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No test data are available with tris(trimethylsiloxy)phenylsilane (CAS 2116-84-9) and terrestrial testing is not a requirement under Annex VII of REACH. However, due to the high log Kow and low water solubility of the registration substance some discussion of the potential for testing of toxicity to terrestrial organisms may be relevant:

Testing for toxicity to terrestrial organisms with soil micro-organisms and a stability test under OECD 222 (earthworm reproduction test) conditions have been carried out with Octamethyltrisiloxane (L3, CAS 107-51-7), a member of the same analogue group as tris(trimethylsiloxy)phenylsilane. 

The tests with L3 have demonstrated that there was significant loss of test item from the test system, very early on during the tests, even though efforts had been taken to minimise losses through volatility. The studies indicate that L3 is too volatile to maintain adequate concentrations in the test system.

Although the vapour pressure and Henry's Law Constant values (HLC) of the registration substance are much lower than those of L3, tris(trimethylsiloxy)phenylsilane still has a high calculated HLC (4.95E+03 Pa m3mol-1), indicating that the susbstance is highly volatile. Therefore, similar experimental difficulties to those with L3 would be expected if terrestrial tests were carried out.