Acetic acid, C8-10-branched alkyl esters, C9-rich

Endpoint summary

Description of key information

Skin irritation: non-corrosive, in vitro EpiDerm OECD TG 431, Envigo Research Limited 2016
Skin irritation: non-irritating, in vitro EpiSkin OECD TG 439, Envigo Research Limited 2016
Eye irritation: non-irritating, in vitro OECD TG 437, Envigo Research Limited 2016

Key value for chemical safety assessment

Skin irritation / corrosion

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Skin Corrosion/Irritation:

In vitro - OECD TG 431, 2016: The study was performed to OECD TG 431 and EU Method B.40 BIS to assess the skin corrosion potential of the test substance in accordance with GLP using a human three dimensional epidermal model (EpiDerm (EPI-200) Lot number: 23331). Duplicate tissues were treated with the test item for exposure periods of 3 and 60 minutes. At the end of the exposure period the test item was rinsed from each tissue before each tissue was taken for MTT-loading. After MTT loading each tissue was placed in 2 mL Isopropanol for MTT extraction. At the end of the formazan extraction period each well was mixed thoroughly and triplicate 200 μL samples were transferred to the appropriate wells of a pre-labelled 96-well plate. The optical density (OD) was measured at 562 nm (OD562). The mean OD562 for the negative control treated tissues was 2.046 for the 3 Minute exposure period and 1.822 for the 60 Minute exposure period. The relative mean tissue viability obtained after the 3-minute and 1-hour treatments with the test substance compared to the negative control tissues was 97.3% and 108.6% respectively. The relative mean tissue viability for the positive control treated tissues was 4.1% relative to the negative control following the 60 Minute exposure period. The quality criteria required for acceptance of results in the test were satisfied. Under the conditions of this study, the test item was considered to be non-corrosive to the skin.

 

In vitro - OECD TG 439, 2016: The study was performed to OECD TG 439 and EU Method B.46 to assess the skin irritation potential of the test substance in accordance with GLP using a human three dimensional epidermal model (EPISKIN Small Model). Triplicate tissues were treated with the test item for an exposure period of 15 minutes. At the end of the exposure period each tissue was rinsed before incubating for 42 hours. At the end of the post-exposure incubation period each tissue was taken for MTT-loading. The maintenance medium from beneath each tissue was transferred to pre-labelled micro tubes and stored in a freezer for possible inflammatory mediator determination. After MTT-loading a total biopsy of each epidermis was made and placed into micro tubes containing acidified isopropanol for extraction of formazan crystals out of the MTT-loaded tissues. At the end of the formazan extraction period each tube was mixed thoroughly and duplicate 200 μL samples were transferred to the appropriate wells of a pre-labelled 96-well plate. The optical density was measured at 562 nm. Data are presented in the form of percentage viability (MTT reduction in the test item treated tissues relative to negative control tissues). The relative mean viability of the test item treated tissues was 115.1% after the 15-Minute exposure period and 42-Hours post-exposure incubation period. All assay acceptability criteria were met. Under the conditions of this study, the test substance is considered not irritating to the skin.

 

Eye Corrosion/Irritation:

In vitro, OECD TG 437, 2016: The study was performed according to OECD TG 437 and EU Method B.47 to assess the eye irritancy potential in accordance with GLP of the test material in isolated bovine corneas. The purpose of this test was to identify test items that can induce serious eye damage and to identify test items not requiring classification for eye irritation or serious eye damage. The ocular irritancy of the test substance was tested through topical application for 10 ± 1 minutes. The negative control responses for opacity and permeability were less than the upper limits of the laboratory historical range indicating that the negative control did not induce irritancy on the corneas. The mean in vitro irritancy score of the positive control (ethanol), was 40.7 and was within the historical positive control data range (29.6 to 52.09). The test substance did not induce ocular irritation through both endpoints, resulting in a mean in vitro irritancy score (IVIS) of 0.8 after 10 minutes of treatment. Since the IVIS was < 3.0 the test substance was predicated as not irritating to the eye. Under the conditions of this study the test material is not considered to be a irritant or corrosive in the Bovine Corneal Opacity and Permeability test.

Justification for selection of skin irritation / corrosion endpoint:
two in vitro GLP compliant Klimisch 1 studies; selected study in accordance with sequential testing strategy of Regulation (EC) 440/2008 and its subsequent amendments.

Justification for selection of eye irritation endpoint:
one in vitro GLP compliant Klimisch 1 studies; selected study in accordance with sequential testing strategy of Regulation (EC) 440/2008 and its subsequent amendments.

Justification for classification or non-classification

The substance does not meet the classification criteria under Regulation (EC) No 1272/2008 for skin irritation

 

The substance does not meet the classification criteria under Regulation (EC) No 1272/2008 for eye irritation

 

For skin irritation, the weight of evidence indicates is the substance is not predicted to be irritating to the skin sufficient for classification purposes. Specifically, the substance is expected to be well tolerated by the human skin. Very mild irritation would potentially be expected although transient in nature and insufficient for classification and labelling.

 

For eye irritation, the weight of evidence indicates that the substance has the potential to cause very mild transient irritating effects to the eye but which are transient and insufficient for classification. Specifically there is an absence of skin irritation and/or the validated guideline BCOP model gives a prediction of IVIS < 3.0 indicative of no prediction for irritancy to the eye within a top-down approach (see: L. Scott et al., 2010).

References:

1. Guidance on Application of the CLP Criteria, ECHA, version 4.1 – June 2015

2. L. Scott et al., Toxicology in Vitro 24: 1–9, 2010