030 Teklad®, Mucedola, Milanese, Italy), once daily throughout the study ; in addition hay was available during the study period.
- Water: municipal tap-water, ad libitum
- Acclimation period: at least 5 days

It is considered that there were no known contaminants in the feed and the water that would interfere with the objectives of the study.
For psychological/environmental enrichment, animals were provided with shelters and wooden sticks.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 - 21
- Humidity (%): 48 - 90
- Air changes (per hr): >= 10
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 01 August 2018 To: 12 September 2018

Type of coverage:

semiocclusive

Preparation of test site:

clipped

Vehicle:

unchanged (no vehicle)

Controls:

no

Amount / concentration applied:

TEST ITEM:
- Amount applied: 0.5 mL

Duration of treatment / exposure:

4 hours

Observation period:

14 days

Number of animals:

3 males

Details on study design:

TEST SITE
- Area of exposure: 2x3 cm
- Type of wrap if used: the test item was applied using a metalline patch, mounted on Micropore tape which was wrapped with Coban elastic bandage

REMOVAL OF TEST SUBSTANCE
- Washing: with tap water
- Time after start of exposure: 4 hours

OBSERVATION TIME POINTS
- Mortality: twice a day (morning and end of the working day)
- Clinical signs: 1, 24, 48 and 72 hours and 7 and 14 days after removal of the test item.
- Body weights: on day 1 (predose) and at the final day of the observation period

The study was performed in a stepwise manner and was started by treatment of a single rabbit (sentinel). The two other animals were treated in a similar manner 4 weeks later.

SCORING SYSTEM:
- Method of calculation: according to Draize system

Irritation parameter:

erythema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

2

Max. score:

4

Reversibility:

fully reversible within: 14 days

Irritation parameter:

edema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

3

Max. score:

4

Reversibility:

not fully reversible within: 14 days

Irritation parameter:

erythema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

2

Max. score:

4

Reversibility:

fully reversible within: 14 days

Irritation parameter:

edema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

2.3

Max. score:

4

Reversibility:

not fully reversible within: 14 days

Irritation parameter:

erythema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

2.3

Max. score:

4

Reversibility:

not fully reversible within: 14 days

Irritation parameter:

edema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

3

Max. score:

4

Reversibility:

not fully reversible within: 14 days

Irritant / corrosive response data:

Skin Irritation: The skin irritation was not fully reversible within 14 days after exposure in all animals. Slight oedema (score of 1 or 2) in all three animals, and slight erythema (score of 1) in one animal were observed at the end of the observation period. Reduced flexibility and scaliness of the skin was observed in all three animals during the observation period. One animal showed bald skin after 14 days.

Coloration/remnants: No staining of the treated skin by the test item was observed and no test item remnants were seen.
Toxicity/mortality: no signs of systemic toxicity were observed in the animals during the test period and no mortality occurred.
Bodyweight: No abnormal change of bodyweight was recorded in the animals.

Interpretation of results:

Category 2 (irritant) based on GHS criteria

Conclusions:

Based on the persisting skin reactions until day 14 and the 24-72 hours mean oedema score = 2.3 for all animals: Tricyclodecanemonomethylol acrylate is considered as a skin irritant.

Executive summary:

An in vivo skin irritation study with Tricyclodecanemonomethylol acrylate was performed in rabbits according to OECD 404 and GLP principles.

The skin irritation was not fully reversible within 14 days after exposure in all 3 animals. Slight oedema (score of 1 or 2) in all three animals, and slight erythema (score of 1) in one animal were observed at the end of the observation period. Reduced flexibility and scaliness of the skin was observed in all three animals during the observation period. One animal showed bald skin after 14 days.

No staining of the treated skin by the test item was observed and no test item remnants were seen.

No signs of systemic toxicity were observed in the animals during the test period and no mortality occurred. No abnormal change of bodyweight was recorded in the animals.

Based on the persisting skin reactions until day 14 and the 24-72 hours mean oedema score = 2.3 for all animals: Tricyclodecanemonomethylol acrylate is classified as a skin irritant.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

16 February 2018 - 28 February 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 437 (Bovine Corneal Opacity and Permeability Test Method for Identifying i) Chemicals Inducing Serious Eye Damage and ii) Chemicals Not Requiring Classification for Eye Irritation or Serious Eye Damage)

Version / remarks:

09 October 2017

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Species:

other: bovine cornea

Strain:

other: not applicable

Details on test animals or tissues and environmental conditions:

Species: bovine cattle (Bos taurus).
Origin: bovine eyes were obtained from freshly slaughtered cattle at the abattoir EVA, Saint Pierre sur Dives, France.
Age: as French Authorities avoid the use of any organs from the head of bovines aged more than 12 months, bovine cattle were up to 12 months old (typically, 5 to 8 months old).
Reason for choice: bovine corneas are recommended by Regulatory Authorities for this type of study. They are adapted for the evaluation of potential ocular irritants since they are part of the target organ.
Transport from Supplier to Citoxlab France: the eyes were immerged in containers filled with cooled buffered Hanks medium and placed into a cooling-box with a sufficient amount of ice packs to ensure cooling until arrival at Citoxlab France. Containers with smooth internal surfaces were used for the transport to avoid damage to the corneas. Hank’s medium contained an antibiotic [Hank’s Balanced Salts Solution (HBSS) plus penicillin/streptomycin (100 units/100 µg/mL final)].

Preparation of the corneas
Upon arrival at Citoxlab France, the selection and preparation of corneas was performed as soon as possible. At each step of the preparation procedure, care was taken to avoid touching the corneas in order not to damage them.

Selection: a careful macroscopic examination was performed on all eyes to detect the presence of any defects (opacity, scratches, pigmentation, etc). Any eyes with defects were discarded. The examination was performed under a lamp, using HBSS in order to keep the eyes moistened and shiny. Particular attention was paid to the corneas and the eyes were swiveled in order to observe the fringe areas and any scratches directly under the light.
Preparation of the selected corneas: the tissues surrounding the eyeball were carefully pulled away and the cornea, surrounded by approximately 2 to 3 mm of sclera, was dissected out. The isolated corneas were stored in HBSS until all corneas had been prepared. The corneas were then used immediately

Vehicle:

unchanged (no vehicle)

Controls:

other: in vitro negative and positive controls

Amount / concentration applied:

TEST MATERIAL
- Amount applied: 750 µL per cornea
- Concentration: undiluted

Duration of treatment / exposure:

Exposure period of 10 minutes (± 30 seconds) at +32°C, followed by rinsing.

Observation period (in vivo):

Not applicable.

Duration of post- treatment incubation (in vitro):

2 hours (± 10 minutes) at +32°C.

Number of animals or in vitro replicates:

Triplicate corneas for each timepoint and tested substance (test item, negative control, positive control)

Details on study design:

ASSEMBLY OF THE CORNEAS AND THE HOLDERS
The corneas were mounted in the corneal holders with the endothelial side against the O-ring of the posterior chamber. Each cornea was identified with the corresponding holder number.

TREATMENT
The medium of the anterior chamber was removed and each item was applied onto the epithelium of the cornea, as specified in the § Test item, positive and negative controls application.

The treatment time of each series of three corneas was carefully measured with a chronometer, starting from the beginning of treatment of the first cornea of each series. Then each further operation (rinsing, measurement, etc.) was carried out in the same order for the three corneas of each series.

After application of the items, the holders were incubated vertically (cornea positioned horizontally with the treated side uppermost) in a water bath at +32°C (± 1°C), for the selected treatment time

REMOVAL OF TEST SUBSTANCE
The purpose of rinsing was to eliminate as much items as possible, while taking care not to damage the cornea. On completion of the treatment period, the test item was removed from the front opening of the anterior chamber (open-chamber method) and the epithelium was rinsed as follows:
- the anterior chamber was emptied using a metal gavage tube attached to a vacuum pump,
-- any residual amounts of the test item, adhering to the walls of the anterior chamber was first removed with a cotton bud and then using a pipette of heated cMEM (32°),
- the corneas were rinsed five times with pre-warmed cMEM containing phenol red (i.e. until the test item had been completely removed from the chamber or until the phenol red was not discoloured). Then, the corneas were finally rinsed with pre-warmed cMEM without phenol red.

POST INCUBATION
Following the 10-minute treatment and the rinsing step, the holders were incubated horizontally (corneas placed vertically) for 2 hours (± 10 minutes) in a water bath at +32°C (± 1°C). On completion of the 2-hour incubation period, the medium of both anterior and posterior chambers was renewed with pre-warmed cMEM (+32°C (± 1°C)), the second opacity measurement (OPT2) was then performed.

SCORING SYSTEM
- Opacity:
An opacitometer was used to measure light transmission (i.e. the level of opacity) through the center of each mounted cornea. A numerical opacity measurement (arbitrary unit) was displayed and recorded.

Just before the first opacity measurement (i.e. OPT0), the opacitometer was calibrated using specific calibrators. Values obtained for each calibrator were as follows:
- calibrator No. 1: set to 75,
- calibrator No. 2: from 145 to 155,
- calibrator No. 3: from 218 to 232.

Just before the second opacity measurement (i.e. OPT2), the opacitometer was calibrated using the calibrator No. 1 set to 75.
Just after each opacity measurement (OPT0 and OPT2), the calibration of the opacitometer was checked by using the calibrator No. 1. The obtained value was between 73 and 77 (see Table 2).
Corneal opacity was determined by reading each holder in the right hand chamber of the calibrated opacitometer, versus an empty holder (without cMEM, cornea and glasses), placed in the left hand chamber.
For opacity measurement, care was taken to make sure that no air bubbles were present within the holders containing corneas (by ensuring that each compartment was filled to overflowing with heated cMEM) and each holder was wiped dry.

- Permeability:
After the second opacity measurement, the medium of the anterior chamber was removed and the anterior chamber received 1 mL of a fluorescein solution.
As the test item was a non-surfactant liquid, the concentration of the fluorescein solution was 4 mg/mL.
Before use, the fluorescein solution was validated. For this purpose, the solution of fluorescein was diluted in cMEM in order to obtain a 5 µg/mL solution and the Optical Density at a wavelength of 490 nm (OD490 nm) of this dilution was measured. As the value obtained was between 0.850 and 0.940, the fluorescein solution was validated.
For each series of three corneas, a chronometer started from the fluorescein solution application time of the first cornea of the series. The holders were incubated vertically (cornea positioned horizontally with the fluorescein-treated side uppermost) in a water bath at +32°C (± 1°C) for 90 minutes (± 5 minutes).
At the end of incubation, the maximum volume of cMEM recoverable from the posterior chamber of each holder was transferred into an identified tube. The medium was homogenized prior to determination of OD490 nm, using single-use cuvettes (1 cm path length) and a spectrophotometer (cMEM used as the blank).

- Scoring:
In Vitro Irritancy Score (IVIS) = cOPT + (15 x cOD490 nm)

Irritation parameter:

in vitro irritation score

Run / experiment:

mean

Value:

0

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

no indication of irritation

Remarks:

The test item was identified as not irritating

Other effects / acceptance of results:

MACROSCOPIC EXAMINATION:
Fluorescein fixation was observed on all corneas treated with the test item and one out of the three corneas treated with negative control (i.e. holder No. 56).
Opacity, fluorescein fixation and thickening of the corneas were observed on those treated with the positive control.

ACCEPTANCE OF RESULTS:
For the validation of an experiment, the following criteria had to be fulfilled:
- the mean In Vitro Irritancy Score (IVIS) of the positive control corneas should fall within two standard deviations of the historical mean,
- the mean opacity and mean OD490 nm of the negative control corneas should be less than the established upper limit of historical mean.

Interpretation of results:

GHS criteria not met

Conclusions:

The test item was identified as not requiring classification for eye irritation or serious eye damage (UN GHS No Category).

Executive summary:

The objective of this study was to evaluate the potential irritant and corrosive properties of the test item to the eye. The Bovine Corneal Opacity and Permeability (BCOP) test method can identify chemicals inducing serious eye damage and chemicals not requiring classification for eye irritation or serious eye damage.

The design of this study was based on the OECD Guideline 437 and the study was performedin compliance with Citoxlab France standard operating procedures and with the OECD Principles of Good Laboratory Practice.

 

Method

Corneas obtained from freshly slaughtered calves were mounted in corneal holders. Both chambers of the corneal holder were filled with complemented MEM culture media (cMEM) and pre-incubated for 1 hour and 5 minutes (± 5 minutes) at +32°C.

A single experiment was performed using three corneas for each treated series (test item, positive control and negative control).

Before the treatment, a first opacity measurement was performed on each cornea using an opacitometer.

The test item was applied undiluted in a single experiment using a treatment time of 10 minutes and using the closed-chamber treatment method. Negative and positive controls were applied using the same treatment time and through the closed-chamber treatment method. At the completion of the treatment period, all items were removed from the front opening of the anterior chamber and the epithelia were rinsed.

The corneas were then incubated for 2 hours (± 10 minutes) at +32°C before a second opacity measurement was performed.

After the second opacity measurement, the medium of the anterior chamber was removed and filled with a fluorescein solution. The holders were then incubated vertically for 90 minutes (± 5 minutes) at +32°C.

At the end of the incubation period, the Optical Density of the solution from the posterior chamber of each holder was measured in order to determine the permeability of the cornea. Each cornea was then observed for opaque spots and other irregularities.

 

Results

Macroscopic examination

Fluorescein fixation was observed on all corneas treated with the test item.

In VitroIrritancy Score

All acceptance criteria were fulfilled. The study was therefore considered as valid.

The mean In Vitro Irritancy Score (IVIS) of the test item-treated corneas was: 0.

 

As the mean IVIS was < 3, the test item was considered as a test chemical not requiring classification for eye irritation or serious eye damage (UN GHS No Category).

 

Conclusion

the test item was identified as not requiring classification for eye irritation or serious eye damage (UN GHS No Category).

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

In vivo skin irritation study (von Sas 2018):

An in vivo skin irritation study with Tricyclodecanemonomethylol acrylate was performed in rabbits according to OECD 404 and GLP principles.

The skin irritation was not fully reversible within 14 days after exposure in all 3 animals. Slight oedema (score of 1 or 2) in all three animals, and slight erythema (score of 1) in one animal were observed at the end of the observation period. Reduced flexibility and scaliness of the skin was observed in all three animals during the observation period. One animal showed bald skin after 14 days.

No staining of the treated skin by the test item was observed and no test item remnants were seen.

No signs of systemic toxicity were observed in the animals during the test period and no mortality occurred. No abnormal change of bodyweight was recorded in the animals.

Based on the persisting skin reactions until day 14 and the 24-72 hours mean oedema score = 2.3 for all animals: Tricyclodecanemonomethylol acrylate is classified as a skin irritant.

In vitro skin irritation study (Valin 2018):

The objective of this study was to evaluate the skin irritation potential of the test item, using the EpiskinTM reconstructed human epidermis model.

The study design was based upon international guidelines (OECD Guideline No. 439 and Commission Regulation (EC) No. 761/2009, B.46). The study was conducted in compliance with CiToxLAB France standard operating procedures and the principles of Good Laboratory Practice.

Preliminary tests were performed to detect the ability of the test item to directly reduce MTT as well as its colouring potential.

Following the preliminary tests, the skin irritation potential of the test item was tested in the main test. The test item and both the negative and positive controls were applied topically on triplicate tissues and incubated at room temperature for 15 minutes. At the end of the treatment period, each tissue was rinsed with D-PBS and incubated for 42 hours at +37°C, 5% CO2 in a humidified incubator. The cell viability was then assessed by means of the colourimetric MTT reduction assay.

Relative viability values were calculated for each tissue and expressed as a percentage of the mean viability of the negative control tissues which was set at 100% (reference viability).

In addition, the concentration of the inflammatory mediator IL-1a was evaluated in the culture medium retained following the 42-hour recovery period. This quantification, based on an ELISA assay, was performed since the mean relative viability of the test item-treated tissues was > 50% following the MTT reduction assay.

Two assays were performed and the results are not reproducible. The results cannot be used to determine the skin irritation potential of the test substance.

 

In vitro eye irritation study (Valin 2018):

The objective of this study was to evaluate the potential irritant and corrosive properties of the test item to the eye. The Bovine Corneal Opacity and Permeability (BCOP) test method can identify chemicals inducing serious eye damage and chemicals not requiring classification for eye irritation or serious eye damage (OECD 437).

A single experiment was performed using three corneas for each treated series (test item, positive control and negative control).

Before the treatment, a first opacity measurement was performed on each cornea using an opacitometer. The test item was applied undiluted in a single experiment using a treatment time of 10 minutes and using the closed-chamber treatment method. Negative and positive controls were applied using the same treatment time and through the closed-chamber treatment method. At the completion of the treatment period, all items were removed from the front opening of the anterior chamber and the epithelia were rinsed. The corneas were then incubated for 2 hours (± 10 minutes) at +32°C before a second opacity measurement was performed. After the second opacity measurement, the medium of the anterior chamber was removed and filled with a fluorescein solution. The holders were then incubated vertically for 90 minutes (± 5 minutes) at +32°C. At the end of the incubation period, the Optical Density of the solution from the posterior chamber of each holder was measured in order to determine the permeability of the cornea. Each cornea was then observed for opaque spots and other irregularities.

Fluorescein fixation was observed on all corneas treated with the test item. The mean In Vitro Irritancy Score (IVIS) of the test item-treated corneas was: 0.

 As the mean IVIS was < 3, the test item was considered as a test chemical not requiring classification for eye irritation or serious eye damage (UN GHS No Category).

Justification for classification or non-classification

A mandatory classification is available for "monoalkyl or onoaryl or monoalkylaryl esters of acrylic acid " : skin irrit.2 (H315), eye irrit.2 (H319), STOT SE 3 (H335).

However, some studies were performed to have the data on the registered substance. The self classification of Tricylcodecanemonomethylol acrylate, based on experimental data, is : Skin irrit.2 (H315).

Based on the available data, Tricylcodecanemonomethylol acrylate should be classified as skin irritant (Skin irrit.2, H315) according to the Regulation EC N°1272/2008.

Based on the available data, no classification for eye irritation is required for Tricyclodecanemonomethylol acrylate according to the Regulation EC N°1272/2008.

No data is available for evaluate the irritation potential on respiratory tract, so no self-classification is proposed for this endpoint.