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Ecotoxicological information

Endpoint summary

Administrative data

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Additional information

The test substance is susceptible to two separate hydrolysis reactions of its different functional groups, as described in Section 5.1.2 of IUCLID. The available aquatic ecotoxicity studies conducted with this substance are consistent with this and also indicate the formation of precipitated condensation products at longer time scales. Therefore it is likely that the test organisms were exposed to a mixture of the hydrolysis products of the substance and the test substance.

 

Reliable short-term toxicity tests results are available for freshwater fish (Cyprinus carpio), invertebrates (Simocephalus vetulus) and algae (Pseudokirchneriella subcapitata). The relevant short-term values are:

 

Fish: LC50 (96 h): 55 mg/l (nominal, expressed in terms of parent). The LC50 is equivalent to 45 mg/l when expressed in terms of concentration of the silanol hydrolysis product [3-(2,3-epoxypropoxy)propyl]silanetriol.

Invertebrate: EC50 (48 h): 324 mg/l (nominal, expressed in terms of parent). The EC50 is equivalent to 266 mg/l when expressed in terms of concentration of the silanol hydrolysis product [3-(2,3-epoxypropoxy)propyl]silanetriol.

Algae: ErC50 (96 h): 350 mg/l; NOEC: 130 mg/l  (nominal, expressed in terms of parent). The ErC50 and NOEC values are equivalent to 288 mg/l and 107 mg/l when expressed in terms of concentration of the silanol hydrolysis product [3-(2,3-epoxypropoxy)propyl]silanetriol.

 

Reliable long-term toxicity test results are available for freshwater invertebrates (Daphnia magna).

Daphnia: NOEC (21 d): =100 mg/l (nominal, expressed in terms of parent). This is equivalent to =82 mg/l when expressed in terms of the silanol hydrolysis product [3-(2,3-epoxypropoxy)propyl]silanetriol.

 

An activated sludge respiration inhibition 3 hour EC10 value of =100 mg/l (nominal) was determined in a reliable study. The EC10 is equivalent to =82 mg/l when expressed in terms of silanol hydrolysis product [3-(2,3-epoxypropoxy)propyl]silanetriol.

 

The rapid hydrolysis of the substance (half-life 6.5 h at pH 7 and 24.5 °C) means it is likely that the test organisms in each test were exposed primarily to the hydrolysis products, [3-(2,3-epoxypropoxy)propyl]silanetriol and methanol.