Disodium (Z)-1-(octadec-9-enyl) 2-sulphonatosuccinate

Endpoint summary

Description of key information

The test substance was predicted to be non-corrosive and non-irritant to human skin based on the three-dimensional EST 1000 human skin model with source substance CAS 90268-36-3. Viability values were 78.8% and 74.9%  in the corrosivity test and 98.3% in the irritation test (all >50% threshold values),  therefore it can be considered to be non-irritant to human skin and no further testing is needed according to ECHA progress report 2010. Eye irritation data were not available for the registered substance, however read across data were available from a category member, CAS No. 37294-49-8 (disodium C-isodecyl sulphonatosuccinate).  In a bovine corneal opacity and permeability (BCOP) test, read-across substance disodium isodecyl sulfosuccinate induced a mean IVIS of 38.1. An IVIS > 3 and ≤ 55 alone does not allow conclusion on classification for eye irritancy according to UN GHS. Furthermore, an in vivo eye irritancy test is available, in which an aqueous formulation with 20-37% and 50% formulation was tested. The formulation was found not to be irritating to the eye.

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:

adverse effect observed (irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Assessment of skin irritation was tested as a weight-of-evidence approach

-A first in vitro study was conducted to study corrosive properties by means of a three-dimensional EST-1000 human skin model (Flügge, 2013a). The test item containing >95% active ingredient was applied to the skin surface. In comparison to the negative controls, the mean viability of cells exposed to the test item was 78.8% after a 3-minute exposure period and 74.9% after a 1-hour exposure.The values were well above the cut-off percentage cell viability values distinguishing corrosive from non-corrosive test items of <50% or <15% for a 3-minute or 1-hour treatment, respectively. Therefore, the test item was non-corrosive in this skin model and is predicted to be non-corrosive to human skin.

-A second in vitro study was conducted to determine irritating properties by means of the three-dimensional EST-1000 model of human skin (Flügge, 2013b). The test item containing >95% active ingredient was applied to the skin surface for 20 minutes, followed by refreshment of the medium and a further incubation period of 42 hours. The mean viability of the cells exposed to the test item was 98.3% of the mean negative control value. The value was well above the cut-off percentage cell viability value that distinguishes irritant from non-irritant test items of >50% for a 20-minute exposure. The test item was considered to be non-cytotoxic and predicted to be not irritant to skin.

- According to ECHA progress report 2010 (p 32), it is accepted that in vitro methods for skin irritation represent a full replacement of the in vivo method in a tiered testing strategy and in conjunction with in vitro skin corrosivity tests, if necessary. A negative result in the human skin model for irritation does not need to be confirmed by additional testing.

In conclusion, the test substance was predicted to be non-corrosive and non-irritant to human skin based on the three-dimensional EST 1000 human skin model, therefore no classsifciation is needed.

Eye irritation

Eye irritation data were not available for the registered substance, however in vivo read-across data were available from read-across source substance CAS No. 37294-49-8 (disodium C-isodecyl sulphonatosuccinate). In a key bovine corneal opacity and permeability (BCOP) test, read-aross substance disodium isodecyl sulfosuccinate induced a mean IVIS of 38.1. An IVIS > 3 and ≤ 55 does not allow conclusion on classification for eye irritancy, however the substance does not lead to eye damage (WIL Research Europe, 2014).

Two supporting in vivo skin irritation tests were performed, one with an aqueous formulation with 50% and the other with a 20-37% of read-across substance disodium isodecyl sulfosuccinate on intact and abraded skin (Carpenter, 1971; Cerven, 2005). These formulations were not irritating. In these studies, no irritation or corrosion was observed.

Conclusion

- The test substance was concluded to be non-corrosive and non-irritant to human skin based on the three-dimensional EST 1000 human skin model. As the test item for skin and eye irritation contained >95% active ingredient, the registered substance can also be accepted to be non irritating for skin.

- Based on the supporting studies wiht read-across substance, the Registered substance was concluded not to be corrosive to the eye, but from a conservative viewpoint it is considered to be irritating for eye, with limit concentration of 50% for non-irritation.

Justification for classification or non-classification

Based on read-across wiht structural analogues and according to CLP (No. 1272/2008 of 16 December 2008), the test substance is not classified and has no obligatory labelling requirement for skin irritation.

Based on the available data, Registered substance is concluded not to induce eye damage, however from a conservative viewpoint, the substance is classified as irritating for eye Category 2 (H319) according to CLP Regulation (EC) No. 1272/2008, with limit concentration of 50%.