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EC number: 232-189-2 | CAS number: 7789-78-8
- 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
Hydrolysis
Administrative data
Link to relevant study record(s)
- Endpoint:
- hydrolysis
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Study period:
- Start of the test period: 26.09.2016 End of the test period: 05.12.2016 Report date: 02.01.2017
- Reliability:
- 1 (reliable without restriction)
- Qualifier:
- according to guideline
- Guideline:
- OECD Guideline 111 (Hydrolysis as a Function of pH)
- Deviations:
- yes
- Remarks:
- Deviation from the OECD guideline was needed due to the fact that the reaction of CaH2 with water is very fast.
- Principles of method if other than guideline:
- - Brief description of the test procedure:
A glass reactor (total volume 1100 ml) was filled with 600 ml of an aqueous buffer solution (see below for details of the buffers). The water phase (600 ml) as well as the gas phase (500 ml) of the reactor was saturated with hydrogen gas at atmospheric pressure. In order to prevent the sample from reacting with air humidity the sample container (a small shuttle made of Polypropylene) was put onto the balance and flushed with Argon. The sample was weighed into the shuttle which was immediately put into the reactor. While the shuttle was swimming on the water surface the reactor was tightly closed and the pressure sensor installed. The hydrolysis reaction started when the shuttle went down into the water phase by vigorously stirring.
- The test was performed at three different pH values (4 / 7 / 9), each at temperatures of 20 °C, 40 °C and 50 °C. An additional test was performed, simulating physiologically significant conditions at 37 °C and pH 1,2. - GLP compliance:
- no
- Remarks:
- this is a physical chemical study not requiring GLP. The institute has an adequate qulaity control system.
- Specific details on test material used for the study:
- - Test substance: Calcium hydride K, <2 mm, Batch no. 75552
- Molecular weight calculated: 42,094 g/mol (formula CaH2 assumed)
- The test substance was supplied by the customer as a grey powder. From data of a certificate of analysis (provided by the customer) a purity of 89,5 % may be calculated. - Radiolabelling:
- no
- Analytical monitoring:
- yes
- Buffers:
- Preparation of the buffer solutions:
- Buffer for pH 1,2:
Hydrochloric acid (0,2 mol/l) + Potassium chloride (0,2 mol/l); pH measured: 1,3
- Buffer for pH 4:
Acetic acid (2 mol/l) + Sodium acetate (2 mol/l); pH measured: 4,1
- Buffer for pH 7:
Potassiumdihydrogenphosphate (0,026 mol/l) + Sodiumhydrogenphosphate (0,041 mol/l); pH measured: 7,1
- Buffer for pH 9:
Glycin (0,039 mol/l) + Sodium hydroxide (0,012 mol/l) + Sodium chloride (0,088 mol/l); pH measured: 9,0 - Details on test conditions:
- - Equipment for recording the pressure: data logger Ahlborn Almemo 710; pressure sensor Ahlborn FDAD3302A
- Duration:
- 1 s
- pH:
- 4.1
- Temp.:
- 19.2 °C
- Initial conc. measured:
- ca. 0.251 other: g/600 mL
- Duration:
- 1 s
- pH:
- 7.1
- Temp.:
- 19.5 °C
- Initial conc. measured:
- ca. 0.251 other: 9/600 mL
- Duration:
- 1 s
- pH:
- 9
- Temp.:
- 20.3 °C
- Initial conc. measured:
- ca. 0.252 other: g/600mL
- Duration:
- 1 s
- pH:
- 1.3
- Temp.:
- 36.7 °C
- Initial conc. measured:
- ca. 0.257 other: g/600mL
- Duration:
- 1 s
- pH:
- 4.1
- Temp.:
- 39.9 °C
- Initial conc. measured:
- ca. 0.26 other: g/600mL
- Duration:
- 1 s
- pH:
- 7.1
- Temp.:
- 40 °C
- Initial conc. measured:
- ca. 0.255 other: g/600mL
- Duration:
- 1 s
- pH:
- 9
- Temp.:
- 40.3 °C
- Initial conc. measured:
- ca. 0.258 other: g/600mL
- Duration:
- 1 s
- pH:
- 4.1
- Temp.:
- 50.1 °C
- Initial conc. measured:
- ca. 0.253 other: g/600mL
- Duration:
- 1 s
- pH:
- 7.1
- Temp.:
- 50.2 °C
- Initial conc. measured:
- ca. 0.256 other: g/600mL
- Duration:
- 1 s
- pH:
- 9
- Temp.:
- 49.9 °C
- Initial conc. measured:
- ca. 0.252 other: g/600mL
- Number of replicates:
- No replicates
- Positive controls:
- no
- Negative controls:
- no
- Preliminary study:
- No
- Transformation products:
- yes
- Remarks:
- Calcium hydroxide
- No.:
- #1
- Details on hydrolysis and appearance of transformation product(s):
- Metal hydrides react quickly with water, forming metal hydroxide and hydrogen gas.
- % Recovery:
- 0
- Duration:
- < 1 s
- Remarks on result:
- other: Calcium hydride reacts instantly with water.
- Key result
- pH:
- 4.1
- Temp.:
- 19.2 °C
- Hydrolysis rate constant:
- < 1 s-1
- Remarks on result:
- other: Hydrolytically unstable
- Validity criteria fulfilled:
- yes
- Conclusions:
- As a final conclusion of all data it can be stated that the test substance Calcium hydride is hydrolytically extremely unstable at all conditions of temperature and pH. This compound will never be found in aqueous phase or environmental water.
Reference
Calcium hydride results:
Test no. | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |
T°/C° | 19.2 | 19.5 | 20.3 | 36.7 | 39.9 | 40.0 | 40.3 | 50.1 | 50.2 | 49.9 |
pH | 4.1 | 7.1 | 9.0 | 1.3 | 4.1 | 7.1 | 9.0 | 4.1 | 7.1 | 9.0 |
Sample (m0/g) |
0.251 | 0.251 | 0.252 | 0.257 | 0.260 | 0.255 | 0.258 | 0.253 | 0.256 | 0.252 |
Sample (mol) | 0.006 | 0.006 | 0.006 | 0.0061 | 0.0062 | 0.0061 | 0.0061 | 0.006 | 0.0061 | 0.006 |
Pressure increase (kPa) | 50.8 | 51.0 | 53.0 | 56.1 | 55.4 | 55.2 | 55.5 | 54.7 | 54.9 | 54.2 |
reaction time (s) | <=1 | <=1 | <=1 | <=1 | <=1 | <=1 | <=1 | <=1 | <=1 | <=1 |
c(Ca) (mg*l-1) | 404.3 | 404.1 | 403.9 | 406.2 | 409.2 | 405.8 | 408.0 | 404.9 | 406.2 | 403.6 |
recovery (%) | 112 | 112 | 111.5 | 110.1 | 109.7 | 110.8 | 110.2 | 111.4 | 110.5 | 111.4 |
k/s-1 | >=2.2 | >=2.2 | >=2.2 | >=2.2 | >=2.2 | >=2.2 | >=2.2 | >=2.2 | >=2.2 | >=2.2 |
T0.5/s | <=0.3 | <=0.3 | <=0.3 | <=0.3 | <=0.3 | <=0.3 | <=0.3 | <=0.3 | <=0.3 | <=0.3 |
Description of key information
As a final conclusion of all data it can be stated that the test substance Calcium hydride is hydrolytically extremely unstable at all conditions of temperature (from 19.2 to 50.2°C) and pH (1.3; 4.1; 7.7; 9.0) This compound will never be found in aqueous phase or environmental water.
Key value for chemical safety assessment
Additional information
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.
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