Zinc bis[O-(6-methylheptyl)] bis[O-(sec-butyl)] bis(dithiophosphate)

Endpoint summary

Description of key information

This substance causes serious eye damage, however read-across data allow a SCL to be set for this effect. 
Read-across from EC 283-392-8 shows that this substance is a skin irritant. 

Key value for chemical safety assessment

Skin irritation / corrosion

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Eye irritation

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Additional information

A read-across substance was instilled into the conjunctival sac of groups of six New Zealand white rabbits at concentrations of 25, 12.5, 10, 7.5, or 6.25% in mineral oil. The eyes of the animals in the 25 and 12.5% groups were examined at 1, 2, 3, 4, 7, 10, 13, 16, 19, and 21 days following instillation in accordance with the Draize method. Examinations were terminated when scores of 0 were observed. The mean (24, 48, and 72 hours) cornea opacity, iritis, conjunctival redness and conjunctival edema scores at the 25% concentration were 1.2, 0.6, 2.6, and 2.2 respectively. The effects on corneal opacity did not clear in 1/6 animals by 21 days. The mean (24, 48, and 72 hour) cornea opacity, iritis, conjunctival redness and conjunctival edema scores at the 12.5% concentration were 0.6, 0.3, 2.2, and 1.7 respectively. The effects in the 12.5% group were fully reversible in all animals except one which exhibited scores of 1 on day 21. In the 10, 7.5, and 6.25% concentration groups the eyes were examine at 24, 48, and 72 hours. The mean (24, 48, and 72 hour) cornea opacity, iritis, conjunctival redness and conjunctival edema scores for the 10% concentration group were 0.1, 0.1, 1.3, and 1.1 respectively. At this concentration scores of 1 for conjunctival redness and edema were noted at the final 72 hour observation. The mean (24, 48, and 72 hour) cornea opacity, iritis, conjunctival redness and conjunctival edema scores for the 7.5% concentration group were 0, 0, 0.9, and 0.1 respectively. At this concentration a score of 1 for conjunctiva redness in 1/6 animals were noted at the final 72 hour observation. The mean (24, 48, and 72hour) cornea opacity, iritis, conjunctival redness and conjunctival edema scores at the 6.25% concentration groups were 0.1, 0.1, 1.0, and 0.4 respectively. At this concentration scores of 1 for conjunctiva redness (5/6) and edema (1/6) were noted at the final 72 hour observation. Based on the weight-of-evidence of number of animals with positive scores at termination in the 25 and 12.5 % concentration groups and the low scores of 1 at 72 hours in the 10, 7.5, and 6.25% groups, the irritation at concentrations of 10, 7.5, and 6.25% was expected to be fully reversible by day 21. In accordance with Directive 67/548/EEC and EU CLP (Regulation (EC) No. 1272/2008) classification of this substance is required for eye irritation with a specific concentration limit of 12.5% for serious eye damage and 10% for serious eye irritation. The results from this substance can be read across to the registration substance.

Data for skin irritation from the same structurally similar material suggest that this material is a skin irritant.

Read-across from other, structurally closely related ZDDPs is justified because of structural similarity and analogy of properties and effects. A category justification document is attached in section 13 which further supports the use of this data.

Effects on skin irritation/corrosion: irritating

Effects on eye irritation: corrosive

Justification for classification or non-classification

The test material is classified for skin irritation endpoints in accordance to Directive 67/548/EEC or the CLP Regulation (EC) No 1272/2008.

 

In accordance with Directive 67/548/EEC and EU CLP (Regulation (EC) No. 1272/2008) classification of this substance is required for eye irritation with a specific concentration limit of 12.5% for serious eye damage and 10% for serious eye irritation. The results from this substance can be read across to the registration substance.