Registration Dossier

Administrative data

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:
PNEC aqua (freshwater)
PNEC value:
0.074 mg/L
Assessment factor:
500
Extrapolation method:
assessment factor
PNEC freshwater (intermittent releases):
0.37 mg/L

Marine water

Hazard assessment conclusion:
PNEC aqua (marine water)
PNEC value:
0.007 mg/L
Assessment factor:
5 000
Extrapolation method:
assessment factor
PNEC marine water (intermittent releases):
0.37 mg/L

STP

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

Sediment (freshwater)

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

Sediment (marine water)

Hazard assessment conclusion:
PNEC sediment (marine water)
PNEC value:
0.034 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:
0.025 mg/kg soil dw
Extrapolation method:
equilibrium partitioning method

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:
no potential for bioaccumulation

Additional information

Data about the parent substance triethoxy(phenyl)silane (CAS 780-69-8) are only available for aquatic invertebrates. Since triethoxy(phenyl)silane hydrolyses rapidly, read across from data available for the similar substance trichloro(phenyl)silane (CAS 98-13-5) was considered appropriate as both substances hydrolyse rapidly to the same hydrolysis product, phenylsilanetriol. Data for the read across substance trichloro(phenyl)silane (CAS 98-13-5), are provided for acute toxicity to fish, aquatic invertebrates and algae. Due to the rapid hydrolysis of the substance the aquatic organisms are very likely exposed predominantly to both the parent and the hydrolysis products.

Short term toxicity data of trichloro(phenyl)silane towards fish, daphnia and algae resulted in an LC50 of > 100 mg/L an EC50 of >100 mg/L and an EC50 of > 100 mg/L (all nominal), respectively. The 48-h EC50 value for Daphnia magna exposed to triethoxy(phenyl)silane (CAS 780-69-8) was 37 mg/L (nominal). The PNEC was derived based on the worst case value obtained from the valid short-term study with Daphnia magna (EC50 of 37 mg/L).

Conclusion on classification

Triethoxy(phenyl)silane (780-69-8) is expected to hydrolyse rapidly (half-life of 1.5 hours at 20-25°C) and the silanol hydrolysis product is not readily biodegradable.

Due to rapid hydrolysis the aquatic organisms are likely to be exposed to the parent and the hydrolysis products. Acute toxicity data was available for all three trophic levels for structurally analogous substance trichloro(phenyl)silane (98-13-5) and additional information for invertebrates for Triethoxy(phenyl)silane (780-69-8). The lowest value was an EC50 of 37 mg/l for invertebrates for Triethoxy(phenyl)silane (780-69-8). The substance is not readily biodegradable. Therefore. the registered substance is classified as chronic 3 according to the Regulation (EC) No.1272/2008 (CLP); there are no long-term data available.