Reaction mass of 1,1'-oxybis(ethylbenzene) and Styrene, oligomers

Endpoint summary

Description of key information

An in vitro skin corrosion test with  undiluted SMPO Heavy Ends was applied using a human skin model (EpiDerm; EPI-200). The relative mean tissue viability obtained after 3-minute and 1-hour treatments compared to the negative control tissues was 94% and 29%, respectively. This was not below 50% after the 3-minute treatment and not below 15% after the 1-hour treatment SMPO Heavy Ends is considered to be not corrosive.  In vitro skin irritation with SMPO Heavy ends was also tested using a human skin model EPISKIN-SMTM. The relative mean tissue viability obtained after 15 minutes treatment with SMPO Heavy ends compared to the negative control tissues was 24%. This was below 50% after 15 minutes treatment it is considered to be irritant. 
Screening for the eye irritancy potential of undiluted SMPO Heavy Ends using the Bovine Corneal Opacity and Permeability test resulted in a mean in vitro irritancy score (IVIS) of 17.9 after 10 minutes of treatment. Since this is > 3 = 55, no prediction on the classification could be made. Acute eye irritation/corrosion was also studied with undiluted SMPO Heavy ends in the rabbit according to OECD No. 405. The corneal injury consisted of epithelial damage and resolved within 72 hours in all animals. Slight dulling of the normal luster of the cornea was noted 24 hours after instillation for all animals. Iridial irritation was observed in one animal and resolved within 72 hours. The irritation of the conjunctivae consisted of redness, chemosis and discharge and completely resolved within 72 hours in two animals and within 7 days in the other animal. Reduced elasticity of the eyelids was noted at 24 hours after instillation for two animals which had resolved within 48 hours in one animal and within 72 hours in the other animal. Remnants of the test substance were present on the outside of the eyelids of all animals on Day 1. 

Key value for chemical safety assessment

Skin irritation / corrosion

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Eye irritation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

An in vitro skin corrosion test with SMPO Heavy Ends was applied using a human skin model EpiDerm - EPI-200 (Verbaan, 2015). The possible corrosive potential of SMPO Heavy Ends was tested through topical application for 3 minutes and 1 hour. SMPO Heavy Ends was applied undiluted (50 µL) directly on top of the skin tissue. Skin corrosion is expressed as the remaining cell viability after exposure to the test substance. The relative mean tissue viability obtained after 3-minute and 1-hour treatments with SMPO Heavy Ends compared to the negative control tissues was 94% and 29%, respectively. Because the mean relative tissue viability for SMPO Heavy Ends was not below 50% after the 3-minute treatment and not below 15% after the 1-hour treatment SMPO Heavy Ends is considered to be not corrosive.

In vitro skin irritation with SMPO Heavy ends was tested using a human skin model EPISKIN-SMTM (Eurlings, 2015a). The possible skin irritation potential of SMPO Heavy ends was tested through topical application for 15 minutes. The substance was applied undiluted (25 µL) directly on top of the skin tissue for 15 minutes. After a 42 hour post-incubation period, determination of the cytotoxic (irritancy) effect was performed. Cytotoxicity is expressed as the reduction of mitochondrial dehydrogenase activity measured by formazan production from MTT at the end of the treatment. Skin irritation is expressed as the remaining cell viability after exposure to the test substance. The relative mean tissue viability obtained after 15 minutes treatment with SMPO Heavy ends compared to the negative control tissues was 24%. Since the mean relative tissue viability for SMPO Heavy ends was below 50% after 15 minutes treatment it is considered to be irritant.

Screening for the eye irritancy potential of SMPO Heavy Ends using the Bovine Corneal Opacity and Permeability test (Eurlings, 2015b).The undiluted substance was tested through topical application for 10 ± 1 minutes. The test substance was applied as it is (750 µL) directly on top of the corneas. SMPO Heavy Ends induced ocular irritation throughout both endpoints, resulting in a mean in vitro irritancy score of 17.9 after 10 minutes of treatment. Since SMPO Heavy Ends induced an IVIS > 3 = 55, no prediction on the classification could be made.

Acute eye irritation/corrosion was also studied with SMPO Heavy ends in the rabbit according to OECD No.405 (Latour, 2015b). Single undiluted samples of 0.1 mL of SMPO Heavy ends were instilled into one eye of each of three rabbits. Observations were made 1, 24, 48 and 72 hours and/or 7 days after instillation. Instillation of the test substance resulted in effects on the cornea, iris and conjunctivae. The corneal injury consisted of epithelial damage and resolved within 72 hours in all animals. Slight dulling of the normal luster of the cornea was noted 24 hours after instillation for all animals. Iridial irritation was observed in one animal and resolved within 72 hours. The irritation of the conjunctivae consisted of redness, chemosis and discharge and completely resolved within 72 hours in two animals and within 7 days in the other animal. Reduced elasticity of the eyelids was noted at 24 hours after instillation for two animals which had resolved within 48 hours in one animal and within 72 hours in the other animal. Remnants of the test substance were present on the outside of the eyelids of all animals on Day 1.

Brown staining of the fur on the head and paws, caused by the test substance, was noted during the observation period.

Effects on skin irritation/corrosion: irritating

Justification for classification or non-classification

Based on the results of an in vitro human skin model for skin corrosion and skin irritation it is concluded that SMPO Heavy ends is irritant according to the Regulation (EC) No. 1272/2008 on classification, labelling and packaging of substances and mixtures.

Based on the results of the BCOP and in vivo eye irritation study, SMPO Heavy ends does not have to be classified and has no obligatory labelling requirement for eye irritation according to the Regulation (EC) No 1272/2008 on classification, labelling and packaging of substances and mixtures (including all amendments).