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Registration Dossier
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EC number: 217-164-6 | CAS number: 1760-24-3
- Life Cycle description
- Uses advised against
- Endpoint summary
- Appearance / physical state / colour
- Melting point / freezing point
- Boiling point
- Density
- Particle size distribution (Granulometry)
- Vapour pressure
- Partition coefficient
- Water solubility
- Solubility in organic solvents / fat solubility
- Surface tension
- Flash point
- Auto flammability
- Flammability
- Explosiveness
- Oxidising properties
- Oxidation reduction potential
- Stability in organic solvents and identity of relevant degradation products
- Storage stability and reactivity towards container material
- Stability: thermal, sunlight, metals
- pH
- Dissociation constant
- Viscosity
- Additional physico-chemical information
- Additional physico-chemical properties of nanomaterials
- Nanomaterial agglomeration / aggregation
- Nanomaterial crystalline phase
- Nanomaterial crystallite and grain size
- Nanomaterial aspect ratio / shape
- Nanomaterial specific surface area
- Nanomaterial Zeta potential
- Nanomaterial surface chemistry
- Nanomaterial dustiness
- Nanomaterial porosity
- Nanomaterial pour density
- Nanomaterial photocatalytic activity
- Nanomaterial radical formation potential
- Nanomaterial catalytic activity
- Endpoint summary
- Stability
- Biodegradation
- Bioaccumulation
- Transport and distribution
- Environmental data
- Additional information on environmental fate and behaviour
- Ecotoxicological Summary
- Aquatic toxicity
- Endpoint summary
- Short-term toxicity to fish
- Long-term toxicity to fish
- Short-term toxicity to aquatic invertebrates
- Long-term toxicity to aquatic invertebrates
- Toxicity to aquatic algae and cyanobacteria
- Toxicity to aquatic plants other than algae
- Toxicity to microorganisms
- Endocrine disrupter testing in aquatic vertebrates – in vivo
- Toxicity to other aquatic organisms
- Sediment toxicity
- Terrestrial toxicity
- Biological effects monitoring
- Biotransformation and kinetics
- Additional ecotoxological information
- Toxicological Summary
- Toxicokinetics, metabolism and distribution
- Acute Toxicity
- Irritation / corrosion
- Sensitisation
- Repeated dose toxicity
- Genetic toxicity
- Carcinogenicity
- Toxicity to reproduction
- Specific investigations
- Exposure related observations in humans
- Toxic effects on livestock and pets
- Additional toxicological data

Ecotoxicological Summary
Administrative data
Hazard for aquatic organisms
Freshwater
- Hazard assessment conclusion:
- PNEC aqua (freshwater)
- PNEC value:
- 0.05 mg/L
- Assessment factor:
- 50
- Extrapolation method:
- assessment factor
- PNEC freshwater (intermittent releases):
- 0.072 mg/L
Marine water
- Hazard assessment conclusion:
- PNEC aqua (marine water)
- PNEC value:
- 0.005 mg/L
- Assessment factor:
- 500
- Extrapolation method:
- assessment factor
STP
- Hazard assessment conclusion:
- PNEC STP
- PNEC value:
- 20 mg/L
- Assessment factor:
- 1
- Extrapolation method:
- assessment factor
Sediment (freshwater)
- Hazard assessment conclusion:
- PNEC sediment (freshwater)
- PNEC value:
- 0.181 mg/kg sediment dw
- Extrapolation method:
- equilibrium partitioning method
Sediment (marine water)
- Hazard assessment conclusion:
- PNEC sediment (marine water)
- PNEC value:
- 0.018 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:
- 0.007 mg/kg soil dw
- Extrapolation method:
- equilibrium partitioning method
Hazard for predators
Secondary poisoning
- Hazard assessment conclusion:
- no potential for bioaccumulation
Additional information
The registered substance, N-(3-(trimethoxysilyl)propyl)ethylenediamine (CAS 1760-24-3, EC 217-164-6), will hydrolyse rapidly (half-life 0.025 hours at pH 7 and 25°C) in contact with water and atmospheric moisture to N-(3-(trihydroxysilyl)propyl)ethylenediamine and methanol.
REACH guidance (ECHA 2016, R.16) states that “for substances where hydrolytic DT50 is less than 12 hours, environmental effects are likely to be attributed to the hydrolysis product rather than to the parent itself”. TGD and ECHA guidance, (ECHA 2016) also suggest that when the hydrolysis half-life is less than 12 hours, the breakdown products, rather than the parent substance, should be evaluated for aquatic toxicity.
The substance may be released to the environment through wastewater treatment plant (WWTP) effluent.
The minimum residency time in the wastewater treatment plant is approximately 7 hours (although this is a conservative figure and wastewater treatment time may be hours to days longer) with an average temperature of 15°C (assumed to be at neutral pH).
Under these conditions, degradation by hydrolysis would be expected before the substance is released to the receiving waters.
The environmental hazard assessment, including sediment and soil compartments due to water and moisture being present, is therefore based on the properties of the silanol hydrolysis product, N-(3-(trihydroxysilyl)propyl)ethylenediamine, in accordance with REACH guidance.
As described in IUCLID Section 4.8, the silanol hydrolysis products may be susceptible to condensation reactions.
Amines are basic, therefore once dissolved they will increase the pH of the test media. In addition, the un-ionised form of the amine is more toxic than the ionised form. This pattern of toxicity is consistent with ammonia, where the un-ionised form, NH3, is more toxic than the ionised form, NH4+. The difference in toxicity is attributed to bioavailability, where the un-ionised form can cross cell membranes more readily than the ionised form. Many of the aquatic toxicity studies for amine-containing organosilicon substances were conducted at pH ~8 and in some cases the pH was not adjusted after the test substances were added to the test media. Therefore, for media and natural waters having a pH closer to 7 it is likely that ecotoxicity might be expected to be less severe than indicated by these test results (i.e. the value of E(L)C50 may possibly be higher under pH-neutral conditions).
Considerations on the non-silanol hydrolysis product:
Methanol is well characterised in the public domain literature and are not hazardous at the concentrations relevant to the studies; the short-term EC50 and LC50 values for this substance is in excess of 1000 mg/l (OECD 2004a - SIDS for methanol). Therefore, at the loading rates experienced in these tests it is unlikely that the presence of methanol would significantly affect the results.
Conclusion on classification
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