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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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:
PNEC aqua (freshwater)
PNEC value:
0.009 mg/L
Assessment factor:
1 000
Extrapolation method:
assessment factor
PNEC freshwater (intermittent releases):
0.09 mg/L

Marine water

Hazard assessment conclusion:
PNEC aqua (marine water)
PNEC value:
0.001 mg/L
Assessment factor:
10 000
Extrapolation method:
assessment factor
PNEC marine water (intermittent releases):
0.09 mg/L

STP

Hazard assessment conclusion:
PNEC STP
PNEC value:
74 mg/L
Assessment factor:
10
Extrapolation method:
assessment factor

Sediment (freshwater)

Hazard assessment conclusion:
PNEC sediment (freshwater)
PNEC value:
0.122 mg/kg sediment dw
Extrapolation method:
equilibrium partitioning method

Sediment (marine water)

Hazard assessment conclusion:
PNEC sediment (marine water)
PNEC value:
0.012 mg/kg sediment dw
Extrapolation method:
equilibrium partitioning method

Hazard for air

Air

Hazard assessment conclusion:
no hazard identified

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:
PNEC soil
PNEC value:
0.019 mg/kg soil dw
Extrapolation method:
equilibrium partitioning method

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:
no potential for bioaccumulation

Additional information

Conclusion on classification

KEY PARAMETERS FOR CLASSIFICATION

The registered (parent) substance dichloro(diphenyl)silane (CAS 80-10-4) hydrolyses rapidly in contact with water under environmentally relevant conditions. Therefore, the environmental hazard and risk assessment is based on the silanol hydrolysis product, i.e. diphenylsilanediol (CAS 947-42-2) and a structural analogue to the parent compound trichloro(phenyl)silane (CAS 98-13-5), which just like the parent compound hydrolyses quickly to a silanol and hydrochloric acid. Hydrochloric acid, generally shows a pH-dependent environmental hazard profile, which is considered a sufficiently manageable risk when appropriate measures are in place (OECD, 2002), thus it is not expected to affect the environmental hazard profile of the parent substance.

Abiotic degradation - Hydrolysis

DT50 = 10 sec (1.5 °C and pH 7, OECD 111)

Biodegradation in water

Not readily biodegradable (1% in 28 d, OECD 310, RA CAS 98-13-5)

Bioaccumulation

log Kow (silanol hydrolysis product) = 2.0 (20°C, QSAR)

 

Aquatic acute toxicity

Fish

LC50 (96 h) = 39 mg/L (measured arithmetic mean, Oncorhynchus mykiss, OECD 203, RA CAS 947-42-2)

Aquatic invertebrates

EC50 (48 h) = 24 mg/L (measured arithmetic mean, Daphnia magna, OECD 202, RA CAS 947-42-2)

Aquatic algae

ErC50 (72 h) = 9 mg/L (measured arithmetic mean, Pseudokirchneriella subcapitata, OECD 201, RA CAS 947-42-2)

 

Aquatic chronic toxicity

Aquatic algae

ErC10 (72 h) = 1.1 mg/L (measured arithmetic mean, Pseudokirchneriella subcapitata, OECD 201,RA CAS 947-42-2)

 

Classification according to CLP

Dichloro(diphenyl)silane (CAS 80-10-4) hydrolyses rapidly under environmental conditions (DT50 = 10 sec, at pH 7 and 1.5 °C) to form the hydrolysis products diphenylsilanediol and hydrochloric acid. The silanol hydrolysis product is not considered to be readily biodegradable and the second hydrolysis product is an inorganic substance, thus not susceptible to biodegradation. Acute toxicity data for the silanol hydrolysis product are available for all three trophic levels (fish, aquatic invertebrates, algae). The lowest L(E)C50 effect was observed in algae with 9 mg/L. On this basis, the parent substance dichloro(diphenyl)silane (CAS 80-10-4) needs to be classified as chronic 2 according to the Regulation (EC) No.1272/2008 and further amendments (ATPs).