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EC number: 945-544-8 | CAS number: -
- 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
Hazard for air
Hazard for terrestrial organisms
Hazard for predators
Additional information
The submission substance is a multi-constituent substance containing two constituents, (trimethoxysilylpropyl)methylmethylphosphonate (Constituent 1) and bis(trimethoxysilylpropyl)methylphosphonate (Constituent 2). Both constituents will hydrolyse rapidly in contact with water. The predicted half-life for Constituent 1 is 4.0 h at pH 7 and 20-25°C. The predicted half-life for Constituent 2 is 10.0 h at pH 7 and 20-25°C. Therefore, for the purposes of the environmental assessment, the hydrolysis products for assessment are:
• methyl 3-(trihydroxysilyl)propyl methylphosphonate (1 mole from Constituent 1; HP1)
• bis[3-(trihydroxysilyl)propyl] methylphosphonate (1 mole from Constituent 2; HP2)
• methanol (3 moles from Constituent 1; 6 moles from Constituent 2)
Over a long timescale, hydrolysis of the phosphonate ester groups may occur. The final hydrolysis products from both constituents are (3-hydroxypropyl)silanetriol (1 mole from Constituent 1; 2 moles from Constituent 2) and methylphosphonate (1 mole from each constituent).
The water solubilities of the constituents have been predicted using a validated QSAR estimation method. The predicted water solubilities are 1.0E+06 mg/L at 20°C and 4.3E+04 mg/L at 20°C for Constituent 1 and Constituent 2 respectively.
The silanol hydrolysis products, methyl 3-(trihydroxysilyl)propyl methylphosphonate (HP 1) and bis[3-(trihydroxysilyl)propyl] methylphosphonate (HP 2) are soluble, both with predicted water solubilities of 1.0E+06 mg/L. However, they may undergo condensation reactions in solution which are expected to become important at loadings above about 1000 mg/L for HP 1 and 100 -500 mg/L for HP 2 (see Section 4.8 for further discussion).
The predicted log Kow using a validated QSAR estimation method for the constituents are 0.3 at 20°C and -0.2 at 20°C for Constituent 1 and Constituent 2 respectively. The predicted log Kow for the silanol hydrolysis products are -2.8 at 20°C and -4.0 at 20°C for HP 1 and HP 2 respectively.
The other non-silanol hydrolysis product is methanol for both constituents.
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”. EU technical guidance for risk assessment (EC 2003) and REACH guidance R.16 (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. Therefore, the environmental chemical assessment (aquatic, sediment and soil) is based on the properties of the silanol hydrolysis products, methyl 3-(trihydroxysilyl)propyl methylphosphonate and bis[3-(trihydroxysilyl)propyl] methylphosphonate, in accordance with REACH guidance. As described in Section 4.8, condensation reactions of the hydrolysis products are possible.
Consideration of the non-silanol hydrolysis product methanol
Methanol is well characterised in the public domain literature and is not hazardous at the concentrations relevant to the studies; the short-term EC50 and LC50 values for methanol are in excess of 1000 mg/L (OECD 2004 - SIDS for methanol, CAS 67-56-1). Therefore, at the loading rates experienced in these tests it is unlikely that the presence of methanol would significantly affect the results of the tests.
Conclusion on classification
The substance has reliable short-term E(L)C50 whole substance values of >100 mg/L in fish, >100 mg/L in invertebrates and >100 mg/L in algae, as well as a NOEC value of ≥100 mg/L in algae.
The constituents of the substance hydrolyse rapidly in water. The hydrolysis products are not considered to be readily biodegradable but have low potential for bioaccumulation (i.e. low log Kow)
These data are consistent with the following classification under Regulation (EC) No 1272/2008 (as amended) (CLP):
Acute toxicity: Not classified.
Chronic toxicity: Not classified.
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