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EC number: 231-701-1 | CAS number: 7691-02-3
- 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
Short-term toxicity to fish
Administrative data
Link to relevant study record(s)
- Endpoint:
- short-term toxicity to fish
- Type of information:
- experimental study
- Adequacy of study:
- weight of evidence
- Study period:
- 1994-03-21 to 1994-03-25
- Reliability:
- 1 (reliable without restriction)
- Rationale for reliability incl. deficiencies:
- guideline study
- Remarks:
- The study was conducted according to an appropriate EU method, and in compliance with GLP, and was considered to be reliability 1 (reliable without restrictions).
- Qualifier:
- according to guideline
- Guideline:
- EU Method C.1 (Acute Toxicity for Fish)
- Version / remarks:
- Cited as Directive 92/69/EEC, C.1
- GLP compliance:
- yes
- Analytical monitoring:
- yes
- Details on sampling:
- - Concentrations: All concentrations at the start of the test and after 24, 48, 72 and 96 hours in fresh and/or old media as applicable
- Sampling method: Not reported
- Sample storage conditions before analysis: Not reported - Vehicle:
- no
- Details on test solutions:
- PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: Test media prepared by mixing for 18 h followed by filtration. - Test organisms (species):
- Danio rerio (previous name: Brachydanio rerio)
- Details on test organisms:
- TEST ORGANISM
- Common name: Zebrafish
- Source: West aquarium, Bad Lauterberg, Germany
- Length at study initiation (length definition, mean, range and SD): 3.0 cm +/-0.5 cm
- Feeding during test: none
ACCLIMATION
- Acclimation period: at least 14 days
- Acclimation conditions (same as test or not): yes
- Type and amount of food: TetraMin® at 1% of body weight
- Feeding frequency: Daily
- Health during acclimation (any mortality observed): The fish exhibit normal behaviour and are free from visible signs of disease at the start of the t
est. - Test type:
- semi-static
- Water media type:
- freshwater
- Limit test:
- yes
- Total exposure duration:
- 96 h
- Hardness:
- 220 mg/L as CaCO3
- Test temperature:
- 20ºC
- pH:
- 7.8-8.7
- Dissolved oxygen:
- 78-99% ASV
- Salinity:
- Not applicable
- Nominal and measured concentrations:
- Nominal test concentrations: 0 (Control), 120, 180, 250, 350 and 500 mg/L
Mean measure concentrations: 0, 25, 41, 56, 77 or 110 mg/L. - Details on test conditions:
- Ten fish per 20 L test aquarium were exposed for 96 hrs to each of the treatments.
Dilution water was Tap water (Gelsenwasser AG)
According to an analysis certificate, the TOC background value is 3 mg/l. - Reference substance (positive control):
- no
- Duration:
- 96 h
- Dose descriptor:
- NOEC
- Effect conc.:
- 56 mg/L
- Nominal / measured:
- meas. (arithm. mean)
- Conc. based on:
- other: test substance hydrolysis products
- Basis for effect:
- mortality (fish)
- Duration:
- 96 h
- Dose descriptor:
- LC50
- Effect conc.:
- 88 mg/L
- Nominal / measured:
- meas. (arithm. mean)
- Conc. based on:
- other: tst substance hydrolysis products
- Basis for effect:
- mortality (fish)
- Duration:
- 96 h
- Dose descriptor:
- LC100
- Effect conc.:
- 110 mg/L
- Nominal / measured:
- meas. (arithm. mean)
- Conc. based on:
- other: test substance hydrolysis products
- Basis for effect:
- mortality (fish)
- Details on results:
- - Mortality of control: 0%
- Reported statistics and error estimates:
- The LC50 was determined graphically from a plot of mortality versus log mean test substance concentration
- Sublethal observations / clinical signs:
Table 1. Test results
Nominal test substance concentration (mg/L) Mean measured concentration over the test (mg/L) Percentage mortality at end of test 0 (Control) - 0 120 25 0 180 41 0 250 56 10 350 77 20 500 110 100 - Validity criteria fulfilled:
- yes
- Conclusions:
- A 96 LC50 value of 88 mg/L and a NOEC of 56 mg/L have been determined for the effects of the test substance on mortality of Brachydanio rerio. It is likely that the test organisms were predominantly exposed to the hydrolysis products of the substance.
- Endpoint:
- short-term toxicity to fish
- Type of information:
- experimental study
- Adequacy of study:
- weight of evidence
- Study period:
- 2004-03-15 to 2004-03-19
- Reliability:
- 1 (reliable without restriction)
- Rationale for reliability incl. deficiencies:
- guideline study
- Qualifier:
- according to guideline
- Guideline:
- OECD Guideline 203 (Fish, Acute Toxicity Test)
- Qualifier:
- according to guideline
- Guideline:
- EPA OPPTS 850.1075 (Freshwater and Saltwater Fish Acute Toxicity Test)
- GLP compliance:
- yes
- Analytical monitoring:
- yes
- Details on sampling:
- - Concentrations: Negative Control, 63, 125, 250, 500 and 1000 mg/L
- Sampling method: Measurement of test concentrations in each test chamber at test initiation, on Day 1 (old solutions) and at test termination : - Vehicle:
- no
- Details on test solutions:
- PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: Direct addition of test article to dilution water
- Controls: Dilution water
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): No organic solvent - Test organisms (species):
- Oncorhynchus mykiss (previous name: Salmo gairdneri)
- Details on test organisms:
- TEST ORGANISM
- Common name: Rainbow trout
- Age at study initiation (mean and range, SD): 77 days
- Length at study initiation: 5.9 cm (Range 5.5 to 6.3 cm)
- Weight at study initiation: 1.7 g (Range 1.4 to 2.3 g)
ACCLIMATION
- Acclimation period: 2 weeks prior to the test.
- Acclimation conditions: same as test - Test type:
- semi-static
- Water media type:
- freshwater
- Limit test:
- no
- Total exposure duration:
- 96 h
- Post exposure observation period:
- None
- Hardness:
- 122 mg/L as CaCO3
- Test temperature:
- 11.3 - 12.2 ºC
- pH:
- 8.3-8.7
- Dissolved oxygen:
- >8.3 mg/L (>77% saturation)
- Salinity:
- Not applicable
- Nominal and measured concentrations:
- Nominal concentrations: Negative Control, 63, 125, 250, 500 and 1000 mg/L in dilution water
Measured concentrations:
Method of Calculating Mean Arithmetic mean
Statistical methods: Binomial Probability, Probit Method - Details on test conditions:
- TEST SYSTEM
- Test vessel:
- Type: open
- Material, size, headspace, fill volume: 38-L or 54-L stainless steel aquaria containing 30-L of test solution
- Renewal rate of test solution: Daily renewal
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2
- Biomass loading rate: 0.3-0.5 g/L
TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Well water
- Alkalinity: 180 mg/L as CaCO3
- Conductivity: 270 mhos/cm
- Culture medium different from test medium: no
- Intervals of water quality measurement: daily
OTHER TEST CONDITIONS
- Adjustment of pH: no
EFFECT PARAMETERS MEASURED: Mortality observed daily
TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2 - Reference substance (positive control):
- no
- Duration:
- 24 h
- Dose descriptor:
- LC50
- Effect conc.:
- > 949 mg/L
- Nominal / measured:
- meas. (arithm. mean)
- Conc. based on:
- test mat.
- Basis for effect:
- mortality (fish)
- Remarks on result:
- other: not calculable
- Duration:
- 48 h
- Dose descriptor:
- LC50
- Effect conc.:
- 523 mg/L
- Nominal / measured:
- meas. (arithm. mean)
- Conc. based on:
- test mat.
- Basis for effect:
- mortality (fish)
- Remarks on result:
- other: 250-949
- Duration:
- 72 h
- Dose descriptor:
- LC50
- Effect conc.:
- 476 mg/L
- Nominal / measured:
- meas. (arithm. mean)
- Conc. based on:
- test mat.
- Basis for effect:
- mortality (fish)
- Remarks on result:
- other: 402-565
- Duration:
- 96 h
- Dose descriptor:
- LC50
- Effect conc.:
- 271 mg/L
- Nominal / measured:
- meas. (arithm. mean)
- Conc. based on:
- test mat.
- Basis for effect:
- mortality (fish)
- Remarks on result:
- other: 128-481
- Duration:
- 96 h
- Dose descriptor:
- LC0
- Effect conc.:
- 128 mg/L
- Nominal / measured:
- meas. (arithm. mean)
- Conc. based on:
- test mat.
- Basis for effect:
- mortality (fish)
- Duration:
- 96 h
- Dose descriptor:
- NOEC
- Effect conc.:
- 128 mg/L
- Nominal / measured:
- meas. (arithm. mean)
- Conc. based on:
- test mat.
- Basis for effect:
- mortality (fish)
- Details on results:
- Biological observations: After 96 hours of exposure, all surviving fish appeared normal.
Lowest test substance concentration causing 100% mortality: 481 mg/L
Mortality of controls: 5%
Abnormal responses: Surfacing, loss of equilibrium, erratic swimming and lying on bottom
Any observations, such as precipitation that might cause a difference between measured and nominal values: All test solutions appeared clear and colourless.
- Sublethal observations / clinical signs:
Table 1. Cumulative mortality:
Mean Measured
Concentration Number Dead/Number Exposed (hours)
(mg/L) 0 24 48 72 96
0 0/20 0/20 0/20 0/20 1/20
65 0/20 0/20 0/20 0/20 0/20
128 0/20 0/20 0/20 0/20 0/20
250 0/20 0/20 0/20 1/20 8/20
481 0/20 0/20 8/20 9/20 20/20
949 0/20 6/20 20/20 20/20 20/20
- Validity criteria fulfilled:
- yes
- Conclusions:
- A 96-hour LC50 of 271 mg/L and a NOEC of 128 mg/L have been determined for the effects of the test substance on mortality of Oncorhynchus mykiss based on mean measured concentrations.
Referenceopen allclose all
Description of key information
(WoE) Short-term toxicity to fish: 96 hr LC50 271 mg/l (measured) (OECD 201), read-across from an analogous substance, trimethylsilanol (CAS 1066-40-6).
(WoE) Short-term toxicity to fish: 96 hr LC50 88 mg/l (measured) (OECD 201), read-across from a structurally related substance, 1,1,1,3,3,3-hexamethyldisilazane (CAS 999-97-3). The LC50 is equivalent to 49 mg/l when expressed in terms of the silanol hydrolysis product, trimethylsilanol and 9.3 mg/l in terms of NH3.
(supporting) Short-term toxicity to fish: 96 hr LC50 191 mg/l (nominal) (OECD 201), read-across from an analogous, trimethoxy(vinyl)silane (CAS 2768-02-7). The LC50 is equivalent to 137 mg/l when expressed in terms of the silanol hydrolysis product, vinylsilanetriol
Key value for chemical safety assessment
Fresh water fish
Fresh water fish
- Effect concentration:
- 271 mg/L
Additional information
There are no reliable short-term fish toxicity data for N-(dimethylvinylsilyl)-1,1-dimethyl-1-vinylsilylamine, therefore good quality data have been for the effects of read-across substances: 1,1,1,3,3,3-hexamethyldisilazane (CAS 999-97-3) and trimethylsilanol (CAS 1066-40-6). The read-across is based on structural similarity and production of ammonia, and structural similarity and log Kow of the silanol hydrolysis product of the registered substance, respectively. In view of this approach to read-across the data are considered together to form a Weight of Evidence approach.
In addition, supporting data are presented for trimethoxy(vinyl)silane (CAS 2768-02-7) to provide evidence of low toxicity of the vinyl group.
96-h LC50 values of 88, 271 and 191 mg/l and NOECs of 56, 128 and 100 mg/l (measured, measured and nominal respectively) have been determined for the effects of the read-across substances 1,1,1,3,3,3-hexamethyldisilazane (CAS 999-97-3), trimethylsilanol (CAS 1066-40-6) and trimethoxy(vinyl)silane (CAS 2768-02-7) respectively, on mortality of Brachydanio rerio, Oncorhynchus mykiss and Oncorhynchus mykiss respectively.
The data on trimethylsilanol (CAS 1066-40-6) are used to derive the PNEC for the silanol hydrolysis product, whereas the data for 1,1,1,3,3,3-hexamethyldisilazane (CAS 999-97-3) are used to establish the classification and labelling of the registered substance due to the presence of the ammonia hydrolysis product, which drives toxicity. The PNECs for ammonia are derived based on literature data.
Trimethylsilanol (TMS, CAS 1066-40-6) has the potential to condense to form hexamethyldisiloxane (HMDS, CAS 107-46-0), which may be present at low levels in the test system. HMDS is classified as Aquatic Acute 1 H400 and Aquatic Chronic 2 H411[1] and therefore its presence has the possibility to impact the results. However, the estimated concentrations of HMDS in the tests with trimethylsilanol are low. Therefore the effects seen in the short-term toxicity to fish study, such as 40% mortality at 250 mg/l test concentration, may be attributable to TMS alone and the study is considered to be conservative and reliable for the purpose of this assessment.
In view of the exposure regime and the fast hydrolysis rates of 1,1,1,3,3,3-hexamethyldisilazane (CAS 999-97-3) and trimethoxy(vinyl)silane (CAS 2768-02-7), it is likely that the test organisms were exposed predominantly to the hydrolysis products of the tested substances.
1,1,1,3,3,3-Hexamethyldisilazane (CAS 999-97-3)
The results may be expressed in terms of concentration of the hydrolysis product, trimethylsilanol, by applying a molecular weight correction: (MW of silanol = 90.2 / MW of parent= 161.4) * 88 mg/l = 49 mg/l. The results may also be expressed in terms of ammonia (NH3), by applying a molecular weight correction: (MW of ammonia 17.03 / MW parent 161.4) * 88 mg/l = 9.3 mg/l. However, data with 1,1,1,3,3,3-hexamethyldisilazane are read across for the purpose of classification and labelling and the relevant values are those determined in terms of the parent substance.
Trimethoxy(vinyl)silane (CAS 2768-02-7)
The results may be expressed in terms of concentration of the hydrolysis product, vinylsilanetriol, by applying a molecular weight correction: (MW of silanol = 106.15 / MW of parent = 148.24) * 191 mg/l = 131 mg/l. This value is used as supporting evidence of the lack of effects of dimethylvinylsilanol without further correction.
Refer to the discussion in the Section 6 endpoint summary (Section 7.0 of CSR) for further discussion of the approach to chemical safety assessment for this registration substance. Please refer to Section 13 of IUCLID for the read-across justification.
Ammonia:
Reliable short-term test results are available for ammonia sourced from the Environment Agency Proposed EQS for Water Framework Directive Annex VIII Substances: Ammonia (un-ionised) 2007. The most sensitive species to ammonia was found to be fish (Oncorhynchus gorbusha- pink salmon), with an LC50 of 0.083 mg un-ionised NH3/L (Rice and Bailey, 1980).
[1]https://echa.europa.eu/information-on-chemicals/cl-inventory-database/-/discli/notification-details/32082/948794
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