4-formyl-2-methoxyphenyl isobutyrate

Endpoint summary

Description of key information

In vitro Skin irritation test (OECD 439) _ Givaudan study 2014 _ negative

In vitro Eye irritation test BCOP (OECD 437) _ Givaudan study 2014 _ negative

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

19 February - 8 July 2014

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

OECD Guideline 439 (In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method)

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

- Name of test material (as cited in study report): Isobutavan
- Physical state: colourless to pale yellow liquid
- Lot/batch No.: SC00010048
- Expiration date of the lot/batch: December 17, 2015

Test system:

human skin model

Source species:

human

Cell type:

other: EpiSkinTM three-dimensional human skin model

Cell source:

other: Reconstructed epidermis with a functional stratum corneum supplied by SkinEthic Laboratories, Lyon, France.

Vehicle:

unchanged (no vehicle)

Details on test system:

The test article was used as supplied.

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

A volume of 40 μL of the undiluted test article was added topically to the tissues. A volume of 40 μL of the positive and negative control solutions was used.

Duration of treatment / exposure:

Exposure was for 15 minutes after which the tissues were washed using PBS and dried using cotton wool buds to remove residual material before being transferred to a new well containing 2 mL pre-warmed maintenance medium.

Duration of post-treatment incubation (if applicable):

The tissues were then incubated at 37°C for the 42 hour recovery time period.

Number of replicates:

The test was performed on a total of three tissues per test article, negative and positive control.

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

Experiment 1

Value:

64

Negative controls validity:

valid

Remarks:

100% viability

Positive controls validity:

valid

Remarks:

4.6% viability

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

Experiment 2

Value:

56.1

Negative controls validity:

valid

Remarks:

100% viability

Positive controls validity:

valid

Remarks:

6.3 % viability

Interpretation of results:

GHS criteria not met

Conclusions:

The test article, Isobutavan, was considered not to be irritant in the in vitro skin model EpiSkin.

Executive summary:

This study was conducted to determine whether the test article causes irritation in the in vitro skin model EpiSkinTM. EpiSkinTM inserts were treated with Isobutavan, negative control (phosphate buffered saline (PBS)) and positive control (5% w/v sodium dodecyl sulphate (SDS)) for 15 minutes. At the end of the treatment period, the tissues were washed with PBS and cell viability was assessed using the MTT assay. The skin irritation potential was classified according to the remaining cell viability obtained after test article treatment. The group mean viability for the test article was 56.1%, for the negative control was 100% and for the positive control was 6.3%. The test article, Isobutavan, was considered not to be irritant in the in vitro skin model EpiSkinTM.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not 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:

19 February - 27 June 2014

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 Ocular Corrosives and Severe Irritants)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

- Name of test material (as cited in study report): Isobutavan
- Physical state: colourless to pale yellow liquid
- Lot/batch No.: SC00010048
- Expiration date of the lot/batch: December 17, 2015

Species:

other: Bovine cornea

Strain:

not specified

Details on test animals or tissues and environmental conditions:

Corneas from bovine eyes were obtained from a local abattoir. The eyes were removed after slaughter, completely immersed in Hanks’ Balanced Salt Solution (containing penicillin at 100 IU/mL and streptomycin at 100 μg/mL) in a suitably sized container and transported on the same day to the testing facility. On arrival at the test facility the eyes were carefully examined for defects including increased opacity, scratches and neovascularisation.
Only corneas free from such defects were used.

Vehicle:

unchanged (no vehicle)

Controls:

yes

Amount / concentration applied:

The test substance was used as supplied.
A volume of 750 μL of the test article was applied to each of three cornea.
A volume of 750 μL of the negative or positive control

Duration of treatment / exposure:

The test substance was applied for 10 minutes

Duration of post- treatment incubation (in vitro):

Incubation period of 120 minutes at 32°C.

Number of animals or in vitro replicates:

Corneas were tested in triplicate

Irritation parameter:

in vitro irritation score

Run / experiment:

Corneal opacity

Value:

0.7

Negative controls validity:

valid

Remarks:

0.0

Positive controls validity:

valid

Remarks:

31.3

Irritation parameter:

in vitro irritation score

Run / experiment:

Corneal permeability

Value:

0.032

Negative controls validity:

valid

Remarks:

0.000

Positive controls validity:

valid

Remarks:

0.288

Other effects / acceptance of results:

Two corneas treated with the positive control (numbers 33 and 39) were noted to be cloudy following treatment. The remaining cornea treated with the positive control (number 37) was only cloudy around the edge of the cornea.

Irritant / corrosive response data:

The assay showed that the test article, Isobutavan, did not cause serious eye damage.

Interpretation of results:

not classified

Conclusions:

The test article produced an IVIS score of 1.14 and therefore does not require classification for eye irritation.
The assay was considered valid as the assay acceptance criteria were met.

Executive summary:

The potential of isobutavan to cause eye irritation was evaluated in a BCOP test in accordance to OECD guideline 437 and GLP. A volume of 750 μL of the undiluted test article was applied to each of three corneas followed by a 10 minute incubation at 32°C ± 1°C. After this incubation, each cornea was washed with media containing phenol red followed by media without phenol red and the corneas assessed for opacity. The corneas were then incubated (horizontally) for 2 hours ± 10 minutes after which, corneal opacity was measured and then the anterior chamber emptied. For the permeability endpoint, sodium fluorescein solution was added into the anterior chamber and the corneas were incubated in the vertical position for 1.5 hours ± 5 minutes at 32°C ± 1°C. Following this period, the media in the posterior chamber was removed and three 350 μL aliquots of this media (per cornea) were analysed for optical density at 490 nanometers (OD490). A volume of 750 μL of the negative or positive control was similarly applied to further groups of three corneas. The mean corrected opacity reading for the test article was 0.7, for the negative control was 0.0 and for the positive control was 31.3. The corneas treated with the positive control were noted to be cloudy following treatment. The mean group corrected optical density for the test article was 0.032, for the negative control was 0.000 and for the positive control was 0.288. The test article produced an IVIS score of 1.14. Under the conditions of the in vitro assay, the test substance was considered to be non-irritating to the eye.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

In vitro Eye irritation (BCOP_ OECD 437):

This study was conducted to determine whether the test article causes serious eye damage or does not require classifying for eye irritation, using the bovine corneal opacity and permeability (BCOP) assay. A volume of 750 μL of the undiluted test article was applied to each of three corneas followed by a 10 minute incubation at 32°C ± 1°C. After this incubation, each cornea was washed with media containing phenol red followed by media without phenol red and the corneas assessed for opacity. The corneas were then incubated (horizontally) for 2 hours ± 10 minutes after which, corneal opacity was measured and then the anterior chamber emptied. For the permeability endpoint, sodium fluorescein solution was added into the anterior chamber and the corneas were incubated in the vertical position for 1.5 hours ± 5 minutes at 32°C ± 1°C. Following this period, the media in the posterior chamber was removed and three 350 μL aliquots of this media (per cornea) were analysed for optical density at 490 nanometers (OD490). A volume of 750 μL of the negative or positive control was similarly applied to further groups of three corneas. These corneas were subject to the procedures detailed above.

The mean corrected opacity reading for the test article was 0.7, for the negative control was 0.0 and for the positive control was 31.3. The corneas treated with the positive control were noted to be cloudy following treatment. The mean group corrected optical density for the test article was 0.032, for the negative control was 0.000 and for the positive control was 0.288. The assay showed that the test article, Isobutavan, did not cause serious eye damage. The test article produced an IVIS score of 1.14 and therefore does not require classification for eye irritation.

In vitro Skin irritation ( skin model EpiSkinTM_ OECD 439):

This study was conducted to determine whether the test article causes irritation in the in vitro skin model EpiSkinTM. EpiSkinTM inserts were treated with Isobutavan, negative control (phosphate buffered saline (PBS)) and positive control (5% w/v sodium dodecyl sulphate (SDS)) for 15 minutes. At the end of the treatment period, the tissues were washed with PBS and cell viability was assessed using the MTT assay. The skin irritation potential was classified according to the remaining cell viability obtained after test article treatment. The group mean viability for the test article was 56.1%, for the negative control was 100% and for the positive control was 6.3%. The test article, Isobutavan, was considered not to be irritant in the in vitro skin model EpiSkinTM.

Justification for classification or non-classification

In vitro Eye irritation (BCOP_ OECD 437):

The test article will be concluded as not requiring classification for eye irritation if the IVIS is ≤3.

In vitro Skin irritation ( skin model EpiSkinTM_ OECD 439):

The test article is considered to be NON-IRRITANT to skin in accordance with UN GHS No Category if the tissue viability after exposure and post-treatment incubation is >50% of the negative control.