Registration Dossier

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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Administrative data

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:
no hazard identified

Marine water

Hazard assessment conclusion:
no hazard identified

STP

Hazard assessment conclusion:
no hazard identified

Sediment (freshwater)

Hazard assessment conclusion:
no hazard identified

Sediment (marine water)

Hazard assessment conclusion:
no hazard identified

Hazard for air

Air

Hazard assessment conclusion:
no hazard identified

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:
no hazard identified

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:
no potential for bioaccumulation

Additional information

Conclusion on classification

KEY PARAMETERS FOR CLASSIFICATION

The key parameters for the classification of the registered (parent) substance are listed below. However, the parent substance hydrolyses rapidly (DT50 < 10 min, OECD 111) to form the silanol hydrolysis product trimethylsilanol (CAS No. 1066-40-6) and urea (CAS No. 57-13-6). According to REACH guidance document R.16, environmental effects are likely attributed to the transformation products rather than the parent substances for substances were the hydrolytic half-life is < 12 h. Therefore, the environmental hazard and risk assessment are based on the silanol hydrolysis product. The other hydrolysis product, urea, is not expected to affect the environmental hazard profile of the parent substance (OECD SIDS, 2002).

Environmental fate and pathways

Water solubility

Parent: not measurable

Silanol hydrolysis product: 1000 g/L (QSAR)

Urea hydrolysis product: 545 g/L (Yalkowsky, 1989)

Stability

DT50 < 10 min (at pH 4, 7 and 9, 20 °C, OECD 111)

Degradation

Not readily biodegradable (0% in 28 d, OECD 301 F)

Bioaccumulation

Parent: log Kow = 2.72 (OECD 117)

Silanol hydrolysis product: 1.14 (QSAR: EPI Suite KOWWIN v1.68)

Urea hydrolysis product: -2.11 (Literature: Hansch et al., 1960)

 

Aquatic short-term toxicity

Fish

No effects up to the saturation level

LC50 (96 h) > 84 mg/L (geom. mean measured, OECD 203, O. mykiss)

Aquatic invertebrates

No effects up to the saturation level

EC50 (48 h) > 49 mg/L (geom. mean measured, OECD 202, D. magna)

Algae

No effects up to the saturation level

ErC50 (72 h) > 50 mg/L (geom. mean measured, OECD 201, P. subcapitata)

 

Aquatic long-term toxicity

Fish

Not available

Aquatic invertebrates

Not available

Algae

No effects up to the saturation level

ErC10 (72 h) > 50 mg/L (geom. mean measured, OECD 201, P. subcapitata)

 

Conclusion on CLP/Classification according to CLP

Short-term aquatic toxicity data are available for all three trophic levels. One long-term effect value is available for aquatic algae. Neither short-term nor long-term effects to aquatic organisms were recorded based on the available data. Furthermore, the substance is not rapidly biodegradable and has a low log Kow (< 4.0). Therefore, the registered (parent) substance is not classified and labelled for environmental hazards according to the consolidated version of Regulation (EC) No 1272/2008 and further amendments (ATPs). Furthermore, there is no harmonized classification for either hydrolysis product (i.e. trimethylsilanol or urea).