Registration Dossier

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Additional information

Reliable short-term toxicity tests results are available for freshwater fish (Brachydanio rerio), invertebrates (Daphnia magna) and algae (Scenedesmus subspicatus). The relevant short-term values are:

Fish: LC50 (96 h): >100 mg/l, equivalent to >79 mg/l when expressed in terms of concentration of the hydrolysis product, (3-chloropropyl)silanetriol.

Daphnia: EC50 (48 h): 869 mg/l, equivalent to 685 mg/l when expressed in terms of concentration of the silanol hydrolysis product, (3-chloropropyl)silanetriol.

Algae: EC50 (72 h): >833 mg/l; NOEC: 167 mg/l, equivalent to >657 and 132 mg/l, respectively when expressed in terms of concentration of the silanol hydrolysis product, (3-chloropropyl)silanetriol.

 

The registered substance (3-chloropropyl)trimethoxysilane (CAS 2530-87-2) hydrolyses rapidly to (3-chloropropyl)silanetriol and methanol (half-life 4.5 hours at pH 7 and 20°C).

The prolonged test solution preparation time (18-24 hours) means it is likely that the test organisms in each test were exposed primarily to the hydrolysis products.

Long-term toxicity to aquatic invertebrates data have been read across from (3-chloropropyl)triethoxysilane (CAS 5089-70-3):

Daphnia NOEC (21 d): ≥100 mg/l for effects on survival and reproduction of Daphnia magna. The NOEC is equivalent to ≥65 mg/l when expressed in terms of concentration of the hydrolysis product, (3-chloropropyl)silanetriol.

A data waiver is applicable to long-term toxicity to fish endpoint.

Toxicity to microorganisms: Activated sludge respiration inhibition 3-hour EC50 value of 400 mg/l, read-across from the analogous substance dichloro(3-chloropropyl) methylsilane (CAS 7787-93-1).

Please see the Toxicity to Microorganisms endpoint summary (IUCLID Section 6.1.7, CSR Section 7.4) for justification of read across.

 

Refer to IUCLID Section 6 endpoint summary (CSR Section 7.0) for further discussion of the approach to chemical safety assessment.

Methanol is well-characterised in the public domain literature and is not hazardous to aquatic organisms; the short-term EC50 and LC50 values for this substance are in excess of 1000 mg/l (OECD 2004a - SIDS for methanol).

References

OECD (2004a): SIDS Initial Assessment Report for SIAM 19, Berlin, Germany, 18-20 October 2004, Methanol, CAS 67-56-1