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Classification & Labelling & PBT assessment

PBT assessment

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PBT assessment: overall result

PBT status:
the substance is not PBT / vPvB
Justification:

Persistence

The tin bis(2 -ethylhexanoate) substance is known to dissociate into its 2-ethylhexanoate and Sn(II) components upon introduction to water. The 2-ethylhexanoate portion of the substance has been shown to be readily biodegradable (90.1% in 7days based on DOC), while the Sn(II) will speciate initially as Sn(OH)2, and spontaneously oxidize in oxygenated water to form the insoluble inorganic solid Sn(IV)O2.

Conclusion:

Tin bis(2 -ethylhexanoate) does not meet the P or vP criteria.

Biaccumulation:

The log Kow for the 2-ethylhexanoate component of the tin bis(2 -ethylhexanoate) salt is log Kow = 2.64 (un-ionized species at pH < 2.8). The estimated log D at pH 7 is approximately 0.6. These values of log Kow and log D indicate a low potential for bioaccumulation in aquatic organisms. The Sn(II) portion of the salt is inorganic and oxidizes in water to form Sn (IV)O2 which is insoluble, therefore bioaccumulation is unlikely.

Conclusion:

Tin bis(2 -ethylhexanoate) does not meet the B or vB criteria.

Toxicity

For algae, the most sensitive species, the 72-hour NOEC and EC50 (based on growth rate) forPseudokirchneriella subcapitata exposed to tin bis(2-ethylhexanoate)were 0.54 and 6.9 mg/L, respectively. These values are above the criteria for T for aquatic toxicity. The substance meets however the T criteria due to a classification as Reproductive toxicant Category 2 based on the hydrolysis to 2 -ethyl hexanoic acid.

Conclusion: the substance meets the T criterion.

Overall Result of the PBT assessment:

The substance does not meet the individual P or B criteria, only the T criterion, so that it is not a PBT substance nor a vPvB substance.